EPA 440/9-76-02
CRITERIA DOCUMENT
PCBs
REPRODUCED BY
U.S. DEPARTMENT OF COMMERCE
NATIONAL TECHNICAL
INFORMATION SERVICE
SPRINGFIELD, VA 22161
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TECHNICAL REPORT DATA
(Please rcaJ lutinicrions on 1'ie rei'ci-sf before cowplctltiel
1. REPORT NO.
EPA-440/9-76-021
4. TITLE AND SUBTITLE
5. REPORT DATE
•Tnlv 1Q76
Criteria Document for PCBs
6. PERFORMING ORGANIZATION CODE
PB 255 397
DA
¥-
MIN
7. AUTHORIS)
8. PERFORMING ORGANIZATION REPORT NO.
Ian C.T. Nisbet, Ph.D.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Massachusetts Audubon Society
Lincoln, Massachusetts 01773
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-01-4154
12. SPONSORING AGENCY NAME AND ADDRESS
Office of Water Planning and Standards
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington. D.C. 20460
13. TYPE OF REPORT AND PERIOD COVERED
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
Some editing was performed by EPA
16. ABSTRACT
This document summarizes the physical/chemical properties, toxicological
information and environmental fate and effects of PCBs, with emphasis on \
its aquatic behavior. From these data criteria are developed for the'
protection of aquatic life.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Criteria
Toxicity
Aquatic animals
Aquatic biology
Human ecology
''""'Safety factor
Toxic Pollutant Effluent
Standards
Federal Water Pollution
Control Act
18. DISTRIBUTION STATEMENT
RELEASE UNLIMITED
19. SECURITY CLASS (TlnSiwportl
Unclassified
|21. NO. OF PAGES
20. SECURITY CLASS (This page)
Unclassified
EPA Form 2220-1 (9-73)
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TABLE OF CONTENTS
I. INTRODUCTION ]
I.I. Principal sources of information ]
1.2. Uses and releases of FCBs into the environment ]
1.3. PCB mixtures and contaminants: the problem of evaluation 3
II. CHEMICAL AND PHYSICAL PROPERTIES 4
II. 1. Nomenclature of chlorobiphenyls and isomers g
II.2. Manufacture and nomenclature of commercial FCB mixtures g
II.3. Constitution of Aroclor mixtures g
II.3.1. Molecular composition g
II.3.2. Isomeric constitution a
II.4. Constitution of other commercial mixtures -t«
II.5. Occurrence of certain substitution patterns in PCB mixtures.... £6
II.5.1. Adjacent unsubstituted positions 34
II.5.2. Number of ortho-chlorines 34'
II.5.3. - 4,4'-substitution 34
II.5.4. 3,4 - substitution 35
II.5.5. Toxic contaminants in commercial-PCB mixtures 3^
II.6. Physical properties of chlorobiphenyls and PCB mixtures on
II.6.1. General properties .__ ™
II.6.2. Vapor pressure and volatilization «?
II.6.2.1.Factors affecting the rate of volatilization «o
II.6.3. Solubility in water CQ
II.6.4. Solubility in organic solvents and partitioning
into lipids 53
II.6.5. Adsorption to soils, sediments, and particulates... 53
II.6.6. Concentration at the air-water interface 54
II.7. Physical properties of chlorinated dibenzofurans gi
II.8. Chemical properties of chlorobiphenyls and commercial mixtures. g-i
II.8.1. General chemical stability g1]
II.8.2. Photochemical reactions g-]
II.8.3. Photochemical production and degradation of chlor-
inated dibenzofurans gg
II.8.4. Probable formation of PCDFs from PCBs in service... 73
III. TOXIC EFFECTS 75 ,
III.l. Introduction 75
III.2. Effects on microbial systems yc
III.3. Effects on phytoplankton og
III.4. Effects on aquatic invertebrates
HI.4.1. Effects on fresh-water organisms
III.4.2. Effects on estuarine organisms
III.4.3. Effects on a marine invertebrate community
III.5. Effects on fish '
III.5.1. Lethal concentrations of PCBs to fish T
III.5.2. Effects on fish reproduction ,
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III.5.3. Other sublethal effects on fish 123
III.5.4. Effects on ATPase and osmoregulation 128
III.5.5. Effects of PCDFs on fish 134
III.6. Effects on birds^ ».. 134
III.6.1. Lethal concentrations in diet: subacute and semi-
chronic studies 138
III.6.2. Chick edema disease and the role of PCDFs in PCB
toxicity 1 38
III.6.3. Porphyria and induction of ALA-synthetase ]4]
III.644. Effects on reproduction 145
III.6.4.1. Effects in chickens 148
III.6.4.2. Effects in pheasants 154
III.6.4.3. Effects in Mallards '. 155
III.6.4.4. Effects in Bobwhite Quail 155
III.6.4.5. Effects in Ring Doves 159
III.6.4.6. Effects in American Kestrels 159
III.6.4.7. Effects in Japanese Quail 163
III.6.4.8. Summary of effects on reproduction in birds 153
III.6.5. Liver and microsomal enzymes 154
III.6.6. Other toxic effects in birds 166
III.7. Toxic effects in mammals: acute and subacute studies 172
III.7.1. Acute toxicity 172
III.7.2. Subacute toxicity 172
III.8. Toxicity of PCDFs in mammals and the role of PCDFs in the
toxicity of commercial PCBs 182
III.9. Chronic effects of PCBs in mammals and effects on reproduction. ]89
III.9.1. Effects on rats 189
III.9.2. Effects on mice 197
III.9.3. Effects on dogs ]gy
III.9.3. Effects on non-human primates 100
III.9.4. Effects on mink 2Q2
III.9.5. Effects on swine 204
III.9.6. Effects on rabbits 2Q4
III.10.Enzyme induction and other effects on the liver 2Q6
III.10.1. Effects on liver weight 206
III.10.2. Proliferation of smooth endoplasmic reticulum pQS
III. 10.3. Microsomal enzyme induction 2Q9
III.10.4. Structure-activity relationships 220
III. 10.5. Enzyme induction by Aroclor 1016 227
III. 10.6. Enzyme induction by PCDFs 23]
III.10.7. Synergistic effects on enzyme induction
III.10.8. Structural changes in liver '.
III.10.9; Changes in biochemical composition of the liver...
III.11. Induction of porphyria
III.12. Miscellaneous biochemical effects
III.12.1. Hypertriglyceridemia
III.12.2. Effects on the adrenal gland
III.12.3. Effects on thyroxine
III.12.4. Hematological effects
III. 12.5. Enzyme inhibition
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III. 13. Immunosuppressive effects ........ . ................. ........... 248
III. 14. Carcinogenic and co-carcinogenic effects ...................... 251
III. 15. Mutagenic and t era to genie effects............. ....... ......... 254
III. 16. Effects in humans ............. . ................. . ........... '... 255
III. 16.1. Chloracne ........................................ 255
III. 16. 2. Yusho ............................................ 25S
III. 16. 3. Animal models for Yusho and chloracne ....... ..... 270
III. 16. 4. The role of PCDFs in the toxicity of PCBs to
humans ...... . ........ ...... ...... .............. 275
IV. ENVIRONMENTAL FATE AND EFFECTS ................................... 276
IV. 1. Persistence, metabolism and f~te ..... .............. ...... ....... 075
IV. 1.1. Persistence .................. .. ..................... 276
IV. 1.2. Differential persistence of lower and higher chlor-
inated biphenyls ...... ............................ 277
IV. 1 .3 . Metabolism .................. . ....................... 279
IV. 1.4. Fhotodegradation ........... ......................... 28]
IV. 1.5. Transport ..................... . .. ............... . .... 282
IV.1.6. Fate ..................................... ........... 283
IV. 2. Bio-accumulation and bio-magnification... ................... .... 283
IV.2.1. Mechanisms of uptake and accumulation.. .............
IV.2.2. Bio-accumulation in aquatic invertebrates ...........
IV.2.3. Bio-accumulation in fish ............................ 288
IV.2.4. Bio-accumulation in model aquatic ecosystems ........ ,95
IV.2.5. Storage and bio-magnification in birds .............. ono
IV.2.6. Storage and bio-magnification in mammals ....... ..... 017
IV.2.7. Storage and bio-magnification in humans..... ........ 325
IV.2.8. Bio-accumulation and bio-magnification in natural
ecosystems... .. ..... ........... ....... ... ........ 339
IV.3. Presence in the aquatic environment... .......... . ............ ... 34-]
IV.4. Effects on biota and natural ecosystems. .................. ...... 342
IV. 4.1. Effects observed in the laboratory ...... . ........... 345
IV.4. 2. Effects observed in the field ....................... 353
IV.5. Potential effects in the human population ....................... 352
V. Criteria Formulation 354
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APPENDIX A. The Chemistry of PCBs (Hutzinger, Safe & Zitko).
APPENDIX B. The Toxicity of Polychlorinated Polycyclic Compounds
and Related Chemicals (Kimbrough).
APPENBIX C. Review of PCS Levels in the Environment (U.S. EPA,
Office of Toxic Substances, Draft report).
APPENDIX D. Review of Carcinogenic and Co-Carcinogenic Effects
of PCBs.
APPENDIX E. Metabolism and Biodegradation.
IV
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Errata
PCB Criteria Document
Sec. III.6.4 Effects on reproduction of birds
Line 3 should read - ppm of PCBs, corresponding to
residues of only 1-2 ppm in whole eggs (150).
Sec. V. Criteria Formulation
Paragraph 1, line 5 should read - affected fish thyroid
(73,95). At the 0.5 ppm dietary level PCBs caused
enzyme induction in rats (219).
p. R-8
Reference 69: Pages cited should be 43-49 not 57-64
p. R-18
Reference 197: Pages cited should be 347-350 not 332-333
Appendices A and B are copyrighted materials and therefore have been omitted.
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I. INTRODUCTION
I.I Principal sources of information
Comprehensive reviews of the occurrence of polychlorinated biphenyls
(PCBs) in the environment and their potential hazards were published in 1972
by an Interdepartmental Task Force (ITF) (1) and by a Panel on Hazardous
Trace Substances (PHTS) convened by the Office of Science and Technology
(OST) and the National Institute for Environmental Health Sciences (NIEHS)
(2). The latter report formed the basis for a draft Scientific and Technical
Assessment Report (STAR) prepared by the Office of Research and Development
(ORD) of the Environmental Protection Agency (EPA) in September 1974 (3).
More specialised reviews oi; the chemistry and toxicology of PCBs were pub-
.lished in 1974 by Hutzinger, Safe and Zitko (4) and Kimbrough (5): these
reviews are attached as Appendices A and B respectively to this document.
A draft report (6) reviewing the occurrence and levels of PCBs in the environ-
ment has been prepared by EPA's Office of Toxic Substances (OTS) in January
1976 and is attached as Appendix C. A summary of industrial uses and en-
vironmental distribution of PCBs in the United States was prepared for OTS
by Versar, Inc., in February 1976 (7). Important collections of scientific
data are included in the proceedings of two conferences on PCBs, held in
1971 and 1975 (refs. 8 and 9).
1.2 Uses and releases of PCBs into the environment
Polychlorinated biphenyls (PCBs) are manufactured by the direct
chlorination of biphenyl. Commercial products are complex mixtures of
chlorobiphenyls and are marketed for various uses according to the percen-
tage of chlorine in the mixture. The major producer of PCBs in the United
States is the Monsanto Company, which now markets four mixtures (with 21%,
\
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41%, 42% and 54% chlorine) for closed electrical system uses under the
trademark 'Aroclor'. Prior to 1970 Monsanto marketed a wider range of
mixtures (containing up to 68% chlorine) and these were used in a number
of other applications, including uses as plasticizers, heat transfer
fluids, hydraulic fluids, fluids in vaccuum pumps and compressors, lubri-
cants, wax extenders, etc. Following the discovery in the late 1960's
that PCBs had become widespread environmental contaminants, Monsanto
voluntarily limited its range of products and restricted sales to those
for closed electrical system uses. However, because of the long life of
many products containing PCBs, it is believed that a substantial fraction
of the PCBs manufactured before 1971 remains in service (7), There is thus
a potential for their discharge into the environment when the components
containing them are scrapped or leak. Moreover, although imports of PCBs
into the United States are small, comprising only 1-2% of domestic sales
(7), much of the imported material appears to be sold for non-closed system
uses (7). Thus, in evaluating the potential impact of PCBs released into
the environment, it is necessary to consider not only the mixtures currently
manufactured and sold by Monsanto, but also the other mixtures manufactured
by Monsanto prior to 1970, and products manufactured overseas. Recent sur-
veys have identified a number of sources of PCBs into the aquatic environment,
.including not only effluents from the manufacturing plant and the electrical
industry, but also sewage treatment plants, urban run-off, steel arid aluminum
foundries, pulp and paper mills, automotive and metal finishing plants, hy-
draulic and heat transfer systems, investment casting operations, and ship-
ping (10-12).
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1.3 PCB mixtures and contaminants: the problem of evaluation
Evaluation of the potential environmental impact of the various com-
mercial mixtures is complicated by the fact that the components of the
mixtures differ greatly in their physical, chemical and biological properties,
Accordingly the constitution of the mixtures often changes as the materials
are transported through the environment, so that plants, animals, and humans
are exposed to mixtures whose constitution differs from those whose toxicity
has been tested in laboratory experiments. Although the environmental be-
havior and biological activity of a number of individual chlorobiphenyl
isomers have been studied in recent years, it is still difficult to evaluate
the potential toxicity of the complex mixtures found in the environment. In
making this evaluation it is necessary to weigh carefully the results of
studies of individual compounds, and to compare critically the environmental
and toxicological properties of the commercial mixtures.
A further complication is that several commercial PCB mixtures have
been reported to contain small quantities of highly toxic contaminants, poly-
chlorinated dibenzofurans (PCDFs). Some of the toxic effects observed in
animals and humans exposed to PCBs appear to be attributable to PCDFs, while
others appear to be caused by PCBs themselves. There is also some evidence
that small quantities of PCDFs may be formed from PCBs either in service or
during metabolism by animals. Accordingly it is necessary to consider the
potential effects of both classes of compounds when weighing the potential
impact of PCBs released into the environment.
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II. CHEMICAL AND PHYSICAL PROPERTIES
jll.l Nomenclature of chlorobiphenyls and isomers
Polychlorinated biphenyls consist of a mixture of chlorinated bi-
phenyls with varying degrees of chlorination and isomeric constitution.
Some confusion has appeared in the literature because of the
nomenclature that is used to describe the commercial preparations and the
individual authenticated chlorobiphenyls. In order to clarify the nomen-
clature to be used herein, it is appropriate to digress briefly as follows.
The biphenyl molecule has a total of ten (10) carbon-hydrogen bonds at
which chlorine substitution can be accommodated. A schematic representation
of the biphenyl molecule with the various positions at which substitution
can be accomplished numbered in the American Chemical Society standard
notation is presented below:
ACS Convention for Numerical Assignments
of Biphenyl Substitution
In the interest of a common usage, the following rules will be
followed in this report:
a. When referring to a mixture of different species, as occurs in
the commercial products, the term polychlorinated biphenyls
(abbreviation, PCBs) will be used.
b. Those species of chlorinated compounds that arise from a
specified number of chlorine substituents on the biphenyl
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molecule will be referred to as chlorobiphenyls with a
suitable numerical prefix to define the number of substi-
tuted chlorines; i.e., dichlorobiphenyl. Thus, there are
a total of ten (10) chlorobiphenyls that might appear in
the commercial mixtures.
c. Those specific compounds that represent the class of
compounds formed by a specific number of substituent
chlorine atoms but differ in the locations at which sub-
stitution has taken place are referred to as isomers.
Thus, in terms of the above, the proper manner of referring to a commercial
PCB mixture is as a "mixture of chlorobiphenyls containing various propor-
tions of the isomers of each".
To illustrate the utility of the numbering system indicated previously,
the correct names of the compounds shown below are:
Cl Cl
2,3',5,5'-tetrachlorobiphenyl
Cl
Cl Cl
3',4,4',5-tetrachloro-2-biphenylamine
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In addition to biphenyl itself, which is found in some commercial
mixtures, there are ten chlorobiphenyls comprising 209 possible isomers
(Table II.1.1.)
In some sections of this report, chlorobiphenyls with 5 or more
chlorine atoms will be referred to as "higher chlorobiphenyls" and those
with 3 or fewer chlorine atoms will be referred to as "lower chlorobiphenyls".
This distinction is made in recognition of the fact that the former group
of compounds is much more persistent in the environment than the latter
group, whereas tetrachlorobiphenyls are intermediate in persistence
(Section IV.1 below).
II.2 Manufacture and nomenclature of commercial PCS mixtures
The world's principal manufacturers of PCBs are listed in Table
II.2.1, with the trade names under which the products are sold. In the
United States the sole manufacturer is the Monsanto Company which sells
four mixtures under the tradename Aroclor^"'. These four products, to-
gether with five mixtures whose manufacture has been discontinued since
1970, are listed in Table II.2.2 (from ref. 13). Except for Aroclor 1016,
the last two digits in the Aroclor number specify the percentage of chlorine
in the mixture. Aroclor 1016, introduced in 1971, is similar in constitu-
tion to Aroclor 1242 but is modified (by distillation) to include only
about 1% of pentachlorobiphenyls (13).
II.3 Constitution of Aroclor mixtures
The commercial process by which the PCBs are made involved the
chlorination of biphenyl with anhydrous chlorine in the presence of a
catalyst which may be either iron filings or ferric chloride. The crude
product is generally purified to remove color, traces of hydrogen chloride,
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Table II.1.1
Empirical Formulation, Molecular Vfeights
and Chlorine Percentage in PCBs
Empirical formula
chlorobiphenyls Molecular weight* Percent chlorine*
C12H1Q 154
C12H Cl 188
C12H8C12 222
C12H7C13 256
C12H6C14 29°
C12H5C15 324
.2H4C16 358
C12H3C17 392
C,2H2Clg 426
C12HClg 460
C12C110 494
0
18.6
31.5
41.0
48.3
54.0
58.7
62.5
65.7
68.5
79.9
No. of iscmers
1
3
12
24
42
46
42
24
12
3
1
*Based on Cl
35
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Table II.2.1
The World's Major Producers of PCBs
Producer
Monsanto
Bayer
Prodelec
Caf faro
Kanegafuchi*
Mitsubishi-*
Monsanto
Sovel
Chemko
Country
U.S.A. and
Great Britain
Germany
France
Italy
Japan
Japan
U.S.S.R.
Czechoslovakia
Tradename
Aroclor^
ClophenW
Phenoclor and
Pyralene(R)
Fenclor
Kanechlor(R)
Santotherm(R)
* Production discontinued for domestic use.
Table II.2.2
AROCLOR PRODUCTS MANUFACTURED IN THE U.S.
Current Discontinued Percent Chlorine
1221
1016
1242
1254
1232
1248
1260
1262
1268
1270
21
32
41
42
48
54
60
62
68
71
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and the catalyst by treatment with alkali and subsequent distillation. The
resulting product is then a more or less complex mixture of the chlorobi-
phenyls, the precise composition depending on the conditions under which
chlorination was carried out.
II.3.1 Molecular composition
Table II.3.1 lists the distribution of the various chlorobiphenyls
in six major Aroclor mixtures, as given by Monsanto (13), Webb and McCall
(14), and Hirwe et al. (15). The differences between the results given
for Aroclors 1242 and 1254 may reflect either differences in analytical
methods or variations in constitution. These and other data are summarized
in histogram form in Figure II.3.1 (16). No data appear to have been pub-
lished on the molecular composition of the other Aroclor mixtures, but the
data in Figure II.3.2 indicate that Aroclor 1262 consisted mostly of nexa-
and heptachlorobiphenyls, and Aroclor 1268 mostly of octa- and nonachloro-
biphenyls; Aroclor 1270 apparently consisted primarily of decachlorobiphenyl.
Figure II.3.2 presents high-resolution gas-liquid chromatograms of
eight Aroclor mixtures (17). Each mixture contained a large number of com-
ponents, including several isomers of each chlorobiphenyl; in most cases
several major components are common to successive members of the Aroclor series.
Figure II.3.3 compares high-resolution gas-liquid chromatograms of
Aroclors 1016 and 1242. The mixtures appear extremely similar except for
the absence from Aroclor 1016 of a few minor constituents with relatively
long retention times present in Aroclor 1242.
II.3.2 Isomeric constitution
A nearly complete identification of the chlorobiphenyl isomers
present in Aroclors 1242, 1254, and 1260 was carried out by Sissons and
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10
70-
(0-
50-
w-
30-
2D*
10-
0-
1?)
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110)
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(101
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12M5 0 1 2 ' < ' 012345 1234)» i 2 ) < 5 » 7 1234567
1014 12n 102 12C 1241 1254
A80CIOR COMPOSITION I No. Oilorlnt Aloms/Motoculnl
The congener composition of commercially available Aroclors
based on the weight percent of biphenyls bearing different numbers
of chlorine atoms/molecule. Data were obtained from reports by Webb
and McCall (ref.20), Sissons and Welti (ref.18), and from information
supplied by the Monsanto Industrial Chemicals Company.
Figure II.3.1 (from ref. 16)
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11
Table II.3.1
Approximate molecular composition of Aroclors, from
data in ref. 13 (M) , ref. 14 (W), and ref. 15 (H).
Chlorobiphenyl
C12H1Q
12 9 ^ 1
C12H8C12
C12H7C13
C12H6C14
C12H5C15
C12H4C16
C12H3C17
C12H2C18
c12ci10
1221
M W
11 7
51 51
32 38
4 3
2
0.5
-
-
-
-
1232
W
6
26
29
24
15
0.5
-
-
-
-
1016
M
Tr
1
20
57
21
1
Tr
-
-
-
1242
M W H
Tr
1 1 Tr
16 17 4
49 40 39
25 32 42
8 10 14
1 0.5
Tr
.
-
1248
W
-
-
1
23
50
20
1
-
-
-
!1254
M W H
Tr
Tr
0.5 -
1 - 0.5
21 16 36
48 60 45
23 23 18
611
_
_
1260
W
-
-
-
-
-
12
46
35
6
-
Tr - Trace (less than 0.1 percent)
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12
150150152 136 160 15J 163 172 1/6 16O
TEMPERATURE t
120130 15- lid 162 166 170 1/4 T/.1 16? Id-j ISO '94 -.96 202 i:06 tlG iM 219 222
Figure II.3.2 Gas-liquid chromatograms of Aroclor mixtures (from ref. 17)
Underlined numbers designate the Aroc'or fnrmulation. Numbers above the peaks designate
the number of chlorine atoms in the compound(s) determined from the mass spectrum; un-
numbered peaks have the same number of chlorine atoms as marked peaks at the same tem-
perature. Temperature program rate 2'C/minute, He 9 psig. 50 ft X 0.020 in. SE-oO SCOT
column, PE-270 glc-MS.
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13
<0
O
r-
cc
O
O
O
CC
CM
DC
g
o
o
CC
CO
(M
N
'' £<
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14
Welti (18) by use of a combination of gas-liquid chromatography, nuclear
magnetic resonance (NMR) and mass spectroscopy (MS). The retention index
(RI) system proposed by Kovats (19) was adopted in order to provide a
characterization of the peak position in gas-liquid chromatography that is
less sensitive to column conditions than retention time or relative reten-
tion time. Retention indices were used to identify minor constituents
after the major constituents had been identified using NMR. The identifi-
cations of a number of the isomers have been confirmed independently (20).
Figure II.3.4 illustrates a gas-liquid chromatogram of Aroclor 1254
with the peaks numbered according to the scheme of Sissons and Welti (18).
Table II.3.2 lists their identifications of the major constituents and
Table II.3.3 lists the probable identities of the minor constituents.
Figures II.3.5 and II.3.6 and Tables II.3.4 and II.3.5 give corresponding
chromatograms and identification of the isomers present in Aroclors 1242
and 1260. Table II.3.6 gives the results of independent identification of
the constituents of the major peaks in the chromatograms of Aroclors 1254
and 1260 (27): these agree closely with those in refs. 18 and 20.
II.4 Constitution of other commercial mixtures
Where data are available, the constitution of PCB mixtures manufac-
tured in other countries appears to agree very closely with that of the
corresponding Aroclor mixtures. Figure II.4.1, for example (from ref. 22)
shows that gas-liquid chromatograms of Phenoclor DP6, Clophen A60, and
Aroclor 1260 (all mixtures with 60% chlorine) are almost identical, except
for a small difference in peak 3 in Clophen A60 . Jensen and Sundstrbm (23)
have identified and measured the relative quantities of most components of
* This peak corresponds to components 11, 14, and 15 listed for Clophen A60
in ref. 23, and to components 40 and 41 listed for Aroclor 1260 in ref. 18.
The difference appears to be the presence of 2,3,6,2,3,6 -hexachlorobiphenyl
in Clophen A60, but not in Aroclor 1260 (18, 23).
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15
V
:g 5117 » it
U IJ H
Figure II.3.4 Gas-liquid chromatogram of Aroclor 1254 (refs. 18, 21)
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16
Table II.3.2 (from refs. 18, 21)
The retention indices, chlorine numbers and structures of the major PCB constituents in
Aroclor 1234.
Peak No. R.I.
22 1994
23 2010
24 • 2022
i
29 2089
32 2119
33 ' ' 2136
' 36 2159
39 2175
41 2191
42 2203
43 2207
44 2228
45 2238
48 2204
50 2299
52 2321
55 2356
56 2356
59 2390
Chlorine No.'
4
4
4
. . (5)
5 '
5
4
5
• 5
(6)
5
5
5
5
—
- 6
6
5
5
6
6
(7)
NMR determined
structure
2,5-2',5'
2 ,3-2', 5'
2,5-2', 3',6'
2, 3-2', 3', 6'
2,5-3',4'
2,5-2',4',5'
2, 4-2', 4', 5'
2, 3-2', 4', 5'
2, 5-2', 3', 4'
3, 4-2', 3' ,6''
2,3,6-2',4',5'
2, 3, 4-2', 3', 6'
3,4-2', 4', 5'
3, 4-2', 3', 4'
2,4,5-2',4',5'
2, 3, 4-2', 4', 5'
Alternative predictions
Structure
2-2', 3', 5'
2-2', 4', 5'
2,4-2',5'
3-2',4',6'
2, 4-2', 4'
2, 6-2', 3', 6'
2,6-2', 3',5'
•
2,5-2',3',5'
2,4-2',3',5'
3, 5-2', 4', 6'
2,6-2',3',4',6'
2, 3, 6-2', 3', 6'
2, 3-2', 3', 5'
2, 4-2', 3', 4'
2,3-2',3',4'
2,6-3', 4', 5'
3, 4-3', 5'
2, 3, 5-2', 4', 6'
2,4-2',3',4'I6'
2, 5-2', 3', 4', 5'
3, 5-2', 3', 4', 6'
2,3-2'>3',4',5'
2,4,6-3',4',5'
2, 3, 5-2', 3', 5', 6'
R.I."
1996
2012
2010
2021
2027 .
2017
2092
2159
2175
2175
(2175)
2172
2189
2226'
2240
2240
2238
2240
(2263)
(2360)
(2357)
(3291)
2388
(2390)
• Cl No. b»tween brackets; Chlorine number of minor constituent not associated with accurate R.I.
b R.I. between brackets: Predicted R.I. using Table VIII of ReflS
-------
17
Table II.3.3 (from ref. 18)
TI1K RETENTION INDICES, CHLORINE NUMBERS AND PREDICTED STRUCTURES OK THE MINOR PEAKS
IN AROCLOR 1254
Peak A'o.
I
2
3
4
5
6
7
8
9
10
II
12
13
M
15
16
'7
18
19
20
21
25
26
•27
28
3°
3'
34
35
37
3s
4°
46
47
R.I.
1490
1570
1672
1688
1750
1758
1763
'774
1782
1833
1849
1863
1879
1896
1922
'935
1943
1952
1963
1966
1980
2040
2051
2058
2072
2097
2115
2146
2152
2164
2169
2186
2246
2254
Chlorine No.
o
I
2
I
2
2
3
2
3
. 3
3
3
—
4
—
—
3
3
3
3
4
4
4
4
—
5
4
— (not 6)
—
—
—
—
—
Structure
Biphenyl
1-
2-2'
4-
2-5'
M-
2-3'
2-2'.6'
2-4'
2-2',5'
2-2',4'
2-2',3'
3-2'.6'
4-2',6'
4-4'
2-2',4',6'
2-3'.5'
i-i',3',6'
• 3-2',5'
4-2', 5'
3--'. 4'
3-2',3'
4-2'.4'
3-2'.;'
4-2', 4'
2-3'.4'
4-2',3',6'
2. 3-2', 4'
2-2'.3',4'
2,3-2',3'
2,3-2',3'
J.6-3',4'
3-2'.3'.5'
2,4-2',4',6'
2.5-3'.5'
2,6-2',3',5'
2,3-2',3',6'
2, 3-2', 4', 6'
2-3',4',5'
3-2'.3'.4'
3-2',3'.4'
2, 4-3', 4'
2.3-3'.4'
2,3,6-2',4',6'
2.3-3'.4'
2, 3, 6-2', 3', 6'
2,3-2'.3',j'
3.5-1', 3', 6'
3~2X'5'
2.5-2'.3'.4'.6'
2, 3, 5-2', 3'. 6'
4-3'.4'.5'
2,3-2'.3',5',6'
3. 5-2', 3', 5'
2,4,5-2',4'.6'
Predicted R.I."
1491"
1577"
1669"
1687"
1754
1756"
1770
1765
I782b
1831
1848
1864
1866
1878
1894"
19240
1932
1932
1932
1944
1949
1963
1962**
1963
1962"
1975
2041
2041
2047
2055
2055
2071
2097
2097
2094
2092
2120
2112
2144
2148
2148
•2154
2168
2160
2168
2173
2183
2185
2245
(2247)
2248
2257
(2256)
2259
2256
-------
Table II.3.3 (continued)
18
Peak A'o. R.I.
C/i'-.'riift' A"'.'. Structure
Predicted II.I.c
49
51
53
54
57
58
60
61
62
63
64
65
66
67
68
69
22S3
2310
2335
2340
2372
2376
2400
2413
2425
2433
2451
2466
2489
2JI9
2543
2577
_
5
(7)'
5
(7)1
6
• —
6
6
7
6
7
-
-
6
6
-
7
2,3-2',3'.4',6'
2.6-2',3',4',5'
3,4-3'.4'
2.5-3'.4',5'
3.5-2'.3'.4'
2,3.6-2'.3',5',6'
2.3-3'i.4'_.5'(
3.5-2'.3'.5'.6'
2.3o-2',4'.5'
2,4-2',3',4',5'
2.3.4-2'.3',5'
2.4-2',3'.4'.5'
3.4-2'.3'.5'.6'
2.3.4-2'.3'.5'
3.4-2'.3',4'.6'
3.4.5-2',3'.6'
2.3.5-2',3'.4'.6'
2,3.4-2',3'.4'
2,3,6-2',3',4',5'
2.4.5-2',3'.4'.°'
2,4.6-2',3',4',5/
2.3.4-2',3'.5'.6'
2,3.4-2'.3'.4'.6'
2.4.5-3'.4'.5'
3.4-2'.3'.4'.5'
2,4.5-2'.3'.4'.5'
3.4.v2'.3'o'/>'
2.3.4-2',3'.4'.5'
(2278)
(2283)
2282b
2307
2310
2303
2338
(2329)
(2335)
23400
(2376)
2374
(2376)
(2379)
2374
(2401)
2396
(2412)
NMR
(2439)
(2428)
(2430)
(2450)
(2462)
24880
NMR
(2541)
(2548)
NMR
• Smaller peaks cluted earlier \\:?-n major parts of peaks 51 and 33, respectively.
b R.I. of synthesiscd cornpo-jnu.
c K.I. between brackets: Predicted R.I. usinc Table VIII.
Table II.3.4 (from ref. 18)
TIIK RETENTION INDICES, CHLORINE .NUMBERS AND PREDICTED STRUCTURES OK AROCLOR I2J2
PEAKS n
Peak A'o. R.I.
Chlorine
Structure
Predicted R.I.°
3
6
8
9
10
II
12
13
15
"7
18
'9
20
21
22
24
3'
34
35
1672
1765
1781
1833
1849
1863
1879
1896
"935
1951
1961
1966
1980
1996
2011
2024
2092
2138
2I.|8
2
2
2
3
3
3
3
2
3
3
. 3
3
3
4
4
4
3
4
(5)
4
4
2-2'
2-3'
2-4'
2-2',3'
2-2',4'
2-2',3'
3-2',6'
4-2',6'
4-4'
2-3',5'
3-2',5'
3-2',4'
3-2',3'
A-l'tf
3-2'.3'
4-2',4'
2-3'.4'
2-2',3'.5'
2.5-2'.5'»
2-2',4',5'
2,4-2'.5'
3-2',3',6'
3-2',4'.6'
4-3',4'
2.5-3'..i'
2.4-2', J'.6'
2,5-2'.3',6'*
2.5-3'.4/4
2-3'.4'-5'
3-2',3',4'
l6og»
1770
I782b
1831
1848
1864
1866
1878
1894"
1932
1932
1949
1963
1962"
1963
I962b
"975
1996
1994"
2012
2OIO
2O29
2O2I
2088
2094
2097
2089
2138
2'44
2148
-------
19
Table II.3.4 (continued): minor peaks in Aroclor 1242
Peak Xo.
R.I.
Clihrim .Y'J.'1
Sliiiclnrc
Predicted R.I.°
I
2
4
5
7
'4
16
23
*5
26
27
28
29
3°
32
33
36
37
38
39
40
41
42
43
44
45
1580
1750
1758
'774
1923
1944
2015
2028
~
2037
2041
2052
2061
2080
2121
2129
2167
2174
21/8
2195
2207
2212
2232
2242
226S
22S7
o
2
3
4
3
4
4
4
4
4
_
3
4
4
4
4
5
5
5
5
6
—
—
_~__
Biphenyt
2-
2.5-
1.4-
2-2'.6'
2-2'.4',6'
2i5~2' 6'
4-2', 5'
2-2',4',5'
3-2',4'.V
2,3"2',5'
2.4-2',4'
2(6-3' 5*
{..|f;
i.3-2',3'
j
3-3'.4'
2,3-3'.5'
4-2',4',j'
-.3-3'o'
4-2',4',5'
..3-3'..,'
i]4-2'.3',5'
^'g^'"1/5'1 ,
3.5-i;'.3;'.6;'
2.'4-2'.'4 ','-'»
2'3~2''4'o'
2.5-2'.3'.4'a
2. 5-2'. 3', 4''
2.4-^'.3'.l'
3.4'i',3'.6'a
2,4-2',3',5/,6'
2.5-2'.3',4'.6/
2.4-2>,3'.4',6'
*'i%.$',3'jj
3.4-3'.4'
2.3,4--'.4'.6'
14910
1577"
'744
1756"
1765
19240
1927
1944
2012
202Q
2025
2O27b
2028
204!
2041
2047
2055
2076
2125
2125
2125
2125
2l6o
2168
2175
2175"
2183
2191
2206"
2210
22IO
2226
2228
(2241)
(2247)
224O
(2263)
2264"
(2283)
22820
2291
» Structures found in Aroclor Uj) by NMK determinations.
* K.I. of synthesised compound or NMK standard.
«R.I._bctwecn brackets: Predicted R.I. using Table VIII.
* Cl No. between brackets: Chiorinc number of minor constituent not associated with
accurate K.I.
Reproduced from
best available copy
-------
16 u
7 j
x2
x2S
120 Mm
60'
0.2 fA of i% Aroclor 1242 solution chromatographed on an Apiezon L SCOT column at 205°. Initial attenuation setting of 5 x 10' reduced as indicated; flame
ionisation detector.
Figure II.3.5 (from ref. 18)
-------
21
Ti u a
Uw
B 25 » ,5 10 s
uJU
1 / WJ
72 7> *>
i 0.25 /il 10% Aroclor 1260 solution chromatographed on an Apiezon L SCOT column at
:O5°. Attenuation setting maintained at I x 10'; flame ionisation detector.
Figure II.3.6 (from ref. 18)
-------
22
Table II.3.5 (from ref. 18)
THE RETENTION INDICES, CHLORINE NUMBERS AND PREDICTED STRUCTURES OF AROCLOR I26O
PEAKS
Peak .Vo.
31
37
38
43
45
47
48
52
55
57
58
59
60
66
6S
76
Peaks 2-21
22
23
24
25
26
27
-
28
29
3°
32
R.I.
2086
2168
2174
2239
2264
2296
2300
2358
2390
2411
2428
2432
2445
2542
2575
2724
in Aroclor
1994
2009
2013
2022
20-24
2O3O
2040
2050
2058
2117
Chlorine Aro.c
5
6
5
6
6
6
7
6
6
(7)
7
6
7
7
8
7
7
7 .
8
1254 chromatogram
4
4
—
4
—
4
4
4
—
Structure
2.5-2',3'.6'm
2.5-2',4',6'
2,3,6-2',3',6'
2.4-2',3'.5'
2,5-2'.4'.5'11
3,5-2',4'.6'
2,4-2',3',5',6'
2.3o-2',4',6'
2,4-2',3',4',6'
2.3.6-2',4',5'*
2,3,4-2',3',6'»
2,3,6-2',3',5',6'
2,4.6-2',3/,5',6'
2.j-2',3'.4'.5'
2.4,5-2',4/,5/t
2,3-2',3',4',5'
2,3,4-2',4',j'«
3,4,5-2',4',6'
2.3-5~2 -3 "5 '^
2,3.5-2',3',4',6'
2, |, 5-2', 3', 5', 6'
2,3,4-2',3',4'i
2, 4, 5-2', 3', 4', 6'
2.4.5-2'.3'.4'.6/
2,4, 6-2', 3', 4', 5'
2,3o,(>-2',3',5',6'
2,3,4-2',3',5',6'
2.3,6-2',3',4',5'
2.4.5-2',3'.4'.5'
2,3.4-2'.3'.4'.5'*
3.4o-2'.3'.4'.°'
2.3,4o-2',3'.4'.5'
were also present
2-2'.3',5'
2,5-2'.5'»
2-2',4',5'
2. 4-2', 5'
2-2',4'.5'
2.4-2'.5'
/ 3"2'i4',6'
\ 2, 3-2', 5'
2. 4-2', 4'
3-3'.5'
3-2',3',6'
4-2',4',6'
2-4-2'.4'
2.6-3',5'
4-2'.3',6'
2.3-2'.4'
2-2',3',4'
2, 3-2', 3'
2,3-2',3'
3-2',4',5'
2,3-2'. 3',6'
Predicted R.I*
2089
2081
2173
2175
2175*
2175
(2241)
2240
(2263)
2264'
2299
(2303)
(2295)
(2360)
(2357)
2356°
(2391)
2391°
2388
(2390)
(2412)
(2406)
2425"
(2428)
(2428)
(2430)
2438"
(244°)
(2439)
(254')
(2575)
(257°)
(2726)
in Aroclor 1260.
1996
1994"
2O J 2
2010
2OI2
2OIO
2021
2025
, 2027«
2033
2029
2033'
2027*
2028
2041
2041
2047
2055
2055
2114
2114
-------
23
Table II.3.5 (continued): minor peaks in Aroclor 1260
Peak No. K.I. Chlorine .Vo.c Structure Predicted K.I.b
33
34
35
36
39
40
41
42
44
46
49
50
5'
53
54
55
61
62
63
64
65
(-7
69
70
71
72
73
74
a
75
77
78
d
2125
2135
2146
2158
219'
2205
2209
2229
2254
2283
2321
2326
2340
2372
2379
2402
2460
2464
2486
2518
25"
2550
257*
258-
2597
260.1
2618
2640
—
2682
2738
2770
—
—
4
4
5
—
5
5
6
—
5
7
6
—
—
6
7
s
S
6
6
7
—
S
S
s
s
9
S
9
—
—
9
10
4-2'.4'.5'
2.3-3'.5'
2,5-3'.4'a
*-3'.4'.5'
3-2'.3'.4'
2.5-2'.3'.5'
2.3-2'.3'.5'
2,4-2',4',5'a
|2.3-2',4',5'
l2.5-2'.3'.4'a
2.4-2'.3'.4'
3,4-2',3',6'a
2,3-2',3'.5',6'
2,4,5-2',4',6'
2,3-2'.3'.4'.°'
2,6-2',3',4',5'
3.4-3'.4'
2.4-3'.4'-5'
3,4-2',4',5'»
2.3.6-2'.3',4',6'
2.4,6-2',3',4',6'
3,5-2',3'.5',&'
2.3.5-2',4',5'
2.4-2'.3'.4'.5'
2.3.4-2',3'.5'
2,4-2'.3',4',5'
3.4-2'.3',5'.6'
=.3.4-2'.3'.5'
3.4-2',3',4',6'
2.3.4-2'.3'.4'.6'
2,3.4.6-2'.3',5',6'
2,3,6-2',3'.4'.5'.6'
2,4,6-2'.3',4',5'.6'
2,3,4.6-2/.3'.4',6'
2,4.5-3'.4'.5'
3.4-2'.3'.4'.5'"
2.3.5-2'.3'.4'.5'
3.4.5-2'.3'.5'.6'
2.3,5--i',3'.4',5'.6'
2,3.4.5-2'.3'.5'.6'
2.3.4o-2'.3'.5'.6'
2.4.5-2',3'.4'.5',6'
2.3.4,5-2'.3'.4'.G'
2.3,5,6-2',3',4',5',6'
2.3.4-2'.3'.4'.5'.6'
2,3,4.6-2',3',4',5',6'
3.4.5-2'.3'.4'.5'
3.4.5-2'.3'.4'.5'.6'
2.3.4.5-2'.3'.4'.5'.6' ,
2.3.4.5.6-2',3'.4',5',6'
2125
2125
2138
2144
2148
2159
2189
2191
2206C
2210
2226
2228
(2256)
2256
(2278)
(22S3)
2282'
2323
2319
(2329)
(2321)
(2335)
234°c
(2376)
2374
(2376)
(2379)
2374
(2401) '
(2462)
(2464)
(2489)
(2481)
2490'
2488=
(2516)
(2525)
(2548)
(2577)
(25SI)
(2581)
(2593)
(2603)
(2624)
(2627)
(2650)
(2685)
(273S)
(2768)
2810°
• Structures found in Aroclor 1254 by NMR determinations.
11 R.I. between brackets: Predicted R.I.'s using Table VIII.
c Cl No. between brackets: Chlorine number of minor constituent not associated with
accurate R.I.
a Peaks observed on mass spectrometer oscilloscope, but not on GI.C.
e 14.1. of synthesist'd compound.
-------
24
Table II.3.6 (from ref. 27)
TAIII.I: 3. Structural identity of the major PCIJs in (lie gas chromalographic peaks of Aroclors 1254 and 1260
Retention time (min)
Aroclor
1254
peak No
1
2
3
4
5
(i
7a
7b
8
9a
9b
10
II
12
15
16
17
IX
•Match
'Maltl
•Inilit:
'SllliM
MUtin
Nun :
Aroclor
1260
peak No
1
2
3
4
5
ft
7
K
9
10
II
12
d to a peak n
d to a peak n
ed lo he pre ei
jlion |'iv ini: Hi
in litno ol v at
cak number ni.
Predicted chlorine substitutions
From peak matching From Table 2
'2,5,2',5'
°2,5,2',3'
J2,4,2',3'
°2,5,2',3',6' r"1(2,5,3',4')
42,5,2',4',5'
•2,4,2',4',5'
•2,3,2',4',5'
Cl''2,5,2'-,3',4'
°3,4,2',3',6'
"2,3,6,2',r,6' J{3,4,3',4')
J2,4,2',3',4',6'
°'B2,4,5,2',3',6'
"3,4,2',4',5'
"•"2,4.5,2',4',5'
J2,5,2',3',4',5'
h"' '\ 5 2' 3' 4'
J2,4,5,2',3',4',6'
'•J2,3,4.2'.3',4'
"2,3,6,2',3',4',5'
"2.4,5,2',.V,4',5'
"2,3,4,2',3',4',5'
Wehb and McCall 11072).
las anil Kleipool (|')7I) or T.is and de Voj (1972).
I hy SisMim and Wc!li (1071).
e clo'.cst prcilicled reljntion lirne.
dard couiponnd.
anil dtromalO!:rapiiie conditions arc yivcn under fiij. 1 and
Frnm
Fig. IB,
3.35
3.78
4.10
5.01
5.90
—
—
6.90
7.35
7.35
8.23
| 8.79
|l0.37
11.27
12.26
14.12
14.30
16.28
17.15
'19.73
23.31
in (tic Mater
Column I
Predicted
f p
irom t re
D Table 2 Fig. 1
•3.35 2.
3.79 2.
3.88 3.
4.91 (4.97) 3.
5.89 4.
6.03 4.
6.68 5.
6.91 5.
7.28 6.
•7. 20 '(7. 35) /,
8.17 i6'
j 8.64 •>_
| 8.73 5'-
j '10.37 8.
\ 10.14(10.24) 9.
11.21 9.
•12.16 10.
14.07 11.
•14.27 13.
16.43 14.
— 15.
- '17.
23.13 22.
als ;ind \feiho»K section.
Column 2
Predicted
c
m I rum
A,C Table 2
38 '2.38
90 2.90
13 2.94
91 3.84(3.87)
43 4.42
80 4.48
40 5.38
70 5.75
17 6.25
,. '6. 20 '(6. 30)
38 6.31
15 7'13
15 7.19
17 '8.20
30 9.28(9.36)
35 9.33
68 '10.68
58 11.56
93 '13.90
58 15.06
93 —
32 —
94 22.55
Reproduced from
best available copy
-------
10 20 30 '»"""
Gas chromalogrnms of A: Phenochlor nP6(Prodelec. Fr),
B: Clophen (Bayer, Gcr.), C: Aroclor 1260 (Monsanto, U.S.)
25
electron capture
Figure II.4.1 (from ref. 22)
-------
36
Clophen AGO and Clophen A50: these are listed in Table IX.4.1 and show
good agreement with those for Aroclors 1260 and 1254 respectively (Tables
11.3.3, II.3.5).
Six major constituents of Phenochlor DP6 have also been identified
(22, 24) as shown in Table II.4.2. These identifications agree with those
of .the corresponding constituents in Clophen A60 (compounds 11, 19, 29, 32,
38, 49 and 50 in ref. 23). No details appear to have been published of the
constitution of the Phenochlor with 42% chlorine which is being Imported
into the United States (7, p. 210).
Table II.4.3 lists the reported constitution of, three commercial
Kanechlor mixtures (from refs. 25, 26). Gas-liquid chromatography suggests
that the constitution of KC-400 was very similar to that of Aroclor 1248
(Figure II.4.3), but the reported correspondence of Eanechlors KC-300 and
KC-500 to Aroclors 1242 and 1254 appears to have bees, less close.
Fenclor DK, now being imported into the United States from Italy
jr
at a rate of about 180,000 kg/year (7, p.210), consists of decachlorobi-
phenyl (ibid.).
II.5 Occurrence of certain substitution patterns in PCS mixtures
The data summarized in Tables II.3.2, II.3.3, II.3.4, II.4.1 and
II.4.2 indicate that certain patterns of chlorine'substitution are much more
frequent than others in commercial mixtures. Figure II.5.1 illustrates the
•
most common substitution patterns on each of the phenyl rings in the biphenyl
molecule. By contrast, chlorobiphenyls with substitutions in the 3-; 3,5-;
3,4,5-; and, especially, the 2,4,6- positions are more unusual (18, 23).
Certain substitution patterns are believed to influence the biological
activity of chlorobiphenyls (see Section IV below) and it is useful to review
the frequency of these substitution patterns in the commercial Aroclor mixtures.
* See Table II.4.4 for 5 isomers identified in KC-AQO (ref. 395)".
-------
27
Table II.4.1 (from ref. 23)
BtUUv* r»Urtion tiw»t on Iwo GLC eolumm and amount* of poIyeHorHatxi bio***** \n CJoo*** A 50, A 60 aixf tn
Percentage in
Compound
No.
1
2
3
4
5
6
7
'8
9
10
11
12
13
14
15
16
17
IS
19
20
21
j-nr
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47 '
48
Structure*
23-2'3'
2.4-2'3'
23-2'3'
(2,-2'3'.4')
f4-2'3'.6')
23-2'3'.6'
23-2'3'-6'
3.4-2'3'
.
23-2'3'3'
23,6-2'3',6'
23-2'.4'3'
2.4-2'.4'3"
23-2'.4'3'
23-2'3'.4'
23-2'3'X
3.4-r3'.6'
233-2'3'.6'
2,43-2'3',6'
23-2'3'3'.6'
23-2'3'3'.6
2J.4-2'3',6'
23.6-2'3f3',6'
3,4-2',4'3' V
23.6-2'.3'.4*'.6'
233-2' ,4'3'
3.4-?'3',4'
2,43-2',4'3'
23,4-2'3'3'
23.4-2'.4"3*
233-2'3'3',6*
2.43-2'3'3'.6"
23,4-2'3'.4''
23.6-2'3'.4'3'
2,43-2'3',4',6'
23,4-2'3'3',6'
233»6-2'3'3',6"
23,4-2'3',4'.6'
23,4.6-2"3'3'.6'
2.43-3',4'3'
23,6-2' 3' .4'3',6"
23,4,6-2'3'.4' 6'
3,4-r.3',4'3'
233-2'3'.4'3'
No. of
ortho*
chlorines
-,
2
2
2
2
3
3
1
Ior2
2
4
2
2
2
2
2
2
3
3
3
3
3
Ior2
' 4
1
4
2
I
2
2 :
Ior2 ,
2
3
4
I or 2
3
2
3
$3
3
"4
3
4
1
4
4
1
2
Relative retention time Oophen
Apiezon L
0,25
0.26
027
030
032
035
038
0.41
0,42
0.45
0.47
0.43
031
033
033
035
036
0,60
0.64
0.65
0.70
0.72
0.76
0.77
0,79 -
0.84
085 T-t
0.87
0.90
0.94
0.96
1.00
1.01
1.02
1.04
1,08
1.11'
1,11
1.14:
1.19V
123
1.28
134
1.41
1.45
1,46
135
139
SF96
030
030
033
0.43
0.43
0.43
0.49
0.42
0.49
0.61
030
031
037 ,
0,58
r>6C
oe:
0.7G
0.73
0.63
0.74
0,83
0.91
0.74
0,95
0,86
0.86
0,86
0.97 -
0.93
.00
.06
.10
.13
.16
129
1.16
132 •
134 •
1.40
1.44
1.19
139
131
137 '
1.49
A 50
5.0
1.4
13
12
. 2.1
4,4b
23°
3.9
22*
22
030
7-°s
1 8
1.4b
5.4
I o
7>
12
2.0"
13
03
1.8
0.6C
0.09
5.0*
0,05
0,90
3"fih
42"
}"1 1 ~
I.I
5.1
0.04
0.05*
1.1"
039
13
0.33
0.17
0.27
0.005
0.13
0.007
0.4?
0.008
c
. 0,81
023
A 60
23
028
1.1
1.0d
5.6
•
1.4
23
4.2
63d
33
32
0.96
1.6
0,37
2.9
I23i
13
t
113d
0.49
2.0s
33
2.0
3.7*
1.8
2.1
0,07
13
,o,os
1.0
0,09
0.03
13
0.90
• Human
tissue
1.1
0.66
036
12
0.48
13
2.0*
12
4.2
13
23
4.7
LO*
0.13
0.43
0.05
0.15 .
5,4
2.7
13 '
213
c
14.0
0.90
1.5* •
33
081
23
13
037
0,49.
2,0
12
-------
28
Table H.4.1 (continued)
Percentage in
Compound
No.
49
50
51
52
53
54
55.
'57
58
59
60
Structure"
2JA5-2'>,5'.6'
2.4^5-2'3',4'>".6'
(2JJ.«'.3V,5',5')
2J.4-2'J'.4'Jf.6"
3/J-2'3\4'S '
2J,'4,5.6-2'J'.4'J'.6'
p#'-DDE
P.P-DDD
No. of
ortho-
chlorines
2
2
3 .
lor 2
3
3
"P
3
1
4
ReLitlve retenrion time Dophen
Aoiezon L
1.71
1.88
154
2.02
2.07
2.15
123
2.40
2.45
2.74
3.18
4.12
0.52
0.71
050
SF96
1.56
1.82
1.99
1.96
2,05
2.04
220
236
2.41
2.81
0.58
0.73
057
A 50
0.98
0.72
0,08
0,06
0.01
0.01
0.35
86.7
A 60
7.6*
4.1"
0.74
1.0C
0.44-
0.28
0.17
e
0.67
99.4
HUTBII
tisSU«
7.7
35 '
0.77
0.94
0.46
e
O.M
1.7
0,62
100,0
percent
* Tentatfve structures are given in brackets.
Component found present in Arocler 1254 by Webb and McCaJI (20)
e Rgures calculated using responses of chlorobiphenyls with similar retention times in
the same fraction frorn the charcoal column.
Component found present in Pher>olclor DP 6 by Tas a al (22 , 24)
* Present in trace amounts only.
-------
-29-
a
a
X '
I
1
60
Ctuematognm of OnrHa** A CO OXy a (Imfttd manhtr of ffgur**
1 tne-j) ».vi Ooc^'m A 50 (low*' traco' «iu« to lick c» sp*««
eo mind Q7 1/3* 96 1 6 T-> eaomn '2/3 Cf 1.
12 pere«nt and 1/3 S? S5. 6 p«*eantj « 20CTC.
Figure II.4.2 Gas-liquid chromatograma of Clophen A60
and Clophen A50, shoving numbering of components listed
in Table II.4.1.
-------
30
Table II.4.2 Six. constituents identified in Fhenochlor DPS (22, 24)
Peak no. in
Figure H.4.1 Identification
3 2,3,6,2*,3*,6*- hexachlorobiphenyl
5 2,3,6,2*,4',5'-hexachlorobiphenyl
6 2,4,5,2*,4*,5*- hexachlorobiphenyl
8 2,3,4,2",4',5'- hexachlorobiphenyl
10 2,3,4,5,2',3'»6'- heptachlorobiphenyl
11 2,3,4,5,2',4f,5'- heptachlorobiphenyl
12 2,3,4,5,2',3',4*- heptachlorobiphenyl
-------
Fig. 1. KanccMor -KM
'Table II.4.3 Reported constitution of Kanechlor mixtures
Kanechlor
KC-200 KC-300 KC-400 KC-500 KC-600
Corresponding Aroclor
(from ref. 25)
1232
1242
1248
1254
1260
Constitution
(from ref. 26)
2-Cl
3-C1
4-C1
5-C1
6-C1
in
60Z
23Z
0.6Z
'-
3Z
33Z 5Z
44Z 27Z
16Z * 55Z
5Z- 13Z
Table II.4.4. Five constituents identified in Kanechlor KC-400 (ref. 395)
Constituent
»
2, 4,3' ,4'- tetrachlorobiphenyl
2 ,5 , 3 ' ,4 ' - tetrachlorobiphenyl
.
3,4,3' ,4'- tetrachlorobiphenyl
2,3, 4, 3 ',4'- pentachlorobiphenyl
Peak no.
81
82
h
k
-------
32
•f=!=t:-£fe~5M^fet£-r-rt=gl"l-:i-{ hi t
^L
lELii:
K£
. Comparison of gas chrotaitpgrama of Kinecklor
400 (Japan) end ArooJor 1248 (USA).
Figure II.4.3 (from ref. 21)
Reproduced from
best available copy
-------
•33
Figure II.5.1
Moieties from Which Principal
Chlorobiphsnyl Isoners are Formed
O per
benzene
most like'/ substitution pattern
/~\a
4 -
a
Die most cannon substitution patterns for the chlorobiphenyls
found in PC3 preparations. Only one phenyl-ring is shown. The
most abundant tetrachlorobiphenyls, for example, are those frcm
the dichlorophenyl-noieties shown. One di- and one trichlorophenyl-
would give most abundant penta-chlorobiphenyls, etc.
-------
II.5.1 Adjacent unsubstituted positions
.The presence of two adjacent carbon atoms without chlorine substitu-
tion in one or both rings is believed to facilitate metabolism, because it
permits the formation of arene oxide intermediates (28). Essentially all
chlorobiphenyls with 5 or fewer chlorine atoms have at least one pair of
adjacent unsubstituted carbon atoms, because of the rarity of 3,5- substi-
tution in the natural mixtures (see above). Hence virtually 100 percent of
the constituents of Aroclors 1016, 1242 and 12&3 fall into this category
(Table II.3.1 above). From the data in Table IT.4.1 it can be determined
that about 927. of the constituents of Clophen A50 and about 66Z of the
constituents of Clophen A60 have at least one pair of adjacent unsubstituted
carbon atoms. The corresponding Aroclors (1254 and 1260) vould presumably
share these properties.
II.5.2 Number of ortho-chlorines
* »'
Jensen and Sundstrom (23) presented evidence that chlorobiphenyls
with three or four chlorine atoms in the ortho-positions (2- and 6- positions)
are more easily metabolized than those with only one or two ortho-chlorines«
Table II.5.1 shows that compounds with three or four chlorines in the .ortho-
position are virtually absent from Aroclor 1242 (and from Aroclor 1016), but
are fairly well represented in Clophens A50 and A60 (which correspond to
Aroclors 1254 and 1260).
II.5.3 4,4*-substitution
McKinney (29) has suggested that chlorobiphenyl isomers with chlorine
substitution in both the 4- and 4*- positions tend to be biologically active
and well retained in tissues. Table II.5.2 shows that the number and propor-
tion of these isomers increases with increasing chlorination of the mixture.
-------
35
Table II.5.1 Frequency of compounds with various numbers of
ortho-chlorine substitutions and with 4-4* substitution in
selected PCS mixtures.
Aroclor 1242 Clophen A50 Clophen A60
(from Table II.3.4) (from ref. 23) (from ref. 23)
percent no. of percent no. of percent no. of
of total compounds of total compounds of total compounds
4- ortho-chlorines
3 ortho-chlorines
2 or 1 ortho-chlorines
0
<1
99
0
4
45
0.7
15.2
69.8
8
17
32 ,
2.6
34.7
62.0
9
16
20
4-4' substitution 10-15 8 25.0 18 47.7 18
3-4 substitution
on one ring
on both rings
ca.20 . f 17
*: 1 ^ 1
1
35.4
23.0
21
17
38.2
49.6
19
18
Note: information for Aroclor 1242 is less complete and precise because the com-
pounds in this mixture were not all identified unequivocally (18).
-------
36
II.5.A. 3.4 - substitution
McKinney et al. (30) have also shown an association between biological
activity and substitutions in the 3,4-, 4,5-, or 3,4,5- substitutions on one
or both rings. 3,4- and 4,5- substitutions are frequently found in PCB
mixtures, but 3,4,5- is usually found only as part of a 3,4,5,6- substitution
pattern (Figure II.5.1). Table II.5.I shows that chlorobiphenyl isomers
with 3,4- or 4,5- substitutions are frequent in PCB mixtures and constitute
more than half of the components in the more chlorinated mixtures. However,
3,4,5,3',4',5'- hexachlorobiphenyl, an exceptionally toxic isomer (30), has
not been detected in commercial mixtures. The nearest equivalent,
3,4,5,2',3',4',5*- heptachlorobiphenyl, is present only in trace quantities
(Tables II.3.5, II.4.1), and 2,3,4,5,2',3',4",5'- octachlorobiphenyl is only
a ttdnor constituent (ibid.). 3,4,3',4'- tetrachlorobiphenyl, which has an
analogous structure, is probably a minor constituent of Aroclor 1242, but
may be absent from Aroclor 1016 (Table II.3.4., Figure II.3.3).
II.5.5Toxic contam-tnants in commercial PCB mixtures
Vos et al. (31) isolated a highly toxic fraction from samples of
Clophen A60 and Phenoclor DP-6 and tentatively identified in it small quanti-
ties of polychlorinated dibenzofurans (PCDFs). This identification has been '
confirmed by Bowes et al. (32), who found several chlorodibenzofurans (CDFs)
vith 4-6 chlorine atoms per molecule in the same mixtures. The total quantity
»
of PCDFs in Clophen A-60 and Phenoclor DP-6 was estimated to be 8.4 and 13.6
ppm respectively (Table II.6.1). PCDFs were also detected in American-
manufactured Aroclors 12&8, 1254 and 1260, at total concentrations varying
from 0.8 ppm (Aroclor 1260) to 2.0 ppm (Aroclor 1248) (Table II.5.2). PCDFs
were not detected in a single sample of Aroclor 1016 (32).
* This isomer is a major constituent of KC-400 (Table II.4.4).
-------
Table II.5.2 (from ref. 32)
Chlorinated dibenzpfuran concentrations* in Aroclor.
Oophen and P"»er»oclor
PCB
Aroctor I248'!9S9>
Arcclor I^I4O96»>
Aroclor 1254 WO)
Aroclor II6Q »»
Afoc'or 1260 Mor, AJC3)
Arodor 10)6(1972)
Clophett A-60
Phcflocior DP-ti
4-C1
0,5 '23)
01 'ft
02U3V
0 1 (105
ND
1.-UJ7)
0.7 (5)
5-C1
1,2f*0»
02(12)
o A ':')
0. *'
03 >?!»)
NO
50 !5=>)
10,004)
6-C1
03 f 151
1 4 >S2)
Qfj (60)
0,5 »50)
0,3 n six successive *tOO nt • clur-a To elrmtnata the polar
schcnts. each eliwu vai e«--arorated t*v.ce just to dryiess and taken
up each time in a minima' amount of hc-ane. Each fraction, in ! ml
bexanc. uas o'aceti on a n- croalunnin^ cu'umn'* and eluted with
10 ml eaea of I % and 20% jnctHyleie ch'onde m hexafie. These «l in
hexane lo eliwmaie the metSylene ch'cnde below gas ehromato-
graphte aaaiysis. A^cuots of all fractions obtamsd before and after
paniMonirg at ilurnwa *erf wjectpd mio a wx fool g»ass column
contajnmg 3% OV1 o?) 100-520 mesh Sueelcooort in Tracer MT220
ai»d Hewlert-Paekard 5"00 gas chromatogjranhs equipped with
**N» eteetron-czoiure detectors, PCHs were found to be present is
each fraction elured from t^e Flonsil co!urr>n in imounu sufficient
to ioterfere with the detec'ion of trace co^taTitants. Partruoniflg oa
the alumna columns seoa'ated most of the PCB interfetwce into tht
1 *, mxhykne ch.'onde fract»cns. On removal of this taerfererwe.
different peak patiemi aooeared in the cbromatogratns of the 20%
,a»ethy!er>e chioniie fracffons. Corrnounds elutipg in the 20% juethy-
low chlorde fraction 'vere collixtsd fcr ir> IB hexana
wit injected into the cac'-Ury as a nnii. removed with a 1 0 ul
tricroD'pette. and oSaced directly on tha mass locctromefer probe.
The prooe *aa inserted into a GEC ACI MSM2 *fcgh resolmion mass
spec.foff^ter and tie jon-ent removed bv toe force Bump. The probe-
was ispidly inserted IMO tHe ion source ard multiple sca,ns were
recorded in the on-l-ne high rcsululion mode14.
Reproduced from
best available copy
-------
38
PCDFs have also been detected in several Japanese-made PCBs at con-
centrations of 1-33 ppm (33-35), with the highest concentration in a. sample
of KC-400 (35) (Table 11.5.3).
The CDFs present in commercial PCS mixtures range from dichloro- to
heptachlorodibenzofurans (33, 34), but most of those detected have been
tetrachloro-, pentachloro- and hexachloro-dibenzofurans (32-3A). At least
11 CDFs were detected in the European and American products (32) and at
least 15 in KC-400 (35). The only isomers that have been precisely identified
to date are 2,3,7,8- tetrachlorodibenzofuran and 2,3,4,7,8- pentachlorodibenzo-
furan (36). (There are 119 structurally different OF isomers.)
Polychlorinated napthalenes (PCTs) have also been identified in
small quantities in Clophen A60, Phenoclor DP-6, Aroclor 1254 and KC-400
(31-33).
Despite occasional statements that commercial PCBs may contain poly-
chlorinated dibenzo-p-dioxins (PCDDs), there appear to be no authenticated
reports of their presence (32). The structure of PCDFs and PCDDs is shown
in Figure II.5.2.
II.6. _Physical properties of chlorobiphenyls and PCB mixture^.
II.6.1 General properties
> »
The general physical properties of some representative chlorobiphenyls
are summarised in Table II.6.1; those of the Aroclcr mixtures, including
- *
Aroclor 1016 and Aroclor 1270 (decachlorobiphenyl), are summarised in Table
II.6.2. Although most chlorobiphenyls are solids at room temperature, lower
chlorinated mixtures (e.g., Aroclors 1221, 1232, 1242, and 1248) are mobile
oils and increasing chlorine content results in mixtures talcing on the con-
sistency of viscous liquids (Aroclor 1254) or sticky resins (Aroclor 1260
-------
39
Table II.5.3 (from ref. 34)
Concentration of chlorinated dibenzofurans in
Kanechlors and "Yusho oil".
Samples
in
o
.c
o
id
«
in
•H
0
0
.c
M
a
300
400
500
600
A
B
C
Chlorodibenzofurans
Di- Tri- Tetra- Penta- Hexa- Hepta-
+ '+ .
+++ U+ U+ +++
+ +++ +
+ + ++ ++
+ ++ +++ ' +
+ ++ • ++ +
+ ++ +++ +
Concentration (ppm)
a
1
18
4
5 •
5
4
5
b
1.5
17
2.5
3
4.5
5
5
a: Calculated from peak heights, b: Calculated by perchlorination method.
-------
40
Figure II.5.2.
Skeletal structures of: c. chlorinated biphenyl, x-ry —
J--11); b, chlorinated dibenzofurans, x+v = 1-8; c, chlorinated
dibenzodioxins, x+y = 1-S.
Cl
-------
41
Table II.6.1 (from ref. 21)
PHYSICAL PKOPMTIES OF CHLOHOUIPHV:NYLS (Hubbard, 1964; Cook, 1972)
Compound
•2-chloro-
.'i-chloro-
•M-chloro-
"2,2'-dichloro-
3,3'-ilichloro-
"4,4'-'-lieptachloro-
Melting point, "C
34
89
76
61
29
148
36
49
44
172
103
J9S
162
S3
85
179
Boiling point, °C (mm Hg)
267-268; 154(12)
284-285
125(14)
322-324; 320-326
315-319
106(10)
ITHlft); 1*2(30)
195-200(15)
172(30)
230(50)
195-220(10)
240-280(20)
Present in commercial mixtures.
-------
Table II.6.2 (from ref. 7)
- Mine chlarim
• - polychlorlmt«d
Q^ilnl and Hylic*! ympaitio off
rroptrty
«n~u*nc.
Coloc, M«IJUI
Odorin*, puroant
• Aclillty, mt KK/I
naxirun
rbistur*. ppjk.
Av*. ccx-rficUnt of
expansion. oc/cc/*C
8|«ciCi= gravity .
Density, lt/9il.25-C
Distillation rang*.
*C, oonecuxl
IAS2I D-20, mdlfi*dl
Evaporation Iocs, t.
ICO'C, 4 hr
(U7TI D-t. nsl.)
I(J"C. 5 hr
Flash foint *C
|Cle%\.-land Cpen *7
Ovl
rii* point "C
(CleveUnJ Open *r)
four tninfC
(ASr< t-5-7) «p
fioftenl^q poir.t X
lAiT: C-lil 'r
n D-20 20*C
loo'r ii7.i*ci
JJOT (5«.5'C)
llO'f 198.9-Cl
Autra-j* ID. of Cl>kDl
Arocloc
1111
Clur,
iw Arm
20.5-21.S
0.014
-
0.00071
1.U2-1.192
I25-/15.5-C)
9.15
275-320
1.0-1.5
141-150
216-101
176
1 Icrysul*)
14 Icryttall!
.
1.417-1.411
lt-41
35-17
10-11
1.15
Amclor
U31
Clou,
^nK| )m oiJ.
loo Ann
11.4-12.5
0.014.
-
0.00073
(2S--100-CI
1.270-1.210
(25-/15.5-C)
10.55
290-325
1.0-1.5
152-154
105-310
131
460
-15.5
-12
.
1.0VI.01
44-51
19-41
11-11
1.04
Aroclor
1016
Cl*ar,
-41
1.J4J-1.172
(25-/15.5'CJ
11.40
1H-3K
170
nan* to
boiling
point
1. (22-1. (14
II 15-C)
71-11
Ml
KN
m
Kraclar
1241
Clear,
.cMJ.otl
100 APIW
42
0.015
50
0.00061
(JS'-iS-C)
1.191-1.392
(25V15.5-C)
11.50
325-366
0-0.4
1.0-3.4
17C-1DO
149-154
IKalo tO
lolling
-19
2
-
1.627-1.429
U2-91
14-15
1.10
Aroclor
1241
door.
100 APIA
41
0.010
50
0.00070
<21'-«S'C|
lisvisis-ci
12.04
110-175
0-0.1
1.0-4.0
191-1)4
379-384
njru to
tolling
point
-7
19.4
-
1.610-1.411
115-240
73-SO
14-17
1.10
rvroclor
1254
Ui|ht-yellow
vlsouus
liquid
100 All*
54
0.010
50
O.C0066
1.405-1.505
(C5V15.5-C)
12.B2
365-190
0-0.2
1.1-1.1
rrvio to
lolling
iwlni
ikjnc to
lulling
paint
10
50
-
1.C19-1.MI
1100-2500
.-40-340
14-41
4.94
Kroclor
1760
90ft,
sticky r«*iA
150 APIA
40
0.014
50
0.00067
(M'-IOO'C)
1.555-1.5(6
(90V15.S-C)
11.50
M5-420
0-0.1
1.5-0.1
ura ta
lolling
[Dint
rune LO
tulluk|
|»lnt
11
8B
-
1.447-1. (49
1700-4500
72-71
4.30
Aroclar
11(1
• Llcfcy
viftoous rvsln
150 APIA
61.5-62.5
0.014
-
0.00064
C25'-6S-C|
1. 572-1. 513
(90V1S.5*C)
11.71
190-425
0-0.1
0.5-0.(
uru to
lolling
foint
rune to
boiling
(oint
35-11
V9
-
1.4501-1. (517
600-150
(I60TI
71'CI
(.10
Aroclor
1161
Mut* to off-
1.5 (PA
tnoltcn)
(A
0.05
-
O.OC067
CO'-lOO-Cl
LC04-l.dll
(25V25-C)
15.09
415-450
0-0.06
0.1-0.2
rvnc t^>
(uint
tuno to
-
1M-170
102- liB
lluM point)
-
1.70
Aroclor
1270-
Uno'|o!2r>1
71
1.914-1.960
(25V25-CI
16.30
450-460
noikl
nan*
149-100
Ml
Aroclor
5442
p.\lvnt
ctidcy tmsln
42
1.470
(25V25-I
12.15
215-100
247
>]»
46
44-51
la
Aroclar
5460"
Cl&lr )«lla^-
to-.rttr
brittle rc
-------
43
and 1262). This results from the mutual depression of melting points of the
components. Resinous Aroclors retain their strictly resinous state perman-
ently; they do not "dry" even when exposed to air in thin films. With the
exception of Aroclor 1221 and 1268, PCBs and Aroclors do not crystallize
upon heating or cooling but at a specific temperature, defined as a "pour
point", change into a resinous state.
II.6.2 Vapor pressure and volatilization
Figure II.6.1 summarizes the vapor pressures of four Aroclor mixtures
as functions of temperature (2). Figure II.6.2 displays the results of
measurements of the vapor loss of Aroclor 1254 from its own surface at two
temperatures (37). Table II.6.3 compares the vaporization rates of a range
of Aroclor mixtures from their own surfaces at the same temperature (4).
Both vapor pressure and vaporization rate are much higher in the less
chlorinated mixtures; this indicates that the lower chlorinated chlorobi-
phenyls are much more volatile than the higher chlorobiphenyls. A conse-
quence of this difference in volatility is that the mixtures are differentiated
on vaporization. Figure II.6.3. shows chromatograms of Aroclor 1016 and of
vapors volatilizing from it (13): the components with shortest retention
times (dichlorobiphenyls -- see Figure II.3.3) are much more prominent in
the vapor than in the standard, whereas the trichlorobiphenyls are much
less volatile and the tetrachlorobiphenyls are hardly represented at all in
the vapors. Similar differentiation of the chlorobiphenyls with 4-7 chlorine
atoms is illustrated in Figure II.6.4, which shows measurements of vapor loss
of components of Aroclor 1254 from dry sand and cycled sand (alternately
moistened with water and dried) (37).
-------
44
1000/T CK)"'
21 2£ 2.9 3.3
300 200 ISO ICO 60 40 20
T ( 'C )
Vapor pressures of selected Aroclors, p,p'-DDT, and p,p'-DDE.
Figure II.6.1 (from ref. 2)
-o--o-o-o-°-c----ocva.— a..--..o,___^.6 _C ______ o^_
Los* «20 i lO
PC3 i254 Vooor Loss
Cms
006
"v-. a
I
20 30
Timf (dcys)
Locs of Aroclor 1254 'com itself as a function of time
Figure II.6.2 (from ref. 37)
-------
Table II.6.3 (from ref. 4)
VAPORIZATION RATES OF AROCLORS
45
roclor
ea: 12.28 cm2)"
1221
1232
1242
1248
1254 .
1262
1260.
4465
5442
5460
Wt . loss
6.5125
0,2572
0.0995
0.0448
0.0156
0.0039
0.0026
0.0064
0.0039
0.0032
Exposure
at 100°C
(hr)
24
24
24
24
24
24
24
72
72
72
Vaporization
rate
(g/cm2/hr)
0.00174
0.000874
0.000338
0.000152
0.000053
0.0.00013
0.000009
0.000007
0.000004
0.000004
-------
Aroclor 1016
Standard
0)
CO
c
o
0.
CO
0)
cc
Aroclor 1016
Vapors
0
0
Time (Min)
.e-
ON
Figure II.6.3. Gas-liquid chromatograms illustrating differential volatilization of
components of Aroclor 1016 (13).
-------
47
%
Lot)
PC8 1234 Vspor LOU '.a! 26* C
from Dry Sond
Loss of Aroclor 1254 from an Otiav/a sand
Figure II.6.4 (from ref. 37)
-------
48
II.6.2.1 Factors affecting the rate of volatilization
Figure II.6.4 shows that the rate of evaporation of the higher
chlorobiphenyls (7, 6 and 5 chlorine atoms) from sand was markedly in-
creased by cycling with water, but that the volatilization of tetrachlorobi-
phenyls was not affected much. In other words, the periodic evaporation of
water from the sand enhanced the total volatilization of PCBs, but reduced
the degree of differentiation of the chlorobiphenyls. When heated at 100°C
in water solution (conditions of co-distillation), however, the total volat-
ilization of PCBs was reduced, and the degree of differentiation was increased
(Table II.6.4) (4, 38). It is known from studies of pesticides that soil
moisture and evaporation of water have a strong influence on the rate of
volatilization of chlorinated hydrocarbons from soils and sand.
MacKay and Wolkoff (39) calculated theoretical evaporation rates for
various Aroclors from water, assuming that they are in true solution, that
the solution is well mixed, and that the vapor formed is in equilibrium
with the liquid at the interface. Because of the very high activity co-
efficients of chlorobiphenyls in water, this analysis predicted very rapid
volatilization rates (Table II.6.5). In fact, under laboratory conditions,
PCBs appear to volatilize fairly rapidly from water in aquaria (40) and
even from flasks plugged with glass wool (41). In the latter experiment,
the time required for half of a 25 Jig/1 solution of Aroclor 1260 to dis-
appear was of the order of 6-12 weeks; only a small fraction was recovered
from the glass wool. However, in the same conditions volatilization was
markedly reduced in the presence of sediments (42) , and there was then
little or no volatilization between 6 and 12 weeks. Hence, in natural
waters, it seems likely that adsorption to sediments (see below) would
limit the rate of vapor loss to the atmosphere.
-------
49
Table II.6.4 (from ref. 32)
PERCENT LOSS IN AREA OF SEVEN CHROMATOGRAM
PEAKS OF AROCLOR AFTER HEATING
% Peak Remaining After Heating
with water without water
Aroclor 1254 peak
' 1
2
3
4
5
6
7
•25 min
34.
59
78
.60
86
100
100
60 min
17
26
27
46
49
85
' 67
10 in
13
15
20
20
27
28
16
Table II.6.5 (from ref. 39)
Solubility, Vapor Presure and Halflife for
Vaporization from Water of Selected Aroclors at 25°C
PCB Type
Aroclor 1242
Aroclor 1248
Aroclor 1254
Aroclor 1260
Solubility
(rag/1)
0.24
5.4 x 10~2
1.2 x 10~2
2.7 x 10~3
Vapor Pressure
(iron Hg)
4.06 x 10~4
4.94 x 10~4
7.71 x 10~5
4.05 x 10~5
Theoretical halflife
for vaporization
from 1 m. water column
5.96 hr.
58.3 min.
1.2 min.
28.8 min.
-------
50
II.6.3 Solubility in water
Table II.6.6 summarizes two sets of measurements of the solubility
of individual chlorobiphenyls in water (43, 44). For the four chlorobi-
phenyls studied in both experiments, the results of Haque and Schmedding
(44) indicate much lower solubilities than those of ref. 43. Metcalf e_t
al. (45) give still lower values for the water solubilities of two of the
same chlorobiphenyl isomers (0.016 ppm for 2,5,2'- trichlorobiphenyl and
0.016 ppm 2,5,2',5'- tetrachlorobiphenyl). Haque and Schmedding (44)
attributed the discrepancy to the long period required to achieve equili-
brium between the chlorobiphenyls and water: they allowed more than one
month to achieve equilibrium, whereas Wollnbfer et al. (43) allowed only
two hours. However, Schoor (46), in a very detailed study, has given
evidence that "solutions" of chlorobiphenyls in water are in fact stable
emulsions of chlorobiphenyl aggregates. A "conservatively high" estimate
based on ultracentrifugation experiments indicated that the average solubi-
lity of the constituents of Aroclor 1254 is less than 0.1 /ig/1 (0.1 parts
per billion) in fresh water and less than 0.04jug/l in salt water (46).
Although the physical nature of the "solutions" of chlorobiphenyls
and their absolute solubilities in water are thus in serious question, there
is no doubt that the equilibrium concentrations of the "solutions" are much
higher for the lower chlorinated biphenyls (Table II.6.6). This reflected
in the reported "solubilities" of the commercial mixtures: over 200 ppb
for Aroclor 1221, 225-250 ppb for Aroclor 1016, 200 ppb for Aroclor 1242,
48-100 ppb for Aroclor 1248, 40 ppb for Aroclor 1254, and 25 ppb for Aroclor
1260 (2, 4, 13, 47). It is also reflected in differential uptake of the
various components of the mixtures into "solution". Figure II.6.5, for
-------
51
Table II.6.6. Solubility in water of various
chlorobiphenyl isomers as reported by two
groups of authors (43, 44)
Monochlorobiphenyls
2- '
3-
4-
Dichlorobiphenyls .
2,2'-
Trichlorohiphenyls
•' 2.A.A'-
2', 3, 4-
2,2', 5-
Tetrachlorobiphenyls
2, 2', 5,5'-
2, 2', 3,3'-
2,2', 3, 5'-
2,2',A,A'-
2,3',A,4'r
2,3',4',5-
3,3', A, A'-
Fentachlorobiphehyls
2,2',3,A.5'-
2.2' .4,5,5'-
Hexachlorobiphenyl
2, 2', 4.4', 5,5'-
Octachloroblphenyl
2,2',3,3'.4,4',5,5'-
Decachlorobiphenyl
Solubility (ppm)
(Wollnflfer et_ (Haque and
al_.,'-1973) Schnedding, 1975)
5.9
3.5
1.19
1.40
1.50
1.88
0.08
0'.085
0.078
0.046
0.034
0.170
0.068
0.058
O.OA1
0.175
0.022
0.031
0.0088
0.0070
" 0.015
0.637 + 0.004
0.248'+ 0.004
0.0265 + 0.008
0.000953 + O.OOQ01
-------
AROCLOR 1016
22.6
STANDARD
19.4
16.3
11.2
WATER SOLUBLE
11.3
7.3
Ul
NJ
Figure II.6.5 (from ref. 13)
-------
53
example, compares a gas-liquid chromatogram of Aroclor 1016 with that of an
extract from a water "solution": it shows that the dichlorobiphenyls are
much better dispersed in water than the tri- and tetra-chlorobiphenyls.
Similar differentiation of the components of Aroclor 1254 on dispersal
into water has been demonstrated (2, 4, 37, 38).
II.6.4 Solubility in organic solvents and partitioning into lipids
Chlorobiphenyls are freely soluble in many organic solvents (4, Table
4). As a consequence of their very low solubilities in water (Table II.6.6)
they are very strongly partitioned into organic solvents, including lipids
in biological systems (2, 45). Metcalf et al_. (45) give figures in the
range 10-20,000 for the partition coefficients between octanol and water
of representative tri-, tetra-, and pentachlorobiphenyls. Partition co-
efficients between these two solvents have been found to correlate well
with ecological magnification factors in aquatic organisms (45 - see Figure
II.6.6).
II.6.5 Adsorption to soils, sediments, and particulates
PCBs are strongly adsorbed from water onto solid surfaces, including
glass and metal surfaces in laboratory apparatus (46) and soils, sediments
and particulates in the environment (37, 42, 48-51). Figure II.6.7 illus-
trates the adsorption of Aroclor 1254 from a water solution onto a variety
of particulate materials (37). Adsorption was much more efficient'onto
Woodburn soil (with a high organic content) and clays than onto sand or
silica gel. Another study (47) showed that Aroclor 1016 was extremely
strongly adsorbed to a silty clay loam soil (36% clay, 6% organic carbon) and
could only be leached with difficulty from sandy and silty loams. Even from
the silty loam, less than 0.05% of the total quantity of Aroclor 1016 added
-------
54
5.0
4.0
- 3.0
I
2
LU
2.0
1.0
0.0
tetra-CI biphenyl
benzole acid
9
aniline
L
penta-CI biphenyl
€&
DDE
V
tri-CI biphenyl
chlorobenzene
anisole
"nitrobenzene
J
J
0.0 1.0 2.0 3.0 4.0 5.0
Log partition coefficient
Plot of log E.M. (ecological magnification) for fish vs. log octanol/water partition
coefficient.
5.0 r
4.0
'•= 3.0 -
I
2
2.0
1.0
0.0
DDE
penta-CI biphenyl
•** tetra-CI biphenyl
\
tri-CI
biphenyl
•
chlorobenzene
benznic acid
nitrobenzene
i i
'anisole
V,
aniline
0.0 1.0 2.0 3.0 4.0 5.0 6.0
Log water solubility - ppb
7.0 8.0
Plot of log E.M. (ecological magnification) for fish vs. log water sclubUity (ppb).
Figure II.6.6 (from ref. 45)
-------
20
""S—
25
PCS C54 Adsorption
Pel Morte Sqnd
I I I
10
Groma ^
7S
100
Percent decrease in the concentration of Aroclor 1254
by the addition of increasing amounts of adsorbent. Origins!
concentration of Aroclor 1254, 50 ppb
55
Figure II.6.7 (from ref. 37)
-------
56
to the soil was leached in a four-month period. It was also observed in
this experiment that the material leached from the soil consisted mainly of
mono- and dichlorobiphenyls: the tetrachlorobiphenyls were apparently
retained completely by the soil particles (Figure II.6.8).
In aquatic environments, PCBs are strongly associated with sediments
and are usually found at much higher concentrations in sediments than in
water in contact with them (12, 48, 49). Munson _et al. (50) have found
that PCBs (and other chlorinated hydrocarbons) in Chesapeake Bay are strongly
associated with suspended sediments (Figure II.6.9): the PCBs are believed
to be transported into the Bay from rivers and harbors and to move around
the Bay in association with the suspended sediments (50). As with other
chlorinated hydrocarbons (51), PCBs are probably associated particularly
strongly with micro-particulates (down to 0.15 urn in diameter or less).
There has been some debate whether PCBs carried in the air are in
the vapor phase or are attached to airborne particulates. Recent measure-
ments of PCBs in air over the North Atlantic Ocean (52, 53) have suggested
that most of the PCBs there are in the vapor phase. However, PCBs have been
detected on airborne particulates in urban areas (2) and on particulate
matter in dry fallout (12, 54). It seems likely that there is some differen-
tiation of the chlorobiphenyls, because the PCBs detected as vapors over the
North Atlantic were reported as matching Aroclors 1242 and 1248 (tri- and
tetrachlorobiphenyls) while those on dry fallout were reported as matching
Aroclor 1254 and Clophen A50 (penta- and higher chlorobiphenyls) (12, 53, 54).
However, the measurements are not definitive, because some of the differen-
* In the study reported in ref. 51, the chlorinated hydrocarbons extracted
from the micro-particulate fraction of suspended sediments in water from
Lake Erie were identified as various pesticides, including aldrin and
endrin. However, this study took place before the recognition of PCBs
as widespread contaminants in the aquatic environment, and it is likely
that at least some of the residues in fact consisted of PCBs.
-------
57
AROCIOR 1016 STD SOLN
PCBs FROM RAY SIITY LOAH
AROCIOR 1221 STD SOLN
Figure II.6.8 (from ref. 47). Gas chromatograms
illustrating differential leaching of components
of Aroclor 1016 from soil.
-------
58
2
O
iZ 1 nn
r~ i uu
e
t-
o —
SPENDEO SEDIMENT CON
(MILLIGRAMS PER LITE
o
3
1 0
0
o
0
0 0
o
o
o
o o
0°
0° °
o o °Woc^° oo o
00° o I o
-. : 1
3 0
O
0.10 1-0 10.0 10C
TOTAL CHC IN WATER ON SUSPENDED SEDIMENT
(PARTS PER TRILLION)
A plot of the log of the suspended sediment concentration in
the water (milligrams per liter) versus the log of the total
CHC concentration in the water associated with the suspended
sediment (parts per trillion).
Figure II.6.9 (from ref. 50)
-------
59
tiation may take place during the process of collection — i.e., the more
volatile lower chlorobiphenyls may evaporate from the particulates as
they are trapped on the collectors.
II.6.6 Concentration at the air-water interface
Two recent studies have indicated that PCBs, like other chlorinated
hydrocarbons, are strongly concentrated into the surface microlayers of
ocean and estuarine waters, especially in surface slicks of natural lipids
or mineral oils. Table II.6.7 summarizes two sets of measurements made in
Narragansett Bay, Rhode Island (55). Sample 1 was from a heavy slick and
Sample 2 from a less visible slick. Table II.6.8 summarizes a series of
measurements in the Sargasso Sea (52). In each case the surface waters
that were sampled contained concentrations of PCBs 3-50 times higher than
the sub-surface waters. Since, for practical reasons, the surface micro-
layer itself could not be sampled, it is likely that the enrichment factor
in the microlayer is often very much higher than this.
There appears to be some differentiation of chlorobiphenyls at the
air-water interface, since Bidleman and Olney (52) reported that airborne
PCBs resembled Aroclors 1242 or 1248 while those in the surface waters
resembled Aroclors 1254 or 1260. However, it is not clear whether this
differentiation results from differential volatility, differential fallout,
or some other mechanism. Indeed, there are several mechanisms by which
PCBs can be transferred across the air-water interface, and it is not yet
clear for either inland waters or the oceans whether the net transfer is
upwards or downwards (56).
* Thomas has recently detected PCBs in both gaseous and particulate
fractions of ambient air, in a ratio of about 5:1 (396). Similar
results have been reported by Tzou (402).
-------
60
Table II.6.7 (from ref. 55)
CONCENTRATION AND ENRICHMENT FACTORS OF POLY CHLORINATED
BIPHENYLS (AS AROCLOR 1254) IN SURFACE MICROLASER SAMPLES FROM
NARRAGANSETT BAY, RHODE ISLAND
Sample 1 Sample 2
Concentration Enrichment ' Concentration Enrichment
kg/liter) factor • f|Ug/liter) factor
Surface Subsurface. Surface Subsurface
4.21 0.15±0.04 28ilO 0.45±0.11 ^0.05 >9
Table II.6.8 (from ref. 52)
POLYCHLORINATED BIPHENYLS (AS AROCLOR 1260) IN SARGASSO
SURFACE MICROLAYER (SM) AND SUBSURFACE WATER (SS)
Collection Sam- PCB* Enrichment
date Location pie (ng/liter) factor
(1973)
4/9 29056'N,64040'W SM 11.2 ' 3.1
SS • 3.6 .
• 4/10 30°45'N,66050'W SM • 4.9 5.4
. SS <0.9
4/10 30°34'N,66059'W SM 8.3 8.3
SS 1.0
' 4/11 28°53'N,65°07'W SM 42.6** 19.3 47.3
SS <0.9**, <0.9 21.4
4/12 29°56lN,63°OOtW SM 3.8 '4.2
SS . <0.9
4/13 30°00'N,64°30'W SM ' 5.6 3.5
SS . 1.6
4/16 .' 31°34'N,63°49'-W SM 5.0 2.8
SS 1.8
4/17 31°38IN,63°57IW SM 8.4 9.3
SS <0.9
*Blank value was 0.9 and was subtracted in. calculating the above
results.
**Sample taken in a Sargassum windrow.
-------
61
II.7 Physical properties of chlorinated dibenzofurans
No measurements appear to have been published of the physical proper-
ties of CDFs that would be required to predict their environmental behavior.
Tetra- and pentachlorodibenzofurans are more polar than the corresponding
chlorobiphenyls (31), but their retention times in gas-liquid chromatography
are similar (36).
II.8 Chemical properties of chlorobiphenyls and commercial mixtures
II.8.1 mGeneral chemical stability
As a general rule, PCBs are considered to be inert to almost all of
the typical chemical reactions. PCBs do not undergo oxidation, reduction,
addition, elimination, or electrophilic substitution reactions except under
extreme conditions. For example, whereas many compounds undergo oxidation
with oxidizing reagents as mild as iodine and household hydrogen peroxide,
mono-, di-, and trichlorobiphenyls require boiling nitric acid (4). Chlorines
can be replaced by reductive dechlorination with any metal hydride such as
lithium aluminum hydride while high temperature (245°) treatment with alkali
in an autoclave can result in chlorine displacement by hydroxide.
II.8.2 Photochemical reactions
The reactions of paramount environmental importance are the few that
PCBs appear to undergo readily. These are alkali- and photochemically-
catalized nucleophilic substitutions and photochemical free radical'substitu-
tions, all of which occur with alkali and water.
Photolysis generally has been found to give three types of products
depending on conditions (4, 57-61). Chlorine is replaced by hydrogen (reduc-
tive dechlorination) in non-aqueous, non-polar solvents and by alkoxy groups
in non-aqueous, polar solvents. Chlorine is replaced by hydroxy groups in
-------
62
aqueous systems and in thin films on glass interfacing with aqueous systems.
Studies in non-aqueous solvents do not appear to be environmentally signi-
ficant in spite of the presence of analogous hydrogen donors in nature unless the
PCB product with one less chlorine is found to be more toxic than the PCB
reactant. Nevertheless, some useful information can be obtained on approxi-
mate rate of decomposition and site of chlorine loss from non-aqueous studies.
'In hexane, the most prominent reactions of 2,5,2',5'-tetrachlorobiphenyl
were the progressive reductive dechlorination and formation of polymeric
materials. Photolysis in hexane also showed 33 percent decomposition of
the PCB in 24 hours. Ruzo et al. (57-59) have performed the most extensive
and thorough studies of the photochemical decomposition of PCBs. They ob-
served the reactions of the tetrachlorobiphenyls shown in Table II.8.1.
It was found that 90 to 95 percent of the starting materials reacted in
methanol solution. Products consisted predominantly of 'dechlorinated PCB
with minor but detectable amounts of methanol substitution (methoxylated)
products. In all cases, the amount of methoxylated products did not exceed
five percent of the total amount of dechlorination products formed, with
trichloromethoxybiphenyls being the main components. Methanol substitution
occurred at the same site from which a chlorine was lost. The methoxylated
product of 2,4,2*,4'-tetrachlorobiphenyl was identified as 2,4,4'-trichloro-2'
methoxybiphenyl by comparison of GC retention time and mass spectra with
those of authentic samples prepared in the laboratory. Each of the tetra-
chlorobiphenyls which contained chlorines in the ortho position lost them
upon irradiation. Similarly, those tetrachlorobiphenyls containing only
meta- and para-chlorines upon irradiation lost the meta-chlorines prefer-
entially. This behavior was also observed in the formation of the secondary
products, dichlorobiphenyls, resulting in loss of ortho- or meta- but not
-------
Table LC.8.L (from ref. S8)
TetrachLorob LphenyLa
I: 2,S,2','5'-
CC: 2,4,2',4'-
CCt: 2,1,2',3'-
CV: 3,4,1',4'-**
V: %•>,!',5'-
Vt: 2,6,2',61-
PttOTOPRODUCTS IN HEXANE AND LN METHANOL
T Lcae , sec
DechLorLnated products
2, V ,S-Tr Lch Lorob Lpheny L
1,\*-DLchLorobLphenyL
1-ChLorobLphPtiy Lfc
2,4,4 '-Tr LchLocob LphenyL
4,4'-DLchLorob LphenyL
4-ChLorob LphenyL*
2,1,V-Tr Lch Lo robLpheny L
1, V-D Lch Locob Lpheny L
*5,4,4'-TrichLorob LphenyL
4,4'-D LchLorob LphenyL
1,V ,S-TcLchlorob LphenyL*
2,2",6-TrLchLorobLphenyL*
2,2'-DLchLorobLphenyL*
L67
L28
L48
182
L92
L47
L8L
IS8
69
Methoxylated products
Tr LchLororaethoxyb Lphenyl
D Lch Lorod Lmethoxyb Lpheny L*
Tr LchLoromethoKyb Lpheny L
D Lch Lorod LmethoKyb Lpheny L*
TrLchloromethoKybLphenyL
DLchLorodLmethpKybLphenyL*
TrichLoromethoxyb LphenyL
Tr LchLoromethoicyb LphenyL*
*Represented less than LZ of totaL product formatLon,
**3,T,4-TetrachLorobiphenyl was observed Ln <2%.
-------
64
para-chlorines. The tertiary products, monochlorobiphenyls, were only
formed in one percent yield or not at all. This occurred either because
of insufficient energy absorption by dichlorobiphenyls at the wavelengths
employed or by decreased reactivity of meta- and para-chlorines relative to
those on the ortho position.
The rate of photolysis reaction for all PCBs studied was found
to be zero order (independent of the amount of each PCB) in both hexane
and methanol (Table II.8.2 — ref. 58). A marked increase in rate was
observed, however, when solutions were degassed prior to irradiation. Oxygen
is known to act as a triplet (free radical) quencher by accepting or sponging
up excess electronic energy from free radicals before any chemical change
occurs. Thus, an increase in rate upon removal of oxygen implies that a
free radical process is occurring. In the environment, this implies that
photochemical transformation will be enhanced under anaerobic conditions.
The two pathways operating to give replacement of chlorine by hydrogen
and methoxyl group and the probable intermediates, inferring the correspond-
ing mechanism, are shown in Figure II.8.1.
The photochemical behavior of higher chlorobiphenyls appears similar
to that of the tetrachlorobiphenyls (60-61). 2,4,5,2',4',5'-hexachlorobi-
phenyl undergoes reductive dechlorination when irradiated in degassed methanol,
losing one or both ortho-chlorines (61). Irradiation of Aroclor 1254 in
aqueous solution gave rise to dechlorinated and hydroxylated products (60).
Hexa- and octachlorobiphenyls are more photochemically reactive than tetra-
chlorobiphenyls (60), so that under irradiation the higher components of
Aroclor 1254 are selectively degraded (60, 61 -- Table II.8.3).
-------
Table II.8.2 Photolysis rates of tetrachlorobiphenyls (from ref. 58)
Tetrachlorobiphenyl
2,4, 2', 4'-
2, 3,2', 3'-
2, 5,2', 5'-
3,4,3',4'-
2, 6,2', 6'-
3, 5,3', 5'-
k, x 108
11 -1
M sec
(degassed)*
1510.
2.4
2.2
1.4
0.4
<0.1
k, x 108
11 -1
M sec.
-------
Cl
Cl
Cl
ci-
_ ., UV-irradiation of 2 ,2 ' }4,4'-tetrachlorobiphenyl in.
methanol and hexane, products formed and probable mechanism.
Figure II.8.1 (from data in ref. 58)
-------
TABLE II.8.3 (from ref. 61)
Sunlight Irradiation of Aroclor 1254.
Initial Concentration of Aroclor 1254 in Hexane
Peak No.
1
2
3
4
5
6
7
8
9
10
\ remaining
1 week
97
111
74
83
103
181
58
84
66
62
1 ppra
after
2 weeks
109
137
76
104
89
211
51
89
47
47
10 ppm
3 .weeks
143
161
79
109
87
196
36
75
30
41
% remaining
1 week 2
65
111
113
127
98
210
68
111
53
49
after
weeks
104
140
94
108
96
206
58
98
44
50
3 weeks
104
180
88
143
94
241
40
90
44
59
100 ppm
* remaining
1 week 2
85
114
110
92
118
157
68
105
80
80
after
weeks
131
164
110
99
70
205
58
96
56
64
3 weeks
139
184
101
120
63
218
42
80
47
54
-------
68
II.8.3 Photochemical production and degradation of chlorinated dlbenzofurans
The creation of free radicals by sunlight allows the environmental
replacement of chlorines by hydroxy groups from water without the inter-
vention of alkali. When this occurs at the ortho position (found to be
the most preferred for chlorine loss) the resulting 2-hydroxychlorobiphenyl
is perfectly positioned to allow oxygen to bond to an ortho position of the
other ring. This results in the creation of potentially the most important
class of contaminant in PCBs or commercial mixtures, the chlorodibenzofurans
(CDFs).
Studies in aqueous solvents have continuously established the hydrox-
ylation of mixtures of PCBs, although at times the location has not been
established. Thus, irradiation of Aroclor 1254 in hydroxylic solvents at
pH 9 yields compounds corresponding to the addition of water to the PCS
molecules and a more polar carboxylic acid fraction. The same sample
irradiated as a thin film does not yield the water-addition products, but
mass spectrometry of 2,5,2',5'-tetrachlorobiphenyl reveals the presence of
new hydroxylated species and a polar "carboxylic" fraction. No attempt was
made to determine whether the polar carboxylic acid fractions in these
studies were the same but it was generally concluded from a number of differ-
ent irradiations of 2,5,2',5'-tetrachlorobiphenyl that dechlorination, forma-
tion of polymers, and carboxylic products, as well as hydroxylation, does
occur (60).
Activating the ring will make it more capable of hydroxylation. Many
means can be used to activate the ring, such as the intermediacy of a copper
complex (the Ullmann reaction). In the presence of powdered copper or
copper salts, a few hours at 160° converts normally unreactive o-chlorophenols
to chlorinated dibenzo-p-dioxins, contaminants of 2,4-D and 2,4,5-T production
-------
69
with very similar chemical, physical and, probably, toxicological properties
to CDFs (62, 63). Thus, in the environment either heat, light, or metals
and metal salts in water could theoretically accelerate the transformation
of PCBs into PCDFs.
The ultraviolet component of sunlight is sufficiently energetic to
generate free radicals from both phenols and PCBs. The energies required
to break the Ar-Cl bond to form hydroxy-PCBs and the ArO-H bond to form
CDFs correspond to wavelengths near 360 and 320 nm, respectively —
clearly within the sunlight region. Analogous free-radical mechanisms have
been proposed to explain reactions of polychlorophenol (PGP) and other chloro-
phenols in sunlight (62).
The alternate photonucleophilic formation of phenols from PCBs was
demonstrated to afford hydroxy PCBs both with simple models and with highly
complex Aroclors. Contrary to previous results (57), irradiation of an
aqueous suspension of 4,4'-dichlorobiphenyl provided 4-chloro-4'-hydroxybiphenyl
and 4-chlorobiphenyl (62, 63). Irradiation experiments with five pure
2-chlorinated biphenyls as 5 mg/1 aqueous suspensions, showed that traces
of 2-chlorodibenzofuran were detectable although only the 2,5-dichloro- and
2,5,2',5'-tetrachlorobiphenyls provided identifiable amounts (a roughly
steady 0.2 percent yield during a seven-day irradiation) (62, 63). The en-
vironmental significance of this is threefold: (1) ortho-chlorobiphenyls
can be hydroxylated by radiation similar to sunlight when they are suspended
in aqueous media; (2) the product(s) are converted to CDFs; (3) rates of
CDF formation by this process are approximately the same as their rates of
degradation, leading to an approximately steady concentration. Hutzinger
also has speculated that chlorodibenzofurans may be formed from chlorobiphenyls
under photochemical conditions which lead to oxygenated products (60).
-------
70
Although no chlorodibenzofurans were detected in a number of chlorobiphenyl
samples which had been exposed to sunlight for over two months, preliminary
results indicated the formation of chlorodibenzofurans from 2,4,6,2',5',6'-
hexachlorobiphenyl in model experiments (irradiation in methanol) (Andersson
et aJ., cited in ref. 64).
Before any knowledge on accumulation of CDFs can be obtained, rela-
tive rates of their formation and decomposition must be determined. Un-
fortunately, only a few rates of decomposition have been determined, such
as those of 2,8-di- and octachlorodibenzofuran, as shown in Figure II.8.2 (64)
Decomposition is faster in methanol than in hexane. In contrast to the
chlorinated dibenzo-p-dioxins, where the degradation of the octachloro deri-
vative on irradiation in methanol solution is much slower than that of the
2,7-dibenzo-p-dioxin, the di- and octachlorodibenzofurans show similar rates
of decomposition.
Hutzinger _et al. (64) observed that photolysis of 2,8-di- and octa-
chlorodibenzofuran in methanol and hexane solutions results in rapid de-
chlorination and accumulation of unidentified resinous polymeric products.
Dechlorination is also observed to a certain extent when thin films of these
compounds were exposed to sunlight. This is similar to the non-aqueous be-
havior of PCBs from which these CDFs arose. This suggests that CDFs in
the environment, like PCBs, will only reductively dechlorinate when in
organic media or thin films. Crosby and Moilanen (63) found that irradiation
*
of 2,8-dichlorodibenzofuran resulted in a slow dehalogenation in hexane, ex-
plaining the previous appearance of 2-chloro-dibenzofuran. Irradiation in
methanol substantiated the rapid disappearance of the dichlorodibenzofuran
(64). Decomposition in aqueous suspension was found to be slow (63).
Unfortunately, these preliminary data do not allow direct comparison
of environmental dibenzofuran degradation rates with rates of their photo-
-------
71
ug ml
Figure II. 8. 2 Cfroir ref.
degradation of chlorodibenzofurans in
solution. Irradiation "avelergt'i 310 rm.
-------
72
chemical formation from corresponding chlorobiphenyls. In view of the
photochemical lability observed for some chlorodibenzofurans, however, it
seems reasonable that most isomers will not accumulate excessively in the
environment with the possible exception of 2-CDF. Since accumulation is
relative when a wide range of toxicity is considered, the steady state con-
version of two-tenths percent of some PCBs to PCDFs is very important and
potentially very significant. A further environmental complication is that
other investigators have been unsuccessful in detecting the conversion of
PCBs to PCDFs in light, perhaps due to the aforementioned rapid decomposi-
tion for most isomers under energetic (254 nm) irradiation conditions or
the presence of sensitizers. The addition of the photosensitizer 4,4'-
dichlorobenzophenone to a methanol solution of 2,8-dichlorodibenzofuran
during irradiation resulted in a sharp increase in the decomposition rate
of that CDF (63) . Both natural and synthetic photosensitizers have been
shown to affect other xenobiotics, and the environmental sensitization of
degradative photolysis of CDFs seems quite plausible.
-------
73
11,8.4 Probable formation of PCDFs from PCBs in service.
In the "Yusho" incident in Japan in 1968, large numbers of persons
were poisoned by consuming rice-oil contaminated with PCBs (Kanechlor
KC-400) from a leaking heat-exchanger (35; see Section III.15 below).
Recent studies have shown that although the original Kanechlor KC-400
contained only about 20 ppm of PCDFs, the toxic rice-oil contained
relatively much larger quantities of PCDFs (PCB/PCDF ratio 84-200 in the
rice-oil, versus 50,000 in KC-400) (34; 35, Table 5). Further, the PCDFs
in the Yusho oil contained substantial quantities of hexachlorodibenzo-
furans, which have not been detected in KC-400 (33-35). This suggests
that most of the PCDFs in the Yusho oil had been formed in service, prob-
ably in the heat-exchanger. According to Kuratsune, elevated levels of
PCDFs have been discovered in PCBs in other heat-exchangers in Japan.*
In a parallel incident in the United States in 1971, fish meal
being processed for poultry food was contaminated with Aroclor 1242 and
proved highly toxic to broiler chickens (65). Subsequent tests with the
contaminated feed, which contained 148 ppm of PCBs, showed it to be much
more toxic to chicks than feed containing 200 or even 400 ppm of Aroclor
1242, and the symptoms of poisoning were different (2, 65: see Section
III.6.2 below). This again suggests that a more toxic agent had been
formed in service. This situation is complicated by the report that the
contaminated feed also included 8.8 ppm of "BHC" (presumably an i-somer
of HCH, hexachlorocyclohexane) (65). However, the identification of
this compound is questionable, because HCH is rarely found in marine
fish or in other components of poultry feeds at more than trace levels.
* This information was presented by Kuratsune at the PCB conference in
November 1975 (9) but documentation is not yet available.
-------
74
Hence the component reported as BHC in the contaminated fish meal may
in fact have been a breakdown product of PCBs.
According to Broadhurst (66), a general disadvantage of PCBs in
many of their applications (including capacitor and transformer uses as
well as heat transfer uses) is their tendency to decompose under the action
of heat or electrical arcing to form corrosive HC1. Hence the evidence
summarized above, that PCDFs or other toxic breakdown products may be
formed in service in heat-exchangers, needs to be followed up by investi-
gation of the composition and toxicity of PCBs after service in electrical
equipment also (2).
-------
75
III. TOXIC EFFECTS
III. 1. Introduc tion
Toxicological aspects of PCBs have been reviewed in
refs. 1, 2 and 5, and in a number of papers presented at the
National Conference on Polychlorinated Biphenyls in November
1975 (9. 16, 29, 35, 67-75). The following summary is con-
cerned especially with three aspects of the toxicology of PCBsi
1. Definition of the toxic effects which have been ob-
served reliably at low levels of exposure to PCBsj these are
of greatest importance in establishing criteria.
2. Review of the differences in toxicity between the various
commercial mixtures, which reflect differences in toxicity among
the individual chlorobiphenyls.
3. Elucidation of the role of PCDFs in the observed toxicity
of commercial mixtures or environmental residues.
III. 2. Effects on microbial systems.
The effects of PCBs on micro-organisms range from stimulus
to inhibition of growth, depending upon the degree of chlorination,
the type of organism, and other environmental factors. When
Aroclors 1221, 12^2, and 125^ were added to bacteria from lake
water (including Achromobacter sp. and Pseudomonas sp.) in 1 per-
cent glucose medium, no inhibition of growth occurred at concen-
trations up to 0.1 percent Aroclor. In fact, there was a slight
stimulation by Aroclors 1221 and 12^2 (76). Lake water samples
incubated with Aroclors as the carbon and energy sources illus-
trated that bacteria could use 0.05 .percent Aroclors 1221 and 1242
-------
76
for growth support (see Figure III.2.1) tut not Aroclor 125^ (?6).
The ability of the "bacteria to utilize PCBs decreased with an in-
crease in percent of chlorination.
When natural waters were enriched by the addition of 0,1 ppra
Aroclor 1260, bacterial counts yielded increasing numbers of viable
bacteria (M). No adverse effects were noted, with growth of the
treated cells exceeding that of the control (see Table III.2.1).
In spite of the slight growth enhancement, no metabolites were
detected and unaltered parent compounds were recovered.
Isolates of estuarine bacteria (including Flavpbacterium,
Bacillus, Corynebacterium, Pseudomonas, Achromobacter, Micrococcus,
and Serratia) were grown on agar with Aroclor 1016 and 12^2 satu-
rated paper discs (77)t Of 85 tested cultures, 26 were inhibited
to varying extents by 0.5 mg (5 mg in 0.1 ml acetone) of either
Aroclor. Cultures sensitive to Aroclor 12^2 were also sensitive
to Aroclor 1016, and 65 percent of the cultures were still sensi-
tive at 0.1 mg. Concentrations of 001 mg Aroclor 1016 inhibited
58 percent of the cultures sensitive at 0.5 mg. Four representa-
tive cultures of the sensitive bacteria (two gram-positive and
two gram-negative) were tested for growth inhibition in liquid
culture with 10 ^ig/ml (10 ppm) of Aroclor 12^2. The extended lag
times suggest an adaptation mechanism (see Figure III.2.2) and
possibly extended time (greater than the 2^ hours used) on agar
would produce similar results. Previous reports indicate that
gram-positive bacterial growth was inhibited by organochlorine
insecticides (chlordane) and gram-negative bacteria were unaf-
fected (77). The bacteria sensitive to Aroclor 125^4- were both
-------
77
10
Acetone
Control
•02 4 6 -8 10 12 14
INCUBATION TIME (DAYS)
The time/growth curve of bacteria in 0.05% Aroclor 1221,
Aroclor 1242, and Aroclor 1254 as .carbon and energy sources.
Figure III.2.1 (from ref. 76)
-------
Table III.2.1 (from -f. 41)
The fate of 0.025 ppm chlorinated hydrocarbon com-
pounds in 150-ml water samples from the Fraser River,
held in the laboratory for 12 weeks at 7°C
The fate of 0.025 ppm chlorinated hydrocarbon com-
pounds in 150-ml water samples from the Nicomekl River,
held in the laboratory for 12 weeks at I6°C
The fate of 0.025 ppm chlorinated hydrocarbon com-
pounds in 150-ml water samples from Georgia Strait,
held in the laboratory for 12 weeks at 9°C
Recovery, %
Time,
weeks
0
6
6
12
12
0
6
6
12
12
0
6
6
12
12
0
6
6
12
12
0
6
6
12
12
0
6
12
0
6
12
Compound
a-Chlordane
a-Chlordane
a-Chlordane
a-Chlordane
a-Chlordane
y-Chlordane
Y-Chlordane
y-Chlordane
y-Chlordane
Y-Chlordane
Lindane
Lindane
Lindane
Lindane
Lindane
DDT
DDT
DDT
DDT
DDT
PCB'
PCB*
PCB'
PCS'
PCB'-
Acetone only
Acetone only
Acetone only
Control
Control
Control
Bacteria /ml
1.8X102
1.3X104
2.3X104
4.2X105
8.8X104
I.8XI02
2.2X104
2.5X104
2.6X105
7.1X104
1.8X102
1.2X104
1.4X104
5.3X105
5.3X104
2.0X102
1.8X104
2.2X104
4.8X104
3.4X104
1.9X102
5.2X104
2.7X104
1.1X105
—
2.2X102
9.3X103
4.6X104
2.3X102
7.1X103
4.5X103
Water
98.7
59.8
59.7
41.7
44.1
90.6
53.0
55.6
37.1
38.1
101 .0
99.7
101.5
96.7
97.2
95.6
67.4
71.3
69.7
68.7
95.6
60.1
60.9
64.1
74.7
0
0
0
0
0
0
Glais
wool
0-
9.5
17.7
7.6
6.3
0
18.6
6.4
9.4
3.4
0
0
0
0
0
0
5.6
3.2
7.2
3.9
0
1.8
4.5
1.2
5.5
0
0
0
0
0
0
•No residue delected.
KM ppm Aroclor 1260.
Recovery, %
Time,
weeks
0
6
6
12
12
0
6
6
12
12
0
6
6
12
12
0
6
6
12
12
0
6
6
12
12
0
6
12
0
6
12
Compound
a-Chlordane
a-Chlordane
a-Chlordane
u-Chlordane
a-Chlordane
y-Chlordane
y-Chlordane
y-Chlordane
y-Chlordane
y-Chlordane
Lindane
Lindane
Lindane
Lindane
Lindane
DDT
DDT
DDT
DDT
DDT
PCB'
PCB'
PCB'
PCB'
PCB'
Acetone only
Acetone only
Acetone only
Control
Control
Control
Bacteria /ml
1.5X10*
—
—
1. IX 105
5.7X105
6.4X103
—
—
1.1X105
5.4X104
8.5X103
—
—
1.2X104
4.0X103
1.5X104
—
—
9.9X104
1.4X103
2.4X104
—
—
7.5X103
4.4X103
1.8X104
—
2.6X104
4.9X104
—
1.4X104
Water
92.0
50.2
51.1
20.5
16.6
100.8
34.0
24.7
2.3
13.9
98.4
90.5
88.5
79.0
76.0
% 3
34.4
43.7
30.1
23.6
96.2
73.8
74.5
33.0
56.7
0
0
0
0
0
0
Glass
wool
0-
0.8
1.5
1.2
0.8
0
0.2
• 1 .3
0.5
1.5
0
0
0
0
0
0
2 2
514
1.1
3.5
0
1.4
1.6
1.1
1.1
0
0
0
0
0
0
•No residue delected.
W.I ppm Aroclor 1260.
Time,
weeks
0
6
6
12
12
0
6
6
12
12
0
6
6
12
12
0
6
6
12
12
0
6
6
12
12
0
6
12
0
6
12
Compound
a-Chlordane
a-Chlordane
a-Chlordane
a-Chlordane
a-Chlordane
y-Chlordane
y-Chlordane
Y-Chlordane
y-Chlordane
y-Chlordane
Lindane
Lindane
Lindane
Lindanc
Lindane
DDT
DDT
DDT
DDT
DDT
PCB*
PCB*
PCB*
PCB'
PCB*
Acetone only
Acetone only
Acetone only
Control
Control
Control
Bacteria /ml
1.0X102
1.1X105
8.9X104
3.0X103
I.3XI05
1.1X103
9.3X104
—
4.5X104
1.3X104
8.6X102
1.4X105
6.0X104
I.3XI04
1.1X104
8.0X102
5.8X104
7.2X104
1.1X104
I.9XI03
7.8X102
9.8X104
6.5X104
3.5X103
1.1X103
1.1X103
3.4XICH
4.5X103
8.0X102
2.4XIOS
5.1X103
Recovery, %
Water
91.3
41.9
30.3
50.7
53.2
94.4
31.9
24.9
28.4
35.6
99.9
91.5
96.0
99.2
90.5
90.8
65.8
49.3
53.0
36.6
93.5
70.7
40.7
37.7
38.7
0
0
0
0
0
0
Glass
wool
0°
0.8
1.0
0.6
0.6
0
21.5
9.5
9.6
4.3
0
0
0
0
0
0
3.2
17.2
6.0
10.7
0
1.3
6.2
2.4
0.8
0
0
0
0
0
0
"No residue delected.
M.I ppm Aroclor 1260.
CO
-------
79
gram-positive and negative, with slightly more (61 percent) of the
sensitive bacteria gram-positive. When PCB-sensitive and non-
sensitive strains were compared, the biochemical activities of
test bacteria fell into two different groups. Amylase was pro-
duced by 76 percent and gelatinase by 86 percent of the sensitive
strains, whereas the nonsensitive strains showed only 33 percent
and 42 percent activities, respectively. No conclusions were
drawn by Bourquin and Cassidy (77) as to the possible significance
of the prevalence of PCB-sensitivity among amylase and gelatinase
producers. However, they suggested further investigation to
determine any relationships to total nutrient catabolism. In
another recent paper, Bourquin _et aJL (78) again reported little
difference in activity between Aroclors 1242 and 1016. Results
for 25 of the 100 cultures tested are shown in Table III.2.2.
Using Escherichia coll, a common human intestinal aerobe,
Keil et al. (79) found that Aroclor 1242 did not inhibit growth
at concentrations up to 1,000 ppm. Aroclor 1242 at a concentration
of 0.1 ug/ml~ (0.1 ppm), and possibly at 0.01 ug/ml (0,01 ppm),
stimulated E. coli growth (see Table III.2.3).
In a separate experiment using E. coli and Bacteriodes
fragilis (an intestinal anaerobe), Greer jet al. (80) found no
detectable.effect on growth using 0.01 ppm (0.01 mg/1) and
0.1 ppm (0.1 mg/1) Aroclor 1242. However, there was an apparently
dose-related depression of lipid synthesis in B. fragilis only
(see Table III.2.4).
The effect of 2,2'-dichlorobiphenyl on microbial predators
of E. coli was found to decrease kill rates at lower concentrations
(81).
-------
80
IcULTURI
NUMMR
.= 31
• = 9
200|
10
CONTROLS
04 S 12 16 30
TIM! 'hour!)
Four sensitive bacteria uere tested r'nr grou'th :n one-half strt'ni-th 2216 Marine Brath containing 10
tig of Arot'lor '.'142 per ml. .S'vm6n',s: (Q) A t hrnmnoacfer ^5.. \Q] £ac;Vu/.'" i.p.. (A j Corn\ebfictcrium ip., and (Q)
Pstudomonnt. sp. (Vn/rof.s contain nrt?.ha!f streng:h 2^16 Marine bro.h vnly: all salinities uert 20r,i.,
Figure III.2.2 (from ref. 77)
Reproduced from
best available copy
-------
81
Table III.2.2 (from ref. 78)
Inhibition of growth of atuarme bttct^ria on nutrient seawattr medium by PCB's
:;BHRL
Culture
No.
3
21
•}5
39
53
54
7
9
21
60
S6
100
S
11
42
44
'.'3
43
5
13
23
32
41
67
69
Gram
Reaction &
Morphology
+ ROD
-ROD
-ROD
-COCCOID
-ROD
+ ROD
+ ROD
+ ROD
-ROD
+ ROD
-ROD
-ROD
+ ROD
-ROD
+ COCCUS
H COCCUS
+ ROD
+ COCCUS
-COCCOID
-ROD
-ROD
-t-ROD
-COCCOID
-ROD
-ROD
Genus
Unknown
Unknown
Flavobacterium sp.
Unknown
Unknown
Bacillus sp.
Bacillus sp.
Bacillus sp.
Unknown
Bacillus sp.
Flavobacterium sp.
Psfudomonas sp.
Corynebacterium sp.
Achromobacter sp.
Micrococcus sp.
.Micrococcus sp.
Unknown
Micrococcus sp.
Serratia sp.
Achromobacter sp.
Achromobacter sp.
Corynebacterium sp.
Unknown
Achromobacter sp.
Unknown
Aroclor® 1242 (rag)
0.1 0.25 0.5
++ -t-t- ++-»•
•H- ++ -H-+
++ -H- -M-
-H- -H-f •(-++
++ +-M- . +-M-
+-H- -(-H- -H-f
+ + +
+ -M- +++
-t- -t- +-H-
+ -h +
+ + +
+ -M- ++
X + -H-
X + -H-
X + ++
X + +
X * +
— + -H-
— — . -H-
— _•)-+
— — -H-
— + +
— — -M-
- + . +
•H-
.JLroclor® 1016 (mg)
0.1 0.25 0.5
•H- +-H -t-H-
-H- ++ -H-h
+ -I-H- -H-f
-H- -H-f +++•
•f-H- +-H- -t-t-r
+ +-M- +-H-
X + -H-
+ -t-t- -H-t-
+ •»• -M-t-
-H- ++ +•»•
X + +
+ ++•«•
X T r+
X + -t-r
\ + ++
— X +
— x -f
— + -H-
— — ++
— — -H-
— — -H-
— X +
— — -H-
- - +
— — -H-
Degree of sensitivity: +++ (18-20 mm zone), *+ (16-18 mm), + (14-16 mm), x (slightly), — (not sensitive).
-------
82
Table III.2.3 (fro- ref. 79)
LYOPHILIZED WEIGHTS AND TOXICANT UPTAKE
BY ESCHERICHIA COLI CULTURES EXPOSED TO PCS
Treatment
Bacterial Series I
PCS 0.1 ug ml"1
PCB 0.01 ug nl""1
Control
Acetone control
Uridine control
LSD05*
Bacterial Series II
PCB 0.1 ug ml"1
PCB 0.01 ug ml"
Control
Acetone control
LSDnc
Mean .,
„ Mean
Harvest _ .,
TT j u_ Residue
Weights 1
(rag) (ug g )
86.0 13.6
90. A A. A
M.5 0
27.2 1.2
£1.6 0
13.6 10.8
186. A
153.2
160.8
133.6
23.6
LSD., = Least significant at 95 percent probability level calculated
fron one way analysis of variance.
-------
83
Table III.2.i (fro~> ref. 80)
HARVEST WEIGHTS, TOXICANT RESIDUE, AND LIPID
YIELDS' OF BACTERIODES FRAGILIS CULTURES TREATED WITH PCB
Treatrent
.01 pp- PCB
,1 pp~ PCB
Control
Acetone
Control
**
LSD05
-
No.
Replicates
A
2
A
A
A/ A
2/A
Mean
Harvest
Weight
(mg)
137.4
210. A
119.7
109.9
26.0
31.8
Mean
Toxicant
Residues
(ug)
N.D.*
*
N.D.
0
0
Mean
Lipid Yields
(ug 'mg dry wt)
23.2
16.2
3^.9
35.7
7.8
9.5
N.D, =• Not Determined
*
LSD = Least significant difference at 95 percent probability level
calculated from one way analysis of variance.
4-26
-------
84
The predators (the dominant Spirillum spp. and a pseudomonad),
were isolated from sea water using E. coli as the sole carbon
source. Neither the predator nor E. coli viability and activity
were affected by ICT^M (200 ppm) 2,2'-dichlorobiphenyl. Table
III.2.5 shows percentage kill of E. coli in the presence of
varying predator populations and dichlorobiphenyl concentrations.
Walsh and Mitchell (81) noted that the lower dichlorobiphenyl
concentrations (10~%) which generally decreased £_._ coli kill are
similar to those used previously to inhibit chemotaxis in motile
marine bacteria. The higher concentrations (10~-%) which increased
kill rates in the standing flasks for lower predator populations
were similar to those Walsh and Mitchell observed to increase
chemotaxis. The standing flasks probably contained a higher con-
centration of both microbes and chemicals at the surface- (^1).
Thus, the changes in E. coli kill by microbial predators may be
due to inhibition or excitation of the chemotactic response by
dichlorobiphenyls.
PCBs may cause changes in the ecological role of micro-
organisms. The differing sensitivities of the bacteria to the
PCBs present may cause changes in composition of community popu-
lations. For example, Escherichia coli appears relatively re-
sistant to PCBs at the concentrations tested (79-81). Stimulation
of !• coli growth occurred at lower concentrations (0.1 and
0.01 ppm) of Aroclor 12*4-2 (79). Achromobacter sp. and Pseudomonas
sp. also had growth slightly stimulated with 5°° Ppro Aroclors 12^2
and 1221. Oloffs et al. (*H) increased bacterial numbers in
natural waters by the addition of 0.1 ppm Aroclor 1260. If, as
Bourquin and Cassidy (77) reported, one-third of a natural
-------
85
Table III.2.5 (from ref. 81)
Percentage kill of E. iv'i i:i -IS li by nioiile marine piedators
in (he presence of chlorinated hydrocarbons
Initial
predator
population
no. per ml.
Standing
10
10J
I04
10!
2, 4-O o,
No
chlorinated 10"1 M
hydrocarbons
°0Killcf£.
0 7
6 3
30 10
72 26
7x IO'3 M
coli
31
32
29
41
rt-Dichlorobiphenyl
10'4 M
0
17
13
41
ID'3 M
31
35
39
47
Fully mixed
10
I03
I04
•I0;
20
54
61
71
23
29
32
77
25
41
43
44
18
31
30
55
27
44
43
51
The initial f. coli population was I07 ml"'. The data are corrected
for kill observed in tbe ub^';ice of the predators.
-------
.
estuarine "bacterial population is inhibited by chlorinated
biphenyls and stimulation of some of the remaining two-thirds
is possible (4l,79)i with no response by other members, a
totally different bacterial community may be created. Although
the concentrations of PCBs required to show effects on single
species cultures are much higher than those occurring in natural
waters, they are comparable with those reported from sediments
and sewage sludge (2,10-12, 48-50). Moreover, as in the case of
phytoplankton (Section III.3)» effects on mixed-tspecies cultures
may take place at lower concentrations of PCBs.
Changes in community composition, coupled with possible
increased (or decreased) chemotactic responses of predatory
micro-organisms (81) may cause further disruption of normal
carbon cycling and pollution control associated with microbes.
It may be necessary, in light of the effects of PCBs, to change
some of the criteria presently used to determine water pollution.
For example, low counts of E. coli may be indicative of high PCB
levels stimulating predators, not clean water.
Natural adaptive mechanisms of micro-organisms may compound
or counteract the effects of PCBs. Baxter et al. (82) stressed
the adaptation of Nocardia spp. grown on biphenyl. The ability
to degrade PCBs and the rate of degradation appear dependent upon
degree of chlorination as well as available precursors. 'Thus,
microbial communities may undergo continual changes or cycles as
bacteria, chemical components and the associated processes and
dependents fluctuate.
III.3 Effects on Phytoplankton
Phytoplankton are the photosynthetic organisms which form
-------
the basis for all marine and some fresh-water food-webs. A
number of experiments have shown that PCBs interfere with photo-
synthetic mechanisms in certain species of phytoplankton at con-
centrations as low as 0.1 ppb (ug/1) or below (83-92). In most
cases the effects measured were reductions in the uptake of radio-
labelled carbon (supplied as bicarbonate), a measure of the rate
of carbon fixation. In a recent assessment, Fisher (83) has
suggested that the primary effects of PCBs are to reduce the
rates of cell growth and cell division? the important consequences
are likely to be changes in the species composition of marine
phytoplankton communities, rather than a reduction in the total
rate of photosynthesis by the community.
The radiocarbon uptake of two green algae, Scenedesmus
quadricauda (fresh water) and Dunaliella tertiolecta (estuarine)
was reduced by 60 percent and 35 percent, respectively, when
they were exposed to Aroclor 125^ at 100 ppb (84). Effects on
§. quadricauda were marked even at 0.1 ppb, the lowest concentra-
tion tested. (Table III.3tl)» Inhibition was greater in
Scenedesmus which possesses a cell wall, as opposed to the naked
Dunaliella (see Table III.3tl). Since the cell wall appears not
to prevent absorption, either the cell or chloroplast membrane
would appear to be the selective barrier. There was no effect
on radiocarbon uptake in either alga by DDT in concentrations up
to 1 ppm. However, photoreduction of isolated chloroplasts was
inhibited by both PCBs and DDT, suggesting that the cell membrane
possesses an active transport site preferentially structured for
PCB (8*0.
-------
Table III.3.1 (from ref. 84)
88
INHIBITION OF CARBON-14 UPTAKE IN SCENEDESMUS
AND DUNALIELLA BY CHLORINATED HYDROCARBONS
Concentration
ppb
0.1
1
10 '
io2
io3
DDT
90.66
111.44
98.85
109.12
101.74
14
C Uptake, % Control
-.Si
Aroclor 1242
79.81
70.45
74.02
40.39
34.53
Aroclor.1242
113.2
94.1
103.6
65.7
56.9 •
Scenedesmus
Dunaliella
Source: Luard, E.J. 1973. 'Sensitivity of Dunaliella and
Scenedesmus (Chlorophyceae) to chlorinated hydro-
carbons. Phycologia 12(1/2):- 29-33.
-------
89
Exposure of the marine diatom Cylindrotheca closterium to
10 or 100 ppb Aroclor 12^2 resulted in inhibition of growth and
diminished levels of chlorophyll and RNA synthesis (Table III.3.2).
Levels of DNA were not. affected, implying selective action by the
polychlorinated biphenyls on cell metabolism (85). The chlorophyll
content per cell was similar in the treated and control cultures,
suggesting that the primary effect of PCBs was to inhibit cell
growth and division rather than to inhibit photosynthesis per se.
A similar result was obtained by Fisher (83).using two other
diatom species exposed to 10 ppb Aroclor 125^.
Sensitivity of two marine diatoms Thallassiosira pseudonana
and Rhizosolenia setigera to Aroclor 125^ increased with decreasing
temperature (Table III.3.3)(87). R. setigera had growth completely
stopped for ^8 hours at concentrations of 0.1 to 10 ppb Aroclor
after which growth resumed with less inhibition at the higher tem-
perature (8?: Figure III.3.1). T. pseudonana was only sensitive
at 10 ppb Aroclor 125^. The effects of temperature, Aroclor 125^»
and the interaction between temperature and Aroclor 125^ were all
significant (P<0.001), indicating that sensitivity to PCBs was
dependent on temperature. The increased inhibition at tempera-
tures at which cell division rates were slowest illustrates the
narrowing of a sensitive species1 niche with environmental stress.
Thus, species more vulnerable to stress would be less capable of
successful competition for resources. If this were true, species
adapted to stressful conditions, such as occur in estuarine en-
vironments with salinity changes, would be expected to withstand
higher levels of PCBs. Supporting this hypothesis is the finding
-------
Table III.3.2--(fron, ref. 85^
90
HARVEST WEIGHT, CELL COUNTS, WJCLEIC ACID LEVELS,
AFD CHLOROPHYLL INDEX OF CYLINDPOTHECA CLOSTERIUM
CULTURES EXPOSED TO AHOCLOR 12 A 2
Harvest Final Cell Chlorophyll
Treatments, Weight Count Index
Aroclor 12A2 fmg) (X 10A) (OD (? 6?0)
PCB .1 ppm 11.5** 16,5**
PCS .01 ppm 38.1 113.7
Control 30.9 116.8
Acetone 33.2 98,5
Control
Significantly different from control at .05
•*
Significantly different from control at .01
Source: Keil, J.E., L.E. Priester and S.1I.
bJphenyl (Aroclor 12^2): Effects of
and chlorophyll of a marine diatom.
.27**
1.26
1.52
1.37
level
level
Sandif er .
uptake on
Bulletin
RNA PCS Levels
(rag/mg) (ppm)
.015** 109.2**
.033* A. 7*
.039 0
,OAO 0
•
19"! . Polychlorinated
growth, nucleic acids,
of Environmental Con-
tamination and Toxicology 6(2) :156-159.
-------
91
Table 111,3.3 (from ref. 86)
GROWTH OF T. psetidonana AND O. tertiolecta AT THREE TEMPERATURES AND THREE CONCENTRATIONS
Of PCBS. GROWTH RATES (/;) ARE EXPRESSED AS DIVISIONS PER DAY AND WERF CALCULATED ACCORDING
TO THE EXPRESSION ft - (33) (In /!, - In /l,p),(< - tn) WHERE t - tn REPRESENTS ELAPSED TIME IN
HOURS AND n, AND «,o ARE THE POPULATION DENSITIES AT TIMES t AND /Oi RESPECTIVELY (EPPLEV &.
STRICKLAND, 1968). THE VALUES SHOWN (MEANS OFTHHEE REPLICATES) ARE GROWTH RATES FOR THE
FIRST 72 H AT IS^C AND 25 C AND FOR THE FIRST 120 H AT 12;C.
Temperature
125C
12°C
12°C
18'C
18°C
18CC
25°C
25°C
25°C
[PCB] in ptm
0-0
0-1
JO'O
0-0
O'l
10-0
0-0
0-1
10-0
Growth rate of
T. pseudonana
1-43
1-57
0-60
2-34
2-15
1-31
2-57
2-59
2-13
°i control
100
109
42
100
84
56
100
101
83
Growth rate of
D. tertiolecta
0-74
0-75
' 0'79
1-22
1-23
1-18
1-66
1-66
1-69
°i control
100
101
107
100
101
97
100
100
102
GROWTH OF R. Setlgtra AT TWO TEMPERATURES AND FOUR CONCENTRATIONS OF PCBS. GROWTH
RATLS ARE EXPRESSED AS DIVISIONS PER DAY AND WERE CALCULATED AS SHOWN IN TABLE 1. THE VALUES
SHOWN (MEANS OF THREE REPLICATES) ARE GROWTH RATES FOR THE FIRST 192 H AT 10:C AND FOR
THE FIRST 144 H AT 15'C.
Temperature [PCB] in ptm Growth rate ofR. seligera % control
10°C
10°C
10°C
10°C
15°C
15°C
15aC
15'C
0-0
0-1
1-0
100
0-0
0-1
1-0
10-0
0-60
0-49
0-46
0-49
0-86
0-81
0-75
0-73
100
82
77
82
100
95
87
85
-------
92
Fig. 2. Growth of R. sen'gera at two different temperatures and with four PCB concentrations.
(•—•) = OptmofPCBs;(A A) = 0-1 ptm;(|J D) = l-Optm:(O O) = 10 ptm.
Data points are the means of three replicates.
Fig. III.3.1 (from ref. 86)
-------
93
that Dunaliella tertiolecta, an estuarine and marine green alga,
was not affected at any of the temperatures or concentrations of
Aroclor 125^ that inhibited the marine diatoms (86» Table III.3«3)«
Mosser et al. (8?,88) also found differences in sensitivity to
Aroclor 125^ between marine diatoms and the green alga D.
tertiolecta. This alga was not affected by concentrations of
Aroclor 125^ up to 1,000 ppb, while 10 ppb and 25 ppb affected
the diatoms Skeletonema costatum and Thalassiosira pseudonana,
respectively (see Figure III.3.2). The viability of T. pseudonana
showed a decrease at 50 and 100 ppb Aroclor 125^« The sensitivity
levels should be considered as maxima, since evaporation loss and
adsorption of the PCBs to the walls of the flask have not been
taken into account.*
Further investigations of geographic differences in sensi-
tivity to PCBs compared estuarine and oceanic colonies of the
same diatom species (89). Three species of diatoms were isolated
from the relatively stable Sargasso Sea and from the more variable
environments of continental shelf and estuarine areas. The diatoms
tested were Thalassiosira pseudonana, Frapilaria pinnata and
Bellerochia sp. All clones grew more slowly with 10 ppb Aroclor
125^ added, but clones from the Sargasso Sea were more sensitive
than estuarine and continental shelf isolates (Table III.3«**•)•
The clone from the continental shelf was, in turn, more sensitive
*This comment applies to all the experiments with phytoplankton
reviewed in this section, since the actual concentration of PCBs
in the culture medium does not appear to have been measured in
any of the studies.
-------
SI It
v a.
0
4.
24 6 8 10 0
TEME (DAYS)
Source: Mosser, J. L., N. S. Fisher, T.-C. Teng, and C, F. Wurstec,
1972, Polychlorinated biphenyls: toxicLty to certain
phytoplankters. Science 175(4018);191-192.
I
Effects of Arorlor T-»«=' '
-------
95
Table ttlTS-.i • ffrwrref. 90)
RATIOS OF MEAN CELL DENSITIES FROM lOppb
AROCLOR 1254-TREATED CONTROL CULTURES AT FIVE SAMPLE TIMES
HOURS AFTER INOCULATION
0 47.5 70 95 118
Thallassiosira pseudonana
clones
3H (estuarine) 1.00 0."694 0.365 0.676 0.976
7-15 (continental shelf) 1.00 0.544 0.368 0.520 0.844
13-1 (oceanic) 1.00 0.422 0.241 0.172 0.341
Fragilaria pinnata clones
0-12 (estuarine) 1.00 0.824 0.909 0.932 0.590
13-3 (oceanic) 1.00 0.688 0.707 0.269 0.387
Bellerochia clones
Say-7 (estuarine) 1.00 0.207 0.064 0.036 0.035
SD (oceanic) 1.00 0.074 0.020 0.013 0.005
-------
96
than its counterpart from the estuary.
Synergistic effects occurred when DDE and Aroclor 125^ were
used simultaneously with the diatom Thalassiosira pseudonana (90).
At concentrations of 10 ppb Aroclor 125^- or 100 ppb DDE, minor
growth inhibition occurred. However, used at the same concentra-
tions simultaneously, there was substantial inhibition of growth,
with still greater inhibition at higher concentrations (see
Figure III.3.3). However, the effects of DDT were opposite to
those of DDE. At 50 ppb, Aroclor 125^ almost stopped diatom
growth. When 500 ppb DDT was added simultaneously with 50 ppb
Aroclor 125^, growth was restored to two-thirds of the control
(see Figure III.3.3)• Lower DDT concentrations reversed Aroclor
1254 inhibition to a lesser extent. . If DDT was added 12 or 24
hours after Aroclor 1242 inhibited diatom cultures, growth was
again restored. Hence, co-precipitation of the inhibitor PCB"
by DDT in the medium was not the mechanism of reversal, but some
intracellular reaction must be involved (90).
The uptake of carbon by natural plankton communities was
affected by Aroclor 1242, Aroclor 1254, and 2,4'-dichlorobiphenyl
(91). The plankton communities were dominated by the diatom genera
Ceratulina, Chaetoceros, Biddulphia, Eupodiscus, Leptocylindrica,
Melosira, Nitzschia, Rhizosolenia, and Thalassionema. Two dino-
flagellate genera were also generally present! Peridinium and
Ceratium. Sensitivity to Aroclor 1242 and 1254 was apparent at
1-2 ppb and to the dichlorobiphenyl at 7 ppb (see Figure III.3.4).
In natural phytoplankton communities all stages of growth are
represented through various phytoplankton species. Hence, while
-------
97
FCBs + DDT
,(0)
PCBs •«• DDT
(12)
0123-4012345
PCBs -?• DDT
(24)
PCBs
pseudonana.
Interactions among PCBs, DDE and DDT in Thallassiosira
Figure III.3.3 (from ref. 90
-------
100
•d .->
H O
80
a
58-
-^J C^
u
o w
M O
60
M
W O
t> p^
M W
H O.
40
20
0.1
10
100
1,000'
2,4'-dlchlorobiphenyl (B); 'Arocloc 1242' (•) and 'Arocloc 1254' (O).
Adapted from: Moore, S. A., Jr. and R. C. HarrLss. 1972. Effects of ^
polychlorlaated bLphenyl oa marine phytoplankton ooamuntties.,
Nature 240: 356-1S8.
- Effect of organochlorLnes on in sLtu radiocarbon uptake
, by marine phytoplankton communities.
Figure Lit.1.4 (from ref. 91)
vo
00
-------
99
overall photosynthesis diminished in the community exposed to
PCBs, the precise species and/or active site cannot be identified,
Nor were changes in species composition investigated.
In a key experiment, Mosser _et al. (88) tested the effects
of PCBs on growth of a resistant species (the green alga D.
tertiolecta) and a sensitive species (the diatom T. pseudonana)
in a mixed culture. Although there were only slight effects on
growth of either species at concentrations of 1 or even 10 ppb
of Aroclor 125^ when cultured alone, there was a large change in
the species ratio when the two species were exposed together to
1 ppb (Figures III.3.5 and III.3.6). Thus Aroclor 125^ signifi-
cantly diminished the competitive success of the diatom and in-
creased that of the alga, even at concentrations well below that
required for detectable effects on either alone (88). Similar
effects on competition between sensitive and resistant species
were demonstrated at still lower PCB levels (0.1 ppb) by Fisher
et al, (92). Figure III.3.7 shows the effect of 0.1 ppb Aroclor
125^ on _T. pseudonana in continuous culture with the resistant
species D. tertiolecta. Table III.3.5 shows the effects of 0.1 .
ppb Aroclor 125^ on a natural phytoplankton community in continu-
ous culture. Not only was the population of the sensitive T.
pseudonana markedly reduced, but the diversity of species in the
culture was also decreased (92, Table 3)»
Such changes in species composition are potentially the most
important effects of PCBs on phytoplankton. Most species of
zooplankton graze selectively, often choosing their food on the
basis of size or shape. Studies on oysters, barnacles, clams,
-------
100
B
—i
>->
a
10-
10
Control~\ ^^m*.
jmffi (DAYS)
Growth of (A) Thallassiosira pseudonana and (B) Dunaliella
tertiolecta in mixed cultures with Aroclor 1254 added.
.Figure III.3.5 (from ref. 88)
-------
101
TIME (DAYS)
Species ratios in mixed cultures treated with Aroclor 1254.
Figure III.3.6 (from ref. 88)
-------
102
PURE CULTURES
)50
eo
400
HOURS
Growth in continuous pure culture of T. pseucionana (• •) and
D. tertiolecta (o o) with (—) or without ( ) 0.1 ppb of PCB. Data
points are means from duplicate cultures. A single classification analysis of vari-
ance [37] showed that treated and control culture values did not differ signifi-
cantly for either species.
0 20 40 60 80 100 120 140 160 180 200 220 240 260 230 100 120 340 J60 380 400
HOURS
' Continuous cultures of gnotobiotic communities containing T. pseudonana
and D. tertiolecta, showing percent of total cell counts represented by T.
pseudonana growing with (- • -) or without ( ) 0.1 ppb of PCB. Duplicate
values are shown.
Figure III.3.7 (from ref. 92)
-------
103
Table III.3.5 (from ref. 92)
Growth of the Three Dominant Species in Natural Phytoplankton
Communities in Continuous Culture11
T, pseudonana
A
B
Hours
0
146
41
184
(X 103
0 ppb
4.0 ± 1
23.5 ±0.
2.0 ± 0.
ll.S±S.
cells/ml)
C.I ppb
4.0 ±0
5 2.5 ± 1.5
5 2.311.3
5 3.0 ±2
Chaetoceros sp.
(X 103
Oppb
5
195
32
469
cells/ml)
0.1 ppb
4
335
!2
37S
5. costatum
(X 103
0 ppb
3
23
4
7
cells/ml)
0.1 ppb
1
12
3
7
aInitial and final coll densities are means from duplicate treat oil anu control
cultures. The dilution rate for experiment A waN .'.1 - .''<• of the volume/24
hr; for experiment B was 47 i 4'> of the volume/24 lu.
Reproduced from
best available copy
-------
104
and copepods have shown that the dietary requirements of
herbivores are not satisfied by all species of algae (88).
The replacement of sensitive diatoms by resistant green algae
in marine phytoplankton communities could thus have profound
effects on their consumers and hence on the distribution and
abundance of many animal populations higher in the food web
(83t 88). In experiments with single species, effects on growth
have been demonstrated at PCB concentrations as low as 0.1 ppb
(8^, 86). The experiments reported in refs. 88 and 92 show that
effects on species composition and hence on foodwebs. are to be
expected at still lower levels (83, 92).
Although most experiments with phytoplankton have been "
carried out with Aroclor 125^» Aroclor 12*1-2 inhibited growth of
Scenedesmus at a concentration of only 0.1 ppb (8*0, and in the
experiment with a mixed culture conducted by Moore and Harriss
(91 )» Aroclor 12*4-2 was more active than Aroclor 125** (Figure
III.3»*Ot Hence tetra- and trichlorobiphenyls are probably at
least as toxic to phytoplankton as higher chlorobiphenyls .
**. Effects on Aquatic Invertebrates
Effects of PCBs on aquatic invertebrates have recently been
reviewed by Walker, Nebeker, and Hansen ( 73-75) •
III. **•.!.- Effects on fresh-water organisms
Fresh-water crustaceans are very sensitive to low concentra-
tions of PCBs. Table III.^.l summarizes the results of static
and continuous flow bioassays conducted with Daphnia magna using
eight Aroclor mixtures (93)» The mixtures appeared much more
toxic in continuous-flow conditions due to continual replacement
-------
105
-~- CALCULATED 2- AND 3-WEEK LC50 AND 16% REPRODUCTIVE
IMPAIRMENT VALUES FOR DAPHNIA MAGUA SUBJECTED TO AROCLOR 1248 AND
AROCLOR 1254 IN CONTINUOUS-FLOW CONDITIONS AND EIGHT ARDCLORS IN
STATIC CONDITIONS AT 18 ±1 C
Aroclor
(PCB)
A-1221
A-1232
A-1242
A-1248
A-1254
A-1260
A-1262
A-1268
A-1248
A-1254
A-1254
Source:
3-wk LC50
(ug/liter)
Confidence
limits "
(0.05)
Static test conditions
180
72
67
25
31
36
43
253
158.0-205.0
62.6- 82.8
55.A- 81.0
21.A- 29.2
25.8- 37.2
27.7- 46.8
37.0- 49.9
222.0-288.0
Continuous-flow test conditions
2.6
(2-wk LC50)
1.8
(2-wk LC50)
1.3
(3-wk LC50)
Reproductive
impairment
(fig/liter)
50%
125
66
63
24
28
33
41
206
16%
89
53
48
16
18
22
24
162
2.1 1.0
1.1 0.48
1.3 1.0
Nebeker, A.V. and F.A. Puglisi. 1974. Effect of Polychlori-
nated Biphenyls (PCBs) on Survival and Reproduction of
Daphnia, Gammarus, and Tanytarsus. Transactions of the
American Fisheries Society 103(4):722-728.
Table III.4.1 (from ref. 93)
-------
106
of fresh PCBs. In static conditions much of the PCBs added to
the test water was lost to the air, with some lost to bacteria,
algae, waste materials, container surfaces, and animal tissues.
The differences shown in Table III.4.1 between results in static
and continuous-flow bioassays show how critical the test methodo-
logy can be for hydrophobic chemicals such as PCBs (7*0.
In the static tests with Daphnia magna, Aroclor 124-8 was
the most toxic of the eight mixtures tested? the 3-week 1050 was 25
^ig/1. In the continuous-flow tests, Aroclor 1254 was more toxic,
with a 3-week 1050 of 1,3 jug/l« No reproduction occurred at
3.8 }ig/I, and reproduction was significantly impaired at concen-
trations below 1.0 jag/1- (Table III.4.1).
The toxicity of Aroclor 1254 to Daphnia magna is significantly
enhanced by the presence of DDT, although the effects of the two
compounds are less than additive (94). In a static bioassay
system, the two-week LC5QS for DDT and Aroclor 1254 to Daphnia
were 0.6? ppb and 24.0 ppb, respectively. Addition of 12 ppb
Aroclor increased the toxicity of DDT by approximately one-third,
and addition of 0.5 ppb DDT doubled the toxicity of Aroclor 1254
(Table III.4.2).
The fresh-water scud Gammarus pseudolimnaeus was also studied
in continuous-flow test systems to determine the effects of
Aroclors 1242 and 1248 on survival and reproduction (93)• Con-
centrations as low as 8.7 /ig/1 Aroclor 1242 and 5»1 >Hg/l Aroclor
1248 caused approximately 50 percent mortality in 60 days* expo-
sure and seriously affected reproduction (Table III.4.3).
Table III.4.4 summarizes the results of static and continuous-
flow tests with five other species. The glass shrimp Palaemonetes
-------
Table III.4.2 (from ref. 94)
The concentrations (ppb) of p,p' DDT and Aroclor 125U alone and in combination that affect
^ „ s ^ —
Toxicant
Combination
Acute Toxicity
14-day LC5Q
mean C.L.*
Reproductive Inhibition ECcg
Average
Total Young Brood Size
mean C.L. mean C.L.
(ppb)
Percentage of
Days Reproducing
mean C.L.
p,p' DDT only
DDT with 12 ppb
Aroclor 12514
Aroclor 125!* with
0.75 ppb DDT
Aroclor 1254 with
0.50 ppb DDT
Aroclor 1251* with
0.30 ppb DDT
Aroclor 125U only
0.6? ( 0.65- 0.69) 0.50 ( 0.1*8- 0.52)
0.1*0 ( 0.38- 0.1*11 0.30 ( 0.28- 0.32)
0.61 ( 0.58- 0.64) 0.75 ( 0.71- 0.79)
0.45 ( O.U3- 0.48) 0.55 ( 0.52- 0.58)
1*.0 ( 3.80- l*.20) 1.8 ( 1.69- 1.91) 6.0 ( 5.82- 6.18) 9.0 ( 8.65- 9.36)
12.0 (11.54-12.1*8) 10.0 ( 9.17-10.90) 13.0 (11.92-1!*. 17) 11.0 (10.09-11.99)
ll*.0 (13.1*6-H».56) 13.0 (12.26-13.78)
2l*.0 (23.08-21*. 96) 19.0 (17.93-20.14)
19.0 (18.27-19.76) 19.0 (17.92-20.1!*)
23.0 (22.12-23.92) 25.0 (23.81-26.25)
Confidence limits for p = 0.05.
o
-------
Table III.4.3 (from ref. 93)
108
Survival and reproduction of Ganmarus
pseudollmnaeus after 2 months'
sure to Aroclor 1242 and 1248
Aroclor
concentration
(ug/1)
Aroclor 1242
234.0
81.0
26.0
8.7
2.8
0.0
Aroelor 1248
18.0
5.1
2.2
0.5
0.2
0.0
Survival
of adults
(percent)
0
0
0
52
77
48
0
53
73
71
73
64
expo-
Young per
surviving
adult
0
0
0
0
4
7
0
7
22
20
11
n
Table III.4.5 (from ref. 93)
Table 5. Effect of Aroclor 12S4 on the growth and
survival of the midge Tanytarsus dlsslmllU
Aroclor
concentration
(ug/1)
33.0
9.0
3.5
1.2
0.4
0.0 (control)
Nunter of mature
larval cues
(percent of
control)
0
0.2
7
35
52
100
Nunter of
pupal cases
(percent of
control)
0
0
7
13
55
100
-------
109
Table III.4.4 (from ref. 95)
Aroclor and DDT toxicity to invertebrates.
Compound
Aroclor 1242 '
Aroclor 1254
Aroclor 1254
DDT
Aroclor 1242
Aroclor 1242
Aroc'.or 1248
Aroclor 1254
DDT
DDT
Aroclor 1254
DDT
DDT
Aroclor 1242
Aroclor 1254
Aroclor 1242
Aroclor 1254
DDT
Organism1
Crayfish
Crayfish .
Crayfish
Crayfish
Scud
Scud
Scud
Scud
Scud
Scud
Glass shrimp
Glass shrimp
Glass shrimp
Dragonfly
Dragonfly
Damselfly
Damselfly
Damselfly
Bioassay type3
static
static
continuous-flow
static
continuous- flow
continuous-flow
static
static
static
continuous-flow
continuous-flow
static
continuous-flow
static
static
continuous-flow
continuous-flow
static
Exposure
(dajn)
7
7
7
4
t
10
4
4
4
5
7
5
5
7
7
4
4
4
LC«
0*/D
30
100
80
100
10
5.0
52
2,400
3.2
0.6
3.0
1.0
1.3
800
1,000
400
200
56
1 Crayfish (Oremeetti now), Scud (Ganmaria famalua), Glass shrimp (Palaemonetes kadiakenain), Dragonfly
cromia »p.), Damselfly (Ischnura verlicalia).
'Temperature, 15.6"C; alkalinity, 35 ppm; pH, 7.1.
-------
110
kadiakensis was very sensitive to Aroclor 125*4-, with a 7-day
LC50 of 3 ;ig/l (95).
In a comparative toxicity test with five individual
chlorobiphenyls under static conditions, Mayer el; al. (96)
found that 2,3i*4-l-trichloro-biphenyl was slightly more toxic to
G. pseudolimnaeus than representative di-, tetra-, penta-, or
hexachlorobiphenylsj the 96-hour LCt0 valves were 70, 100-120,
110, 21-0 and 150 /ag/1 respectively. Under static test conditions,
the toxicities of Aroclors 1016 and 12^2 to D. magna were similart
no young survived after 3 weeks1 exposure to 125 Jig/I of either
mixture (7^t 97).
Aquatic insects also appear to "be very sensitive to pro-
longed exposure to PCBs (7*0. The midge Tanytarsus dissimilis
was tested through its full life cycle (93) and found to be af-
fected at levels below 1 ;ig/l. Survival arid growth of the midge,
when tested with Aroclor 125^t were excellent in control chambers
but were reduced by 50 percent at the lowest test concentration
of O.JJ-5 }ig/l (Table 111.^.5). At 1.2/ig/l, the numbers of larval
cases were reduced to 35 percent of the control, and the numbers
of pupal cases were reduced to 18 percent of the control. No
adult emergence occurred above 3*5 >igA» and abundant adult
emergence did not occur above 3 fig/1* even though larvae were
present. No pupal cases were constructed at 9 pg/1 and no larval
cases were formed at 33 Pg/1 A-125^. The calculated 3-week LC^0
for A-125^ (50-percent reduction based on control as 100 percent)
was 0.65 ug/1 for larvae and O.it-5 jug/1 for pupae. Adult midges
emerged at concentrations up to 9 /ig/1 Aroclor 12^8. Larvae were
present at 18 jig/1, but adult emergence did not occur. Abundant
-------
Ill
emergence did not occur above 5«1 Pg/1 (93) •
Studies by Sanders and Chandler (98) have shown that larvae
of the stonefly Pteronarcys dorsata , the dobsonfly Corydalus
cornutus , and the phantom midge ChaQborus punctipennis survived
concentrations of up to 2.8jug/l for up to 21 days without signi-
ficant mortality. However, in similar experiments, larvae of the
mosquito Culex tarsalis, exposed to 1.5 ^ug/1 Aroclor 125^1 sur-
vived well and pupated, but many of the pupae were unable to
metamorphose into the adult form. Control organisms pupated
with success.
^.2 Effects on estuarine organisms
PCBs are acutely toxic to estuarine organisms (7^.99-101) •
For Aroclors 1016, 12^2 and 125^, the ^8-hour or 96-hour l>C$o
values for brown shrimps Penaeus aztecus, pink shrimps P. du or arum ,
and grass shrimps Palaembnetes pugio fall into the range 9-32
fig/l ( 7^ 1 99 » 100). Exposure to 10 ^ig/1 Aroclor 1016 for 96 hours
'caused 4-3$ mortality in brown shrimps and J8% mortality in grass
shrimps (100), whereas the same concentration of Aroclor 125^
caused no mortality in pink shrimps in the same period (102).
The acute toxicities of Aroclors 1016 and 125^ to oysters
Crossostrea virginica appeared to be similar (99*100).
Laboratory bioassays lasting longer ' than two weeks have de-
monstrated that acute bioassays underestimate the toxicities of
Aroclors 1016 and 125^. Aroclor 125^ is toxic to commercially
valuable penaeid shrimps and grass shrimps at concentrations as
low as 0.9-l.J* pg/1 (102-105J Tables III. 4-. 6, III. 4. 7). Exposed
shrimps are particularly sensitive to salinity stress (103) and
apparently to viral disease (106,107). Aroclor 125^ also decreases
-------
Table III.4.6.(from ref. 102)
" RESULTS OF CHRONIC BIOASSAYS WITH AROCLOR 125A AND THE
PINK SHRIMP PENAEUS DUORARUM IN FLOWING WATER
Shrimp
rostrum-telson
length (cm)
2.5-3.8
2.5-3.8
2.5-3.8
2.5-3.8
2.5-3.8
4.2-7.2
4.2-7.2
4.2-7.2
6.6-9.0
6.6-9.0
7.6-8.5
7.6-8.5
9.5-12.5
9.5-12.5
Concentration
(ppb)
Control
0.57
0.94
9.4
19.0
Control-
2.4
3.1
Control
4.3
Control
4.0
Control
3.5
Average
salinity
CO
32
32
32
32
32
29
29
29
29
29
31
31
28
28
Average
temperature
(°C)
29
29
29
29
29
28
28
28
20
20
•29
29
20
20
No. of
test
individuals
65
20
45 •
20
20
25
20
25
43
46
60
60
50
50
Replicates
5
2
3
2
2
1
1
1
1
1
1
1
1
1
Days
Exposed
. 15
15
15
15
15
32
17-
32
53
53
18
18
35
35
Average
mortality
CO
12
30
51
90
100
4
65
80
26
83
9
41
8
50
Level
of
Significance
0.10\
o.oosj
O.OOlf
" O.OOl"
—
0.001°
0.001C
__
0.001°
—
0.001°
0.001C
No data
Average of at least three determinations.
Student's t-test.
Chi-square.
to
-------
Table* [[[,4,7 (from
104$
MORTALITY AND ACCUMULATE OF ARQCLOR 1254 tN PaLaemonetes pugLo*
Test Cone.
CONTROL
0.17
0.62
9.1
CONTROL
1.1
4.0
12 . 5
Days
Exposed
7
7
7
7
16
16
16
L6
Average MortaLLty
(%) **
4(0 - 20)
8(0 - 40)
4(0 - 20)
60(20 - 80)***
25(0 - 50)
40(0 - 100)
45(25 - 50)***
55(50 - /•>)***
Body Cone,
(mg/kg)
O.L
L.I
5.4
65.0
0.05.
-------
114
the growth rates of oysters at concentrations as low as ^ ug/1
(111? Figure III.^.l).
III.^-.2 Effects on a marine invertebrate community
Hansen (109) showed that Aroclor 125^ affected the composi-
tion of communities of estuarine. animals which developed from
planktonic larvae in seawater flowing through aquaria in the
laboratory. In control aquaria, the communities were dominated
by arthropods, primarily the amphipod Corophium yolutator. In
aquaria receiving Aroclor 125^ at 1 or 10 pg/1, the number of
arthropods decreased and the communities were dominated by
tunicates (a group of animals characteristic of polluted waters).
The numbers of amphipods, bryozoans, crabs, and molluscs were also
reduced in these treated aquaria. These effects were manifested
even in aquaria receiving only 0.1 /ig/1 of Aroclor 125^« the
number and variety of molluscs were markedly reduced and the
number of tunicates was increased (Table 111.^.6). This experi-
ment is important because it shows that PCBs can have marked
effects on species composition and biological diversity at levels
much lower than those required to demonstrate effects with single
species.
III.5. Effects on Fish
Effects of PCBs on fish have recently been reviewed by
Walker, Nebeker, and Hansen (73-75)•
III.5.1. Lethal concentrations of PCBs to' fish
Table III.5.1 summarizes measurements of the acute and chroni'c
toxicities of eight Aroclor mixtures to four species of fish (73i
citing data from refs. 95, 96). As in the case of the aquatic
invertebrates, PCBs do not appear very toxic in short-term static
-------
115
H
a
o
oJ x>
to C/5
I
z
AO
30
20
10
V
X
i I t
^,~"- Control weights
.._-• Experimental weights
8 12 16 20 2A- 2'8 32 36 ~10 'AA A8 ^52 56
(A)" (8)(12X16X20)(2A)(28)(32)
EXPOSURE
WEEKS
for 2A weeks.
Change in oyster weight after exposure to 5 ppb Aroclor 125A
Figure III.A..1 (from ref. 108)
-------
116
Table III.4.6 (from ref. 109)
Species and total number of animals collected from the effluents of 10 control aquaria and
10 aquaria contaminated for four months with 0.1, 1 or 10 fig/I Aroclor 1254.
Taxon
Annelida
Eupomatus dianthus
E. protulicola
Neanthes succinea
Total
Arthropoda
Balanus sp.
Caprella sp.
Clibanaris tricolor
Corophium volutator
Eurypanopeus depresia
Neopanope texana
Pagurus longicarpus
Pinnixa chaetopterana
Upogebia a/finis
Decapod zoea, unident. sp.
Portunidae, unident sp.
Pycnogonidae, unident sp.
Total
Chordata
Bostrichobranchus pilularis
Branchiostoma caribaeum
Molgula manhattensis
Total
Coelenterata
Leptomedusae*, unident sp.
Echinodermata
Hemipholis elongata
Ectoprocta
Membranipora tenuis*
Mollusca
Anadara ovalis
A. transversa
Bittium altemata
B. varium
Crassostrea virginica
Doridella obscura
Laevicardium mortoni
Mitrella lunata
Musculus lateralis
Nassarius albus
Tagelus divisus
Eolidacea, unident sp.
Total
Totals: Animal*
Species
Control
1
0
1
2
10
0
0
7
5
10
1
1
1
0
2
0
37
3
1
72
76
1
1
1
1
12
0
3
2
' 12
1
2
1
2
1
1
38
156
27
0.1 US/1 .
1
1
2
4
2
8
1
15
2
6
0
0
1
0
1
0
36
0
0
103
103
1
0
1
0
0
1
0
0
1
0
0
0
0
2
1
5
150
18
1 MS/I
0
1
2
7
2
4
0
32
5
3
0
0
0
1
0
3
50
0
1
304
305
1
3
1
0
4
0
1
1
2
0
2
1
0
0
J
12
375
20
10/ig/l
0
0
0
0
1
0
0
1
0
0
0
0
0
0
0
0
2
0
0
35
35
1
0
0
0
1
0
0
1
1
0
2
0
0
0
3
8
47
10
1 Colonieii Counted u ont animal.
-------
Table III.5.1 Toxicity of PCBs to fish (refs. 73, 95, 96)
PCB Fish
(Aroclor)
1221 Cutthroat trout
1232 Cutthroat trout
1242 Cutthroat trout
Rainbow trout
Bluegill
Bluegill
Channel catfish •
Channel catfish
1248 Cutthroat trout
Rainbow trout
Blucglll
Bluegill
Bluecill
' Channel catfish
Channel catfish
Channel catfish
Channel catfish
1254 ' Cutthroat' trout
Kjilnbow trout
KaXnbow trout .
niuep.ill
Bluegill
lUucgill
Channel catfish
Channel catfish
Channel catfish
Temp
8.9
8.9
8.9
17.0
20.0
17.0
20.0
17.0
8.9
17.0
18.3
20.0
17
18.3
27.0
20.0
17-0
8.9
20.0 .
17.0
18.3
20.0
17.0
J8.3
20.0
17.0 .
Bioassa
method-i
A
A
A
C
C
C
C
A
C
A
C
C
A
C
C
C
A
C
C
A
C
C
A
C
C
y
/ ^d
1170
2500
4530
5750
~-
278
— ••
—
6000
—
— •
- —
42500
~
_
2740
—
•..
12000
—
• ~ .•
;•.._: LC^Q- value in jug/1 at exposure time of
5d
67
154
—
54
•~
307
136
—
__
—
—
-.. '.
156
— •
—
—
' ... ' .
.• . -^
— . •
lOd
48
72
174
__ •
38
—
160
115
—
94
225
121
„.. '
8
160
—
443
.
~ '
-» .
303
15d
18
54
164
107
219
'~—
16
_-
76
111
' —
57
127
121
• --.
—
64
• —
204
' 303
- —
741
286
20d
10
125
150
__
6.4
—
10
106
.—
~
-J.
115
~ •
. ~-
39
—
135
260
-™
300
293
25d
12
120
132
__
3.4
• —
—
100
—
—
—
/ 104
„_ '
^~
27'
—
54
239
— •
113 .
181
30d
84
87
„
--
~
—
78
—
—
™
75
__
~
__
—
~
177
—
—
139
-------
Table III.5.1 (continued)
1260
1262
1268
Cutthroat trout
Rainbow trout
Rainbow trout
Uluegill
Blucgill
Channel catfish
Channel catfish
Cutthroat trout
Cutthroat trout
8.9 '
20.0
17.0
20.0
17.0
20.0
17.0
8.9
8.9
A . 60900 ^ • • ~ —
C — 156 5
C . — 326 143
c — *.- ... ..-, - — ••'
C • ••«" " —•• ' «••• MNB •
c — ~ ' — —
• C — — . 535 482
A 50000 • -~ . —
A 50000 — — ' • .—
-—;..
78 '
245
~
296
512
: — .
*
M
—
49
212
—
166
465
—
~
^^^
—
51
151
400
137
433
—
. — .
\J A*> Acute toxicity by static test procedure
C- Chronic toxicity by flow-through procedure
00
-------
119
bioassays, but are-lethal at much lower concentrations on pro-
longed exposures. The rainbow trout was the most sensitive of
the four species listed in Table III.5.1» being killed by levels
as low as 3^/ig/l Aroclor 12^8 in 25 days, or 5 jug/I Aroclor
1260 in 10 days. Aroclor 12^8 was generally the most toxic mix-
ture tested in prolonged exposures.
In a separate series of tests under static conditions, the
96-hour 1050 for Aroclor 1016 was determined to be 650 jug/1 for
bluegills and 750 ^g/1 for channel catfish at 18°C> that for
Aroclor 1221 was determined to be 230 ppm for bluegills and.
33^0 pig/1 for channel catfish (110). These figures suggest that
the' acute toxicities of Aroclors 1016 and 1221 are comparable
with or greater than those of Aroclor 12^8 (Table III.5.1).
In chronic studies with estuarine fish, Aroclor 1016 appeared
somewhat less toxic than Aroclor 125^. Spot and pinfish died when
exposed for 14— V? days to 5 /Jg/1 of Aroclor 125^ (111), whereas
pinfish were only slightly affected by exposure for ^2 days to
7 ^ug/1 of Aroclor 1016 and their mortality was not significantly
increased until the measured concentrations of Aroclor 1016
reached 13 /ig/1 (100). The longnose killifish is the most sensi-
tive species tested, being killed by prolonged exposure to 1 p.g/1
of Aroclor 125^ (105).
Other recent work conducted by Mayer and Johnson has sug-
gested that the toxicity of Aroclor 1016 to fresh-water fish is
generally similar to that of Aroclor 12^2 (75). Bluegills had a
96-hour LC^o of 4-8-260 jig/l Aroclor 1016; rainbow trout, 135/ig/lj
Atlantic salmon, 13^ ^g/1; and yellow perch, 185 jug/1. On longer
exposures, rainbow trout had a 10-day LCo of 39 *gA for Aroclor
-------
120
124-2 and a 17-day LC^0 of 4-9 ^g/1 for Aroclor 1016. Bluegills
had a 15-day LC^0 of 54- pg/l for Aroclor 124-2 and a 35-day
LC50 for Aroclor 1016 (75).
All of the LC,-0 values decreased with higher temperatures
and longer exposure to PCBs (Table III. 5.1) • An increase in
temperature from 20° to 27°C approximately doubled the toxicity
of Aroclor 124-8.
Recent studies have shown that young fish are more sensitive
than older fish (75» 112). Ninety-six-hour LC^0 values for newly
hatched fathead minnows were 15 jug/1 for Aroclor 124-2 and 7. 7
for Aroclor 125^. After 60 days, half were dead at 8 8 jug/1
Aroclor 124-2 and 4-. 6 ^g/1 Aroclor 1254- . Newly-hatched young were
the most sensitive life stage. Growth of young fathead minnows
was also affected at 2.2 ^ig/1 Aroclor 124-8 and none survived above
5.1 ;ig/l after 30 days. Young flagfish did not survive at con-
centrations of Aroclor 124-8 above 5»1 /ig/1 and did not grow well
above 2J2;ug/l (112).
III. 5. 2. Effects on fish reproduction
Two 9-month continuous-flow bioassay tests were conducted
with fathead minnows to determine the effects of Aroclor 124-2
and Aroclor 1254- on survival and reproduction (112). Concentra-
tions of Aroclor 124-2 above 10 ^ug/1 were lethal to newly-hatched
fry. Reproduction occurred and good egg hatching took place at
and below concentrations of 5-4-^g/l, but the number of eggs pro-
duced was reduced at all concentrations tested down to 0.9yag/l
(Table III. 5. 2). Aroclor 1254- appeared more toxic than Aroclor
124-2, as fathead minnows did not survive and reproduce at concen-
trations above 1.8/ig/l (Table 111.5,2). Spawning was signifi-
-------
121
Table III.5.2 (from ref. 112)
Table 2. Spawning and egg production of fathead minnows exposed to
Aroclor 1242 and 1254
Aroclor
concentration
(vg/D
Aroclor 1242
51.0
15.0
5.4
2.9
0.9
0.0
Aroclor 1254
15.0
4.6
1.8
0.5
0.2
0:0
Number of
spawnings
per female
0
0
2.5
3.9
1.3
4.6
0
0
1.0
5.2
3.0
2.4
Number of
eggs per
spawning
Q
0
30
63
28
90
0
0
63
105
64
104
Number of
eggs per
female
0
0
151
283
35
442
0
0
106
556
221
253
Percent
eggs
hatched
0
0
81
38
84
53
0
0
79
63
55
75
-------
122
cantly reduced at 1.8 jug/1; reproduction was good at 0.5/ig/l
and lower concentrations. In chronic tests with Aroclors 12^8
and 1260, fathead minnows were able to reproduce at concentra-
tions which were acutely toxic to the larvae. Reproduction oc-
curred at and below concentrations of 3 ,ug/l Aroclor 12^8 and
2.1 ug/1 Aroclor 1260,'but mortality of the newly hatched larvae
led to a 20 percent reduction in the population in the second
generation at concentrations as low as O.^^ug/l (H3)»
Aroclor 125^ also affects reproduction of the sheepshead
minnow, an estuarine fish (11^, 115)•• Adult fish exposed for ^
weeks to 0.1 jug/1 appeared to be unaffected, but when eggs from
these fish were fertilized and placed in PCB-free water, the
survival of fry was diminished. Mortality was observed also in
fry from eggs that contained more than 5 PPro of PCBs and increased
as the PCB content of the eggs increased (75» 11^, 115)• However,
sheepshead minnows exposed to Aroclor 1016 at levels from 0*3 to
3*0 ^Jg/l of Aroclor 1016 reproduced successfully« although the
eggs contained 3-77 ppm of PCBs, fry hatched from them appeared
to be unaffected (116), This is one of the few examples in which
Aroclor 1016 appears to have been significantly less toxic than
other mixtures.
In tests with rainbow trout, fry from eggs containing 2»7 ppm
Aroclor 12^2 together with 0.09 ppro DDT suffered a 75 percent mor-
tality in the 30 days after hatching. In five other groups of
eggs with still lower residues, 10-28 percent mortality was noted
within the first 30 days. About 60-70 percent of the fry that
survived were deformed (117. 73). Swedish investigators have
-------
123
reported a statistically significant association between hatching
failure in eggs of Atlantic salmon and PCB residues. Concentra-
tions in the range 0»*J- to 1*9 ppm, wet weight (7*7-3^ ppro» lipid
weight) were associated with mortalities between 16 and 100
percent (118).
Coho salmon eggs hatched two to five days premature whan ex-
posed to Aroclor 125^ (119« see Table III.5.3). Yolk-sac utili-
zation was considerably reduced in the exposed eggs. Early
hatching was preceded by changes in the egg surface, possibly
decreasing the permeability of the chorion to oxygen and thus
inducing early hatching (119). Survival following hatching was
inversely related to the exposure concentration and time. Early
hatching and reduced survival were noted even at the lowest
concentration tested, 5 ;ug/l (Table III.5.3).
In contrast to these reported effects of low levels of
PCBs on reproduction in rainbow trout and salmon, no adverse
effects were observed on survival, growth, or reproduction of
brook trout exposed for 71 weeks to 0-9^ jug/1 and lower concen-
trations of Aroclor 125^. Survival and growth of alevins from
exposed parents were also unaffected.(75» 120).
III.5.3. Other sublethal effects on fish
.Inclusion of Aroclor 125^ in fish food at a level of 0*^5 ppm
resulted in a 52 percent increase in thyroid activity in coho
salmon (Figure III.5.1)• The lowest detectable stimulation of
thyroid activity occurred in salmon ingesting a dose no more than
one-thousandth of that required to cause mortality (73, 96).
Similar results were obtained in channel catfish exposed to 2*4 ppm
-------
Table III.5.3 (from ref. 119)
Table 6.41 INCUBATION TIMES AND HATCHABILITIES OF COHO SALMON (Oncorhynchus kisutch)
EGGS, AND SURVIVAL AND SIZES OF ALEVINS 4 WEEKS AFTER HATCHING, AFTER
AROCLOR 1254 FOR 6 AND 2 WEEKS AT 12-14C
PCB
(ppb)
0
5
10
15
25
55
Incubation
Time
(degree-days)
Exposure
511
485
485
-
459
462
Hatchability,
(%)
for 6 weeks (2
95.5
88.0
78.5
38. 01
96,5
63.0
Exposure for 2 weeks
• 0
5
10
15
25
55
. 503
475
490
490
.481
488
93.0.
95.5
90.0
91.5
97.5
66.0
Alevin
Survival
(%)
before and 4 after hatching)
91.0
75.5
64.0
24.0
6.8
6.5
(to 2 days before hatching)
93.0
! 69.5
88.0
83.5
74.5
39.5
EXPOSURE TO
Mean alevin
Length
(mm)
36.0
34.7
34.4
31.9 (12) 2>
29.8 (4)
28.3 (3)
35.3
35.2
34.7
33.3
34.5
33.7 (15)
size
Weight
(g)
0.30
0.30
0.30
0.27
0.28
0.24
0.30
0.30
0.30
0.26
0.29
0.26
A fungus caused high mortality.
numerals in parentheses are numbers measured; 20 were used in each of other tests.
-------
125
of Aroclor 125^J effects were smaller with other Aroclors
(Figure III,5<>2). These sublethal effects were associated with
whole-body residues of PCB in the range 1-5 ppm (Figures III.5.1,
III.5«2). Mayer et al. also found that incorporation of Aroclor
12^8 into the diets of lake trout at concentrations in the range .
0*2-6 ppm suppressed growth and serum cortisol levels, but
stimulated thyroid activity during the first 160 days of ex-
posure (73i 96).
Walker (73) also reported unpublished experiments in which
lake trout exposed to PCBs in the diet developed lesions in the
gills and liver during a 6 - 9 month exposure period. Nonspecific
degeneration of liver parenchyma and cytoplasmic vacuolation of
liver cells were reported in addition to pleomorphism. Spot
exposed for two weeks or longer to 5/ig/1 of Aroclor 125^ showed
fatty changes in their livers, characterized by the presence of
large vacuoles within hepatocytes and disorientation of liver
cord distribution (105). Affected fish usually developed ragged
fins and lesions on the body (111).
Pinfish sublethally poisoned by exposure for 1^-^-5 days to
5 ^g/1 of Aroclor 125^ similarly developed fungus-like lesions
on the body, especially around the mouth, where hemorrhaging also
occurred (111). Pinfish similarly exposed to 32 ^g/1 of Aroclor
1016 suffered progressive erosion of scales, skin and finally,
flesh in front of the dorsal fin. These fish also showed several
changes in liver and pancreatic tissues. Normal liver cord
orientation was altered and severe vacuolation developed in the
pancreatic exocrine tissue surrounding the portal veins (100).
-------
126
12
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24 2.4 24 2.4 24 2.4 24
1232 1248 . 1254 1260
PCS (Aroclor) in diet 193 days
Figure 3. Whole-body residues and thyroidal uptake of 12S I in channel
catfish fed diets containing Aroclors 1232,1248,4 253, and •
1260forl93days(ref.40).
Figure III.5.1 (from ref. 73)
-------
u-
•-•10-
o
IL
•MM
•C
•*•
X8'
-Q
O
5 6"
a.
3
1
•MM*
5 4-
^
<*•
c
U 2"
O
Q.
1
-, A
1 -g
i
^—J. *— J-
„ , ,_ ,_ ^
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•*-
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M
•10
O
"**
•o
5 0
CD
%wr
o
0.048 0.48 4.8 48 480
Control 1*9/9 Aroclor 1254 in diet 260days
Figure 2. Whole-body residues and thyroidal uptake of m I In coho salmon
fed diets containing Aroclor 1254 for 260 days (ref. 4J3).
Figure III.5.2 (from ref. 73)
-------
128
"Fin rot syndrome" has been induced in the laboratory in
spot exposed to 3-5 /ig/1 of Aroclor 125^ (106), The syndrome
appears identical to that observed in wild fish (croakers and
spot) which died under conditions of warm weather and oxygen
depletion in Escambia Bay, Florida (106).
Growth of juvenile coho salmon was significantly reduced
(from 1»0 percent of body weight per day to 0«7 percent) when
they were fed a diet containing 10 ppm of a mixture of tetra-
and hexa-chlorobiphenyls for 165 days (121).
Johansson et al. (122) found that sublethal doses of
Clophen A 50 caused metabolic disturbances in brown trout
(Salmo -trutta) . The experimental trout were given two 'doses
(intramuscular injection or capsules directly into the stomach)
of 5 rog/kg body weight on days one and five. Analyses were made
on day ^3 and, after 116 days starvation, on day 203. While the
PCB-treated trout seemed to be in good condition after both kj
and 203 days, metabolic changes had taken place. Among the
differences on day ^3* the treated trout showed anemia, hyper-
glycemia and altered cholesterol metabolism. After starvation
and refeeding, the PCB-treated trout differed from the controls
by increased body-weight, a more pronounced decrease in liver
triglycerides and muscle glycogen, and no hyperglycemic response
5.^ Effects on ATPase and Osmor emulation
The effect of polychlorinated biphenyls on the ATPase
enzyme system was examined in tissues of the bluegill sunfish
(Lepomis machrochirus) by Yap et al. (123). ATPase activity was
determined in homogenized tissue fractions that contained
mitochondria plus nerve endings. Three Aroclors, 1221, 125^, and
-------
129
O J. ~L I
1268, inhibited MG and Na -K ATPases in concentrations less
2+
than 1 ppm, with the most pronounced inhibition on Mg ATPase
of muscle (see Table III. 5. -4-) (123). Cutkomp et al. (124) also
found the maximum effects in vitro were on oligomycin-insensitive*
2+
Mg ATPase, with greatest inhibition in muscle. The effective-
ness of Aroclor 1242 on oligomycin-insensitive and oligomycin-
2+
sensitive Mg ATPase from bluegill muscle was compared at 50
percent inhibition, with values of 0.6 ppm and 2,0 ppm, respectively
In general, the PCBs do not reveal any obvious relationships
between chlorination and inhibitory effects. The action of Aroclor
?+
1268 on Mg ATPase from different tissues ranged from inhibition
(muscle) to activation (brain, liver, and kidney), dependent upon
concentration (124, 125). Aroclor 1242 inhibited Na+-K* ATPase
from fish brain homogenates but about five times the concentra-
tion was required as compared to inhibition of mitochondrial
?+ 2+
Mg ATPase. Mitochondrial Mg ATPase was more sensitive 'to
2+
Aroclor 1242 in vivo than non-mitochondrial Mg ATPase, the
reverse of in vitro findings with fathead minnows (124). Thus,
although results are more accurate in vitro than in vivo, both
approaches seem desirable. Of the Aroclors tested, those in the
intermediate range of chlorination appeared to have the greatest
inhibitory effect on the ATPase system, especially Aroclor 1242.
Data on inhibition of ATPase from brain, liver and kidney of
fathead minnows (Pimephales promelas ) are given in Tables
III.5.5 and III. 5. 6 (126). Koch et al. (126) feel that there
is sufficient evidence to indicate ATPase inhibition may be the
*01igomycin-insensitive — non-mi trochondrial.
-------
130
Table HI.5.A (froo.ref. 123)
INHIBITION OF mg2+ ATPase and Na+-K*" ATPase
FROM TISSUES 01 BLUEGILL FISH
Concentration
(p. p.m.)
Brain
0,03
0.33
3.33
10.00
Kidney
0.33
3.33
10.00
Liver
0.03
0.33
3.33
10.00
16.70
Muscle
0.03
0.33
3.33
10.00
'Aroclor
1221'
Mg2" Na"
0.3 4.6
8.4 10.5
7.2 20.4
36.0 46'. 4
7.4 15,1
5.0 24,3
42.8 43.3
2.2
2.6
2.9
35.8
45.9
18.7
29.9
65.4
80.4
Percentage
'Aroclor
1254'
Mg Na+
4.2 16.9
0.7 19,1
27.7 41,5
57.9 45.5
"1.3 35.2
33.4 AS. 9
60.1 51.7
3.9
19.4
24.3
53.0
74.1
20.6
30.6
73.1
84.3
Inhibition
'Aroclor
1268'
-J1-
0.4 29.4
•••1.5 27.6
^14.0 43.6
8.3 39.4
0,0 25.4
^-7.9 AO.l
"j-4.8 48.0
—
J-5.3
•••5.1
+2,4
6.2
37.2
47.1
60.3
67.5
"Aroclor
5460'
2.3 26.
2.9 26.
2.5 38.
11.2 42.
0.0 22,
4.5 25,
+1.4 33.
—
6.6
9.3
15.8
—
31.9
42.9
—
__
9
3
9
7
3
2
3
-------
Table [[[.5.5 (Erom reE, 126)
CNHLBLTLON OF ACTCVLTY OF ATPases BY A 4 MONTH EXPOSURE TO AROCLOR 1242
CN FAT HEAD HCNNOW TISSUES
Concentration
Cppb)
Na+ -K+
BraLn
Percent LnhLbLtLon*
KLdney
01 Lgomyc Ln**
Sens. tnsens.
0 L Lgomyc Ln
Sens. Lnsens. Na1" -
L Lver
01 Lgomyc Ln
Sens. Cnsens.
0.93
2.8
8.3
atrol***
'. Act.
21.1
4.9
2.9
• 34.3
iL.8
28.1
53.2
43.6
5.2
*L.l
L5.0
2.3
+0.7
12.6
bO.45
20.5
36.2
18.3
39.3
b2.02
56.0
75.4
45.2
9.0
bL.85
22. /
20.7
35.0
L8.4
bL.35
(-41.6
(-40.7
42.4
3.6
fcO.61
0.8
40.5
40.7
7.6
bL.6
7.9
3.7
L5.5
8.2
bl.9
bS.E.
* (+) Values represent Increased enzyme activity.
** Sens. (sensLtLve) Lnsens. (insensLtLve). ,
*** SpecLELc actLvLty calculated as J^moles PL mg""- protein hr~ ,
mean Erom three separate detenu[natLons.
Each vaLue represents the
-------
Concentrat ion
Table III.5.6 (from ref. 126)
INHIBITION OF ACTIVITY OF ATPases BY A 4 MONTH EXPOSURE TO AROCLOR 1254
IN FAT HEAD MINNOW TISSUES
Percent Inhibition*
(ppb)
0.31
0.93
2.8
8.3
introl**;
>. Act.
Brain
Oligomycin**
Na+ -K+
+20.3
+11.2
+ 3.2
5.2
* 32.6
±1.95
Sens.
- 31.3
35.2
35. 8_
7.5
5.2
±0.34
Insens.
+21.8
+ 9.8 .
+ 5.5_
2.2
12.5
±0.68
Na+ -K+
+20.0
14.3
5.1
30.7
31/4
±2.45
Kidney
Oligomycin-
Sens.
M 2+
+53.7
, + 7-3
' 3.3
+ 4.2
7.9
±2.05
Insens.
+14.3
+ 4.9
+22.5
+31.6
12.6
±3.85
Na+ -K*
—
+20.8
1.0 .
4.4
5.9
±2.0
Liver
Oligomycin
Sens. Insens.
Mg2+ Mg2+
--
+37.8 +11.4
20.3 20.8
30.7 + 2.2
.7.9 9.5
±2.31 ±3.61
±S.E.
* (+) Values represent enzyme activation.
** Sens, (sensitivity) Insens. (insensitive).
*** Specific activity calculated as p. moles Pi mg~^- protein hr~^-. Each value represents the
mean from three separate determinations.
u>
N>
-------
133
specific action of PCB in fish tissues. While kidney tissue
appeared most sensitive to Aroclor 12^2, both liver and kidney
had undergone considerable degradation by Aroclors 12*1-2 and
when observed during dissection (126).
Aroclor 1221 affected the ability of the killifish to
osmoregulate, since both osmolality and Na concentration in-
creased toward that of sea water (127). Since Na -K+ ATPase is
believed to be involved in the process of sodium transport across
cell membranes and to function in osmoregulation in marine teleosts,
Aroclor 1221 probably acts to disrupt the Na -K ATPase system.
Serum osmolality and K concentrations were increased well above
normal in fish blood sampled before the fish died (12?)a
-------
III. 5.& Effects of PCDFs on fish
Zitko and Choi (128) fed a diet containing about 20 ppm of PCDFs
(2.7 ug/g di-, 5.7 ug/g tri-,2.8 ug/g tetra- , and 9.1 ug/g octa-chlorodibenzo-
furan) to juvenile Atlantic salmon. This level of dietary exposure proved
only moderately toxic, the median time to death being 120 days. For com-
parison, coho salmon died after 260 days when fed a diet containing about
100 ppm of PCBs (14.5 mg/kg body weight per day of Aroclor 1254) (96, 121).
This indicates that PCDFs are somewhat more toxic than PCBs to fish, but
not dramatically so as in the case of birds and mammals (see below).
III.6 Effects on birds
Effects of PCBs on birds were reviewed in 1972 by Vos (129) and
most recently by Standell (130).
III.6.1 Lethal concentrations in diet: subacute and semichronic studies
The subacute toxicity of six Aroclor mixtures was studied in 2-week-
old chicks of four species of wild birds (mallard, pheasant, bobwhite quail,
and Japanese quail) (131). The experimental results were expressed as
LC-QS based on 5-day feeding (Table III.6.1). In most cases Aroclor 1260
was significantly more toxic than the less chlorinated mixtures. The bob-
white quail was the most sensitive of the four species tested, but even
for this species the LCcnS were quite high (Table III.6.1).
Numerous studies have been reported of the toxicity of PCBs to young
chickens. Five such studies are summarized in Table III.6.2 (from ref. 129).
In a feeding study with 400 ppm Aroclor 1260, only 15% mortality was noted
in 60 days (137); in the same conditions.Clophen A60 and Phenoclor DP-60
were much more toxic (see next section).
In a study with 10-day old chickens, using Aroclor 1248, mortality
after 25 days was 16/30 at 50 ppm in the diet, 4/20 at 40 ppm, 1/30 at
-------
135-
Table III.6.1 (from ref. 131)
ToxiriTv Co.\nv..iti.i<>xs OF Auoci.O'.ts AND 1'ocii OUOANOCHI.OIU.SK P;:ST'CIDKS IN
HIKTS OF 2-\Vi;i:K-Oi.i) Biltns llfu-itii et a!., I'lTOl
Chemical
Aroclor 12:52
\.-oo!or 1242
Aroclor 124H
Aroclor 12.5-1
Arocior 1200
Arnolor l'JC'2
DDK
PDT
Dteldriu
Ertdrin
LC-^.s" with 0.5 VJ cur
Mallard Phea;:iint
— .1150
lilSO 20SO
(2Gio-:j.ssi)i (1S40-2U.50)
27'.)". i:.',ii)
( :'2()."i-:;420'i ( 1 1 G">- 1 4SO)
27i)0 ] 000
' 21 do-:-;:) 10 1 (Oii.5-12M)
l!)7."i 10i>()
;i:jir)-27.'ii). (no:.-u:s.yi
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(24(iU-:W.'J.Y/ nOS.VUOo)
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•2S10-4070) (7.00-1)70)
1870 :HO
(1500-23701 (2.V)-:57.")
200 .",
.'H)0-240) l tfi-cr
22 ' 14
(17-31) (10.'!-17."j)
^aiviinut.pm^the
Bohwhite Quail
noon
2100
(170.5-20101
117.5
fJO-'i-M-iOi
li(!:5
f410~j,J.01i
715
(o7.5-0.<")'i
,S7'I
('700-1070,
S2.5
(6!)5-(.)>0)
610
(51.5-72.5;.
30
(33-4.51
15
(10. .5-24)
si/ed
Japar.c?(: Quail
>;«.oo
>5000
4.S4.5
(4:i.".)-a410)
2001.1
(21.00-32101
L'l.V-
'. l!U.5-24SiVi
I."-'!"'
f2010-i."i7.5'i
1 :..'.•
;ino-i'i",C:
.170
(470-o!)C;
.It)
(.51-01)
l'>
:12.-i7)
" i,da'. ppni cl-.oraii.'!!! in nil libitum diet u.\j>ecuul to pro dnyt, o d;'y? .
toxic diet, fi.>llo\veU l»v :i tls-ys of uutre^t-ed diet. Ead) dotennitiation based oa fit)' binis.
Reproduced from
best available copy
-------
Table III.6.2 (from ref. 129)
Semichronic Oral Toxioily Studies of PCB Prspnrations.
Vi^pn- Animal
ration
Aroclor Chicken
•12% Cl
Aroclor Chicken
42% Cl
43% Cl Chicken
KG -400
Aroclor Chicken
iSTi Cl
Aroclor Chicken
5-1% Cl
Treatment
100, 200, 400, and
and lOO'J ppm
in diet for
4 weeks
200 and 400 ppm
in diet for
3 v.'ceks
1, 5, 10, 25. 50,
100. 300, 000,
ICDO, 2400, and
4,800 ppm in
diet for 20 day?
10, 20, 30, 50, IOC',
and 150 ppm in
dice for 4.5-5
weeks
250 and 150 ppal
in diet for 6 to
13 weeks
*
Mortality Liver effects
0, 0, 50, and Enlargement;
90% respectively d:ir.ir\ge at the
higher leveis
0 and 12%
respectively
0% from 1 to 100
ppm; 100% from
the 100 ppm level
After 3 weeks: 0, 0, Enlargement
30, 30 and 20%;
at the end 0. 0,
80, tiO, and SC%
respectively
250 ppm 100% be-
tween 3 and 10
weeks; 500 ppm
soEe mortality at
the end • .
Other afocts Refer-
ences
Edema formation
from 200 ppm; at ]_;
aik'Ii levels internal
haemorrhage and
tubular dilatation
in kidneys
Pronounced edema
at 400 ppm; en- 1
largea kidneys;
small spk-en;
defeatherins; and
dermatitis
Edema formation
100 ppm level 1
General edema and
depression of the 1
=econdar' sexual
characteristics
frorti the 30 ppm
level
500 p-'Ti: at .;nd:
co:nb weights 20- ^
f A! and testes
weights 2-fold
. louver than controls
135
136
Reproduced from
best available copy
-------
137
30 ppm and 0/10 at 10 ppm. Only 2-4 out of 10 chicks survived on diets
containing 100 and 150 ppm (138). In a comparative study with Aroclors
1242, 1254 and 1260, Aroclor 1242 proved the most toxic, causing 100%
mortality at 400 ppm in the diet and 40% mortality at 200 ppm in 4 weeks;
Aroclor 1254 caused 60% mortality at 400 ppm and 20% mortality at 200 ppm;
Aroclor 1260 caused no mortality even at 400 ppm (65). Together these
studies show that chickens are more sensitive than any of the species
listed in Table III.6.1; also in contrast to these species, chickens are
more sensitive to the mixtures with lower chlorination. Marked variations
in the toxicity of PCB mixtures to chickens have been noted (2, 136: see
next section).
The toxicity of PCBs has been studied in several other species of
birds. In Japanese quail, 2000 ppm of Aroclor 1254 in the diet caused
100% mortality between 6 and 55 days (139). In Bengalese finches, a dose
rate of about 250 mg/kg/day of Aroclor 1254 was needed to cause 50%
mortality in 56 days (140), but the dose-response curve was very shallow
and some birds died even at the lowest treatment level (about 6 mg/kg/day).
Some mortality was caused among subadult pheasants by doses of Aroclor 1254
as low as 10 mg per day (about 15 mg/kg/day) (141). Cormorants treated with
Clophen A60 at 200-400 ppm in the diet died after 55-124 days (142).
Residues of PCBs in the brains of experimentally killed birds were in
the range 350-760 ppm in blackbirds (130), 300-400 ppm in pheasants' (141) and
75-180 ppm in cormorants (142). Brain residues in these ranges are believed
to be indicative of death by PCB poisoning (130). Residues in the livers of
poisoned birds were in the range 200-300 ppm in cormorants (142) and 70-700
ppm in Bengalese finches (141), but much higher in pheasants (142).
No investigations appear to have been reported of the toxicity of
Aroclor 1016 to birds.
-------
138
III.6.2 Chick edema disease and the role of PCDFs in PCS toxicity.
The most characteristic signs of toxicity in chickens experimentally
poisoned with PCBs are subcutaneous edema, hydropericardium, and in some
cases enlargement of the liver, liver necrosis, reduction in the size of the
spleen, and kidney damage (Table 111,6.2; 65, 129, 132-139). Hydropericar-
dium has also been recorded in some, but not all, treated individuals of
Bengalese finches (140), Japanese quail (139) and pheasants (141), but not
cormorants (142). Atrophy of the spleen and liver changes were prominent
in poisoned pheasants (141). Hemorrhaging in breast muscle and other tissues
has also been reported (65, 138).
Edema and hydropericardium are characteristic signs of "chick edema
disease", a syndrome which periodically affects flocks of domestic chickens.
The cause of "chick edema disease" has been traced to toxic fat included in
•commercial feeds, and the usual toxic agent has been identified as poly-
chlorinated dibenzodioxins (PCDDs) (143, 67). However, outbreaks of chick
edema disease in Japan in 1968 and in the United States in 1971 were traced
to contamination of chicken feed with PCBs (144, 65). At least in the latter
case, the concentration of PCBs in the feed seemed insufficient to account
for its toxicity (65; 2, pp. 327-328). This prompted the search for another
toxic contaminant.
Vos and Koeman (137) found that under identical conditions Clophen A60
and Phenoclor DP-6 were much more toxic to chicks than Aroclor 1260', and that
most of the classic signs of chick edema disease were caused by the first
two mixtures (Table III.6.3). On fractionating the mixtures most of the
toxicity was traced to the most polar fractions of Clophen and Phenoclor and
compounds tentatively identified as PCDFs (4-Cl and 5-C1) were identified in
them. Subsequently PCDFs have also been identified in the PCBs which caused
the Japanese incident in 1968 (34).
-------
TABLE III.6.3 (from ref. 137)
MORTALITY, MEAN SURVIVAL TIME AND PATHOLOGIC OUSERVATIONS OF CHICKS FLD sCO pi>m PCB FOR 60 DAVS
AND OF CONTROL BlRDS '•
Groups
1 (Phcnoclor)
H (Clophcn)
III (Arocior)
IV (Control)
N
24
22
20
20
Number of
deaths
24
22
3
0
Mean survival"
time
(days)
24.3(12-53)
20.5 (13-29)
—
—
Number of birds with edema
Hydropcricardium*
18
20
3
0
Abdominal
8
9
0
0
Subcutaneous
5
7
0
0
Number of birds
with liver necrosis
9
9
0
0
* "The range of values is shown in parentheses.
* Positive hydropcncarduim response was considered to be over 0.2 ml pericardial fluid in chick* ^.0
-------
In recent direct studies, 2,3,7,8-tetrachlorodibenzofuran (TCDF)
proved exceptionally toxic to chicks (30, 71). Birds which were treated
with 5 /ig/kg/day TCDF died in an average of 11.5 days. Chicks which were
treated with 1 jag/kg/day started to die on the 19th day, and were in very
poor condition when the experiment was terminated. The most striking gross
pathologic change observed was the accumulation of clear fluid, as evidenced
by marked subcutaneous edema, ascites, and hydropericardium, with the
severity of the fluid accumulation greatest at the 5 ug/kg dose. The hearts
of these birds also appeared enlarged and flabby (rounded). The second
striking change was a marked reduction in size of the thymus and spleen.
Histologically, size reduction could be accounted for by the marked depletion
of lymphocytic cell types in the spleen and cortex of the thymus. Similar
pathologic changes were found to occur at the 1 ^g/kg dose, albeit to a
milder extent. There were no significant effects observed on liver weight;
mild liver pathology was found to occur only at the 5 /ig/kg dose. Total
serum protein levels were reduced with.a marked reduction in serum albumin (71).
Although this experiment and that of Vos and Koeman (137) indicate that
PCDFs are major causes of chick edema disease, they do not exclude the possi-
bility that some PCBs do so also. For example, Aroclor 1260 caused some
deaths and hydropericardium in Vos and Koeman's experiment (Table III.6.3),
although the intake of PCDFs by these chicks would have been only about 50
ng/kg/day (400 ppm Aroclor x 0.8 ppra PCDF x 160 g/kg/day food intake; refs.
32, 137). Mortality and hydropericardium have been recorded in other species
treated at even lower dose rates of Aroclor 1254 (65, 140, 151). In pheasants,
marked atrophy of the spleen, liver enlargement and degeneration, and one
case of hydropericardium were induced by daily doses as low as 15 mg/kg/day
of Aroclor 1254, an intake which is unlikely to have represented more than
25 ng/kg/day of PCDFs (141, 32).
-------
In another recent study, chicks were dosed with five symmetrical
isomers of hexachlorobiphenyl (30, 70). Although four of these had little
effect except on the liver (and slight effects on the thymus) at doses of
400 ppm, 3,4,5,3',4',5'-hexachlorobiphenyl proved exceptionally toxic,
causing 100% mortality even at 3 ppm in the diet and producing the classic
symptoms of chick edema disease at that level (Tables III.6.4, III.6.5).
This isomer apparently is not present in commercial PCB mixtures, although
structurally similar isomers are present in small quantities (Section II.5.4
above). It is not yet clear whether the effects of this isomer are due to
its structural similarity to the most toxic CDFs and CDDs, or whether CDFs
may be produced from it by metabolism.
It is therefore impossible with existing information to disentangle
the roles of PCBs and PCDFs in chick edema disease. Although PCDFs seem to
play a major role in the toxicity of Clophen A60 and Phenoclor DP-6 to
chickens (137), the same symptoms are produced by at least one specific PCB
isomer. Further, some of the symptoms of chick edema disease are produced
by Aroclor mixtures which contain extremely small quantities of PCDFs, and
most of the effects on the liver appear to be attributable to PCBs them-
selves (129). For further discussion of the environmental significance of
PCDFs see below in Section III.16.
Chick edema disease has also been induced experimentally with poly-
chlorinated naphthalenes (67) but this effect also is probably attributable
at least in part to PCDFs (see Section III. 1.6).
III.6.3. Porphvria and induction of ALA-synthetase
Vos and Koeman (137) found that experimental poisoning of chicks with
PCBs was accompanied by increased fecal excretion of coproporphyrin and
-------
IV2.
TABLE III.6.4 (from ref. 70)
Summary of the biological effects of
hexachlorobiphenyl isomers in chicks
Dose Body weight Porphyrin
level gain Liver • Accumula- Thymus
Chemical (ppm) Mortality (% of control) effect tion effect
3
2
2
2
2
,4
,3
,4
,3
,4
,5,
,4,
,5,
,6,
,6,
3'
2'
2'
2'
2'
,4'
,3'
,4'
,3'
,4'
,5'
,4'
,5'
,6'
,6'
-HCB
-HCB
-HCB
-HCB
-HCB
3
10
400
400
400
400
10/10
10/10
0/8
0/10
1/10
0/10
.
-
68
66
80
83
-H-+ - -H-+
++ +-H- +++
++ - +
•H- +
•H- +
-H-+ - +
-------
Summary of major pathological changes in
given different hexachlorobiphen} Lsomers
Dose
level
Chemical (ppni)
3,4,5,3',4',5'-HCB 3
2.3,4,2', 3' ,4'-HCB 400
2,4,5,2',4',5'-HCB 400
2,3,6,2',3',6'-HCB 400
2,4,6,2', 4', 6'-HCB 400
2,3,7,8 -TCDF 5 jig/kg
Liver
Marked; fatty
metamorphosis,
focal necrosis.
Moderate;
•hyalinization,
single-cell
necrosis.
Moderate;
single-cell
necrosis.
Moderate;
fatty metamor-
phosis, focal
necrosis, giant
cell formation.
Marked; fatty
metamorphosis,
focal necrosis,
giant cell forma-
tion, marked focal
dilatation of
sinusoids.
Mild; passive
congestion
Thymus
Marked;
involution.
Slight;
Involution.
Slight;
involution.
Slight;
involution.
Slight;
involution.
Marked;
involution
>
chicks
for 21 days
Spleen
Marked;
depletion of
lymphocytes.
NSa
NSa
NSa
NSa
Marked ;
depletion of
lymphocytes
Fluid
Accumulation
1
Subcutaneous edema,
ascites, hydroperi-
cardium.
Epicardial edema.
NSa
NSa
NSa
Subcutaneous edema,
ascites, hydroperi-
cardium
NS = not significant.
-------
protoporphyrin and fluorescence of tissues. Chicks which died during the
experiment had a much higher incidence of fluorescence in liver, bile, and
small intestine than did those that survived; fluorescence in bone was
prominent in both groups. The effects were similar in chicks treated with
Aroclor 1260, Clophen A60 and Phenoclor DP-6, suggesting that the porphyria
is an effect of PCBs themselves rather than PCDFs (129).
In a subsequent study with Japanese quail, Vos e£ al. (145) found
that treatment with Aroclor 1260 at doses of 100 mg/kg/day for 7 days or
greater induced porphyrin fluorescence in the liver. Mitochondrial activity
of o-aminolevulinic acid (ALA)-synthetase was greatly increased. Together
with the doubling of mitochondrial protein, liver enlargement, and pyronino-
philic staining of liver nucleoli, this suggested an increased protein syn-
thesis (145). Further testing at lower doses showed a significant induction
of ALA-synthetase at 1 mg/kg and a marked but non-significant increase even
at 0.1 mg/kg (Table III.6.6). A significant increase in ALA-synthetase was
associated with PCB residues in the liver as low as 1 ppm (Figure III.6.1).
This is one of the lowest levels of PCB exposure associated with a measurable
effect in an experimental animal.
Testing five individual isomers of hexachlorobiphenyl, Goldstein et al.
(146, 147) found that all five stimulated ALA-synthetase, but that there were
marked differences in their porphyrinogenie effects (Tables III.6.5, III.6.7).
The 3,4,5,3',4',5'- isomer had by far the greatest effect; the 2,4,5,2',4',5'-
and 2,3,4,2',3',4'- isomers also had marked effects, but the other two isomers
had no significant effects. 2,3,7,8-TCDF had no effect either on ALA-synthetase
or porphyrin accumulation (Table III.6.7). The lack of effect of 2,3,7,8-TCDF
contrasts strongly with that of the structurally similar 2,3,7,8-TCDD, which
is a potent inducer of ALA-synthetase in chicks (148). Furthermore, the
-------
TABLE III.6.6
(from ref. 145)
FORMATION OF S-AMINOLEVULINIC ACID nv LIVER MITOCHONDRIA, CviociiROME_P-450, PROiFIN CUNTI-.NT OF THE MITCCHONDKIAL
FRACTION, LIVER WEIGHTS, Livrn RF.SIDUFS, AND Tissut FLUORESCENCE IN Fn.iAi.r JAPANESE QUAIL
ORALLY DOSED WITH PCB FOR 7 DAYSJ
Aroclor
1260
(mg/kg
body weight)
/
0
O.i
1
10
100
ALA formed
(fri/xruolcs ALA/B
liver/lirj
6.46± 1.65
8.76 -i 4.0l.
IU.50± 1.21*
17.3 .6.4*
1I9.9C
Cylochrome
IM50
(m/imoles/
g liven
<9.l
<6.9
<4.3
14.0
19.7r
Protein content
mitochondria!
fruition
(mg/g liverj
19.1 ± 5.3
17.7± 1.8
20.9 i 3.7
17.8 ±2.5
29.1C
Tissue fliioresccncc
incidence
Liver
(8)
4.43 1 0.51
4.31 ±0.62
4.22 i 0.76
5.09 ± 1.19
4.73 rr 0.82
Liver
(B/IOOB
body weight)
3.13±0.13
3.09 ±0.51
2.76 :h 0.35
3.52 ± 0.65
3.89 ± 0.63
PCB Content
liver
(ppm)
0.1 5r
0.54 ± 0.27
1.4! ±0.67
27.0 J. 9.4
478 ± 294
Macroscopic
0/5
0/5
0/5
0/5
3/5
...-._
Microscopic
(liver)
0/5
0/5
0/5
0/5
2/5.
• Mean values _L SD, 5 birds per group.
* Significantly different from controls, P --; 0.01.
c Pooled samples.
-------
11]
100 ICOQ
r content of PCS (asm)
V***'^ ' nls' j,J|,m)andthcmiicchondriaIALAsynthetase
V.\*^A <»£ • ixvvvioPS kg: 2, 1 nu>,k;; a, 10'mg/kg; C. tUO
nntcnt. a?El Liver .suni|it» were pooled in 'he
he 10(v n:g;kg group tor tht deiermina-
Reproduced from
best available copy
-------
EFFECT OF 400 PPM PURIFIED HEXACHLOROBIPHE.NYL COMERS AND TCDF ON CHICK LIVERS3
ALAS Incidence of Liver Porphyrin
Treatment nmol/g/hr . Porphyria0 Levels (pg/g)
(> 10 pg/g) (Range)
Control 55 ± 2 0/10 0.4-1.4
261 ± 15b 0/10d 0.5 - 1.4
303 ± 15b 0/10d ' 0.7 - 2.9
2,4i,5,2l,4',5'-HCB 309 ± 13b 3/9 d 1.5 - 82
2,3,4,2',3',4'-HCB 250 ± 28b . 2/8 d 1.2-81
.3,4,5,3',4',S'-HCB DEAD 1/7 d 2.4-5,000
Corn Oil 74 ± 2 0/33 0.4 - 1.2
1 vg/kg/day TCDF x 21 days 63 ±20 0/5 • 0.4-2.9
5 pg/kg/day TCDF x 21 days DEAD 0/5 0.3-0.7
treatment described in Fig. 1.
Significantly greater than controls, p <; o.Q5 CDuncan's Multiple-Range test).
Proportion of animals wh<
at P < 0.01 is 2.3 vg/g.
Uroporphyrin detectable in all samples after thin-layer ciromatography.
Table III.6.7 (from ref. 147)
cProportion of animals whose liver porphyrin levels exceed lOpg/g. The upper 99% tolerance levels for controls
' '
-------
strong contrast between 3,4,5,3',4',5'-hexachlorobiphenyl and 2,3,7,8-TCDF
in their effects on ALA-synthetase and porphyrogenesis (Table III.6.7) show
that contamination with the latter compound cannot account for the extreme
potency of the former in producing chick edema disease (Table III.6.4).
Only hexa-chlorobiphenyls and Aroclor 1260 appear to have been
tested for these effects in birds, but since lower chlorobiphenyls and mix-
tures are also active in rats (see below) there is no reason to assume that
the effects in birds would be limited to the more highly chlorinated compounds.
III.6.4 Effects on reproduction
III.6.4.1 Effects in chickens
Numerous studies have been carried out of the effects of PCBs on
reproduction in chickens, because of their apparent sensitivity and be-
cause of several commercially damaging incidents (65, 144).
In an experiment reported by Scott e£ al. (149, 150), Aroclor 1248
was fed to White Leghorn chickens at dietary levels of 0.5, 1, 10 and 20
ppm. Egg production was significantly reduced in the 10 and 20 ppm groups
after 8 weeks. There was no significant reduction in the breaking strength
of eggs at any dose level, but hatchability was severely reduced in the
groups fed 10 and 20 ppm. Hatchability was reduced to 72% of normal when
the PCB level in the eggs reached 2.2 ppm (wet weight), to about 56% at
3 ppm, and almost to zero at 4.5 ppm.
In another study, White Leghorn and broiler hens were fed diets con-
taining 20 and 50 ppm Aroclor 1242 for six weeks. Even at 20 ppm hatcha-
bility was reduced to half that in controls by the second week of feeding
and almost to zero in the fourth and fifth weeks. Broiler hens were slightly
more resistant than White Leghorns. Most of the embryonic mortality took
-------
//f
place in the middle and late stages of development. No hydropericardium was
observed in the affected embryos, but abnormal anatomy of the heart was
observed, involving ridges on the exterior of the right ventricle (151).
In another study involving several dose levels of Aroclor 1242,
there was no effect on egg production, egg weight, or eggshell thickness at
any dose level. Hatchability was reduced in the group fed 10 ppm for six
weeks, and reduced markedly in the groups fed 20, 40 or 80 ppm. Significant
reductions in hatching success were noted when PCS residues in the yolk
exceeded 2.4 ppm (about 1.0 ppm in the whole egg). Hatchability recovered
almost to normal after a 6-week period on clean food in which the yolk resi-
dues fell below 1.8 ppm (152).
In another study involving feeding Aroclor 1254 at dietary levels of
5 and 50 ppm, egg production and fertility were reduced at both exposure
levels; hatchability of fertile eggs was affected only in the 50 ppm group (153).
In another study in which Aroclor 1254 was included in drinking water
at 50 ppm (corresponding to an intake of about 6.3 mg/kg body wt/day),
fertility was unaffected but hatchability dropped to zero by the third week.
Hatchability started to increase after nine weeks on uncontaminated diets,
but did not return to normal until about the 17th week, when yolk residues
had declined to about 10 ppm (Figure III.6.2). Deformities of the legs,
toes, and neck were observed in many chicks hatching from eggs with yolk
levels 10-15 ppm or more (154, 155). Other developmental defects were ob-
JLJU
served in the few chicks surviving these concentrations (154). Teratogenic
effects were also observed when 5 mg Aroclor 1242 was injected into the yolk
sac of fertile eggs (156).
In a comparative study, White Leghorn chickens were treated with
Aroclors 1016, 1232, 1242, 1248 and 1254 for eight weeks at dietary levels
* Abnormalities of the epicardium (fenestration and fibrous degeneration)
were reported in another study involving feeding of Aroclor 1254 (400).
** Toe deformities were also seen in birds of the second (F£) generation,
suggesting a mutagenic effect (155, p. 204).
-------
Figure III.6.2
(from ref. 155)
150
100
•PCB started
•PCB stopped
Week
PCr? levels in egg yolk, determined by TLC, and hatachability of experimental
eggs. • = PCB level; = hand-interpolated curve; = least-squares fit to a
thjrd-order regression; o = hatchability.
-------
of 5, 10 and 20 ppm. None of the mixtures affected egg production, egg
weight, eggshell thickness or food consumption. Hatchability of fertile
eggs was severely reduced by Aroclors 1232, 1242 and 1248 at the 10 or 20
ppm levels (Fig. III.6.3), but there were no significant effects induced
at 5 ppm, nor by Aroclors 1016 or 1254 at any level. The growth rate of
the surviving chicks was reduced by maternal exposure to all 5 mixtures
(chicks were exposed only via the egg); this reduction was most marked for
Aroclors 1242 and 1248. Embryonic death was most pronounced in two periods
of development: on days 3-10 and after the eggs were pipped (Table III.6.8).
Abnormal embryos were found in eggs treated with Aroclors 1242 and 1248
(Table III.6.8): abnormalities included edema, unabsorbed yolk, small
bodies, external hemorrhage, and leg malformations (157). In an earlier
study with 20 ppm Aroclors 1242 and 1248 as many as 33-50% of the dead em-
bryos showed these abnormalities (158). In this earlier study Aroclors
1221 and 1268 appeared to have no effects on chicken reproduction at levels
of 20 ppm (158).
In another comparative study with White Leghorn chickens no effects
were found with Aroclor 1260 at any dose level up to 100 ppm; Aroclor 1254
affected egg production and hatchability at 100 ppm, and chick viability was
reduced at 10 ppm; Aroclor 1242 reduced egg production at 100 ppm, chick
viability at 10 ppm, and hatchability at 8 ppm, but not 'at 4 ppm (68). Egg-
shell thickness is said to have been reduced by Aroclor 1242 at 10 and 100 ppm,
but no details were given and this result conflicts with that obtained by
other experimenters.
Finally, in the East Coast Terminal incident in which commercial
chicken feed was contaminated with Aroclor 1248 (65), hatchability of eggs
from chickens ingesting the feed dropped to about 2% (2). In affected
-------
Figure III.6.3
(from ref. 157)
1*2.
;oo
on
10
70
bO
50
.1)
30
:o
!•••
" — 10'J 1
*^^*^^Cr"r°' fmau^T^j Jf? 1
n ^^^ ^^•^^•i^^^^'j11' v**"iiAp^T!ffrT 00
fcti****** »^ / ^^^
\ \IJ32 / /' J0
, \ »••••....- r
- \\ / ! °
\ \«« / 5^0
\ V X -
\ *\J! - 50
1248 \ S*
• V^ -0
* 3 J'J
r
™ I -°
» . h>
•
^ (^»*'*^^^i"ontrol ^^^^pM^i^^^^1^ ,
• ^^^•••••i*^^^^^ %»* y *•*
.x /
\ -"• /
• •. •• * _*•
• i ^
\ '•• / i i
• \ \ / / /
• \ \»-7 / /
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1C- ;.p- FCi
1
1 I
1
Effect of 10 p.p.m. PCB feeding and Effect of 20 p.p.m. PCB feeding and
subsequent PCB withdrawal on haichability of subsequent PCB withdrawal on hatchabi!U> of
fertile eggs in a 16-week period. fertile eggs in a 16-week period.
-------
TABLE III.6.8
(from ref. 157)
—Fertility, hatchability. abnormal emhryns and peak of embryonic death during feeding of
Arodors 1242 and 1243 in the maternal diet
PCB
Aroclor
None
1242
1248
1242
1248
1242
124?
PCB
level
p.p.m.
0
5
5
10
10
20
20
Fertile
eggs
Number
163
106
109
103
114
194
204
Hatch
•~ of fertile
egss
91
76
87
*?
69
.8
•>•>
Abnormal embryos
as "c of
Fertile
eggs
•>
8
i
9
5
12
13
Dead
embryos
20
35
14
26
17
17
16
Embryonic death
% on incubation Jay
1-2
53
54
36
12
11
4
9
3-10
•7
15
21
47
40
38
33
11-19
26
0
7
9
0
13
9
.0-2!
14
31
36
32
49
45
45
Pipped eggs
c'c 01 day
21 dead
0
33
40
43
29
29
31
-------
samples of eggs, fresh yolk prior to incubation contained about 0.29 ppm,
yolk of fertile eggs contained 0.97 ppm and 1-day-old dead embryos con-
tained 0.35 ppm (2). Comparison with the levels required to reduce hatcha-
bility in other experiments (149, 150) indicates that the material which
leaked from the heat exchanger was considerably more toxic than fresh Aro-
clor 1248 (2: see Section II.8.4 above).
To summarize these studies with chickens, marked effects on reproduc-
tive success have been noted at dietary levels as low as 8-10 ppm, correspond-
ing to residues of only 1-2 ppm in whole eggs. Aroclors 1242 and 1248 are
much more potent than higher or lower chlorinated mixtures, but Aroclor 1016
was much less active than Aroclor 1242 in one test. The principal cause of
reproductive failure is embryonic mortality, and abnormal embryos and terato-
genic effects have been reported in several experiments.
The possible role of PCDFs in embryonic mortality is not clear. PCDFs
appear to be embryotoxic in chickens (129) and the high toxicity of the PCBs
in the East Coast Terminal incident suggests the presence of a toxic contami-
nant (2). However, it is difficult to attribute the greater toxicity of
Aroclor 1242 than Aroclor 1016 (157) solely to the presence of PCDFs in the
former mixture, because Aroclors 1254 and 1260 (which also contain PCDFs - 32)
appear much less embryotoxic (157, 68). It seems more plausible to attribute
the high toxicity of Aroclors 1242 and 1248 in chicken embryos to the presence
f
of a specific tetrachlorobiphenyl which is less well represented in Aroclors
1016 and 1254. Ax and Hansen (399) report that 2,4,5,3',4'- pentaCB is very
toxic to chick embryos, but this isomer is not present in Aroclor 1242.
III.6.4.2 Effects in Pheasants
Dahlgren _e£ aL (141, 159) dosed female pheasants with Aroclor 1254 by
capsule at rates of 12.5 or 50 mg weekly (approximately 2.5 and 10 mg/kg/day,
equivalent to about 50 and 200 ppm in the diet). Egg production was
-------
significantly reduced in all treated groups, and there was a significant
increase in the number of eggs that were pipped but not hatched. Although
egg fertility and hatchability were not significantly reduced, survival of
chicks was reduced in all groups and the overall reproductive success was
significantly reduced. No effects were found on eggshell thickness (141).
III.6.4.3 Effects on Mallards
In a two-year study with Mallards, Aroclor 1254 at 25 ppm in the diet
had no significant effects' on any aspect of reproductive success except for
a reduction in the number of eggs laid, which took place only in one of
four pens and was believed to be unrelated to treatment (131) (Table III.
6.9). Eggshell thickness was unaffected by Aroclor 1254, although in a
parallel experiment DDE caused significant eggshell thinning (Table III.6.10).
Residue levels in eggs (33 ppm wet weight) were much higher than those
associated with embryonic mortality in chickens.
Similar results were reported in another experiment in which Mallards
were fed 40 ppm Aroclor 1254, 40 ppm DDE, and the two compounds together
(160). Unlike DDE, Aroclor 1254 did not cause significant eggshell thinning,
and it caused only a slight and non-significant increase in the degree of
eggshell-thinning induced by DDE (Table III.6.11). However, egg production
was markedly reduced in the Mallards fed PCBs and DDE simultaneously, and
there was-a significant increase in egg-eating by the birds on combined
dosage (160) .
III.6.4.If.. Effects in Bobwhite Quail
Reproduction in bobwhite quail was not measurably affected by dietary
exposure to either Aroclor 1254 or DDE, administered singly or in combination
(131) (Table III.6.12).
-------
TABLE III.6.9
(ref. 131)
REPRODUCTIVE SUCCESS AMONG PENNED MALLARDS MAINTAINED FOK TWO SEASONS* ON rcsus
CONTAINING AROCLOR I2J4 OR DDE
season
chemical added to feed
(ppm)
control Aroclor DDE
1254 ^o)
Pens of birds
(5 9°, 2 43 each)
Hen-seasons
(S weeks each)
Total eggs laid
Eggs laid per
hen-seasons
Eggs cracked (%)
Ei^gs embrvonnred of
"eggs sit (%1
Embryos alive at
3 W(xki (°r)
Normal hatchlincs of
j-\vecl-: embryos (%)
Normal hatcinini;< alive
at u day.-: (uj)
14-day dacljlings "f
embryonated e_a?s (%)
14-day citickiinqs per
hcn-soa^ons
1969
1970
1969
1970
1969
1970
1969
1970
1969
1970
1969
"970
1969
1070
1909
iyo
1969
I'i/C
1969
1970
TOup
1970
4
4
20
20
590
630
29.5
31-5
4
9
86
S8
98
9^
7°
59
94
95
64
5-
13.0
TI.6
4
4
20
"9 .
433
468
. 21.7
24-6
6
9
94
90
96
02
6?
6,;
oi
96
55
5-7
i.8
ic. 4
4
4
19.1
18
628
6»2
32.S
35-i
20J
2S2
80
63
94
SB
47s
53
97
92
4'*
<Iu\- i_, 1370
Differences from controls statistically signir.c?.nt'(l- < 0.05).
-------
TABLE III.6.10
(ref. 131)
Me.»N THICKNESS OF EGGSHELLS OF PENNED NfALLARDS MAINTAINED THROfOH TWO SEASONS ON
FEED CONTAINING AROCLOR I2J4 OR DDE
chemical added to -feed (pom)
No. of eggs
Shell thickness
(mm)
season
1969
1970
1969
1970
none
28
3*
O.J75
0.365
Aroclor
(*5)
27
'7
0.360
0.368
DDE
(10)
*7
26
0.3391
o.328l
1 Differences from controls statistically significant (P < 0.05).
-------
TABLE III.6.11
(from ref. 160)
Mean eggshe'l thickness indices for 1-day eca collections from capes of mallards fed four experimental
I
Single 1-day egg .-ollcctions
Day 30
Treatment
Control
PCB
DDE
DDE J- PCB
F-valuese
No.
1
4
6
8
Mean
0.212 A
0.193 AB
0.177 BC
0.16-1 C
7.73
Day 32
Xo.
eggs
.5
4
5
6
Mean
index
0.214 A
0.211 AB
0.1SO C
0.170 C
12.00
Day 50
N'o.
e?ss
5
8
7
S
index
0.213
O.ilR
0.170
0.161?
20.00
A
AB
C
C
Larecst 1-aay collections
auric? J-day periods
Days 30-02
No.
9
5
6
9
indox.
0.212 A
0.201 AB
0.177 C
0.167 C
1S.50
Dayi 50-32
No.
eggs
S
9
S
8
Me;m
Index
0.217 A
0.216 AB
0.172 C
0.166 C
.'•2.00
•\\ih.es for each troatm:-:it n.'pn«i'iil combined ilata fur tha slni;le I.nr;c-3t l-'iay ei;g collegium dunns the 3-iiay
pfriofi trom each of rwo rpplicatfl c.iuf«.
b \Vi:h:ii a colim.n, nieai.s followed hv the same letter are not siiinu'icamly different (?<0.05).
c.^ll /--values are significant (J?< 0.005).
-------
III.6.4.IT Effects in Ring Doves
Peakall et_ al. (161) studied reproduction in ring doves exposed to
10 ppm Aroclor 1254 for two generations. Although there were no effects
in the first generation, there was high embryonic mortality in the second
generation (Table III.6.13). Cytogenetic studies of treated embryos showed
a number of chromosomal aberrations (primarily chromatid, some isochromatid,
and one rearrangement). Thirteen of 17 treated embryos had aberration
rates exceeding the mean rate in controls (161). Eggshell thickness was
not affected (162). In a subsequent study it was found that embryonic
mortality was due in part to abnormal, incubation behavior by the PCB-treated
parents (163). Eggs incubated artificially, or by untreated parents, had a
higher hatching success. However, significant embryonic mortality was ob-
served even in artificially incubated eggs, and this was attributed primarily
to the chromosomal effects (163).
III.6.4.£ Effects in American Kestrels
Because residue levels of PCBs are often very high in predatory birds
(1, 2, 6) special interest attaches to an experiment in which the effects of
dietary PCBs were studied in captive American Kestrels (164). Groups of
breeding Kestrels were fed diets containing 10 ppm Aroclor 1254 (wet weight
of diet), 3 ppm DDE, and a combination of the two chemicals. Eggshell-thick-
ness was slightly increased in the PCB-treated birds (statistically signifi-
cant in one experiment, but not in others), markedly decreased in the DDE-
treated birds, and still further decreased in the birds treated with DDE
and PCBs (Table III.6.14). The difference between the birds treated with
DDE and those treated with both chemicals was statistically significant.
All the eggs from birds treated with both chemicals were broken during
incubation (Table III.6.14). When eggs were artifically incubated, embryonic
-------
I/O
TABLE III.6.12
(from ref. 131)
REPRODUCTIVE SUCCESS AMONG PENNED BOBWIUTE FED DIETS CONTAINING AROCLOR 1154. DDE,
OR A MIXTURE OF BOTH CHEMICALS1
chemical added to feed (ppm)
control Aroclor DDE Aroclor 1154 4- DDE
(jo) (jo) (25) +(i 5)
Pens of birds
(3 99, 2 o'o* each)
Hen-seasons
(8 weeks each)
Total eggs laid
Eggs laid per hen-season
Eggs cracked (%)
Eggs embryonatcd of
eggs set (%)
Embryos alive at
3 \veeks C"0)
Normal hatchlings of
3-week embryos (%)
Normal hatchlings nlive
after 14 days (%)
14-day chicks of
embryonated e?gs (%)
14-day chicks per
hen-season
6
16.6
347
'.0.9
10
88
97
96
73
73
11. 5
6
16.4
368
22.4
7
90
97
91
72
64
11.5
6
15-3
27.1
5
93
08
96
7°
66
15.1
J
14-9
386
26.0
7
93
97
92
7'
63
13-5
1 Dosage started April 3, 1968; sags collected from April 27 through June 21, 1068.
of thi ahore dififrtmis vas significant st tilt 9} percent level of a>>:,ieince.
MEAN THICKNESS OF EGGSHELLS OF PENNED SOB-.VHITE MAINTAINED THROUGH ONE SEASON ON
FEED CONTAINING AROCLOR 1154, DDE, OK. A MIXTURE OF BOTH CHEMICALS
No. of eggs
Shell thickness
(mm)
chemical added to
none Aroclor DDE
(5°) (3°)
14 17 20
0.107 0.208 0.205
feed (ppm)
Aroclor 12^4 -j- DDE
(*S)-r(i5)
18
0.21;
AW of the abovt differences tvat significant at tilt 9? Circuit level of confidence.
-------
TABLE III.6.13
(from ref. 172)
Breeding success of Ring Doves fed 10 ppm
PCBs over two generations.
Pre -experiment
1st generation PCBs
2nd generation PCBs
Cnd generation Control
No. of
pairs
6
6
6
6
No. of
eggs
laid
24
24
20*
24
No. of
eggs
hatched
22
24
4
22
No. of
young
fledged
22
24
2**
22
* One pair failed to produce any eggs during the period
of the experiment.
** Fledging losses consisted of one young found outside
the nest at one day of age and one deformed bird killed
at the age of three weeks.
-------
Table III. 6. 14 (from ref. 164)
Kestrel Eggshell Thinning in Response to Chronic Dietary p,p'-DDE and/or Aroclor
Based on (A) Ratcliffe's Index*, (B) Direct Measurement of Shell With
Membrane sv™1), (C) Incidence of Egg Breakage**.
# of Eggs
x - s.d.
Standard Error
% Difference
from Control
Statistical
Significance**
Control 3 ppm DDE
15 17
0.920 t .050 0.799 - -05^
0.010 0.010
o.oo -13.16
<.0005
10 ppm 1254 3 ppm DDE +
10 ppm 1254
18 12
0.977 - .080 0.770 - .045
0.017 o.oio
+6.19 -16.31
< .005 <.0005
(B)
# of Eggs
X -
Standard Error
% Difference
!?
0.171 t .013
0.003
18
0.145 + .009
0.002
14
0.176 t .015
O.OOU
15
0.139 - .008
0.002
from Control
Statistical
Significance**
0.00
—
-15.21
< .0005
+2.92
<.025
-18.72
< .0005
(c)
0(3)
0(5)
0^(5)
100(5)
* Oven dry shell veight (mg/length x breadth of egg (mm).
** Percent of total number of pairs; number of pairs in parentheses.
t One pair exhibited breakage but was attributable to other causes.
tt Probability of a larger Student's t value vhen compared with controls using a one-tailed
t-test (Steel and Torrie, I960; Table A. 3).
-------
113
mortality was increased in all treated groups but was greatest (100%) in
the eggs from birds treated with both chemicals (164). Thus, while 10 ppm
Aroclor 1254 appeared to cause some embryonic mortality, it also significantly
potentiated the effects of DDE in causing eggshell thinning, egg breakage,
and embryonic mortality. PCS residues in the eggs of the jointly-dosed
groups averaged 184 ppm (dry weight), i.e., about 30 ppm, wet weight.
III.6.4.1 Effects in Japanese quail
Japanese quail appear relatively resistant to reproductive effects of
PCBs and have been tested only at high dietary levels. Dietary exposure to
312 ppm Aroclor 1242, 78 ppm Aroclor 1254, and 62.5 ppm Aroclor 1260 caused
a significant reduction in egg production and significant reductions in egg-
shell thickness (by 4%, 12% and 10% respectively). Egg weights were also
reduced in birds fed Aroclor 1260 (165). In another experiment 100 ppm
Aroclor 1242 caused a reduction in egg production, but 100 ppm Aroclor 1254
did not. Aroclor 1242 increased the number of broken eggs (166). Dietary
exposure to 50 ppm Aroclor 1254 caused only a slight and non-significant re-
duction (4.5%) in eggshell thickness (167).
III.6.4.% Summary of effects on reproduction in birds
There are marked differences between species in sensitivity to PCBs.
Chickens are very sensitive, particularly to Aroclors 1242 and 1248; their
reproduction is markedly affected by dietary levels of 8-10 ppm, correspond-
ing to residues of 1-4 ppm in eggs. Ring doves were seriously affected by
dietary exposure to 10 ppm over two generations, and American Kestrels by
exposure to 10 ppm in combination with DDE. In contrast, mallards, bobwhite
quail and Japanese quail are much less affected by PCBs. There is.little
evidence of significant effects on eggshell thickness, except in kestrels in
-------
combination with DDE. Indications of synergistic effects between PCBs and
DDE on reproduction in kestrels and mallards may have important ecological
implications, as may the second-generation effects in ring doves.
III.6.5 Liver and microsomal enzymes
The liver has been the primary organ used in delineating effects of
PCBs on birds. This concentration of interest can be attributed to the high
liver PCS levels found, and to the responsibility of the hepatic systems for
metabolizing foreign compounds. Increases in liver weight and size are
commonly noted (157, 168). Increase in amount of liver lipids present and
a decrease in the storage of liver vitamin A have been frequently reported
(158, 166). The liver vitamin A storage reduction has not evidenced symp-
toms of vitamin A deficiency. However, it was speculated that birds in-
taking marginal dietary levels of vitamin A, coupled with the liver vitamin
A storage reduction, might be susceptible to avitaminosis.
Elevations of the liver cytoplasmic RNA content in PCB-treated birds
have been related and correlated with increases in hepatic enzyme activity.
Lower cytophotometric readings of percent transmission in experimental livers
was determined to be a consequence of increased cytoplasmic RNA (169).
Bailey and Bunyan (170) noted increased cytochromeP-450 levels which are
indicative of microsomal induction in the livers of birds given PCBs.
These elevated levels existed for six months after the withdrawal of dietary
PCBs indicating that extremely low PCB residues can cause significant in-
creases in microsomal enzymatic activity.
Several hepatic enzymes have been reported to be induced by PCBs.
Evaluation of the liver enzyme controlling pentobarbital metabolism (166)
revealed that PCBs exhibit a diphasic effect on pentobarbital induced •
sleeping times. The PCBs initially inhibit the enzymes metabolizing pento-
-------
barbital. Subsequently, these same enzymes are induced, by the PCB stimu-
lation, to greater activity yielding more rapid than normal metabolism of
pentobarbital.
Estradiol degradation is another function which PCBs have been found
to alter. Lincer and Peakall (169) reported a dose-dependent breakdown of
estradiol to a more polar metabolite. Nowicki and Norman (171) reported
increased _in vitro hepatic metabolism of two additional natural steroids:
testosterone and 4-androstene-3,17-dione. These two were reduced to polar
metabolites as was estradiol. The biological effects of this increase in
metabolism of sex hormones to polar forms is relatively unknown but it may
be a significant contribution to reproductive problems and failures that
have been reported.
A study of hepatically-directed plasma enzyme activity was conducted
by Dieter (172). Sublethal doses in quail produced elevation in enzyme
activity and reductions in hematocrit and hemoglobin concentrations. The
plasma enzymes increased were: (1) cholinesterase by 80%; (2) fructosedi-
phosphate aldolase by 5 to 6 fold; (3) creatine kinase, 4 fold; (4) lactate
dehydrogenase, 9 fold; and (5) aspartate aminotransferase by 75%. ChE, LDH,
and AAT elevations were dose-related enzyme releases which could be used to
quantitatively establish PCB exposure. Qualitative exposure assays were
judged possible due to differentiation of enzyme activity in birds exposed
to DDE, malathion, mercuric chloride and Aroclor 1254.
Goldstein et_ al. (147) studied the effects of five isomeric hexa-
chlorobiphenyls and 2,3,7,8-TCDF on liver enzymes in the chicken in order to
elucidate structure-activity relationships. All the hexa-CB isomers induced
a number of parameters of drug metabolism in chicks including cytochrome P-450,
increased liver weight, and p-nitrophenyl glucuronyl transferase, but not
-------
Iti
testosterone glucuronyl transferase activity. The most active inducers were
the 2,3,4,2',3',4'- and 2,4,6,2',4',6'- isomers (Figures III.6.4 and III.6.5).
The effects of 2,3,7,8-TCDF were both quantitatively and qualitatively differ-
ent: it induced only a small increase in cytochrome P-450 and this cytochrome
differed from that induced by the foexa-CBs, differing by a shift in the peak
of the CO-difference spectrum from 450 nm to 449 nm and in characteristics
of the ethyl isocyanide difference spectra (Table III.6.15). This is again
important in showing that PCBs and PCDFs have independent toxic effects.
III.6.6 Other toxic effects in birds
Alteration of the thyroid has been reported in conjunction with PCB
exposure. Hurst et al. (168) found depression of thyroid size, with low
dosages or early in the experiment, followed by stimulation of thyroid
growth yielding increased size with higher dose levels or later in the
study. Increased thyroid weight and size in treated gulls were also reported
by Jefferies and Parslow (173) . These elevations did not appear to be dose-
related and were accompanied by large, colloid-filled thyroid follicles.
This condition parallels simple goiter resulting from insufficient intake or
utilization of iodine. Decreased mean heart weights were tabulated which
would support the possibility of hypothyroidism suggested by the involution
of the thyroid tissues and by a minimal decrease in secretion. Jefferies
(174) has recently reviewed the role of the thyroid in the production of
sublethal effects by PCBs and has suggested that effects on the thyroid may
be linked with several other effects, including changes in vitamin A storage,
decreased reproductive success and effects on behavior.
Cardiovascular effects of PCBs on birds were evaluated by Iturri jit al.
(175). Heart rate was reduced by Aroclors 1242 and 1254, but not affected
by Aroclors 1221 or 1260. Aroclor 1254 lowered arterial blood pH significantly,
which can lower cholinesterase activity.
-------
MICROSOMAL PROTEIN
- 3
Figure III.6.4. Effects of purified hexachlorobiphenyl isomers and
TCDF on chick livers (147) . The heavy lines below the bar graph
indicate groups which do not differ significantly from each other.
-------
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CD
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Figure III.6.5 (Erom ref. 147) Effects of hexachlorobLphenyl Isomers and TCDF on chick liver enzymes.
-------
\tfl<\
Table III.6.15 (from ref. 147)
EFFECTS OF HEXACIILOROBIPIIOIYI. ISOMERS AND TCDF ON
ETHYL 1SOCYANIDE DIFFERENCE SPECTRA IN THE CHICKa
TREATMENT 455/430 RATIO
Controls 0.42 ± 0.01
2,4,5,2'S4',5'-HCB .0.40 ± 0.04
2,3,6,2I,3I,6'-HCB 0.40 ± 0.10
2,4,6,2',4',6',-HCB 0.37 ± 0.01
2,3,4,21,3',41-HCB • . 0.43 ± 0.01
Corn Oil . 0.51 ± 0.07
1 yg/kg TCDF . . 0.74 ± 0.06b
treatment is described in Figure 1. Values represent the means ± SE.
Significantly different from controls, P < 0.05 (Duncan's Multiple-
Range test). . ..
-------
17Q
iveral authors have reported sublethal effects of PCBs on behavior.
exposure of ring doves to 10 ppm Aroclor 1254 disrupted their in-
ton behavior, which caused intermittent chilling of eggs and contributed
dficantly to hatching failure (163). A similar phenomenon appeared to
significant in American kestrels (164). Low doses of Clophen A50 (0.25
.g/kg/day in the diet) are reported to have increased the nocturnal activity
of migrating robins (176). Pheasant chicks hatched from hens fed 50 mg of
Aroclor 1254 weekly made significantly more inappropriate choices in a visual
cliff test than did controls, and were significantly easier to catch by hand
&
in their pens (141, 159). Exposure to Aroclor 1254 also significantly im-
paired the escape responses of quail chicks when presented with strange
objects (73). Although these behavioral effects may have little effect on
the performance of birds in aviary situations, they have potentially large
ecological significance for wild birds under natural environmental stresses.
Harris et al. (177) found a reduction in the size of the spleen and
bursa of Fabricius in chicks hatched from chickens fed 10 and 20 ppm of
Aroclors 1232, 1242, 1248, 1254 (Table III.6.16). As in earlier experiments
(157) the effects of Aroclor 1016 were smaller than those of Aroclor 1242
and not statistically significant. An effect on the bursa of Fabricius was
noted even at 5 ppm Aroclor 1248 (Table III.6.16) — a level corresponding
to a residue of only about 1.5 ppm of PCBs in the eggs (150). The bursa is
the lymphoid organ responsible for establishing immunoglobin synthesis, but
Harris et al. did not find a clear effect of PCB treatment on antibody pro-
duction (177). However, Friend and Trainer (178) found that PCB-treatment
increased the susceptibility of ducks to viral hepatitis.
* The effect on escape behavior was also mailed when the male parent was
treated, suggesting a possible mutagenic effect (141).
-------
171
Table III.6.16 (from ref. 177)
Hatchability of eggs and bursa of Fabricius and spleen weights of
chicks from hens fed Aroclors for 8 weeks (Experiment 1).
Progeny organ weights
treatment
roclora)
None
1232
1016
1242
1248
1254
.
PCS level
(p. p.m.)
0
5
10
20
5
10 .
20
5
10
20
5
10
20
5
10
20
Hatchability of • eggs
(nercent)
90
90
77b
b
51
S3
87
92
87
b
46D
4b
86
48b
b
6°
98
88
88
n
15
5
5
10
5
5
5
5
10
8
5
10
5
5
5
-10
bursa weight
mg±SE
62.7 ± 4.0
54.1 ± 4.0
59.2 ± 1.5
b
43.7 ± 3.5
49.0 ± 4.8
46.5 ± 3.2
77.8 ± 2.8
59.0 ± 9.6
• h
40.3 ± 3.2D
36.3 ± 2.5b
39.1 ± 3.3b
42.5 ± 3.8b
b
36.3 ± 4.6°
52.8 ± 1.6
48.7 ± 4.9
41.2 ± 2.9b
spleen weight
mg±SE
17.0 ±1.1
17.0 ± 0.6
12.4 ± 0.8b
,
13.8 ± 0.8
15.1 ± 1.1
. 13.8 ± 1.3
20.0 ± 0.7
16.4 ± 1.0
v
13.6 ± 0.9°.
14.5 ± 1.2
16.7 ± 2.3
13.5 ± 1.0b
v,
13.6 ± 2.2°
15.3 ± 1.4
18.1 ± 1.4
14.5 ± 0.7b
Last two digits of Aroclor designate the % Cl, except Aroclor 1016 which
contains 41% Cl.
Significantly different (p<0.05) from the unsupplemented control Using
Student's "t" test.
-------
-------
. 171 fl
Combs et al. (397, 398) found that 10 ppm of Aroclor 1254 in
the diets of female chickens increased the susceptibility of their
offspring to vitamin E-selenium deficiency when the chicks were reared
on a diet deficient in vitamin E and supplemented with a marginal
level of selenium. Susceptibility to this deficiency, as measured by
the incidence of exudative diathesis, was also increased when PCBs
were added to chick diets. PCBs at 10 ppm in the diet caused a ten-
fold increase in benzopyrene hydroxylase activity and this led to a
decrease in the biological utilization of dietary selenium. The
mechanism of the effect appeared to be oxidation of selenium, leading
to reduction in its incorporation into glutathione peroxidase and its
conversion into selenium compounds of limited biological usefulness
(398).
Preceding Page Blank
-------
172
III.7. Toxic Effects in Mammals; Acute and Subacute Studies
III.7.1. Acute toxicity
PCBs do not have high acute toxicity. Table HI.7.1 summarizes
measurements of the single-dose oral LDso in rats and the single-dose
dermal MLD in rabbits, for a range of Aroclor mixtures, as reported by
the U.S. Food and Drug Administration (1). Weanling rats are more
sensitive: the single-dose oral LD50S for Aroclors 1254 and 1260 are
1,295 and 1,315 mg/kg (179). The single-dose i.v. LD50 for adult rats
was 358 mg/kg (179). Grant and Phillips (180) obtained similar values
for oral ID50 of Aroclor 1254 in 30-day-old rats (1,300-1,400 mg/kg)
and higher values for 120-day-old rats (2,000-2,500 mg/kg).
The single-dose oral LD^g ^or Kanechlor KC-400 in mice was
reported to be about 2,000 mg/kg (181).
III.7.2. Subacute toxicity
Table III.7.2 summarizes reports of the subacute toxicity of
PCBs available in 1972 (129, summarizing data from refs. 181-186).
Together these data show that PCBs are toxic to mammals by ingestion,
dermal absorption, and inhalation. Guinea pigs seem to be much more
susceptible than rats and mice. Among signs of toxicity, liver damage
is the most consistently observed (Table III.7.2). However, more
thorough-examination of rats killed by single doses of 4-10 g/kg of
Aroclors 1254 and 1260 revealed hemorrhage into the lung, stomach and
pancreas (187). Foci of ulceration surrounded by a severe inflammatory
reaction were observed primarily in the duodenum and occasionally in
the glandular part of the stomach.
-------
TOXICITY OF AROCLORS .
Aroclors
1221 1232 1242 1248
1260 1262
1268 4465
5442
5460 2565
Oral LD,n mg/Kg 3980a 4470a 8650a ll.OOO3 10,000b ll,300b 10,900b 16,000b 10,600b 19,200C 6,310C
"50
(rats)
Skin MLD mg/Kg >2000a >1260a >794a >794a >1260b >1260b
>2000b >1260b >7940C >2000C
(rabbits)
<3169a <2000a <1269a >1269a <2000b <3160b >2500C <3160b <2000b
<3160
-Undiluted.
i
Administered as 50% solution in corn oil.
Administered as 33.3% solution in corn oil.
FDA Status Report on the Chemistry and Toxicology of Polychlorinated Biphenyls (PCB) or Aroclors as of June 1, 1970.
i •
Table III.7.1 (ref. 2)
GM
-------
Table III.7.2 (ref. 129)
Acute and Subacute Oral Toxicity Studies of PCB Preparations.
Preparation
Unknown
Aroclor 54% Cl
Aroclor 42, 54, 60, and
68% Cl
42% d
42% Cl
65% Cl
t>5','( Cl
Prepa- Animal
ration
42% Cl Guinea pig
42% Cl Rabbit
Aroclor Rabbit
Aroclor Rat
65% Cl
Animal Treatment Mortality Liver effects References
Mouse single dose of LD50
approx. 2000 mg/kg
Rat single dose of 0% Increase of weight and
500 mg/kc lipid; potentiation of
CCU toxicity
Mallard single dose of 0%
2000 mg/kg
Rat 20 daily doses of 0% in 3 Hyalin bodies in liver cells
138 mg months
Guinea pig 2 doses of 69 mg 100% between Fatry metamorphosis;
1 week apart 11 and 29 i-cntral atrophy
days
Rat 6 daily doses of 70% in 14 Increase of weight; eel!
300 mg days swelling: hyalin
granules
Rat Doses of 50 mq; .60% in 5 weeks y\c.'(. weight increase;
every second cell swelling;
day liyulin globules
Dermal Toxicity and Inhalation Studies of PCB Preparations.
Treatment Mortality Liver effects Skin effects
11 daily skin 100% between 11 Fat; central atro- Occasional thieken-
applications of and 21 days phy; perinuclear ing of the
34.5 mg basophilic granu- epidermis
lation; focal
necrosis in a few
animals
Skin application 100% between 17 Fatty degeneration; Thinning of prickle
at alternate and 98 days . central atrophy cell layer and
days, total dose thickening of
from 946 to outer cornified
19SO rag layers
Daily skin appli- High dose died be- Moderate doses: Reddening; fonna-
cations of 0.3, fore liver necrosis mottled liver, sub- tion of small
0.6, and 0.9 (; developed acute yellow papules and
atrophy, fatty blisters; finally
degeneration, and desquamaticn of
marked necrosis external epidermal
layers
Inhalation of 0% Pale and yellow;
0.57 mg/cubic cell swelling;
meter for 16 hyalin degenera-
hours for 37 to tion; potentiauon
134 days of CCU and
CtH4OH toxicity
181
182
183
184
184
185
185
Refer-
ences
184
184
186
185
Reproduced from
best available copy
-------
In recent studies of subacute toxicity, Allen and Norback (69)
reported that rats fed 1000 ppm of Aroclors 1248, 1254, and 1262
died after 6-8 weeks due to widespread hepatic degeneration (188).
After six weeks liver weights had increased from 2.8% of body weight
in the controls to 9-107= of body weight in the treated animals.
There was also marked atrophy of the thymus (188) . Rats fed 1000
ppm of Aroclors 1254 and 1260 mostly died after 2-6 months with ex-
tensive liver damage (187); liver damage and a few deaths were ob-
served also at 500 and 300 ppm (187, 189). In these cases the
animals also suffered from severe pulmonary congestion and, in a few
cases, from massive hemorrhages into the soft tissue or peritoneal
cavity (187). Rats fed at 1000 ppm and 500 ppm of Kanechlors KC-500,
400 and 300 apparently had excess mortality within 25 weeks in conjunction
with liver damage (190) .
Mice fed 300 ppm of Aroclor 1254 for 6-11 months survived almost
as well as controls but exhibited liver damage (191) . Mice similarly
survived well on a diet of 250 ppm KC-500, even in conjunction with
BHC, but suffered liver damage (192). In comparative tests with three
isomeric hexachlorobiphenyls (hexa-CBs) in male mice, the 28-day dietary
1050 was estimated to be over 300 ppm for 2,4,6,2',4',6'-hexa CB, 100-300
ppm for 2,4,5,2',4',5'-hexa CB, and only 86 ppm for 3,4,5,3',4',5'-hexa
CB (193). In a subsequent test with 10 ppm of the last isomer, mice
died in an average time of 39 days (193). The corresponding daily in-
take was about 2.1 mg/kg/day. In these experiments, atrophy of the thy-
mus and spleen and porphyrla were noted in addition to the liver effects
-------
(193, 70 : Tables III.7.3 and III.7.4); these effects were especially
marked with the exceptionally toxic isomer 3,4,5,3',4",5"-hexa CB.
Rhesus monkeys are considerably more sensitive to PCBs than
rodents (69). Monkeys fed diets containing 100 and 300 ppm Aroclor 1248
developed facial edema, erythema, acne, and alopecia within 3 weeks.
The lesions became progressively more severe with increased length of
exposure. In addition, the animals developed anorexia, loss in weight,
hypoproteinemia, hypolipidemia, and anemia. Within 3 months the
majority of the monkeys were moribund. Necropsies of these animals
revealed decided mucosal gastric'hyperplasia with penetration of the
glandular epithelium into the underlying submucosa (194). Numerous
ulcerations of the hyperplastic gastric mucosa were also present (195).
In addition, there was a decided hypertrophy of the liver.
Female rhesus monkeys fed 25 ppm Aroclor 1248 in the diet de-
veloped facial lesions similar to those observed in the animals receiv-
ing higher levels of PCBs (196). After two months on the PCB diet it
was necessary to discontinue the exposure due to the severity of intoxi-
cation. One of the six experimental animals died 4 months after initial
exposure to PCBs. Necropsy evaluation demonstrated severe gastric hyper-
plasia and ulceration, in addition to anemia, hypoproteinemia, bone
marrow hypoplasia, and focal necrosis of the liver. The surviving
adult female monkeys continued to be devoid of eyelashes and displayed
facial acneform lesions 2 years following exposure to PCBs (69).
Rhesus monkeys appear to be even more sensitive to Aroclor 1242
than to Aroclor 1248. Although in the studies of Allen et al.
-------
Table III.7.3 (from.ref. 70)
Summary of the biological effects of
hexachlorobiphenyl isomers in mice
Dose Body weight Porphyrin
level gain Liver Accumula- Thymus
Chemical (ppm) Mortality (% of control) effect tion effect
177
10 0/5
3,4,5,3',4I,5I-HCB 100 3/5
300 5/5
2,4,5,2',4I,5I-HCB 100 0/5
300 1/5
12
91
58
+-H- •+++
2,4,6,2I,4'S6I-HCB 100 0/5
300 5/5
85
-------
Table III.7.4 ffr:om ref. 70)
Summary of major pathological changes in mice given different
hexachlorobiphenyl isomers for 28 days
Chemical
S^.S.S'^'.S'-HCB
2,4,5,2',4',5'-IICB
2,4,6,2',4',6MICB
Dose level
(ppm) Liver
30 Marked; fatty
metamorphosis,
single-cell
necrosis.
300 Slight;
swelling of
hepatocytes.
300 Marked; fatty
metamorphosis,
single-cell
necrosis.
Thymus
Marked;
involution.
Slight;
involution.
Marked;
involution.
-
Spleen
Moderate;
depletion of
lymphocytes.
NSa
Moderate;
depletion of
lymphocytes.
Heart
NSa
NSa
Moderate;
cardiomyopathy.
NS = not significant.
-------
rhesus monkeys survived and even produced a few young on diets of
5 and 2.5 ppm Aroclor 1248 (69), in studies by McNulty (197) all
animals exposed to dietary levels of 100, 30, 10 and even 3 ppm of
Aroclor 1242 died. The monkeys fed 3 ppm died after 8 months. The
symptoms of poisoning were similar to those induced by Aroclor 1248,
including cystic eyelids, loss of sebaceous glands, atrophy of the
thymus, proliferation of the smooth endoplasmic reticulum of the
liver, hyperplasia and ulceration of the gastric mucosa, with pene-
tration of the epithelium into the submucosa (197, 198).
In tests with individual isomers, 2,4,4'-trichlorophenyl and
2,4,5,2',5'-pentachlorobiphenyl proved relatively non-toxic, causing
no histopathological changes in 90 days at 10 ppm; for comparison,
Aroclor 1242 at 10 ppm causes clinically detectable changes within
30 days and outspoken disease at 60 days. However, 3,4,3',4'-
tetrachlorobiphenyl was very toxic and killed the test animal in less
than 60 days (197). These preliminary experiments indicate a high
degree of structural specificity for the toxic effects of chlorobi-
phenyls in monkeys.
Mink also appear to be extremely sensitive to PCBs (199, 200).
Mink fed on a diet containing 30 ppm PCBs (10 ppm each of Aroclors
1242, 1248 and 1254) all died between the beginning of the breeding
season and the end of the whelping period. Clinical signs and lesions
included anorexia, bloody feces, fatty infiltration and degeneration
of the liver and kidneys, and haemorrhagic gastric ulcers (199). In
subsequent tests with Aroclor 1254, reductions in weight gain and
-------
increased mortality were noted at dietary levels of 10 and 5 ppm;
the effect of Aroclor 1254 was enhanced by simultaneous feeding of
either DDT (10 ppm) or dieldrin (0.5 ppm) (Table III.7.5). All the
mink fed 10 ppm of Aroclor 1254 and 0.5 ppm dieldrin died within
9 months (200). In a separate experiment, mink were fed on a diet
containing beef from cows which had been fed with Aroclor 1254:
the concentrations of PCBs in the total diet of two groups of mink
were 3.57.and 0.64 ppm. All of the mink fed at the 3.57 ppm level
died within 105 days, and 2 of 12 females fed at the 0.64 ppm
level died at 122-129 days (201). Clinical signs of poisoning
included yellowish discoloration of livers and blood in the gastro-
intestinal tract or intra-abdominal hemorrhage (see also Table III.
6.6). The PCBs fed in this experiment appeared to be markedly more
toxic to mink than those in the first experiment, in which the
animals even on the 10 ppm dose were still growing after 4 months
(Table III.6.5). This suggests the possibility that the toxicity of
the PCBs had been enhanced during metabolism and storage in the cows.
Another species which appears to be extremely sensitive to
PCBs is the big brown bat Eptesicus fucus. When fed only 10 ppm
Aroclor 1254 big brown bats grew more slowly than controls and some
individuals died (72).
No studies appear to have been reported of the acute or sub-
acute toxicity of Aroclor 1016 in any species of mammal.
-------
1*1
Table III.7.5
Effect of Aroclor 1254, Mono or In Combination with Pesticides,
* on Body Weight Cains of Fomale Mink
Body weight gain (gm) + S.E. from initial wt.
Initial
body wt.
No. (gro) 1 mo. 2 wo. 3 mo. 4 no.
Dietary treatment Hink (Aup,. 25) (Sept. 24) (Oct. 25) (Nov. 25) (Dec. 22)
Basal diet (307. ocean
fish mix; control) 6 1020 43 + 17.4 203 + 25.4 187 + 46.2 210 + 35.1
Basal diet plus 5 ppm
PCB<1) 6 940 62+22.4 153+44.2 138+42.7 128+43.7
Basal diet plus 10 ppm
PCB 6 923 43+20.4 148+32.0 132+26.3 92+35.1*
Basal diet plus 10 ppm
PCB and 10 ppm DDF 6 1052 43 + 14.5 57 + 14.6** 28 + 21.5** -15 + 35.4*»
Basal dirt plus 10 ppm
PCB and 0.5 ppm
dicldrin 6 940 108 + 25.1 133 + 26.7 115 + 18.9 57 + 24.4**
(1) Aroclor 1254.
-Slgnif ic'ant ly iliCforcnt (P < 0.05) from controls.
'•-Significant ly diffcrc-nt (P < 0.01) from controls.
Effi-ct of Aroclor 1254, Fed Aloni- or in Combination with Pesticides,
on Mortality and Rcproiluction of Hink (Aug. 25 to May 10)
(6 females and 1 male/group)
Females Females Kits born Kits/female
7. mortality alive uholpcd Alive Dead alive
Control 14 5 3 17 8 5.0
5 ppm PCB(l) 29 40000
10 ppm PCS 71 10-000
10 ppm PCB + 10 ppn DDT 43 40000
10 ppm PCB + 0.5 ppm
dirldrin 100 00000
(I) Aroelor 1254.
-------
.1*2.
III.8. Toxicity of PCDFs in Mammals and the Role of PCDFs in the
Toxlcity of Commercial PCBs
Preliminary studies of the toxicity of 2,3,7,8-tetrachlorodi-
benzofuran (TCDF) in mammals have been reported by Moore et al. (71)
and Goldstein _et al. (146). In guinea pigs, the single-dose oral
LD5Q is between 5 and 10 ^ig/kg (Table III.8.1). The bottom of the
table shows, for comparative purposes, that the H)^ of 2,3,7,8-
tetrachlorodibenzodioxin (TCDD) (2 ug/kg) compares quite closely
with the TCDF value. TCDF toxicity in guinea pigs is one of a
progressive weight loss followed by depression at least 24 to 36
hours preceding death. As was observed in the chicken toxicity
studies, there was severe diminution in size of thymus and spleen.
Similarly, this finding was found to correlate with a lymphocyte
depletion in the periarterialor lymphocytic sheaths and follicles
of the spleen; or severe atrophy of the thymus cortex. Although
the numbers of animals evaluated were small, the trend of changes
present in the bladder, adrenal, kidney, and liver were similar to
that previously associated with TCDD toxicity . (202). In contrast,
TCDF appears to be much less toxic to rats and mice than to guinea
pigs (71). A single experiment in which TCDF was administered to
rats at doses up to 1,000 ^jg/kg failed to show any toxic effects.
These rats were terminated 4 weeks after dosing. Histopathologic
evaluation of tissues from the rats failed to reveal any changes
that could be associated with tetrachlorodibenzofuran toxicity.
Table III.8.2 summarizes the TCDF toxicity findings in
male mice. Per os dose levels up to and including 6,000 jig/kg in
-------
IS3
Table III.8.2 (from ref. 71)
2,3,7,8-tetrachlorodi benzofuran toxlc1 ty
In male CS7 BL/6 mice8
Dose:
Mortality:
Body weight:
Liver/body weight:
Ratio:
Thymus/body weight:
Ratio:
0 ug/kg
None
Normal gain
1.513 + 0.05
5.76 + 0.05
0.045 + 0.002
0.19 + 0.01
6,000 ug/kg
None
SI. depression 2nd-5th day
1.728 + 0.04
6.86 + 0.06
0.017 + 0.001
0.06 + 0.007
Administered subcutaneously to 6-week-old mice. Animals sacrificed 30
days post-administration. "No effects" per, os, at 6,000, 4,000, 2,500,
1,500, 1,200, 1,000, 800, 600, and 400 u9/kg. L0,n 2,3,7,8-TCCO -
200-250 ug/kg. 3U
Table.III.8.1 (from ref. 71)
2,3,7,8-tetrachlorod1 benzof uran toxldty
1n Hartley guinea pigs
Per os
dose (ug/kg)
80
40
20
15
10
5
0
Mortality
5/5
5/5
5/5
6/6
9/11
" 3/n
0/11
Mean time
10.8
11.6
12:2
12.0
15.5
18.0
-0-
to death
days
L0go 2,3,7,8-TCDO • 2.0 ug/kg; MTO « 20.6 days.
-------
a single dose failed to produce any observable effects during the
ensuing 28 to 30 days. Histopathologic examinations of these
animals failed to reveal any effects on thymus, spleen, or other
organs, save for the liver. Here, a mild effect with the sugges-
tions of a mild toxicity was observed in mice that received 6,000
ug/kg per os. A definite toxic response was observed in mice that
received a 6,000 ^g/kg dose administered subcutaneously. Although
mortality was not observed, there was a depression in body weight
gain during the second to fifth day following dosing. Organ
weights recorded at time of necropsy 30 days after the dose had
been administered showed an increase in the liver weight as well
as liver to body weight ratio.
A more striking finding was the reduction in thymus weight
with a concurrent reduction in thymus to body weight ratio. Histo-
pathologic evaluations of tissues from these animals confirmed that
the reduction in thymus weight was due to loss of lymphocytic ele-
ments. Evaluation of the liver evidenced a clear, but moderate,
toxic response characterized by focal areas of single- cell necrosis
and pleomorphism. The movsse studies show that there is at least a
30-fold diminution in TCDF toxicity when compared to TCDD. It
further indicates, however, that the pattern of the toxicity will
mimic that which is observed with TCDD (203).
Although 2,3,7,8-TCDF is the only CDF isomer whose toxicity
has been investigated to date, it is expected to be the most toxic
CDF, by analogy with the structurally similar 2,3,7,8-TCDD (148). It
-------
)O.—
/ i'JJ
is important to note that 2,3,7,8-TCDF is one of the CDFs that has
been identified in Aroclors 1248 and 1254 (36).
The toxic effects of TCDF in mice are similar to those of
3,4,5,3',4',5'-hexa-CB (Tables III.7.3, III.7.4), but there are
some important differences. The hexa-CB had a proportionately
greater effect on the thymus and liver, and induced p-nitrophenyl
glucuronyl transferase and ALA-synthetase, causing porphyria (146);
as in the case of chicks (Figure III.6.4, Table III.6.7), TCDF did
not have these effects in mice, even at comparable dose-levels
(71, 146).
In a comparative study, Vos and Beems (204) found differen-
ces in toxicity between Aroclor 1260, Clophen A60 and Phenoclor DP-6
when applied to the skin of rabbits (118 mg PCS per rabbit 27 times
in 38 days). Clophen A60 and Phenoclor DP-6 caused mortality (3/4
and 1/4 respectively) and severe skin lesions, whereas Aroclor 1260
caused no mortality and only slight skin lesions. All three mix-
tures caused liver damage, abdominal and pericardial edema, kidney
lesions, and porphyria, but the liver damage was less severe in the
Aroclor 1260-treated animals (Table III.8.3). Since PCDFs were
known to cause skin lesions of this type, Vos attributed the differ-
ence in toxicity primarily to the PCDFs in the Clophen and Phenoclor
mixtures (204, 129). However, in a subsequent experiment (205) both
Aroclor 1260 and 2,4,5,2',4',5'-hexa-CB* caused liver injury, porphyria
* Some synthesized samples of 2,4,5,2',4',5'-hexa-CB are now known to
be contaminated with 2,3,7,8-TCDF (206), but this does not appear to
have been the case for the sample used in ref. 205.
-------
Table III.8.3 (from ref. 204)
PATHOLOGIC FINDINGS IN LIVERS OF RAIIUITS TREATED WITH PCB FOR 38 DAYS, AND OF CONTROL ANIMALS"
Phcnoclor
Fatty degeneration
Ccntrolobular loss of glycogcn
Centrolobular degeneration
Focal hydropic degeneration
Focal necrosis
C'cnlrolobular liver cell atrophy
linlargemcnt of nuclei
Cytoplasmic hyalin degeneration
Ccroid pigment in Kupffer eel s
Peri portal flbrosis
2
--
1
—
—
2
2
1
—
2
2
1
2
1
1
1
1
—
1
—
h
1
2
—
—
—
1
—
1
—
2
1
1
1
—
—
2
1
2
2
1
Clophen
b
\
2
1
—
2
2
2
2
1
1
1
1
7
2
2
1
2
1
1
1
A
1
1
1
2
2
2
2
2
1
2
/,
—
2
2
—
2
1
2
2
1
2
Arodor
- — 1 2
._. _ i _
— 1 1 1
1 2
— — 1 2
_ _ ._ |
1—12
_____ i
— ' 2 1 2
1—11
Control
— — — —
— — — —
— — — _
_ — — —
— — — —
— — — __
1
__ — — —
— — — —
— — — —
• Severity of lesion: I -- slight, 2 - marked.
* Animals that died during the experiment.
-------
1*7
and slight skin lesions. Vos (129) concluded that both PCDFs and
PCBs cause liver damage and skin effects, but that
PCBs are the primary cause of porphyria (Table III.8.4). This
conclusion has been confirmed by subsequent experimentation (70,
71, 146, 147, 193), but several experiments have suggested further
that PCBs play some role in the induction of edema and hydroperi-
cardium also (Section III.6.2 above, 204).
McNulty (197) has discussed the possibility that PCDFs
might be responsible for the extreme toxicity of PCBs in rhesus
monkeys. In a preliminary test, 2,3,7,8-TCDD was lethal to a
rhesus monkey after feeding for two months at 2 ppb in the diet --
i.e., it was about 5,000 times as toxic as Aroclor 1242 under
the same chronic feeding conditions. TCDD is usually 4 to 10
times as toxic as TCDF (71, 129): hence it is unlikely that TCDF
will prove,to be more than 1,000 times as toxic as Aroclor 1242.
Accordingly it is very unlikely that the presence of PCDFs at 1
or 2 ppm in Aroclor 1242 could account for its toxicity to monkeys
(197). McNulty suggested the possibility that PCDFs might be pro-
duced by metabolism in monkeys (197) . The relative roles of PCBs
and PCDFs in causing skin lesions in humans will be discussed fur-
ther below.
In summary, 2,3,7,8-TCDF is extraordinarily toxic to guinea
pigs and to chickens, but not to mice or rats. There are both paral-
lels and differences between the toxic effects of PCBs and PCDFs.
Some, but not all, of the toxic effects of PCB mixtures can be attri-
buted to contamination with PCDFs. Since PCDFs are present in
-------
Table III.8.4 (from ref. 129)
Probable Contribution of Polychlorinated
Dibenzofuran (PCF) and Pure PoIycbJorinatcd
Biphenyl (PCB) in the Toxicity of Crude
PCB Mixtures.
Chlor- Edema Liver Hepatic
acne forma- damage porphyria
tion
Polychlorinated
Dibenzofuran
Polychlorinated
Biphenyl
-------
commercial mixtures (Section II.5.5) and appear to be formed from
them in the environment (Section II.8.3), in service (Section II.8.4),
and by metabolism (Appendix E), it is difficult and probably aca-
demic to attempt to distinguish their effects completely in weigh-
ing the environmental hazards posed by PCBs.
III.9 Chronic Effects of PCBs in Mammals and Effects on Reproduction
This section summarizes the results of long-term chronic
toxicity tests with PCBs in mammals and the gross effects observed,
including effects on reproduction. Discussion of biochemical
effects is reserved to Sections III.10 and III.11 and discussion of
carcinogenic effects to Section III.14.
III.9.1 Effects on rats
In a study reported by Linder et al. (179), Sherman rats were
exposed for two generations to dietary levels of 1, 5, 20 and 100
ppm Aroclor 1254, and 5, 20 and 100 ppm Aroclor 1260. Exposure of
the FQ generation started at 3-4 weeks of age and continued through
mating, gestation and lactation. Each generation was mated twice.
Rats exposed to dietary levels of 20 ppm (1.5 mg/kg/day) or more had
fewer pups per litter than controls in the Fiv and T?n generations.
The 100 ppm exposure level of Aroclor 1254 increased mortality in
the FI^ offspring and markedly decreased mating performance of the
Flb adults (Table III.9.1). The 500 ppm dietary level of Aroclor
1260 reduced litter size and decreased survival in the F^ litters.
Dietary levels of 5 ppm Aroclor 1254 and 100 ppm Aroclor 1260 had no
-------
Table III.9.1 (from ref. 179)
Ri-proiliiclinii and ;>»/> survival in i/roiips of rats fed Arnclor 1254
Dietary
level
Generation (ppm)
F,. 0|
100H
500J
0
20
too
0
1
5
Fib 0||
1006
0
20
100
0
1
5
F2. 0
20
100
0
1
5
Fjb 0
20
too-
Parental
exposure
(days)t
67
67
'67
62
62
62
67
67
67
186
186
188
188
188
201
201
201
129
129
129
125
125
125
274
274
274
No. of
females
milled
10
10
10
20 ,
20
20
20
20
20
10
10
20
20
20
20
20
20
20
20
20
20
20
19
20
20
20
No. of litters
BornJ
8
9
4 (2)
17
19
19
18
16
17
7
8
17
18
20
18
18
20
18
17
7(2)
19
15
17
17
12
4 (2)
Weaned
7
8
0
17
19
19
18
15
17
7
6
17
18
19
18
17
19
18
17
4
19
15
17
16
12
2
Litter sizes!)
At
birth
11-1
9-4
4-0*
12-4
11-7
10-7*
11-2
9-2
108
11-6
11-8
12-3
104*
95**
12-3
11-1
11-1
12-5
106*
7-2**
11-7
11-7
12-1
12-7
96*'
3-5"
At
weaning
10-6
8-1
—
11-8
11-5
103
11-1
9-1
108
11-6
8-0
11-1
10-1
7-0
II-O
98
10-2
12-2
10-1
56
11-5
11-5
11-7
11-3
8-5
3-5
Total pups/group
Born (found)
Dead
3 -
6
5
0
3
10
2
3
1
1
0
2
1
6
6
3
2
0
5
7
3
0
1
4
6
7
Alive
89
85
8
211
222
204
202
147
184
81
94
209
188
189
222
200
222
225
181
36
223
175
205
216
115
7
Alive at
Day 3
86
78
0
205
220
199
200
145
184
81
74
194
187
164
211
194
218
221
174
29
220
174
199
201
103
7
Weaning
85
73
0
201
219
196
200
145
183
81
64
189
181
139
198
176
203
220
171
28
218
173
198
191
102
7
Survival
95-5
85-9
0
95-3
98-6
96-1
99-0
98-6
99-5
100
6S-1**
90-4
96-3
73-6
89-2
88-0
91-4
978
94-5
77-8**
97-8
98-9
96-6
88-4
88-7
1000
Mean
body weight
at weaning
(E)
392
31-4
—
38-7
38-3
32-9
38-5
42-3
42-1
37-9
27-9
37-1
390
32-1
407
380
389
35-5
36-8
35-2
37-4
37-2
35-7
31-9
36-1
38-3
t Conception to mating for the parents of the Fj. and F2b generations.
J Numbers in parentheses indicate numbers of litters in which no live offspring were found.
§ Number of live offspring/live litter born.
I Onc-pcncralion study.
Values marked with asterisks differ sipnificanlly frtmi the control value: * /' < 005; •• /' < 0005.
-------
effects on reproduction. Liver weights were markedly increased in
21-day-old male weanlings at the 1 ppm level of Aroclor 1254 and in
both sexes in both generations at 5 ppm or higher levels of Aroclor
1260 (Table III.9.2).
In this study rats were killed when their offspring were weaned
(after 180-330 days' exposure) (179). In this and in earlier studies
in which rats were exposed to Aroclor 1254 and 1260 for periods of
6 to 8 months (187, 189), the principal pathological lesions observed
were in the liver. These included hypotrophy, brown pigment in
Kupffer cells, adenofibrosis and hyperplastic nodules (179, 187, 189).
Adenofibrosis and nodules were observed principally at the higher
levels of exposure and were most frequent in the second generation
animals exposed to Aroclor 1254 (Table III.9.3). Liver nodules were
even seen in F-^ rats exposed to 20 ppm Aroclor 1254 (ibid.). For
further discussion see below under Carcinogenesis and Appendix D.
In another three-generation reproduction study in rats involv-
ing exposure to Aroclors 1242, 1254, and 1260, reproduction was un-
affected in the first generation, but was adversely affected at
dietary levels of 10 and 100 ppm of all three Aroclors in the second
and third generations (68). No adverse effects were reported at 1 ppm.
The cause of the adverse effects was a decrease in mating indices and
in the incidence of pregnancy (68). Other aspects of reproduction
are said to have been unaffected, but no details have been given, and
in earlier reports on this study decreased survival of offspring was
reported at 100 ppm of Aroclors 1242 and 1254 (1, p. 142). In a con-
comitant 2-year study of rats exposed to the same three Aroclor
-------
Table III.9.2 (from ref. 179)
liter weights of2L-ttay-cld ruts from parents fid Aroclor J2S4 or 1260
Liver weight
Aroclor
• Dietary
level
Generation (ppm)
Males
% of body
weight
Females
% of body
weight
J254 F,. 0
1
5
FIb 0
1
5
F,. 0
20
100
F,, 0
1
5
1260 Fu 0
5
F,> 0
20
100
FU 0
5
F,, 0
20
100
F,, 0
' 5
1-40
1-81*
1-92*
1-58
1-54
1-77
1-37
2-26*
2-63*
1-63
1-49
1-56
1-54
1-73
1-59
2-06*
2-59*
1-35
1-58
1-65
2-06*
2-50*
1-41
1-66*
3-69
4-01* -
4-34*
3-69
3-94*
4-63*
3-81
5-78'
6-97»
3-78
3-74
4-23*
3-66
4-18*
3-73
5-04'
6-33»
3-59
4-01*
3-82
5-21*
6-)2«
3-85
4-21*
•38 3-83
•63 3-91
•86* 4-43*
•58 3-84
•49 3-92
•72 4-75"
•28 - 3-74
2-23» 6-03*
2-67* 7-10*
1-42 3-63
1-36 3-69
•38 4-09»
1-57 3-92
I '70 4-39*
i-55 3-93
2-14* 5-18*
Z'59" 6-48*
1-29 3-70
1-52* 4-07«
1-64 4-02
•94 5-06*
2-49» 6-S5*
1-36 3-87
1-60* 4-25*
Values marked with an asterisk differ significantly from the control value: *P < 0-05
-------
Table III.9.3 (from ref. 179)
. Body wcU/lil, liivr weight and liver pathotoyy of Fu and /•}/, adult ratxfeJ Aroclor 1254 or I2MI
Exposure
Generation Sex (days)
Fo
F".
F,,,
Fo
F,,,
HI»
M
F
M
F
M
F
M
F
M
F
M
F
310
313
328
328
190
190
250
250
179
179
217
217
Dietary
level
(ppm)
0
1
5
0
I
5
0
20
100
0
20
100
0
1
5
0
1
5
0
5
0
5
0
20
100
0
20
100
0
. 5
0
5
Terminal
body
weight
(B)
601
602
614
370
358
362
588
602
554
349
340
300»
475
453
495
287
294
299
563
567
322
331
472
494
509
297
304
304
492
505
279
2X6
Liver weight
B
15-22
15-88
15-37
10-34
10-14
10-66
14-51
16-11*
19-43*
9-92
9-41
10-53
11-13
11-14
12-19
8-27
8-44
8-92
14-45
15-06
1009
10-80
12-68
14-72*
16-63*
9-66
10-30
11-14*
1197
1316
7-93
H-49
% of No. of
body livers
weight examine
2-53
2-60
2-51
2-SO
2-84
2-94
2-47
2-67*
3-54*
2-85
2-78
3-60*
2-34
2-44
2-46
2-87
2-86
2-98
2-57
265
3-13
3-25
2-68
2-99*
3-27*
3-27
340
3-70*
2-43
2-60*
2-84
296
10
10
10
10
10
10
10
8
10
10
7
iot
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
Liver pathology (no. oflivcrs affected)
Enlarged
d hcpatocytcs Inclusions
Aroclor 1254
0
0
0
0
I
4
0
8
10
0
7
10
0
0
2
0
1
1
Aroclor 1260
1
3
0
1
0
8
10
0
6
<)
0
7
0
2
0
0
0
0
0
I
0
3
5
0
2
2
0
0
0
0
1
0
0
0
0
0
0
5 '
10
0
0
0
0
2
0
()
Foamy
cytoplasm
0
0
1
0
0
0
0
7
7
0
5
8
0
0
2
0
0
0
0
2
0
0
0
4
3
0
0
1
0
2
0
0
Pigment
0
0
2
1
4
3
0
1
4
0
7
9
0
0
0
0
0
0
0
0
0
&
0
0
0
0
n
5
0
1
<)
tl •
Fibrous
strands
0
0
0
0
0
0
0
0
2
0
0
3
0
1
1
0
4
1
0
0
0
0
0
0
0
0
0
2
0
0
0
0
Adcnofibro.sis
0
0
0
0
' 0
0
0
0
3
0
0
5
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
1)
Nodules
0
0
0
0
0
0
0
0
1
0
3
7
0
0
0
0
0
0
0
0
0
0
0
0
1
0
I)
2
0
0
O
1)
f Necrosis in two livers.
Values marked with an asterisk differ significantly from the control value: * P
0.05.
-£>
t/J
-------
mixtures, the most noteworthy effects were increases in liver weight
and pathological changes in the liver (68, 207: for further discus-
sion see below under Carcinogenesis and Appendix D).
Sherman rats exposed to 100 ppm of Aroclors 1016 and 1242 for
4-10 months also showed a variety of microscopic changes in their
livers (208). These changes were somewhat less severe than those
observed in animals fed 100 ppm of Aroclors 1254 and 1260 (Tables III.
9.4, III.9.5), in that the animals fed Aroclors 1016 and 1242 did not
show the lipid accumulation pronounced in the other groups. The
changes were slightly, but not markedly, less severe in the rats fed
Aroclor 1016 than in those fed Aroclor 1242 (Table III.9.4).
In a short-term (90-day) oral toxicity study with Aroclor 1016,
liver weights were significantly increased at dietary exposure levels
of 300 ppm, but not at 100 or 30 ppm (209). The study was too short,
however, to provide a useful comparison with that in ref. 207, in
which no changes in liver weight were reported in rats exposed to 100
ppm Aroclor 1242 for 3 months. However, in another study, the liver
weights of rats were markedly increased by oral dosage of only 1
mg/kg (equivalent to about 15 ppm in the diet) for only 21 days
(Table III.10.5): the effects of Aroclors 1016 and 1242 were similar
(243). In another study, rats exposed to 100 ppm Aroclor 1242 for 2
months showed a significant increase in liver weight and a marked
decline in liver vitamin A (166). Aroclor 1242 also had estrogenic
effects in female rats (166), and dietary exposure to 30 or 100 ppm
Aroclor 1016 markedly reduced gonad weights in female rats (209).
-------
Table III.9.4 (ref. 208)
—Incidence of Microscopic Changes Observed In Livers of Rats Fed Aroclor 1242 or 1016
Length of
Exposure
4
6
8
10
6 mo exp
2 mo rec
6 mo exp
4 mo rec
6 mo exp*
6 mo rec
Enlarged
Hepatocytes
Aro 1242
2/4
4/4
4/4
4/4
2/4
3/3
3/4
Aro 1016
4/4
4/4
3/4
4/4
1/4
3/3
...
Vacuolated
Cytoplasm
Aro 1242
. . .
3/4
3/4
4/4
3/4
1/3
Aro 1016
1/4
1/4
1/4
1/4
1/3
...
Foci of Necrosis
Inclusions Brown Pigment Foamy Cytoplasm Hemorrhage
Aro 1242 Aro 1016 Aro 1242 Aro 1016 Aro 1242 Aro 1016 Aro 1242 Aro 1016
1/4
3/4 3/4
3/4 ... 2/4 ... ... ... 1/4
1/4 ... 2/4 ... 2/4
1/4
1/3 1/3
2/4
* Only rats fed Aroclor 1242 were examined microscopically.
-------
Table III.9.5 (ref. 187)
—Light Microscopic Findings in the Liver of Rats Fed Arocior 1260*
Dietary
Level
(ppm)
0
20
100
500
1.000
0
20
100
soot
i.ooot
Sex
M
M
M
M
M
F
F
F
F
F
Enlarged
Hepato-
cyte*
10
10
10
10
3
7
9
6
Inclusions
In
Cytoplasm
...
9
9
4
6
...
2
5
Adeno-
flbrosli
...
...
...
2
...
...
1
1
4
Increased
Llpld
...
10
10
10
...
10
9
7
Foamy
Cytoplasm
...
3
7
9
...
...
...
8
4
Pigment
...
...
..*
1
2
...
...
1
6
2
• In their diet (or eight months; ten rats/group, t Only nine animals were studied. { Only seven animals were itudleo
. —Light Microscopic Findings In the Liver
Dietary
Level
(pom)
0
20
100
500
0
20
100
soot
Sen
M
M
M
M
F
F
F
F
Enlarged
Hepito-
cyte*
...
7
10
10
10
9
Inclusions
in
Cytoplasm
...
1
7
2
7
2
Adeno-
flbrosls
...
1
10
7
9
of Rats Fed
Increased
Llpld-
...
...
10
10
...
...
10
9
Arocior 1254*
Foamy
Cytoplasm
...
1
10
4
...
...
9
2
PI|IH*«t
*.«
***
3
2
...
1
10
7
* In their diet for sight months! ten rats/group.
t Only nine tested since one rat that died showed too much autolysis.
-------
III.9.2 Effects on mice
In chronic feeding studies with mice, the most noteworthy
effects were on the liver (see below under Carcinogenesis and
Appendix D). Daily dosage of mice with 1 ml KC-400 caused effects
on the skin (loss of hair, erosion and ulceration after 3 months)
in addition to enlargement of the liver and other pathologic
changes (210).
No chronic studies of effects on reproduction have been re-
ported, but a single dose of 20 mg/kg Clophen A60 lengthened
oestrous cycles in mice (211).
III.9.3 Effects on dogs
A two-year chronic feeding study was conducted in beagle
dogs exposed to 1, 10, and 100 ppm of Aroclors 1242, 1254 and 1260
in the diet (68, 212). Four dogs of each sex were included in each
of the 9 feeding groups and in a tenth control group; the dogs were
4-7 months old at the start of exposure. Six dogs died during the
experiment: of these three females died from chronic peritonitis
(one on 100 ppm Aroclor 1242,"one on 10 ppm Aroclor 1254, and one
on 100 ppm Aroclor 1260). Table III.9.6 summarizes the principal
findings at the end of the two-year exposure period: there were
dose-related increases in liver weights, serum alkaline phosphatase
levels, and leukocyte counts. The most noteworthy findings on gross
pathologic observation were "numerous pinpoint nodules" in the stom-
achs of dogs in all treatment groups (except the 1 ppm Aroclor 1242
group). These nodules were observed in 22 of the 66 treated dogs,
-------
Table III.9.6. Effects in dogs after two-year oral
exposure to PCBs (from data in ref. 212)
Serum
Leukocyte
counts
(thousands /mm^)
Controls (8)
Aroclor 1242:
1 ppra (8)
10 ppm (7)
100 ppm (7)
Aroclor 1254:
1 ppm (8)
10 ppm (7)
100 ppm (7)
Aroclor 1260:
1 ppm (8)
10 ppm (8)
100 ppm (6)
11.45
12.44
13.46*
19.93***
14.26**
14.19**
20.59***
14.28
14.69**
12.11
alkaline Liver weight,
phosphatase % of body
KA units/ 100 ml weight
5.22
4.48
5.93
5.91
1
5.62
7.49
9.64**
5.77
4.98
30.22***
3.51
3.26
3.62
3.87
3.52
3.64
4.11*
3.77
3.73 .
5.03**
Pinpoint
nodules
in stomach
0/8
0/8
3/7
4/7
3/8
1/7
5/7
2/8
2/8
2/6
*, P<0.05; **, P<0.01, ***, P< 0.001; significant differences from controls,
-------
versus none in the 8 controls. No histopathological diagnoses
of these lesions were included in the original report (212), but in
1975 it was reported that re-examination of the slides had shown
evidence of "gastrointestinal inflammatory lesions and ulcerations
which appeared similar to those reported by Allen (69) in rhesus
monkeys".* Six of the dogs with stomach lesions, and two of the
others, also had inflamed kidneys. The stomach lesions were equal-
ly prominent in dogs fed all three Aroclors, but the effect on
liver weight was greatest in those fed Aroclor 1260 (Table III.9.6).
III.9.3 Effects on Non-human Primates
Rhesus monkeys are extremely susceptible to the effects of
PCBs (69). Female monkeys fed 25 ppm Aroclor 1248 in the diet
developed severe facial lesions and alopecia and had to be removed
from the contaminated diet after 2 months. The five surviving
females were still devoid of eyelashes and had facial acneform lesions
two years later. Although several of these females conceived, all but
one appeared to experience either fetal resorption or abortion. The
one infant born was underweight (375 g versus 544 g) and had high
levels of PCBs in the fat (28 ppm) and adrenals (24 ppm) (196)..
Female monkeys given 2.5 and 5.0 ppm Aroclor 1248 in their diets
developed facial edema, swollen eyelids, erythema, loss of hair, and
acne within 2 months (213). By the fourth month, irregularities in
the menstrual cycles and an increased level of urinary ketosteroids
* This statement, made at the National Conference (9), was deleted from
Calandra's published paper (68), which states that "No remarkable histo-
pathologic changes were found".
-------
were recorded (214). Following 6 months of PCB exposure the female
monkeys were bred to control males. Six of eight animals on the 5.0
ppm diet conceived (Table III.9.7). The remaining two were bred on
five separate occasions without conceiving. Four of the six females
experienced abortion early in gestation. Eight of eight of the 2.5
ppm PCB-fed animals conceived; however, only five were able to carry
their infants to term. As was the case with infants of animals
given the higher levels of PCBs, all the infants were small and at
birth their skin contained detectable levels of PCBs.
The infants were permitted to nurse their mothers for 4
•k
months. Within 2 months focal areas of hyperpigmentation, swollen
lips and eyelids, loss of eyelashes, and acneform, lesions of the face
developed. The skin of these infants showed a decided increase in
the PCB level over this period. Within 4 months, 3 of the 6 in-
fants died due to PCB intoxication. After weaning, the remaining
three have shown improvement of the skin lesions during the 4-month
period.
Earlier studies by this group have shown that infant rhesus
monkeys are susceptible to other effects of PCBs. Month-old rhesus
monkeys dosed with 35 mg/kg Aroclor 1248 for only four weeks suffer-
ed, in addition to skin lesions, atrophy of the thymus, edema and
hyperplasia of the gastric mucosa, enlargement of the liver with
proliferation of the smooth endoplasmic reticulum, and an increase
in the RNA/DNA ratio in liver (214). Adult rhesus monkeys dis-
played hyperplasia and ulceration of the gastric mucosa after a
single dose of 1.5 g Aroclor 1248 (215).
* The mothers' milk contained 0.15-0.40 ppm of PCBs (69).
-------
Table III.9.7 (from ref. 69)
Modification in reproduc-
tion in primates that were exposed
to Aroclor 1248 in the diet
Control 2.5 ppm 5.0 ppm
Total
impregnated
(no./no.
animals) 12/12 8/8 6/8
Resorptions
or abor-
tions (no./
no. animals) 0/12 3/8 4/8
Stillborn
(no./no.
animals) 0/12 0/8 1/8
Normal
births (no./
no. animals) 12/12 5/8 1/8
-------
Male monkeys appear to be less susceptible than females to
reproductive dysfunction by PCBs (69). Four adult male rhesus
monkeys were also exposed to a diet containing 5.0 ppm Aroclor
1248 for 17 months (average total intake of PCBs 460 mg). They be-
gan to develop a slight periorbital edema after 6 months of exposure;
however, it was much less severe than in the female monkeys receiv-
ing a similar level of PCB. The morphological features and viability
of the spermatozoa as well as the ability to fertilize control fe-
male rhesus monkeys was unaffected during the initial 12 months of
PCB exposure. Subsequently one of the four males lost weight and
developed alopecia, acne, periorbital edema and decreased libido. A
testicular biopsy of this animal showed a decided hypoactivity of the
seminiferous tubules. There was an absence of mature spermatozoa
and a predominance of Sertoli cells of the tubules". The remaining
three males have remained healthy and sexually active (69).
III.9.4 Effects on Mink
Mink also appear extremely sensitive to the effects of PCBs.
In tests with Aroclor 1254, most females died and none produced young
when fed diets containing 15 or 10 ppm (199, 200). In one test at 5
ppm no young were produced, and in a second test only 3 young were
born alive from 12 exposed females (Table III.9.8). Reproduction1 was
also reduced at 1 ppm Aroclor 1254, because one female died and two
others produced no young (Table III.9.8). In another experiment in
which mink were fed a diet containing 0.64 ppm of PCB residues in
beef resulting from feeding PCBs to cows, only one of ten exposed
-------
263
Table III.9.8 (from ref. 200)
Effect of Aroclor 1254 Fed Singly and in Combination with Hydrocarbon
on Reproductive Parameters (Jan. 1 to May 10) (12
females and 4 males/group)
•I,
mortal! tv
Females
.Females
whelped
Kits
A live
born
Scad
Kits/female
alive
Control (or can fish) 6 11 11 56 10 6.0
Raw coho salmon 19 11 0 00 0
Cooked coho salmon 6 12 0000
1 ppm PCB(L> 5* 10 8 35 8 4.3
5 ppm PCB 0 12 3 36 0.8
15 ppm PCB 31 8.0 00 0
5 ppm PCB + 6 ppm DDT 0 12 '4 5 6 0.9
5 ppm PCB + 6 ppm DDT
+ 0.2 ppm dieldrin 19 10 5 15 7 2.2
(1) Aroclor 1254.
* One fcra-ile escaped.
-------
females produced a litter: three kits were born to this female but
they died during their first day of life (201). Thus, as already
noted in Section III.7 above, the toxicity of the PCBs appears to
have been enhanced during their metabolism and storage in the cows.
III.9.5 Effects on Swine
Hansen et al. (216) reported an experiment in which sows were
fed a diet containing 20 ppm Aroclor 1242 from three weeks prior to
conception throughout gestation and nursing. One of five treated
sows failed to conceive and the other four produced significantly
fewer live young than controls, due to an excess of stillbirths and
fetal deaths (Table III.9.9). Treated sows had enlarged livers and
their offspring had unusually small spleens and thyroids (Table III.
9.10).. The principal lesions observed in both sows and offspring were
erosions in the gastric mucosa. A number of the treated offspring,
but no controls, died from chronic septicemia, suggesting that the
exposure to PCBs had increased their susceptibility to infection.
These adverse effects were associated with residues of only 4-20 ppm
in the fat of the sows, and less than 2 ppm in their milk (214).
III.9.6 Effects on rabbits
Oral administration of a single dose of 12.5, 25, or 50 mg/kg
of Aroclor 1254 to pregnant rabbits had embryotoxic effects, but single
doses of 10 and 1 mg/kg did not (217, 218).
-------
Table III.9.9 (from ref. 216)
Farrowing Records and Polychlorinated Biphenyl (PCB)
Residues of Sows Fed PCB Mixture in Ration and of Nontreated Con-
trol Sows
Offspring
Live
Farrowing
weight
(kg)
CONTROL SOWS
258
277
266
259
264
TREATED sows
268
264
270
289
286t
Total JTB
(ppm)
Blood
0.001
0.001
0.001
0.001
0.001
0.096
0.192
0.363
0.337
Fat
0.1
0.1
0.1
0.1
0.1
4.1
11.8
19.8
8.1
11.7
No.
13
12
10
11
11
11
10
6
5
Mean
body
(kg)
1.1
1.5
1.6
1.5
1.5
1.2
1.5
1.4
1.5
Still-
born
5"
0
1
0
1
2
1
1
0
Fetal
deaths'
0
0
0
0
1
0
1
8
1
0 Mummified, fetuses (2.5 crn (o near term) from examination ot placenta.
"' Last 5 in Utter of 18; delivered 28 to 36 hours after 1st pig. t Fed control
ration for 5 weeks before slaughter; this sow did not conceive.
Table III.9.10 (from ref. 216)
Organ Weight to Body Weight Ratios for Sows Given PCB Mixture in the Feed, for Nontreated Control Sows,
and for Their Offspring
Organ weight to body weight ratio (mean x 10s * so)
Sows
Offspring
Organ
Liver
Kidney
Spleen
Heart
Brain
Thyroid ([land
Adrenal gland
Control
11.37 ± 0.08
1.71 ± 0.33
1.09 ± 0.05
2.64 ± 0.40
0.70 ± 0.40
0.055 (n = 1)
0.070 ± 0.002
Treated
U.fiO £1.88..
2.02 ± 0.40
1.19 * 0.19
2.53 ± 0.22
0.57 ± 0.08
0.050 ± 0.003
0.056 =t 0.008
Control
24.23 ± 0.97
5.08 ± 0.35
1.72 st 0.24
4.82 * 0.51
3.55 ± 0.44
0.111 ± 0.015
0.080 ± 0.010
Treated
25.20 ± 1.70
4.39 *0.70
U7- * 0.13
fAO ± 0.35
3.70 ± 0.34
0.076 ± 0.008
ToeS ±0.012
Number of towa; 6D = ctandard deviation.
-------
Zot
III.10. Enzyme Induction and Other Effects on the Liver
Some of the most general and significant sublethal effects of
PCBs in mammals are on the liver and on hepatic enzymes. This sec-
tion reviews these effects, with the exception of chemical porphyria
(Section III.11) and carcinogenesis (Section III.14).
III.10.1. Effects on liver weight
An increase in liver weight and/or in liver-to-body weight
ratio has been noted in many studies. Litterst £t al. (219) observed
increased liver-to-body weight ratios in rats fed 50 and 500 ppm of
Aroclors 1242, 1248, 1254 and 1260 for only 4 weeks (Table III.10.1).
Similar increases in liver weight have been noted in long-term feed-
ing studies with these mixtures in rats (69, 166, 179, 207). In
general the effects were greater with the more chlorinated mixtures
(Table III.10.1, 207), but in an experiment with Aroclor 1016 marked
effects were seen in only 21 days after oral dosage of only 1 mg/kg/
day (equivalent to about 12 ppm in the diet) (Table III.10.5). In
addition, effects were noted at much lower dietary levels in offspring
of treated rats (exposed during gestation and prior to weaning):
significant increases in liver weight were noted in weanling rats
after maternal exposure to only 5 ppm Aroclor 1260 and only 1 ppm
Aroclor 1254 (179: Table III.9.2).
Increase in liver weight has been noted as an effect of PCBs
in many other species (188, 193, 129, 210, 212, 214, 216), and is
also a toxic effect of PCDFs (129, 71).
-------
Table III.10.1 (ref. 219)
itfj
EFFECT OF PCB TREATMENT ON FINAL LIVER WEIGHTS AND ON LIVER : BODY
WEIGHT RATIO IN MALE OSBORNE-MENDEL RATS"
Aroclor
No."
1242
1248
1254
1260
Dose
(ppm)
500
50
5
0.5
0
500
50
5
0.5
0
500
50
5
0.5
0
500
50
5
0.5
0
Final body
weight
(g)
273 - 20
297-31
295 - 33
290- 7
287- 18
307 - 25
329= 16
290 ~ 30
274= 13
318 = 26
240 = 33
255 = 24
259 = 20
262= 15
272 = 22
267 - 22
285= 15
278 - 22
259 = 23
286 = 21
Liver
weight
(g>
12.98 r 1.03
9.93 - 1.40
9.19= 1.16
8.71 =0.67
8.69 - 0.69
16.90 -2.31
11,59- 1.16
8.70=; 1.64
8.53 .- 0.95
9.93.-. 1.24
15.14 = 2.53
9.43 = 1.25
7.87 = 0.68
8.38= 1.23
8.02 - 0.89
15.90 = 2.56
11.96= 1.54
9.11 =0.85
8.21 -0.65
8.65 = 0.98
Liver: body
weight ratio
0.047 - 0.002C
0.033 = 0.002
0.031 =0.001
0.030 = 0.001
0.030 .-0.001
0.055 - 0.005C
0.035 = 0.003J
0.030 = 0.003
0.031 =0.002
0.031 =0.002
0.063 = 0.003C
0.038 ~ 0.003''
0.030 = 0.002
0.032 = 0.004
0.029=0.001
0.060 = 0.009C
0.042 = 0.004'
0.033=0.003
0.031 ±0.002
0.030 = 0.002
' Results are given as the mean of 6 rats =SD.
* Polychlorinated biphenyl compounds containing 42" 0 (1242) to 60^, (1260) by
weight of chlorine, fed in the diet for 4 wk.
' Significantly different from control group at P ••:, 0.001 as judged by the student
/ test.
'P <. 0.05.
-------
III.10.2 Proliferation of smooth endoplasmic reticulum.
The initial increase in liver weight is due mainly to prolif-
eration of smooth surfaced membranes of the endoplasmic reticulum, a
network of interconnected channels present in the cytoplasm of most
animal cells. The endoplasmic reticulum contains complexes of en-
zymes which play a role in metabolizing foreign substances such as
drugs or environmental pollutants. These foreign substances are
usually transformed into substances which can be more easily excre-
ted by the body. A control'step in metabolism of most foreign agents
involves an oxidation reaction mediated by enzyme complexes (220).
When liver samples are homogenized, the endoplasmic reticulum is
broken up into particles referred to as microsomes and the enzymes.
are often referred to as microsomal enzymes. The liver microsomal
enzymes responsible for metabolizing substances not normally expected
to be present in the human body are sometimes referred to as drug-
metabolizing enzymes. Norback and Allen (221) observed a prolifera-
tion of smooth endoplasmic reticulum (SER) in rats fed PCBs for one
to five weeks. Similar proliferation of SER has been observed in
mouse and monkey livers (197, 210).
The proliferation of SER is accompanied by increased activity
of the microsomal enzymes responsible for metabolizing drugs and
other foreign substances. Related observable changes in liver in-
clude increase in protein content and cytochrome P-450 content of
microsomes.
* Cytochrome P-450 — a microsomal hemoprotein implicated as the
terminal oxidase in hepatic enzyme systems.
-------
The duration and intensity of action by many drugs, carcino-
gens and other environmental chemicals which enter the body depends
to a large extent on the rates at which they are metabolized by the
cytochrome P-450 containing mixed function oxidase system in liver
cells (222) . Alvares eit al. (223) found that Aroclor 1254 treatment
(25 mg/kg per day for 6 days) nearly tripled cytochrome P-450 con-
centrations in rat liver. Litterst _et al. (219) observed a signifi-
cant increase in microsomal cytochrome P-450 content in rats fed 50
and 500 ppm Aroclors 1242, 1248, 1254, and 1260 for four weeks. In
addition, a P-450 increase was apparent at 5 ppm of Aroclors 1248,
1254 and 1260 (Table III.10.2). The increase in cytochrome P-450
content appears to be dose-related and to increase somewhat with
increasing chlorine content.
III.10.3 Microsomal enzyme induction
Disruptions in normal enzyme activity have been observed even
at dose levels which had no effect on liver weight or on liver-to-
body weight/ratios (219). Several hepatic enzyme systems are
affected at oral doses as low as 5 ppm (224) or even 0.5 ppm (219):
"no effect levels" have not been found (Table III.10.3). A chronic
exposure to low dose levels of PCB is likely to exact an effect on
t /
enzyme activity in human liver.
The ability of PCBs to induce enzymes was first shown by Rise-
brough e_t al. (225) . Allen and Abrahamson (188) found that PCBs
caused overall increase in enzyme activity of rat livers which varied
from approximately 2 to 10 fold when expressed in relation to the
-------
Table III.10.2 (from ref. 219)
210
EFFECT OF PCB TREATMENT ON LIVER MICROSOMAL
PROTEIN AND CYTOCHROME P-450 CONTENT OF RATS"
Aroclor
No."
1242
1248
1254
1260
Dose
(ppm)
500
50
5
0.5
0
500
50
5
0.5
0
500
50
5
0.5
0
500
50
5
0.5
0
Protein'
51 ±2
43 ±4
45 = 4
40 ± 3
45 ±5
84 ± 2'
54 ±4
54 ±5
51x4
66 ±1
60 ±3'
60 ±4
45 ±2
45 ±2
40 = 3
100 ± 8'
73 ±4'
60 = 5
53 ±3
•47 ±3
P-450J
1.26 ±0.09'
0.69 ± 0.05
0.42 ± 0.03
0.51 ±0.03
0.46 ± 0.04
1.29 ±0.11'
0.71 ± 0.04'
0.46 ± 0.02
0.59 ± 0.04
0.37 ±0.05
1.42 ±0.12
0.88 ±0.06
0.71 ±0.04
0.61 x 0.04
—
1. 24 ± 0.09'
1.20 ±0.10'
0.71 ±0.04
0.54 ± 0.03
0.57 ± 0.02
" Values are the results ±SD of duplicate determinations
conducted on a microsomal pellet from six pooled livers.
' PCB compounds containing from 42% (1242) to 60%
(1260) by weight of chlorine, fed in the diet for 4 wk.
' Expressed as mg microsomal protein/g liver.
J Expressed as nmoles of cytochrome P-450/g of micro-
somal protein.
' Significantly different from control values at P < 0.05 as
judged by the student; test.
-------
Table III.10.3 (from ref. 219)
211
EFFECT OF PCS TREATMENT ON DEMETHYLATION ACTIVITIES IN HEPATIC
MlCROSOMES OF RATS'
Substrate
Aminopyrine
Aroclor
No."
1242
1248
1254
.
1260
Dose
(ppm)
500
50
5
0.5
0
500
50
5
0.5
0
500
50
5
0.5
0
500
50
5
0.5
0
% of
Units' control
1 4.2 ±0.4"
9.6 ±0.1"
7.6-0.4
9.3 ± 0.2*
5.9 ±0.2
17.4 ±0.5"
10.4 ±0.4"
7.6 ±0.3
5.1 ±0.2'
6.4 ± 0.4
19.3 ±0.2"
16.6 ±0.2"
8.9 ± 0.3"
7.2 ± 0.2"
5.8 1 0.2'
22.2 ± 0.2".
18.6 ±0.3"
13.0 ±0.3"
9.6 ±0.3"
8.1 ±0.1
240
163
129
108
100
272
163
120
79
100
336
289
155
127
100
274
229
160
118
100
Codeine
%of
Units' control
22.4 ± 0.3"
15.1 ±0.4"
11.6 ±0.2
9.1 ±0.2
9.1 ±0.1
24.8 ± 0.4"
16.5 ±0.4"
11. 5 ±0.3'
8.5 ±0.3'
9.6 ±0.1
25.3 ± 0.3"
24.4 ± 0.5"
13.2 ±0.3"
12.2 ±0.2"
9.6 ±0.2
28.5 ±0.5"
26.6 ± 0.3"
20.7 = 0:3"
14.9 ±0.3
14.5 ±0.1
245
165
127
99
100
258
171
119
88
100
264
253
138
127
100
197
183
143
103
100
Ethylmorphine
%of
Units' control
15.9 ± 0.1"
11.2 = 0.3"
8.7 ± 0.2
7,8 = 0.1
7.2 ± 0.3
17.6 ±0.5"
12.1 ±0.5"
9.6 ± 0.4"
7.4 ±0.3
7.2 ±0.1
17.9 ±0.5"
17.9 = 0.4"
11.1 ±0.2"
9.6 ± 0.2'
7.6 ±0.3
17.4 ±0.3"
18.0 ±0.2"
15.9 ±0.2"
12.4±0.3«
10.7 ±0.2
219
155
121
108
100
243
166
133
102
100
236
236
146
127 .
100
162
167
148
116
100
• Each value is the mean mSD of 3 replicates.
6 Polychlorinated biphenyl compounds containing 42% (1242) to 60% (1260) by weight of chlorine.
fed in the diet for 4 wk.
' Expressed as ^moles of product Jbrmed,'g liver 30 min.
J Significantly different from control group at P <.0.01 as judged by the student t test.
c P < 0.05.
-------
total weight of the liver. Since PCBs are relatively resistant to
metabolic breakdown, they persist as enzyme inducers. As the enzymes
are continuously induced, hormones and perhaps other compounds may be
metabolized at rates faster than normal over the whole life span of
the organism. Increased metabolism of several hormones in birds and
mammals has been demonstrated (225-227).
After a single oral dose of 50 mg/kg body weight Aroclor 1254
administered via stomach tube, microsomal enzyme activities increased
until 24 hours after treatment and then either remained elevated or
declined. Enzyme activities were still significantly increased over
control values 48 hours after the single administration (228). Young
rats are more susceptible to the enzyme inducing effects than adult
rats (229).
With continuous exposure to high dietary levels of PCBs, a
decrease is eventually observed in SER proliferation and concentric
membrane arrays pervade the cytoplasmic reticulum. The induced
levels of microsomal enzyme activity persist (221).
After termination of exposure, the enzyme inducing effect of
PCBs appears to be reversible. Litterst and Van Loon (228) main-
tained rats on a diet of 50 ppm PCB for seven days. Discontinuation
/of PCB treatment resulted in a slow decay of the induced enzyme
activity to approximately control levels 'after ten days.
Increased activities of the drug metabolizing enzymes aniline
hydroxylase and aminopyrene n-demethylase were observed in pregnant
rabbits exposed to single doses of 10 mg/kg Aroclor 1254 (217).
-------
Carboxylesterase activity and the ability to degrade parathion to
p-nitrophenol were significantly increased by the same doses. The
effects of Aroclor 1221 were smaller than those of Aroclor 1254 at
the same doses, but both Aroclors affected vitamin A storage after a
single dose of 1 rag/kg (217).
Application of very small amounts of PCBs to the skin of ex-
perimental animals can cause a marked increase in mixed function
oxidase activity (220).
A significant increase in activity of demethylating, reducing
and hydroxylating microsomal enzymes was observed in livers of rats
fed 150 ^oles per kg of food for 30 days. PCBs at this dose pro-
duced a significantly greater increase in activity than did DDT on
all but the demethylating reaction where the effect was equal (228).
Specific enzyme activity, expressed per unit weight of micro-
. somal protein or per unit weight of liver may increase or decrease
under the influence of PCBs. However, when these data are expressed
in relation to the total liver, a decided increase has been observed
in activity of all enzymes assayed (188). PCB exposure can cause
changes in activity of specific enzyme pathways in liver microsomes.
The following alterations in enzyme activity have been observed:
o Nitroreductase -- Specific activity increased during the
first week under the influence of Aroclors 1248 and 1254.
Activity returned to near normal values during the second
week and continued to decrease through the sixth week. In
rats fed Aroclor 1262, a much greater increase in activity
persisted-(188).
Litterst eit al. (219) observed a striking increase in nitro-
reduction of p-nitrobenzoic acid. The effect was dose- '"
-------
related. The activity of nitroreductase in rats fed 500
ppm of Aroclor 1260 was 10 times the control values while
all 4 Aroclors (1242, 1248, 1254, and 1260) at 0.5 ppm
caused a 50 to 70 percent increase in activity (Figure
III.10.1). The nitroreductase induction effect increased
with increasing chlorine content (219) . Nitroreductase
activity levels continued to increase during four weeks
of treatment with PCBs (228).
o Demethylase — PCBs induced activity of demethylases in
rat liver microsomes. The increase in amounts of product
formed with increased PCB concentrations suggests that a
dose-response relationship exists between any one specific
Aroclor and this enzyme. Litterst e£ al. (219) observed
that demethylase activity reached a peak at 54 percent
chlorine content and then decreased in amplitude with
Aroclor 1260 (Table III.10.3). Chen and DuBois (229),
however, observed an increase in demethylase activity with
a degree of chlorination for Aroclors 1.221, 1254, and 1260.
Even at the highest dose of all the Aroclors tested, demeth-
ylase activities do not exceed a level of 2 to 3 times the
control values (219). In PCB-treated rats, demethylase
activity reached the maximum level of induction within
seven days (228).
Vaino (230) observed a 16-fold increase in p-nitroanisole
0-demethylase activity after treating rats for 6 days with
daily injections of Clophen A50 (15 rag/kg).
Allen and Abrahamson (188) observed an increase in specific
activity of rat liver demethylase throughout the 6-week
PCB feeding period.
o Deethylase -- Wilson and Hansen (231) observed a marked in-
crease in deethylation of p-nitrophenetole in microsomal
preparations from sheep after feeding for 15 weeks with 20
ppm Aroclors 1242 or 1254 (Table III.10.4).
o Glucose-6-phosphatase — Specific activity in rat liver
decreased continuously for six weeks (188). Litterst _et
al. (219) also observed a decrease in specific activity' of
glucose-6-phosphatase in livers of PCB-dosed rats: the
effect was most marked for Aroclor 1242 and was significant
at the lowest dose tested (0.5 ppm for 4 weeks).
o Hydroxylase -- Although overall increase of hydroxylase
activity has been consistently observed on administration
of PCBs, patterns of change in specific hydroxylase
activity observed by different investigators have varied.
-------
2MT
Figure III.10.1 (from ref. 219)
woe -
aoc •
Dose-response relationship of 4 Aroclors on nilrorcduaion of/>-nitroben/oic acid in rat
User microtomes. Each point represents the msun of 3 replicates. The SD values were all less than 5"0
of their respective means.
-------
2/6
Table III.10.4 (from ref. 231)
SPECIFIC ACTIVITY OF P-NITROPHENETOLE O-DEETHYLATION COMPARED TO THE SLOPE OF
LlNEWEAVER-BURKE KINETIC PLOTS AT LOW (0.0125-0.15 HIM) AND HlOH (0.15-2 HIM)
SUBSTRATE CONCENTRATIONS
Specific activity"
Slope
Treatment
0.05 IUM"
0.5 HIM 1 mM 0.15-2 m.M 0.0125-0.15 HIM
Normal control
Normal 1242
Normal 1254
Low-protein control
Low-protein 1242
Low-protein 1254
High-fat control
Highrfat 1242
High-fat 1254
2.67
4.07
5.67
5.44
9.26
13.72
10.70
4.55
8.42
6.98
6.66
9.48
8.40
13.07
16.82
16.94
7.36
12.60
7.48
7.61
11.22
10.36
14.94
18.35
17.31
7.30
14.08
0.0233
0.0103
0.0074
0.0177
-0.0094
0.0030
0.0030
0.0089
0.0092
0.0035
0.0022
0.0024
0.0025
0.0022
0.0023
0.0023
0.0023
0.0034
' nmol/min/mg protein.
' Substrate concentration.
-------
Vaino (230) observed a 7.5-fold increase in hepatic aryl
hydrocarbon hydroxylase activity after treating rats for 6
days with consecutive daily injections of 15 mg/kg Clophen
A50. A slight enhancement in the overall hydroxylation
reaction was already observable 24 hours after a single
intraperitoneal injection.
Allen and Abrahamson (188) observed a continuous decrease
in specific activity of aromatic hydroxylase in rat liver
for six weeks: this anomalous result is perhaps due to the
very high dose used, which caused overt liver damage and
ultimately death.
Litterst and Van Loon (228) observed two peaks in hydroxy-
lase activity after PCS administration to rats. One peak
occured 7 days after treatment and the other peak occured
28 days after treatment. Activity was slightly lower after
14 days than it had been after 7 days. Litterst and Van
Loon used l^C-pentobarbital as their substrate.
Alvares et al. observed an 11-fold increase in activity of
benzo(a)-pyrene hydroxylase after application of micro-
scope immersion oil containing PCBs to rat skin (222) .
o Esterase -- Specific activity decreased continuously for
rats on Aroclor 1248 and 1254 diets. With Aroclor 1262
there was a slight increase the first week, then specific
activity leveled off (188).
By increasing activity of drug-metabolizing enzymes, PCBs can
reduce the pharmacological effect of certain drugs. One parameter
used to measure enzyme induction is reduction of hexobarbital or
pentobarbital induced sleeping time (220). After treatment with
PCBs, the rate at which rats metabolize the barbiturates to non-
narcotic substances is increased. Decrease in pentobarbital sleep-
ing time following dietary administration of several PCB isomers'
was demonstrated in rats (232, 233), mice (234) and rabbits (235).
Diminished pharmacological actions of zoxazolamine and hexobarbital
have also been observed (236).
-------
2)2
The various effects of PCBs on liver microsomal enzymes can
be blocked by the prior administration of actinomycin D (5). Actino-
mycin D acts as an inhibitor of DNA-dependent RNA synthesis. Al-
vares &t_ al. (223) interpreted the inhibitory effect of Actinomycin
D on PCB-induced increases in enzyme activity as support of the
view that PCBs enhance the synthesis of a distinct microsomal hemo-
protein not present in liver of untreated rats.
There are substances other than PCBs which are also known to
increase the activity of drug metabolizing enzymes in the liver
microsomes. Litterst and Van Loon (228) compared the enzyme-induc-
ing effect of Aroclor 1254 with the effects of DDT and phenobarbital.
Rats were fed 5, 15, or 150 u moles per kg of food for 30 days. They
concluded that at 150 u moles per kg food, PCBs were far more effec-
tive enzyme inducers than phenobarbital and at least as effective
as DDT.
Two types of inducers of drug-metabolizing enzymes of the
liver have been reported. One group, which includes phenobarbital,
enhances the metabolism of a_large variety of substrates. The other
group, which includes such polycyclic aromatic hydrocarbons (PAH) as
benzo(a)-pyrene and 3-methylcholanthrene, stimulates the metabolism
of only a few compounds. The effects of these two groups of in-
ducers on cytochrome P-450 differ. Cytochrome P-450 is a micro-
somal hemoprotein which has been implicated as the terminal oxidase
in the hepatic enzyme systems. Treatment of rats with inducers
from either group increases concentration of cytochrome P-450, but
-------
the PAH also induce formation of cytochrome P-448. Cytochrome P-448
differs from cytochrome P-450 in spectral properties and catalytic
activities (223). Polychlorinated biphenyls appear to be a new type
of hepatic enzyme inducer, sharing the properties of both groups.
PCBs cause the formation of cytochrome P-448 (like the PAH group)
while eliciting the more general enzyme induction response of the
phenobarbital group.
Data of Vaino (230) support the hypothesis that PCBs form a
new type of inducer group enhancing drug biotransformation in liver
microsomes. PCBs were observed to produce a cytochrome P-448 with
catalytic properties differing from those of P-448 induced by PAH
(223, 230). PCBs were also able to increase the NADPH cytochrome
reductase activity which is uninfluenced by PAH. Alvares et al.
(222) also reported induction of NADPH cytochrome c reductase in
addition to cytochrome P-448 by PCBs.
Barbiturates and PAH both stimulate the UDP glucuronosyl-
transferase activity of liver microsomes. The enhancement of UDP
glucuronosyltransferase activity caused by Clophen A50 was consider-
ably greater than obtained by any of the previously known inducers
(230) .
Wilson and Hanson (231) have also given evidence from the
kinetics of 0-deethylating reactions in sheep microsomal prepara-
tions that PCBs stimulate two distinct types of enzyme system.
Alvares and Siekevitz (237) have shown by means of gel electro-
phoresis that PCBs induce three distinct subunits of cytochrome P-450.
-------
ZlO
III.10.4. Structure-activity relationships.
A number of recent studies have started to elucidate
structure-activity relationships in enzyme induction by chlorobi-
phenyls (146, 224, 238-242). The results of some of these studies
are summarized in Figures III.10.2 - III.10.6 (from ref. 242).
Figure III.10.3 summarizes the influence of the various agents
tested on the hepatic mixed function oxidases aniline hydroxylase (A),
p-nitroanisole 0-demethylase (B), and aminopyrine N-demethylase (C).
The most responsive enzymes were those closely associated with the
smooth endoplasmic reticulum. The results in vitro reflected the
observations of altered sleeping times in vivo (Figure III.10.2).
One can see that, even with this limited number of pure chlorobi-
phenyls, not all caused effects of the same magnitude. To summarize
the results of this study, treatment with biphenyl caused slight in-
duction while 4-chlorobiphenyl did not. The mixed function oxidases
were markedly induced by pure hexa- and octa-chlorobiphenyls and also
by di- and tetra-chlorobiphenyls with chlorines substituted at the
4-positions of the rings. Considering the dichloro-isomers, when
the 4- and 4'-positions were occupied, there was a much greater in-
ductive effect for all of the enzyme activities than was observed
with the 2,2'- and 2,4'-isomers. The same positional phenomenon was
observed for the two tetra-chlorobiphenyls studied, the induction
caused by 2,4,2',4'-tetra-chlorobiphenyl being much greater than
that observed with the 2,5,2',5'-isomer. The results obtained for
the higher chlorinated analogs suggested that the positions of the
-------
211
TIME (minutes)
40 SO
120
1
3-
-H
i— }— i
i — i —
i — j — i
-H
3-
j-1 (P
3-
13
—
<
-j — i
SLEEPING TIME
ntobaro - 40 mg/'Kg)
'
CONTROL
P.P'DDT
o.p'DOT
AROCLOR 1254
ARCCLOR 1260
BIPHENYL
4-MONO-CI
2,2'Di Cl
2,4'Oi Cl
4,4' Oi Cl
2.5.2,'5I TETRA Cl
2.4.2M1 TETRA Cl
2,4,5,2;4:?' HEXA Cl
2.3,5,213:5' HEXA Cl
2,4.6.2:4:5' HEXA Cl
2.3.4.5, 2!3;4!5' OCTA Cl
The effect of p re treatment
of young male rats with DDT (o,p' and
p,p'-isomers), Aroclor 1254 and 1260,
biphenyl, and a series of isomerically
pure chlcrobiphenyls on the sleeping
time produced by an injection of
40 mg/kg sodium pentobarsital .
Figure III.10.2 (from ref. 241)
-------
50
nMCtES/mg PROTEIN
100 150
200 0
CONTROC
p.p'DDT
o.p'SOT
AROCLOR 125J
AROCLOR 1260
8IPHENYL
4-MONO-CI
2.2'OI Cl
t.4' 01 Cl
2,5.2,'5' fETRA Cl
2.4,2:4' TURA Cl
2,4,5,2:4:5' HEXA Cl
2,3.5.2:3:5' HEXA Cl
2.4,6.2:4:6' HEXA Cl
4,5. r-JMIS' OCTA Cl
1 . 1 . 1 . 1
=^
i
i "~H — '
i
i 'HH
1
! -H
1
1 '"*"'
1
1 1 1 1
==p-
,,, , ! , AMI INF "YPfVYMSE
| 1 '
i i — '1 i
1
1
i i [ .
!
L ' ' '
i
1
! -H
i
i 1 1
r
i • 1
i
i
! , — Lj 1
nMOUS/mg PROTEIN
50 100 150
i . i . :
nMOUS/mg PROTEIN
.3*
200 0
I
100
I
200
I
300
«0
N-OEVETHYUSE
B
The effect of pretreatment of young male rats with DDT (o,p'-
and p.p'-isomers), Aroclor 1254 and 1250, biphenyl, and a series of
isomerically pure chlorobiphenyls on hepatic microsomal aniline hydro-
xylase (A), p-nitroanisole 0-demethylase (B), and aminopyrine N-derre-
thylase (C) activities. Activities are expressed as nmoles of product
formed/mg microsomal protein/30min incubation.
Figure III.10.3 (from ref. 241)
-------
Ill
ACTIVITY (In total wt of fresh liver/lOOg body wt)
nmole/min nmole/min \i mole/min mg/mln
0 100 200 300 400 0 100 200 300 400 0 100 203 300 400 500 0 5 10 15 20
BIPHENYL
2.2'
2,4'
3,3'
4.4'
^^M- '
00
AH
CE
BSP
The effect of pretreatment of younq male rates with biphenyl
and a series of isomerically pure dichlorobiphenyls on hepatic p-nitro-
anisole 0-derr.ethylase (00), aniline hydroxylase (AH), carboxylesterase
(CE), and sulfobromophthalein-glutathione conjugating enzyme (BSP)
activities. Animals wers treated by i.p. injection for 3 consecutive
days and were killed and assayed'96 hr after the last injection. The
values (bars) represent the rcean enzymatic activities +, S.O. (lines)
of 18 control, biphenyl-treated rats and 5 animals per treated group.
The asterisk (*) indicates values statistically different (p < 0.55)
from biphenyl-treated controls.
Figure III.10.4 (from ref. 241)
-------
ACTIVITY (In total wt. of fresh llver/lOOg body wt)
nmole/min nmote/min umole/min mg/min
02004006008000100200300-«X)02t»4006008000 5101520
i | i t l ( i ± i ] I i ' I I
BIPHENYL
2,5.4'
2,4,4'
2.5,2'
2.5.3'
3.4,2'
:!&?'
*
^
H"
5^"
00
AH
CE
BSP
The effects of pretreatment of young male rats with biphenyl
and a series of isomerically pure trichlorobiphenyls on hepatic p-nitro-
anisole 0-demethylase (OD), aniline hydroxylase (AH), carhoxylesterase
(CE), and sulfobrcmophthalein-glutathiona conjugating enzyme (BSP)
activities.
Figure III.10.5 (from ref. 241)
-------
ACTIVITY (In total vrt. of fresh liver/lOOg body wU
nmole/mln nmols/min (j mole/min mg/min
020040060n8C001002C03C002004036008000 5 10 15 20
I I I I _ I
BIPHENYL
2,4.2',4I
3A3'.4'
2.5,2',51
2.3,21,3I
2.6,2',6'
00
AH
CE
BSP
The effects of pretreatment of young male rats with biohenyl
and a series of isomerically pure tetracnlorobiphenyls on hepatic
p-nitroanisole 0-demethylase (00), aniline hydroxylase (AH), carbo-
xylesterase (CE), and sulfobromophthalein-glutathione conjugating 'enzyme
(BSP) activities.
Figure III.10.6 (from ref. 241)
-------
chlorine atoms were not as important. These results, with the ex-
ception of the marked effects obtained following treatment with 4,4'-
dichlorobiphenyl, confirmed the observations of other investigators
who have found that penta-, hexa- and octa-chlorobiphenyls had greater
enzyme-indueing potential than did low chlorine-containing biphenyls
(205, 224, 239).
The influence of a series of di-, tri-, and tetrachlorobi-
phenyls on the selected enzymatic functions are shown in Figures
III.10.4-6, respectively. With each series of isomers, a chlorine
atom on the 4-position caused a more marked induction of hepatic
drug-metabolizing enzyme activities than did a chlorine atom at any
other position. As one increased the degree of chlorination, subse-
quent substitution at the 2-position was next in importance followed
by substitution at the 3-position. The results conclusively demon-
strated that not all isomers of the mono-, di-, tri-, and tetrachloro-
biphenyls possess the same toxicologic properties, the position of
chlorination being as important as degree of chlorination (242).
Fujita £t. al. (239) also noted high specific activities of
several isomers with 4,4'-substitution, including especially 3,4,3',4'
tetraCB, 2,4,5,3',4'-pentaCB, and 3,4,5,3',4',5'-hexaCB.
As a general summary of these results, for the mono-oxygenases
closely associated with the hepatic endoplasmic reticulum, enhanced
induction of activity was observed with highly chlorinated biphenyls
and by low chlorine-containing congeners having chlorine atoms sub-
stituted at the 4- and 4'-positions irrespective of chlorination at
-------
2*7
other positions. For those enzymes less discretely localized in the
hepatocyte, the position of the chlorine atoms appeared to be less
important (242).
III.10.5. Enzyme induction by Aroclor 1016
Three studies have compared the activity of Aroclor 1016 in
inducing liver enzymes with that of more highly chlorinated mixtures.
Iverson e£ al. (243) compared the responses of rats after 21 daily
oral doses of 1, 10 and 100 mg/kg of Aroclors 1016 and 1242. In
male rats the responses were generally similar and if anything
slightly larger for Aroclor 1016 (Table III.10.5): Aroclor 1016
caused significant increases in body weight gain, liver-to-body-
weight ratio, and activity of aniline hydroxylase and aminopyrine
demethylase at doses as low as 1 mg/kg, and increases in cytochrome
P450 at 10 mg/kg. In female rats, by contrast, neither Aroclor
caused significant changes at 1 mg/kg and the effects of Aroclor 1242
were more pronounced on all parameters measured except P450 at 10
and 100 mg/kg (Table III.10.6). Neither mixture had significant
effects at 0.1 mg/kg (243).
Bickers et al. (244) compared the effects of Aroclors 1016
and 1254 on liver enzymes of male rats following six daily doses of
25 mg/kg. The effects of Aroclor 1254 were larger than those of
Aroclor 1016 on each of the six enzyme functions measured (Table
III.10.7) and Aroclor 1016 did not have significant effects on ani-
line hydroxylase or cytochrome b^. The contrast between this result
and the strong induction of aniline hydroxylase by Aroclor 1016 in
-------
Table III.10.5 (from ref. 243)
Effect of Aroclor 1016 on male rats after daily oral dosing for 21 days
CONTROL
BODY HEIGHT GAIN 74.0+4.6
d;)
LIVER 4.11+0.08
*> BODY WEIGHT
P. r „ 0. 92±0. 04
ni;i/imj protein
ANILINE 2.09±0.10
HYDROXYLASE
Um/hr/g
AMINOFYRINC 1.04+0.11
N-DEMETHYLASE
pm/hr/g
LIVER PORPHYRINS ' 0.18±0.01
1 'g liver
IJUSt, 1
1 mg/kg
90.7±2. 8
ft ft
4.48+0.04
ft ft
0. 90±0. 05
2.45+0.13
:': :':
1.44+0.10
ft ft
0.20±0.03
U1D
10 mg/kg
83.1±4.1
4.66±0.07
!'! ft
1.43+0.11
ft ft
4.50+0.35
ft ft
2.39+0.19
ft ft
0.16+0.02
100 mg/kg
90.4±4.4
ft ft
6.0410.10
ft ft
1.7610.17
ft ft
5.60+0.28
ft ft
2.56+0.20
ft ft
0.44+0.04
ft ft
100 mg/kg
(% control)
122
147
181
269
246
244
.
•<* P^O.05
Effect of Aroclor 1242 on male rats after daily oral dosing for 21 days
CONTROL
BODY WEIGHT GAIN 74.7+5.2
LIVER 3.9710.06
% BODY WEIGHT
PMCA 0.9210.04
nm/mg protein
ANILINE ' 1.81+0.07
HYDROXYLASE
ym/hr/g
AMINOPYRINE 1.71+0.21
N-DEMETHYLASE
ym/hr/g
LIVER PORPHYRINS 0.21+0.03
ym^'r liver
1 mg/kg
67.0+8.7
4.26+0.06
ft ft
1.03+6.05-
2.11+0.11
ft ft
2.11+0.18
0.19+0.02
— DOSF 1 ?M "> ...
10 mg/kg
75.0+3.4 #
4.64+0.11
ft ft
1.29+0.05
*ft
3.81+0.17
ft ft
3.37+0.28
ft*
0.30±0.05
100 mg/kg
74.0+6.6
6.8310.18
ft*
1.7710.09
ftft
5.75+0.39
ftft •
3.85+0.21
ftft
1.0710.11
ft*
100 mg/kg
(% control)
100
172
192
318
225
510
** P«0.05.
# Misprinted in original
-------
Table III.10.6 (from ref. 243)
Effect of Aroclor 1016 on female rats after daily oral dosing for 21 days
CONTROL
20DY WEIGHT GAIN 29.2±2.7
LIVER 3.98±0.23
"•. BODY WEIGHT
P . 0.62+0.08
nm/mg protein
ANILINE 1.10+0.06
HYDROXYLASE
pm/hr/g
AMINOPYRINE 0.40+0.02
N-DEMETHYLASE
ym/hr/g
L-/ER PORPHYRINS 0.21+0.02
ym/g liver
1 mg/kg
30.511.8
4.05+0.08
0.77+0.05
1.13+0.09
0.44+0.02
0.14+0.01
10 mg/kg
35.512.4
4.4510.08
0.7810.04
1.2310.13
0.38+0.04
0.2410.05
100 mg/kg
33.611.9
5.7310.14
A ft '
1.10+0.03
ft ft
2.48+0.19
Aft
0.70+0.05
ftA
1:14+0.20
A A
100 mg/kg
(% control)
115
144
177
226
175
543
-* P^O.05
Effect of Aroclor 1242 on female rats after daily oral dosing for 21 days
CONTROL
BODY WEIGHT GAIN 28.7±2.3
(g)
LIVER 3.63+0.13
% BODY WEIGHT
P 0.85+0.05
nm/mg protein
ANILINE 1.01+0.02
HYDROXYLASE
ym/hr/g
AMINOPYRINE 0.45+0.01
N-DEMETHYLASE
LIVER PORPHYRINS 0.2010.04
ym/g liver
1 mg/kg
28.013.7
3.71+0.11
0.8210.03
1.08+0.03
0.48+0.05
0.23+0.02
10 mg/kg
35.313.7
4.19+0.09
ftA
1.14+0.04
A A
1.8410.10
ft ft
0.81+0.02
Aft
0.4410.06
AA
100 mg/kg
18.315.5
6.18+0.22
_.' l.SOiO.OS
3.0H0.23
Aft
1.12+0.12
Aft
1.76±0.30
AA
100 mg/kg
(% control)
64
170
177
298
249
871
P^O.05
-------
Table III.10.7 (from ref. 244)
Changes in microsomal hemoprotein levels and N-demethylase and hydroxylase
activities in response to Aroclor 1254 and Aroclor 1016
Measurement
Mg microsomal protein/
g liver, wet weight
Aniline hydroxylase, mumoles
p-aminophenol/mg protein/hr
Ethylmorphine N-demethylase,
ymolcs HCHO/mg protein/hr
Cytochrome P-450, mumoles
/mg protein
Cytochrome br, mymoles .
/mg protein
Zoxazolamine paralysis
time, minutes
Hexobarbital sleeping
time, minutes
Controls
25.14
±0.85
36.42
±1.55
0.349
±0.022
0.637
±0.027
0.399
±0.019
549
±58
101
±5
Aroclor 1016
27.07
±0.58
35.83
±1.90
0.498 2
±0.036
0.8S4 -
±0.051
0.423
±0.009 '
275 '
±13
48 2
±4
Aroclor 1254
28.88 2
±0.88
48.06 2
±2.82
1.075 2
±0.056
1.776 ~
±0.109
0.561 '
±0.014
02,3
24 2
±1
Rats were pretreated with Aroclors 1016 or 1254, dissolved in corn oil, at
a dosage of 25 mg/kg/day for 6 days. Controls received corn oil only. Each
value represents mean ± S.E. for 5 rats.
Values significantly different from the respective control values (P<0.05).
No loss of righting reflex occurred in any of the 5 rats.
-------
the experiment of Iverson et. aU (243, Table III.10.5) probably
results from the more extended dosage regime in the latter experi-
ment, and emphasizes the complexity of the effects under review.
Goldstein £t al. (245) compared the responses of female rats
to Aroclors 1016 and 1242 after feeding at 100 and 500 ppm. After one
week of feeding there were marked differences in response: Aroclor
1242 had markedly increased liver weight and alldrtrg metabolizing
systems tested including cytochrome P-450, N-demethylase, nitro-
reductase, aniline hydroxylase, and glucuronyl transferase, whereas
Aroclor 1016 had produced only minimal effects (Figure III.10.7).
After six months' exposure, however, the effects of the two mixtures
were much more similar (Figure III.10.8). Thus the action of Aroclor
1016 on female rats appears to involve a time lag. It should be noted
also that Goldstein et al. tested only female rats, whereas "Iverson
et al. (243) found that males were more sensitive to Aroclor 1016.
Although in some experiments Aroclor 1016 had less pronounced effects
on hepatic enzyme systems than Aroclor 1242, its effects thus appear
similar after prolonged exposure.
III.10.6. Enzyme induction by PCDFs.
No studies appear to have been reported of the activity of
PCDFs in inducing hepatic microsomal enzymes in mammals. In chickens,
2,3,7,8-TCDF is as potent as 2,3,7,8-TCDD in inducing aryl hydrocarbon
hydroxylases in the embryo (36), but it is much less active in in-
ducing cytochrome P-450 in the hatched chick (146, 147).
-------
231
800
TOO
600
500
WO
300
200
100
1 WEEK
gj 100 ppm AR 1242 '|C
~ 'E3 SOOppmAR 1242
_ 0100 ppm AR
HMO ppm AR
-
a.c
- _L
—
a
--P
|
1
1016
1016
a.t
a.c
*3 ^
T
f
a
J
i.
S
s
-
_
-
_
a.c
a
T
m
T '
JV 5
&* ii_l
r2]
i'
;•,
-
—
t
T _
^
LA5E HYOROXY- REDUCIASE IRAf.SFERASE
LASE
PROTOHWi LIVER MICRCSOi'AAL UVER/60DY ALA
WEIGHT PROTEIN «yEIGHT SYNTWTASf.
. Effect of Aroclors 1016 and 1242 on cytochrome P-450, drug-metabolizing enzymes, proto-
heme, liver weight, liver microsomal protein, and ALA synthetase activity at 1 wk. Groups of six
female rats were fed 100 or 500 ppm of Aroclors 1016 or 1242 and sacrificed at 1 wk. Values represent
means ± SE. a—Significantly greater than controls at p < 0.05. b—100 ppm Aroclor 1242 significantly
greater than 100 ppm Aroclor 1016, p < 0.05. c—500 ppm Aroclor 1242 significantly greater than
500 ppm Aroclor 1016, p < 0.05.
Figure III.10.7 (from ref. 245)
-------
IJCC
. 1200
1100
lit
gi'WQO
25 *
JOB
200
100
1000
900
800
*• TO
O
CB
8 M0
MO
200
100
i
— 1.6
_ 4 MONTHS Pp
— QWOppmAR 1242 ^
EJlMppmAR 1016 #
_ BsMppmAR 1016 ^
- . v -I I
-••' • fiili'
C
6 ~
5 -
; *
P- 550 M-Ct'-'ilHV- A:.li. :.£ M 80- CLyCWQiSYI.
USE MVOROXV- REOUCIA5E IRANSFCRASC
LASE
a.b
-
^ a
~ ji
~ m
— a ».t ^ ;';
PROtOhEMt IIWR MICRO- UVERIBOOY ALA
WEICHf SOMAL AEIGHl SVN1
PROTEIN
-
-
a
I-
5 -
1
3 H ~
1 H -
s
H!US£
Effect of Aroclors 1016 and 1242 on cytochrome P-450, drug-metabolizing enzymes, proto-
heme, liver weight, liver microsomal protein, and ALA synthetasc activity at 6 mo. Groups of six
female rats fed 100 or 500 ppm of Arociors 1016 and 1242 were sacrificed at 6 mo. Values represent
weans ± SE. a—Significantly greater than conirols at p < 0.05. b—100 ppm Aroclor 1242 significantly
greater than 100 ppm Arocior 1016, p < 0.05. c—500 ppm Aroclor 1242 significantly greater than
500 ppm Aroclor 1016, p < 0.05.
Figure III.10.8 (from ref. 245)
-------
III.10.7. Synergistic effects on enzyme induction.
Araki and Tanaka (246) reported significant synergistic
effects between PCBs, DDT and BHC (HCH) in inducing hepatic micro-
somal enzymes in vivo. Using hexobarbital sleeping time as the in-
dicator of enzyme activity, they found that the activities of DDT
and 8-HCH were about one-eighth of those of the same dose of PCBs
(KC-400). When a small dose of DDT or ft-HCH was combined with a very
small dose of PCBs (each about one-quarter of the minimal effective
dose when tested singly) the inducing activity was strongly potentia-
ted.
III.10.8. Structural changes in liver.
Structural changes in liver cells, in addition to proliferated
smooth endoplasmic reticulum, include: increase in lipid droplets
within the cytoplasm, the formation of numerous multi-layered con-
centric membrane arrays, increase in numbers of microbodies and lyso-
somes within cells, and reduction of rough endoplasmic reticulum.
Microscopically, enlargement of individual hepatocytes was
apparent. Present in the abundant cytoplasm of these cells were
numerous small fat vacuoles, proliferated endoplasmic reticulum and
large concentric membrane arrays (CMA). The CMAs encircled lipid
droplets and other cytoplasmic organelles. There was a moderate in-
crease in lysosomes. Other organelles, including the nucleus, were
normal in appearance (188).
The CMAs may represent a means by which the hepatic cells
are able to incorporate more membranes in a given area, thereby
-------
enhancing metabolic activity of the cell. CMAs were observed in rats
after three weeks on a PCB-containing diet. The arrays increased in
size and complexity in direct relationship to the time the rats stayed
on the experimental diet (188).
Several other liver lesions have been observed after exposure
to PCBs. Dietary exposure (500 ppm) of Sherman rats to Aroclor 1254
for 6 to 8 months produced extensive areas of adenofibrosis in the
liver. Fatty metamorphosis, accumulation of brown pigment in hepatic
macrophages and Kupffer cells are also seen (187, 189, 208; Tables
III.9.4, III.9.5). Adenofibrosis is firm and grayish white, with a
pitted or granular surface. On microscopic examination it consists
of fibrosis and proliferated, atypical glandular epithelium that forms
ducts and cysts. The cysts usually contain mucus or cellular debris
(189). Some clusters of atypical glandular cells resemble pancreatic
tissue in appearance and staining properties (247). The relation of
these and other liver lesions to the development of neoplasia is
discussed below under Carcinogenesis (Section III.14).
Nishizumi reported some variation in size of nucleus of mouse
liver cells after 17 weeks of oral administration of PCBs (1.5 mg/day).
He also noted enlargement of Kupffer's cells in livers of PCB-treated
mice and monkeys (210) .
III.10.9. Changes in biochemical composition of the liver.
Biochemical data obtained from liver homogenates of PCB-treated
rats clearly indicates hypertrophy of the liver. As a result of
membrane proliferation and more numerous ribosomes, there was an
-------
increase in protein content and RNA levels. Increased protein
content of liver homogenate indicates more protein containing mem-
branes within the cells. More ribosomes and the related increase
in RNA would be necessary for production and maintenance of the
elaborated membrane systems. These ribosomes are apparently not
attached to the endop.lasmic reticulum. A relative decrease in DNA,
when expressed in relation to total liver weight, further signifies
the proliferated state of the cytoplasmic components. There was no
appreciable change in total DNA of liver or in amount of DNA per
cell (188).
Changes in biochemical composition of the liver after expo-
sure to PCBs include a significant increase in total lipid content
(182). Triglyceride content of the liver increased with increased
dosage of PCBs (from 5 to 500 ppm) in the diet (219). This in-
crease was greater with Aroclor 1248 than with 1242, 1254 or 1260
(Figure III.10.9). The ratio of phospholipids to protein increased
and the ratio of cholesterol to protein increased (221), The in-
crease in liver lipid following PCB exposure is due in part to an
increase in lipid synthesis and in part to a decrease in transport
from the liver (248). Marked increases in liver lipids have also
been noted in treated rabbits (256).
Allen and Abrahamson (188) observed compositional changes in
liver microsomes of PCB-treated rats. Increase in protein content
of microsomes was apparent soon after ingestion of PCBs and per-
sisted throughout the four-week examination period. The levels of
-------
300
200
100
50
* CHLORINE
Effect of dose and chlorine content of Arodorson hepatic triglyceride concentrations in rats
after 4 \vk. Each point represents the mean of 3 replicates. With one exception all SD values were less
than 10% of their respective means (SD of the 5 ppmdoseof Aroclor 1248 was IS? „ of its mean!.
Figure III.10.9 (from ref. 219)
-------
phospholipids also increased moderately. There was a decided de-
crease in cholesterol and RNA in all experimental liver microsomes.
The increase in microsomal protein further substantiates the
proliferated state of the endoplasmic reticulum since there would be
more membranes per gram of liver. The decrease in microsomal choles-
terol and the moderate increase in phospholipid content were, however,
unexpected since proliferation of endoplasmic reticulum is usually
accompanied by increases in protein, phospholipid and cholesterol
at approximately the same rate. The decrease in microsomes is com-
patible with a proliferated state of the smooth endoplasmic reticulum.
The increase in microsomal protein is related to an enhanced activity
of the microsomal enzymes (188).
Bitman e_t al. (166) observed a very striking decrease of about
50% in liver concentration and content of vitamin A in rats fed 100
ppm Aroclor 1242 for 2 months. A decrease in liver storage of vita-
min A in rats is also a symptom of repeated exposure to other chlorin-
ated hydrocarbons (166, 5, 174).
III.11. Induction of Porphyria.
Porphyria cutanea tarda in humans is an acquired defect in
hepatic porphyrin metabolism, characterized by uroporphorinuria (ex-
cretion of porphyrins in the urine), photosensitivity as manifested
by blisters, and mechanical fragility of the skin (5). The hepatic
porphyria which is responsible for the increase in porphyrins and for
the skin photosensitivity can be produced experimentally by a number
of drugs and chemicals which have the ability to stimulate activity
-------
of the initial enzyme in the heme synthesis, o-aminolevulinic acid
(ALA)-synthetase (249: see Figure III.11.1).
PCBs produce hepatic porphyria in animals. Goldstein et al.
(250) observed hepatic porphyria in Sherman rats exposed to Aroclor
1254 in the diet for at least seven months. The porphyria resembled
human porphyria cutanea tarda. When female rats were fed 100 ppm
Aroclor 1254 in the diet, they developed hepatic porphyria in two to
. four months. At this time, the urinary porphyrin excretion increased
rapidly. Uroporphyin excretion was elevated to a maximum of 540-fold,
coproporphyrin, porphobilinogen 50-fold and ALA 18-fold. Massive
amounts of 8- and 7-carboxyporphyrins accumulated in the liver. The
major porphyrins excreted in the urine of PCB-treated rats were 8-
carboxyporphyrin (73%) and 7-carboxyporphyrin (167«). Substantial in-
crease in amounts of 5- and 6-carboxylic porphyrins were also observed.
Excretion of coproporphyrin increased 10-fold while excretion of uro-
porphyrin increased 1400-fold. In control rat urines, coproporphyrin
made up 81% of the porphyrin fraction. Porphyrin concentrations were
high in livers of PCB-dosed rats but only a trace of porphyrin was
found in liver samples in control rats.
The tremendous accumulation of uroporphyrins in the liver and
urine of rats fed Aroclor 1254 suggests that PCBs may affect uropor-
phyrin formation or utilization. Hemosiderin has "been found in the
liver of rats treated with Aroclor 1254 (187). A partial block in
heme synthesis may be involved in PCB-induced porphyria.
Induction of porphyria by PCBs is dependent on protein syn-
thesis, endogenous iron, and perhaps cytochrome P-450 (251). There
-------
The purphyrin baem
biosynlhetic pathway.
Glycine* Succinyl- Co A
ALA Syntase
ALA
Intramitochondrial
Extramitochondrial
ALA
ALA Det-.ydratase
PBG
Uro i Syntase
Uro in Cosyntase
Haem
rerrocheiatase
Proto ix
Copro ui Oxidase
Copro HI gen
oxidation
Cooro in gen » Ccpro
Uro Decarboxylsse
Ufo
Figure III.11.1 (from ref. 248)
-------
24-1
is some evidence that the active agent is an unstable metabolite,
perhaps a hydroxylated chlorobiphenyl (251).
Aroclors 1016 and 1242 also induce porphyria in rats (243,
245). After dosing at 10 and 100 mg/kg/day for 21 days, both mix-
tures caused a significant accumulation of porphyrins in both sexes,
but Aroclor 1242 was nearly twice as effective at 100 mg/kg and pro-
duced a significant effect at the lower dose (Tables III.10.5, III.
10.6). After feeding at 100 and 500 ppm, both Aroclors induced
porphyrins in liver and urine (Figure III.11.2, Table III.11.1), but
Aroclor 1016 did so only at the higher dose. Induction of ALA-syn-
thetase followed the same pattern (Figure III.10.8).
Rabbits developed symptoms of porphyria after application of
Clophen A60, Phenoclor DP6 and Aroclor 1260 to their back skin (204).
Increased fecal excretion of coproporphyrin and protoporphyrin was
observed in rabbits with a chromatographic fraction of the PCS mix-
tures which would contain any dibenzofurans present. Hence Vos
suggested that porphyria is caused by PCBs themselves and not by
PCDFs (128, 204). This has been supported by the recent work of
Goldstein et al. (146, 193),'who found that mice fed 3,4,5,3',4',5'-
hexaCB developed porphyria, but those dosed with 2,3,7,8-TCDF did not.
In the same experiment 2,3,7,8-TCDD induced porphyria in mice (146),
but TCDD is not a potent inducer of ALA-synthetase in other species
of mammals (202, 252).
-------
Zft-i.
270
260
250
2JO
220
^210
§200
I HO
2 ISO
S !70|
. HCCMROLS
• OHOppnARU.
Effects of Aroclors 1016 and 1242 on urinary coproporphyrin and uroporphyrin excretion.
Treatment is described in Fig. 3. Values represent means ± SE. The numbers above the bars represent
the proportion of animals whose individual values were outside ihe 99°'0 confidence limits of the
controls at p < 0.01. a—Significantly different from controls, p < 0.01.
Figure III.11.2 (from ref. 245)
-------
Table III.11.1 (from ref. 245)
EFFECT OF AROCLORS 1016 AND 1242 ON LIVER PORPHYRINS IN THE RAT*
1 Week 6 Months
Treatment 7-COOH 8-COOH 7-COOH 8-COOH
Control
100 ppm Aroclor 1242
500 ppm Aroclor 1242
100 ppm Aroclor 1016
500 ppm Aroclor 1016
Trace"
Trace*
Trace"
Trace"
Trace*
Trace*
Trace*
Trace*
Trace"
Trace"
Trace*
164±27
227 ± 59
Trace"
89 ±23
Trace*
534 + 61
669 ± 146
Trace"
343 ± 65
* Porphyrins were methylated and analyzed by thin-layer chromatography. Female rats were
treated as described in Fig. 1. Results are given as the mean ± SE.
-------
III.12. Miscellaneous Biochemical Effects
III.12.1. Hypertriglyceridemia
In addition to the increases in liver lipids noted above in
Section III.10.8, PCBs have been shown to cause increases in serum
lipids in rats (181, 253) and in rabbits (254, 255). The doses used
to show these effects were quite high (100-300 mg/kg/day in rats,
10-100 mg/kg/day in rabbits).
III.12.2. Effects on the adrenal gland
Wassermann et al. (257) observed a rise in the activity of
the zona fasciculata of the adrenal gland in PCB-treated rats.
After ten weeks of receiving 250 ppm of Aroclor 1221 in their drink-
ing water, rats had a mean corticosterone plasma level twice as high
as control rats. Morphological changes in the zona fasciculata of
the adrenal gland also indicated increased activity, corroborating
the biochemical data.
III.12.3. Effects on thyroxine.
Hepatic conjugation of thyroxine to glacuronic acid and excre-
tion in the bile of thyroxime-glucuronide is a major route of thyrox-
ine metabolism. Thyroxine-glucuronide formation is rate limiting for
biliary thyroxine excretion.
The effects of PCB on thyroxine metabolism resemble the effects
of such polycyclic aromatic hydrocarbon (PAH) enzyme inducers as 3,
4-benzo(a)pyrene and 3-methylcholanthrene. The polycyclic hydro-
carbon type of hepatic microsomal enzyme inducer enhances biliary
-------
thyroxine-glucuronide formation (258). After daily treatment of
rats with 25 mg/kg body weight of Aroclor 1254 for four days, biliary
thyroxine excretion increased 4- to 5-fold. The ratio of iodine in
bile to iodine in plasma was elevated tremendously. The rate of
clearance of thyroxine from the blood through biliary excretion
was greatly increased by PCB treatment. In PCB-treated animals, the
proportion of free thyroxine in bile was reduced while the propor-
tion of thyroxine in its metabolized form (thyroxine-glucuronide)
was increased.
In PCB-treated rats, serum protein-bound iodine concentrations
were less than half of normal. This may be attributed to enhanced
biliary excretion of thyroxine and also to inhibition of thyroid
hormone binding to plasma proteins. PCB, administered _in vivo or
added in vitro to rat serum, reduced binding of thyroid hormone to
serum protein. This inhibition of plasma protein-binding of thyrox-
ine may, in turn, contribute to the enhancement of biliary thyroxine
excretion induced by PCB (258).
PCBs increased thyroid function, as shown by elevated
uptake (258). For a review of effects of PCBs on the thyroid, see
Jefferies (174).
III.12.4. Hematological effects.
Changes in blood composition and bone marrow histology have
been observed in animals after exposure to PCBs.
Allen et al. (195) found that hematological changes developed
gradually in rhesus monkeys fed diets containing 300 ppm Aroclor 1248.
-------
Over three months, there was a decrease in hemoglobin of approxi-
mately 2 g/100 ml and a decrease in hematocrit from 40 to 33%. No
major modifications of total white cell count were noted. However,
there was a gradual decrease in the number of lymphocytes and a con-
comitant increase in neutrophils. There was also a decrease in
total serum protein of 1.5 - 2 g/100 ml. A gradual shift in albumin/
globulin ratio of serum protein also occurred. Allen _et al. (215)
speculate that PCBs may have an inhibiting effect on the red-blood-
cell-forming tissue of bone marrow.
Bruckner et al. (259) found some evidence of anemia in rats
given intraperitoneal injections of Aroclor 1242. Hematocrit,
erythrocyte count,erythrocyte diameter, mean corpuscular hemoglobin
concentration, and total blood hemoglobin concentration were all
somewhat lower in PCB-dosed animals than in controls. An elevation
in the leukocyte count was noted in the blood of PCB-dosed rats, with
a large increase in the proportion of circulating neutrophils. In-
creased leukocyte counts were a consistent finding also in dogs
chronically exposed to PCBs (212).
Other changes in blood of PCB-dosed animals observed by
Bruckner et al. (259) include an elevation of serum iron and a de-
crease in both plasma corticosteroid and glucose concentration.
Blood urea nitrogen concentration and serum bilirubin values were
unchanged. The elevated serum iron and the decrease in hemoglobin
concentration suggest a decreased incorporation of iron into proto-
porphyrin. Bruckner _e_t al. (259) decided that the mild reduction in
-------
erythrocyte count in PCB-dosed animals was not due to hemolytic
action since they found identical bilirubin values in serum of
PCB-dosed and control rats. No alteration in osmotic fragility of
erythrocytes was observed.
III.12.5. Enzyme inhibition.
PCBs have an inhibitory effect on some enzymes. Hendrickson
and Bowden (260) demonstrated _in vitro competitive inhibition by PCBs
of lactic dehydrogenase in rabbit muscle. Lactic dehydrogenase is
the terminal enzyme of anaerobic glycolysis.
Sharp jjt al. (261) showed that beef brain and rabbit kidney
(Na+ + K*) - ATPases were inhibited by PCBs. The (Na+ + K*)ATPase
is generally thought to comprise the membranal sodium pumping system.
The extent of enzyme inactivation increased as the degree of chlorin-
ation increased (262). Sharp et al. (261) obtained experimental
evidence to support the hypothesis that PCBs inactivate membrane
(Na+ + *d")ATPases by interfering with the stabilizing function of
acidic phospholipids. Similar effects have been reported on ATPases
in fish and have been linked with disruption of osmoregulation (127).
-------
III.13. Immunosuppressive Effects
The ability of PCBs to inhibit immune responses has been
demonstrated in several mammalian species. Following dermal expo-
sure of rabbits to PCBs, Vos and Beams (204) observed atrophy of the
thytnus and a reduction in the number of germinal centers in spleen
and lymph nodes. The thymus, spleen and lymph nodes are all lympha-
tic structures vital to the body's immune defense system. The
germinal centers in spleen and lymph nodes are the principal produc-
tive field of lymphocytes. The thymus secretes a hormone that enables
lymphocytes to develop into plasma cells which can synthesize anti-
bodies against foreign proteins. Vos and Beems (204) also observed
a reduction in total white cell counts in rabbits whose skin had been
painted with PCBs. These observations suggest immunosuppressive
action of PCBs.
Vos and de Roij (263, 129) reported a function test of the
immunological system on three groups of twelve female albino guinea
pigs fed 0, 10 and 50 ppm Aroclor 1260 for eight weeks. Tetanus
toxoid injection was used to test the humoral immune response. They
observed a significantly reduced number of Y-globulin-containing
cells in lymph nodes of PCB-fed guinea pigs stimulated with tetanus
toxoid, together with a significantly decreased V-globulin level in
the serum of toxoid-stimulated animals fed 10 ppm PCB. These obser-
vations demonstrated that some immunosuppression is produced by PCB-
feeding.
Vos and van Driel-Grootenhuis (264) investigated cell-mediated
immunity as well as the humoral immune response in guinea pigs. A
-------
suppression of the humoral immunity, after stimulation with one dose
of tetanus toxoid was found at the 50 ppm level. The antitoxin levels
were significantly decreased. The number of antitoxin-producing cells
in skin reactions after tuberculination was the parameter of cell-
mediated immunity. This test indicated a significant reduction in
cell-mediated immunity at the 50 ppm level of PCBs in the diet.
Major effects on the lymphoid system due to the suppressive
activity of PCBs included strongly reduced weights of the thymus,
lymph node and, to a lesser extent, of the spleen (128, 264). Atrophy
of the thymus in newborn rodents reduced the capacity of these ani-
mals to produce serum antibodies, resulting in wasting disease
(cachexia). Such animals are then incapable of rejecting foreign
skin grafts (5). Cachexia and depletion of the lymphoid system were
observed in PCB-fed guinea pigs (264).
Roller and Thigpen (265) compared effects of Aroclors 1221,
1242 and 1254 on the humoral antibody response of rabbits exposed to
pseudo-rabies virus. Rabbits fed all three PCB formulations had
significantly lower serum-neutralizing antibody titers to pseudo-
rabies virus than did rabbits who were not given PCB formulations.
The serum titers from rabbits given PCBs were approximately one-half
those of controls. Aroclor 1242 produced the lowest titers, succeeded
by Aroclor 1254 and then Aroclor 1221.
Atrophy of the thymus and/or the spleen has been reported in
several other species treated with PCBs, including chickens (146,
147, 70), mice (146, 147), monkeys (197) and pigs (216). Atrophy
-------
of the thymus and spleen are also striking effects of TCDF in
chickens, guinea pigs and mice (70, 71, 146).
Immunosuppressive effects of PCBs may have been involved in
several instances in which PCB-treated animals appeared more suscep-
tible to disease than controls. These cases included increased sus-
ceptibility of piglets to septicemia (216), of ducks to viral hepa-
titis (178) and of fish to fungal disease (111).
Another potentially serious consequence of immunosuppression
is an increased susceptibility to carcinogens, since suppression of
immune response may make an animal more susceptible to establishment
of neoplastic cell lines and development of malignant tumors.
-------
III.14. Carcinogenic and Co-Carcinogenic Effects
Studies of carcinogenic and co-carcinogenic effects of PCBs
are reviewed in detail in Appendix D and only a brief summary is in-
cluded here.
In a long-term study by Kimbrough et al. (266), Sherman rats
fed 100 ppm Aroclor 1260 in the diet for 21 months developed hepato-
cellular carcinomas (26/184) and neoplastic nodules (144/184) in the
liver, whereas 173 control animals developed only one carcinoma and
no neoplastic nodules. The terminology used to describe the liver
lesions is that developed at a recent workshop of experts in liver
pathology (269), where some of the slides from the PCB-treated animals
were reviewed. The study reported in ref. 266 followed a sequence of
shorter-term studies in which the earlier stages of development of
liver lesions in PCB-treated rats had been described (see Section III.
10.3); in one of these studies, liver nodules had been reported in the
second generation of rats exposed to 20 ppm Aroclor 1254 at an age of
only 330 days (179). Other significant findings in the livers of
treated rats were adenofibrosis (cholangiofibrosis) (189) and abnormal
pancreatic-type tissues (247). The significance of these findings is
not clear. Adenofibrosis has been reported in the livers of rats fed
with carcinogens (268); some experts believe that they have the poten-
tial to develop into cholangiocarcinomas (283), although an earlier
review concluded that they were not convincingly pre-cancerous (284).
In another long-term study (207), groups of Charles River rats
were fed with 1, 10, and 100 ppm Aroclor 1242, 1254, and 1260 for 24
-------
months. Although the initial report indicated only mild liver lesions
(207), a more recent review (68) reports the occurrence of lesions
classified as nodular hyperplasia, hepatomas and cholangiohepatomas
in 44/74 of the rats surviving near to the end of the experiment in
the groups fed 100 ppm of all three Aroclors. Although there are
some terminological problems and findings have not been adequately
reported, these results appear consistent with those of Kimbrough et
al. and suggest an oncogenic potential for all three Aroclors. There
was also an excess incidence of pituitary tumors (chromophobe adenomas)
in all treated groups in this experiment.
Other studies reviewed in Appendix D were conducted for much
shorter periods and generally at higher dose levels; they constitute
little more than preliminary screening tests. Kanechlors KC-500,
KC-400, KC-300 induced nodular hyperplasia and cholangiofibrosis, but
not hepatocellular carcinomas, in rats within 28-52 weeks (190). KC-
400 induced multiple adenomatous nodules in the livers of rats within
400 days (271). Aroclor 1254 induced adenofibrosis and hepatomas in
mice fed for only 6-11 months (191). KC-500 induced nodular hyper-
plasia and hepatocellular carcinoma in mice within 32 weeks, whereas
KC-400 and KC-300 did not do so within the same period (192) .
These six studies are consistent in showing that PCB mixt.ures
with 42-60% chlorine content induce neoplastic and pre-neoplastic
lesions in the livers of rats and mice, and that this induction is
very rapid at high dietary levels (250-500 ppm). Because most of the
studies have been terminated early, the full development of the lesions
-------
has not yet been studied. No long-term feeding studies have yet been
reported which have failed to show some evidence of neoplastic change:
the longest such study was terminated after 12 months (69).
Among co-carcinogenic studies conducted in vivo, KC-500
markedly promoted or accelerated the hepatocarcinogenicity of cxC-BHC
and 8 -BHC in mice (192). However, KC-400 did not promote the develop-
ment of cervical carcinomas in mice induced by methylcholanthrene (272),
and KC-500 inhibited or delayed the hepatocarcinogenicity of three
other carcinogens in rats (273).
Numerous studies have shown that PCBs, by stimulating the
cytochrome P-450 dependent mixed function oxidase system in the mam-
malian liver, can activate secondary carcinogens and mutagens or de-
activate primary carcinogens and mutagens. Pretreatment with PCBs
markedly increases liver injury by vinyl chloride, a known human liver
carcinogen, but decreases injury by 1,1-dichloroethylene (274). PCBs
promote the metabolism of dimethylnitrosamine to .an active mutagen
(281, 282), but de-activate a primary carcinogen (MNNG). PCBs are
exceptionally efficient stimulators of the mixed function oxidase
system and are now used routinely to activate suspect carcinogens in
bacterial mutagenesis bioassays (276, 280).
PCBs are known to stimulate the mixed function oxidase system
at extremely low doses (219) and their action in doing so is potentia-
ted by other environmental pollutants such as BHC and DDT (246).
In addition to their direct carcinogenic effects and co-carcino-
genic effects, the immunosuppressive effects of PCBs are also expected
to be important in potentiating the action of other carcinogens.
-------
III.15. Mutagenic and Teratogenic Effects
Green et al. (285) found no evidence of cytogenetic effects
in bone marrow or spermatogonial cells of rats after treatment with
single or multiple doses of Aroclors 1242 and 1254. There was a signi-
ficant decline in the rate of cell division in rats treated with
multiple doses (150-500 mg/kg/day for 4-5 days). Calandra (68) re-
ported that a dominant lethal mutagenic study with Aroclors 1242, 1254,
and 1260 in mice had given negative results, but details were not
presented.
Villeneuve et_ al. (218) reported that single oral doses of
12.5, 25 and 50 mg/kg Aroclor 1254 administered to pregnant rabbits
were fetotoxic, but did not induce teratogenic effects. Linder et al.
(179) reported that Aroclors 1254 and 1260 had minor fetotoxic effects
when administered at 100 mg/kg/day to female rats on days 7-15 of
pregnancy; Aroclor 1254 also caused substantial mortality in pups
prior to weaning. The pups were described as "grossly normal" but
'apparently were not autopsied.
Teratogenic effects and mutagenic effects of Aroclor mixtures
have been reported in birds (141, 154, 15§, 156, 157, 158, 159, 161).
By analogy with PCDDs, PCDFs might be expected to be mutagenic and/or
teratogenic. Hence it is regrettable that the studies in mammals'
have been reported incompletely. Except for that of Green et a_l. (285),
none of the studies listed above can be regarded as satisfactorily
negative.
-------
III. 16 Effects in Humans
III. 16.1 Chloracne
Chloracne is an occupational disease associated with occupational
exposure to PCBs, poly-chlorinated naphthalenes (PCNs), chlorinated
phenols, 2,4,5-T, PCDFs, and perhaps polychlorinated diphenyl ethers.
The etiology of the disease has been reviewed by Schulz (286), Crow (287),
and Kimbrough (5).
Exposed workers develop small dermal cysts, pustules, and comedos.
These are most commonly found on the face and ears, although other areas
are commonly affected, including the abdomen, back, thighs, forearms,
buttocks, and scrotum. This widespread distribution has been ascribed
to direct contact of the affected parts with contaminated clothing. Mel-
anosis and secondary inflammation may occur also. Systemic effects have
also been stated to occur in several cases, perhaps due to inhalation of
toxic vapors. These systemic effects include nausea, lassitude, anorexia,
digestive disturbance, edema of the face and hands, abdominal pain,
vomiting, burning and soreness of the eyes, impotence and hematuria (2,5).
Deaths due to liver damage have also been reported in association with
exposure to PCNs (2,5). Hepatic porphyria has been associated with
exposure to 2,4,5-T (5), but Crow has suggested that these cases might
in fact be attributable to exposure to chlorinated benzenes used in the
same plant (287).
The onset of chloracne following initial exposure is usually quite
slow. After occupational exposure to PCBs and PCNs, the latent period is
typically about 7 months. The course of the disease is protracted. Chlor-
acne usually persists for several months following removal from the source
and may last up to four years (2).
-------
The extent to which PCBs, and PCDFs, and other chemicals are
responsible for chloracne is still not fully clear. PCDFs are said to
be particularly toxic and acneigenic and to have been abandoned by
industry for that reason (287). The symptoms arising from exposure to
the other chemicals named above are said to be generally similar, except
for the liver effects associated with PCNs. In the case of 2,4,5-tri-
chlorophenol, Kimrnig and Schulz, using an animal model, traced the acne-
igenicity primarily to contaminants, which they identified as PCDDs,
especially 2,3,7,8-TCDD (288). Chloracne has been induced in human
volunteers by skin application of TCDD and commercial PCNs (5, 286).
However, Vos and Beems (204) reported that commercial PCNs are contamin-
ated with PCDFs, as a result of the contamination of commercial naphth-
alene with dibenzofuran. As pointed out in Section II.5.5 above,
commercial PCBs also are now known to contain trace quantities of PCDFs.
Hence the relative roles of PCBs, PCNs, and PCDFs in causing chloracne
are confused.
According to Crow, chloracne has been associated primarily with
mixtures containing .penta- and hexachloronaphthalene, and tetra, penta-
and hexa-chlorobiphenyl. This suggests a structure-toxicity relationship
parallel to that of the CDDs (148). Chloracne is now reported much less
frequently than prior to 1944, and only one recent outbreak associated
with manufacture of PCBs has been reported (5, 289). It is not clear
whether the decline in cases associated with PCBs reflects improvements
in industrial hygiene, reduction in PCDF contamination, or other factors.
Epidemiological studies have recently been started (290).
No long-term follow-up studies of occupationally exposed workers
have yet been reported, so there is no information on the carcinogenicity
of PCBs.
-------
III.16.2 Yusho
"Yusho" is a disease reported in Japan late in 1968 and traced
to consumption of rice-oil contaminated with PCBs from a leaking heat-
exchanger on 5-6 February 1968. Extensive reports on Yusho have been
published by Japanese investigators and several summaries in English
are available (35, 291-293). At least 1,291 persons were affected by
the disease and descriptive epidemiology has been presented for 325
cases (291).
The contaminated rice-oil is reported to have contained about
1,000 ppm of PCBs (Kanechlor KG-400) and is now known to have contained
also about 5 ppm of a mixture of CDFs (34, 35, ; Tables II.5.3, III.16.1).
Thus the Yusho episode involved proportionately much greater exposure to
CDFs than is normal for occupational exposure to PCBs or likely for envi-
ronmental exposure to PCBs. This provides some interesting information
about the effects of PCDFs on humans, but limits the value of the Yusho
episode as a predictor of the effects of environmental exposure to PCBs.
A rough dose-response relationship was constructed relating
severity of symptoms to estimated consumption of the oil (Table III.16.1).
Severe cases were induced by consumption of less than 700.mg of PCBs (and
less than 3.6 mg of PCDFs). According to Kuratsune (291) the smallest
dose causing overt symptoms was about 500 mg of PCBs ingested over approx-
imately 50 days by an individual weighing about 50 kg (i.e. about 200
^ig/kg/day PCBs).
However, these figures are probably too high by a factor of 2-3,
since they were based on an estimate of 2,000-3,000 ppm for the concen-
tration of PCNs in the Yusho oil, whereas the most recent measurements
place the average concentration at only 900-1,000 ppm (Table III.16.2).
-------
Table III.16.1 (from ref. 291)
. Relation between the amount of the K rice oil used by patients and their clinical severity.
Non-affected Light cases Sev?re cases - Total
Loss than 720 ml
720-1,440 ml
More than 1/,40 m!
10
0
0
No. %
(12.0)
(0.0}
(0.0)
39
14
3
No. %
(40.0)
(31 .01
(H.O)
No.
31
31
IS
%
(39.0)
(Gf'.O)
(Rfj.0)
80
45
21
No. %
(100. 0)
(100.0)
(100.0)
-------
Table 3. PCDF's and PCB's in Kan^hlors and Yusho oil.
.
SAMPLE
KANECHLOR
YUSHO OIL
300
400
500
600
A
B
C
PCDFs
PEAK
HEIGHT
METHOD
1
18
5
5
4
5
(PPM)
PERCHLO-
RINATION
METHOD
1,5
16,6
2,5
2,7
4,4
5,1
5,2
PCBs
PEAK
HEIGHT
METHOD
-
;
-
830
900
1030
(PPM)
PERCHLO-
RINATION
METHOD
-
—
-
870
920
. 980
Table III.16.2 (from ref. 35)
-------
Hence the minimal dose for overt symptoms would have been about 70-100
ug/kg/day of PCBs, together with about 0.4 yug/kg/day of PCDFs. The most
highly exposed individuals would probably have ingested more than 3
ug/kg/day of PCDFs (Table III.16.1), a dose that is comparable with the
lethal dose of 2,3,7,8-TCDF in guinea pigs (71). However, it is not
clear that any individuals actually died as a direct result of Yusho
(291).*
As in the case of chloracne, the onset of symptoms was delayed:
reported cases peaked 3-7 months after the contaminated oil was shipped
(291, Table III.16.3). Table III.16.4 summarizes clinical findings on
180 patients studied in detail. The general clinical findings were simi-
lar to those in industrial chloracne, but the Yusho patients had several
additional symptoms. Outstanding among these were hypersecretion of
the Meibomian gland, and hyperpigmentation of the skin; the latter was
associated with increased melanization. Porphyrins were not measured
in Yusho victims, but other signs of porphyria such as photosensitivity
were not reported. Liver damage apparently was not marked, but there
was elevation of serum alkaline phosphatase in severe cases, and in-
crease in smooth endoplasmic reticulum in biopsied material (292).
Other characteristic findings in Yusho were elevated blood-serum tri-
glycerides, increased excretion of 17-ketosteroids in the urine, respi-
ratory distress with secondary infections (292), and peripheral 'neuro-
pathy (Table III.16.4). Unfortunately parameters of the hepatic mixed
function oxidase system do not appear to have been measured.
* One 25-year-old male admitted to hospital in June 1969 (one year after
contracting Yusho) with severe abdominal pain and suspected perforated
duodenal ulcer died from heart failure 3 weeks after operation (401).
-------
Two Yusho victims who died in 1968-69 were autopsied. In addi-
tion to pathological skin changes, both had cystic dilatation, hyper-
plasia, and hyperkeratosis of the excretory duct of the esophageal
gland. The 25-year-old male mentioned in the footnote to the previous
page also had marked fibrinous pericarditis and multiple myocardial fibro
sis with myofibrillar degeneration (401).
A number of live-born and at least 2 still-born infants were
afflicted with Yusho (34, 291, 295). Their symptoms included hyper-
pigmentation of the skin, nails and gingivae, eye discharge, abnormally
large fontanelles, swollen faces, and exophthalmos (259). The abnormal
-------
-------
Table III.16.3 (from ref. 291)
Distribution of patients with yusho diagnosed by January 20,1969, by sex and month when symptoms
appeared.
Month
Before 1968
1968
January
February
Mcrch
Apiil
• May
Juno
July
Auguxt
September
October
November
Dumber
Males
Number
2
0
4
8
15
18
23
27
34
17
8
1
i
Females
Percent
1.3
0.0
2.5
5.1
9.0
11.4
14.6
17,1
21.5
10.8
5.1
0.6
0.6
Number
2
0
8
12
10
15
33 .
32
30
12
14
1
0
Percent
1.2
0.0
3.6
7.2
6.0
9.0
19.8
in. 2
18.0
7.2
8.4
0.6
0.0
Number
4
0
10
20
25
33
56
59
04
29
22
2
1
Total
Percent
1.2
0.0
3.1
6.2
7.7
10.2
17.2
18.1 •
10.7
8.9
b.8
0.6
0.3
Total
158
100.0
167
100.0
325
100.0
-------
Table III.16.4 (from ref. 291)
. Percent distribution of symptoms of Yuoho
reported by 189 patients examined before October 31,
1968.
Symptoms
Dark brown pigmentation of nails
Distinctive hair follicles
Increased sweating at palms
Acnelike skin eruptions
Red plaques on limbs
Itching
Pigmentation of skin
Swelling of limbs
Stiffened soles in feet and palms
of hands
Pigmented mucous membrane
Increased eye discharge
Hyperemia of conjunctiva
Transient visual disturbance
Jaundice
Swelling of upper eyelids
Feeling of weakness
Numbness in limbs
Fever
Hearing difficulties
Spasm of limbs
Headache
Vomiting
Diarrhea
Males
(N-S9)
83.1
61 0
50.0
S7.6
20.2
42.7
75.3
20.2
24.7
56.2
SS.8
70.8
58.2
11.2
71.9
58.4
32.6
16.9
18.0
7.9
30.3
23.6
19.1
Females
(N-100)
75.0
56.0
55.0
82.0
16.0
52.0
72.0
41.0
29.0
47.0
83.0
71.0
55.0
11.0
74.0
52.0
39.0
19.0
19.0
8.0
39.0
28.0
17.0
-------
pigmentation gradually faded but growth was normal, in contrast to that
of children poisoned post-natally, whose growth was retarded.
One infant born before its mother was poisoned apparently contracted
Yusho via breast-milk (296).
Recovery from Yusho has been very slow. Table III.16.5 shows that
there was little significant improvement during the first two years. By
1974, the dermal and mucosal symptoms that had been most marked at the
beginning of the episode had gradually improved, while symptoms such as
general fatigue, poor appetite, inconstant abdominal pain, heavy headed-
ness and headache, feeling of numbness and pain at the limbs, cough and
expectoration of sputum, have become more prominent year by year (29-7:
Table III.16.6). These are considered to reflect some internal distur-
bances (35).
Serum triglyceride levels have remained high in males, but have.
started to decline in females (Table III.16.7). Poisoned women continued
to give birth to affected children at least until 1972 (35). However,
liver function tests have not yet given evidence of serious liver lesions
(35).
A preliminary tabulation of deaths among Yusho patients (Table III.
16.8) suggests the possibility of an excess of cancer, especially in the
stomach and liver, but there are too few cases as yet to draw conclusions.
t t'
The scanty data available suggest that tissue levels of PCBs in
Yusho victims declined rapidly in the first year after their poisoning
and are now only a few times higher than the average in the Japanese
population (Table III.16.9). However, dermatological symptoms and other
signs, including serum triglyceride levels, are correlated with concen-
trations of PCBs in the blood (Table III.16.10).
-------
Table III.16.5 (from ref. 291)
• '. • Prognosis of patients with Yunho.*
Grade of clinical
severity** —
0
1
ft
3
4
Total
Improved
13 (66.7)
30 (51.7)
23 (52. 3^
12 (52.2)
0 (0)
81 (50.9)
Clinical
Stational
6 (25.0)
16 (27.6)
16 (36 -i)
10 i!3.5)
• 10 (100.0)
58 (36.5)
conditions
Worsened
'J (8.3)
12 (20.7)
5 Ul 4)
1 (4. 31
0 (0)
20 (12.fi)
Total
24 (100.0)
58 (100.0)
44 (100.0)
23 (100.0)
10 (100.0)
150 (100.0)
' Calculated from the figures reported by Toshitani and Kitamura.
'* 0: Physhul complaints without skin-lesions.
1: Pigmentation of the skin and the mucous membrane.
2: Comedo formation.
3:.Acneform eruptions.
4: Extensive distribution of acneform eruptions.
-------
Table III.16.6 (from ref. 35)
Frequency of subjective
symptoms complained by patients with
Yusho from 1973 to 1974
Proportion3
Symptoms %
Fatigue 51.4
Headache 41.7
Phymata in articular
region 8.3
Fever 2.8
Cough and sputum 56.9
Digestive disorder 40.3
Numbness of
extremities 33.3
Menstrual disturbance 26.9
(7/26)
Calculated by Kuratsune from
original figures published by
Koda and Masuda (ref. 4).
-------
Results of followup six y on serum triglyceride
a
levels in patients with Yusho .
TR,6LYCER|DE _
PATIENTS • MEAN ± S.D,
• SEX AGE No. 1969 1970 1971 1972 1973 1971
HALE 11-73 11 159 ± 57 166 ± 55 169 ± 60 171 ± 69 161 ± 68 160 ± 118
FEMALE 7-59 26 155 ± 75 161 ± 70 155 ± 80 153 ±63 129 ± 50B 111 ± 56B
A i CITED FROM A REPORT BY OKUMURA ET AL. (REFt19K
B '. SIGNIFICANTLY LOWER THAN IN 1969, 1970, 1971, AND 1972 (p<0.05).
Table III.16.7 (from ref. 35)
-------
Table III.16.8 (from ref. 35)
. Deaths seen among patients with Yusho
CAUSE OF DEATH
MALIGNANT NEOPLASMS
STOMACH CANCER
STOMACH CANCER + LIVER
NUMBER
9
2
CANCER ' I
LlVER CANCER + LIVER CIRRHOSIS I8
LUNG CANCER
LUNG TUMOR
BREAST CANCER
MALIGNANT LYMPHOMA
CEREBROVASCULAR LESION
AMYLOIDOSIS
OSTEODYSTROPHIA FIBROSA
MYOCARDIAL DEGENERATION •*•
STATUS THYMICOLYMPHATICUS
LIVER CIRRHOSIS
SUICIDE
SENILITY
TRAFFIC ACCIDENTS
TOTAL
A : CITED FROM A REPORT BY
B ! AUTOPSIEO CASES.
1
1
1
2
5
, 1B
la
PERICARDITIS I8
I8
1
1
1
5
22
URABE 197«f CREF.2).
-------
Table III.16.9 (from ref. 35)
PCB's concentration in tissues of itients with Yusho and other diseases.
CASE
CASE 1
HIGH SCHOOL
CASE 2,3
ADULT MALE,
FEMALE
CASE 4
BOY, 13
- YRS.
CASE 5
CASE 6
MALE
73 YRS.
CASE 7
FEMALE
48 YRS.
CASE 8
MALE
•• 46 YRS.
CASE 9
FEMALE
35 YRS.
CASE 16
MALE
72 YRS.
NATIONAL SURVEY
MALES AND
FEMALES
25-49 YRS.
TIME OF
DEATH. SKIN
OPERATION WHOLE BASIS
Nov. 1968
Nov. 1968
JULY 1969
JULY 1969 1.2
Nov.1969 1.0
DEC. 1970 0.6
MAY 1972 1.8
SEPT. 1972
APRl975
1973 PfeP
P:iTs (PPM)
ADIPOSE TISSUE LIVER KFFERFNCE
FAT BASIS WHOLE BASIS FAT BASIS WHOLE BASIS FAT BASIS
76 (FACE)
13 (ABDOMEN) . ._ '
32,46 10
(CHEESE-LIKE
SUBSTANCE FROM
ACNEFORM ERUPTIONS)
1.3, 3.7 0.14 9.5
(MESENTERY)
8.7 2.8, 15.1 0.2 10.4
(MESENTERY)
4.4 3.8, 8.4 0.07 3.1
(MESENTERY)
11,12
0.8 0.7, % 0.9 0.07 1.3
(MESENTERY)
3.2 4.3 6.5 0.08 8.4
(MESENTERY)
1.9 . 2.9
(SUBCUTANEOUS)
0.19 0.4 0.04 3.0
(MESENTERY) 14
0.2-4 0.3-6.4 0.01-0.6 0.2-3.1
(N=47) (N=48) (N=51) (N=36)
oO
-------
Table III.16.10 (from ref. 35)
Prevalence of dermatol ical and other signs
among patients with Yusho from April 1973 to
March 1974, in connection with concentration
and gaschromatographic pattern of PCB's in
blood.
PREVALENCE (%)L
SIGNS GROUP A GROUP B GROUP C
(43 CASES) (26 CASES) (3 CASES)
SKIN 51. 2* 0B 0
PALPEBRA 72.1 19.2 0
PIGMENTATION GjNGI1A .95,38 ^y ^
NAIL 74. 4B 34fe6 0
ACNEFORM ERUPTION 34.9 0 0
COMEDO 34.9 23.1 0
INFECTION OF SKIN ^.6 •^'•'A ^
DEFORMATION OF NAIL 65.1 38.5 0
ALOPECIA 0 3.8 0
' DISORDER IN TEETH 18.6 7.7 0
HYPERSECRETION OF 93.0 80.8 100.0
ME 1 BOM I AN GLAND
, CQNC.(PPB)
PCBs IN BLOOD Av.±S.D, 7.2+4.9 4.3±3.1 1.7±0.2
PATTERN A B CD
A : SIGNIFICANT (P<0.05) DIFFERENCE.
B : SIGNIFICANT (P<0.01) DIFFERENCE.
C : CALCULATED BY KURATSUNE FROM FIGURES PUBLISHED BY KODA
D : "A" MEANS THE CHARACTERISTIC GASCHROMATOGRAPHIC PATTERN
REMAINING IN THE BODY OF MOST PATIENTS WITH- TUSHO, B
GASCHROMATOGRAPHIC PATTERNS SOMEWHAT SIMILAR TO "A". "
PATTERNS INDISTINGUISHABLE FROM THOSE OF NORMAL PERSONS
TOTAL
(72 CASES)
30.6
50.0
80.6
56.9
20.8
29.2
23.6
52.8
1.4
13.9
88.9
5.9±4.5
(ref. 4).
AND MASUDA
OF PCBs
MEANS
C MEANS
•
o.
-------
An important new finding is that PCDFs have been retained in
the tissues of Yusho victims, expecially in the liver where their ratio
to PCBs is as high as 1:4 (Table III.16.11), versus 1:200 in the Yusho
oil and 1:60,000 in the original Kanechlor mixture (Table III.16.2).
»
The CDFs found in the tissues consist mainly of one penta- and one
hexa-GDF: most of the isomers in the Yusho oil have not been retained
(Figure III.16.1). The gas-chromatographic pattern of PCBs in Yusho
victims also differs from that in ordinary persons (Figure III.16.2).
Thus there appears to have been selective metabolism and/or excretion
of certain CBs and CDFs in Yusho victims. The possibility that CDFs
have been formed in the liver by metabolism should not be overlooked.
From the data available it is not possible to determine to what
extent the persistence of symptoms in Yusho is due to tissue injury, persis-
tence of PCBs in the body, and/or persistence of PCDFs in the body. The
parallels between Yusho and chloracne are very close, and it is not clear
to what extent the differences (such as the greater frequency of hyper-
pigmentation and eye discharge) are attributable to the high concentra-
tion of PCDFs in the Yusho incident.
III.16.3 Animal models for Yusho and chloracne
Yusho and chloracne are closely related to two diseases in domes-
tic animals. "Chick edema disease" has been discussed in Section III.6.2:
the incident of contamination which caused the'^lfeho episode in 1968 also
caused an outbreak of chick edema disease (144). "X-disease" in cattle,
characterized primarily by hyperkeratosis, but also by diarrhea, poor
appetite and symptoms of the mucous membranes, has been associated with
exposure to PCNs and PCBs ( 5, 298). In each case it is likely that
PCDFs are responsible for some of the toxic effects (298, Section III.6.2).
-------
PCB's and PCDF's in tis es of patients
with Yusho and ordinar., persons.
CASE
SUBJECTS TISSUE No.
1
2
ADIPOSE 3
YUSHO Av,
PATIENTS
2
LIVER 3
Av.
1
ADIPOSE 2
ORDINARY ^
PERSONS LIVER 2
TIME
OF
DEATH
1969
1969
1972
1969
1969
1972
1975
1975
1975
1975
PCBs(ppM)
BASIS
WHOLE
1
1
1
1
0
0
0
0
1
0
0
0
.1
.3
.2
.3
.05
.06
.03
.05
.0
.4
.08
.02
FAT
3
3
2
4
i\
5
3
4
1
0
1
1
.1
.5
.1
.7
.7
.6
.5
.6
.4
.7
.3
.0
PCDF's(ppM)
BASIS
WHOLE
0.
0.
0.
0.
0.
0.
0.
0.
013
006
007
009
025
010
003
013
ND
ND
ND
ND
FAT
0.
0.
0.
0.
2.
1.
0.
1.
ND
ND
ND
ND
03
01
01
03
3
1
3
2
RATIO
PC&S/PCDF's
WHOLE
ioa
217
171
Ml
2
6
10
4
FAT
113
213
210
157
2
5
12
1
Table III.16.11 (from Tef. 35)
-------
-UPPER ;
PCDF FRACTION FROM
LIVER OF YUSHO PATIENT,
LOWER :
PCDF FRACTION FROM
YUSHO OIL,
10
20
30
MIN.
Gaschromatograms of PCDF fractions from liver of patient
with Yusho and from "Yusho oil."
Figure III.16.1 (from ref. 35)
-------
A : FATTY TISSUE OF YUSHO PATIENT
B i FATTY TISSUE OF ORDINARY PERSON
C : KANECHLOR 500 + 600 (1:1)
50
60
rnin.
:• . ", Gaschromatograms (ECO) of PCB's on SE-30,
Figure III.16.2 (from ref. 35)
-------
Some traditional laboratory animals have proved to be poor
models for Yusho and chloracne. Rodents in particular seem to be re-
latively resistant both to PCBs and to PCDFs (Sections III.6 - III.10
above) and some of the symptoms induced in rodents, such as hepatic
porphyria, are not prominent in affected humans. However, hairless
mice fed Yusho,oil developed skin lesions, including hyperkeratosis
of the hair follicle and sweat gland and cystic dilatation (298).
These symptoms appeared more severe than those in mice exposed to
Kanechlor KC-400 (210), suggesting a possible effect of PCDFs. HowT
ever, mice were unaffected by doses of 2,3,7,8-TCDF as high as 6
mg/kg (71), 100 times higher than the cumulative doses of PCDFs in-
gested by Yusho victims. Rats also were affected by Yusho oil,
showing hyperkeratosis of the epidermis and hair follicles, parakera-
tosis of epidermis, and hyperplasia and keratotic metaplasia of the
ductal epithelium in the Meibomian glands of the eyelids (403). These
symptoms parallel those of the Yusho victims, but have not been reported
in other experiments with rats.
Rabbits have been used as a model for screening acneigenic
agents (5, 129, 288). Rabbits are very sensitive to toxic-effects of
PCDFs (129) and application to rabbit skin causes chloracne-like symp-
toms (288). Vos and Beems (204) found that the rabbit skin test was a
sensitive bioassay for PCDF contamination in PCB mixtures, but as dis-
cussed above a later experiment suggested that individual PCB isomers
also have acneigenic action.
Recent work with rhesus monkeys suggests that this species is
the best model for chloracne and Yusho (69, .194-198). The symptoms
-------
found in rhesus monkeys and their offspring fed low doses of PCBs are
quite similar to those found in humans. It is not yet clear whether
the severe gastric ulceration found in monkeys (and to a lesser extent
in other species, but not in rodents) has a parallel in humans, but
the long persistence of digestive disturbances reported in victims of
Yusho and chloracne suggests that it may do so. The occurrence of
cystic dilatation and hyperplasia of the duct of the esophageal gland
in two autopsied victims of Yusho (401) is a close but not exact para-
llel to the findings in monkeys.
III.16.4 The role of PCDFs in the toxicity of PCBs to humans
A key question in formulating criteria for human exposure to
PCBs is the extent to which PCDFs or other contaminants may be respon-
sible for the toxicity of commercial PCBs or environmental residues.
Since many of the symptoms of chloracne and Yusho are known to be pro-
duced in humans (287) or animal models (205, 129, 299, 288) by PCDFs and
PCDDs, it could be hypothesized that PCDFs are the primary or exclu-
sive toxic agents. However, as pointed out in Section III.8 above,
PCB mixtures with extremely low levels of PCDFs have caused chloracne
in monkeys, and apparently pure chlorobiphenyl isomers have done so
also (197). Hence it seems more probable that some chlorobiphenyls --
perhaps isomers with 3,4,3',4'-substitution or other structural simi-
larity to 2,3,7,8-TCDF -- or their metabolites share the toxic proper-
ties of PCDFs. In any case, since PCDFs are present in commercial mix-
tures (Section II.5.5) and appear to be formed from them in the environ-
ment (Section II.8.3), in service (Section II.8.4) and by metabolism
(Appendix E), it is difficult and probably academic to attempt to dis-
tinguish their effects completely in weighing the environmental hazards
posed by PCBs.
-------
IV. ENVIRONMENTAL FATE AND EFFECTS
IV.1. Persistence, Metabolism and Fate
IV.1.1. Persistence
PCBs have a long life in the environment (1-3). The more
chlorinated compounds in particular are resistant to metabolism
(Appendix E) and persist in soils (305), water (41, 42), sediments
(50, 99, 105) and biological tissues (111, 130, 141, 155, 170, 208,
35) for weeks, months or even years. Indirect evidence for their
persistence in the environment is provided by their wide distribution,
even in remote parts of the earth where PCBs are unlikely to have been
used (1-3, 56, 225, Appendix C).
Precise data on the life-time of PCBs after release into the
environment are difficult to obtain, because natural systems are open:
if a decline in concentrations is observed it is difficult to distin*
guish degradation from net export. Horn et al. (329) provided almost
the only unequivocal data: they found PCBs in dated (varved) sedi-
ments in the Santa Barbara basin off southern California. PCBs were
first detectable in sediment layers dated to the mid-1940's and their
concentration in the overlying sediments increased steadily in para-
llel with the known increase in PCB usage. This shows that PCBs can
last for at least 30 years in these circumstances (anaerobic sediments
with no burrowing organisms). More recently Risebrough et al. (56)
have identified PCBs in Antarctic snow at depths up to 6 metres be-
low the surface.
-------
277
Figure IV.1.1 shows concentrations of PCBs measured in oysters
in Escambia Bay, Florida, since 1969 (330). . PCBs in Escambia Bay are
believed to have originated largely from a single point source, iden-
tified and closed in 1969 (99, 330). The residues in oysters in the
bay show seasonal fluctuations (related to spawning) but otherwise
have declined only slowly over the years since 1969.
All these data indicate that the more chlorinated PCBs have a
life-time of years, if not decades, in at least certain compartments
of the environment (2, 331).
IV.1.2. Differential Persistence of Lower and Higher Chlorinated
Biphenyls.
Nisbet and Sarofim (332, 2) pointed out an anomaly, viz.. that
most PCBs found in environmental samples consisted of penta- and
higher CBs, whereas a substantial fraction of the PCBs released into
the environment in the past must have consisted of tetra- and lower
CBs. They suggested that the discrepancy was probably due to differ-
ential degradation of the lower CBs, ruling out the main alternative
explanation (differential mobility) primarily because samples of PCBs
from remote areas also consisted primarily of higher PCBs. A critical
set of observations was that of Veith and Lee (333, 334), who showed
j
from samples of water and fish from the Milwaukee River that the
proportion of lower CBs declined as the water and sediments moved
downstream away from the major industrial sources. However, this
decline could be explained either as differential volatilization or
differential degradation (333).
-------
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-£
I
Mtachm&nt 1
Figure IV,1.1, (ref. 330)
o&
-------
27?
The differential persistence and/or bioaccumulation of lower
and higher CBs is important in establishing criteria, because it im-
plies differential exposure of human and other target organisms to
the various components of the various commercial mixtures. According-
ly the following sections of this document will pay particular atten-
tion to differences in environmental behavior between lower and higher
CBs. The potential for human exposure to tetra- and lower CBs is of
especial importance, because the main difference between Aroclors
1016 and 1242 is the lower proportion of the more persistent penta-
CBs in the former (Table II.3.1). In 1972 it was believed that most
human exposure was to penta- and higher CBs, but recently more evi-
dence for human exposure to tetra-CBs has been presented (331, 332).
IV.1.3. Metabolism
Studies of the metabolic transformation and degradation of
•
PCBs are summarized in Appendix E. Bacteria are able to metabolize
biphenyl and mono- and di-CBs fairly rapidly, but tri- and tetra-CBs
are degraded more slowly and penta-CBs hardly at all (Section E.I).
Accordingly there is considerable differentiation of PCB mixtures
during microbial degradation, as illustrated in Figures E.4 to E.7.
Figure IV.1.2 (from ref. 13) shows that even 14 days' ^.ncubation
/
with activated sludge had little effect on the higher components
(mostly tetra-CBs) in Aroclor 1016.
Aquatic invertebrates and fish are able to metabolize tri-CBs
to a substantial degree but have very little ability to metabolize
tetra- or penta-CBs to non-polar products (Sections E.2 and E.3).
-------
AROCLOR 1016 BIODEGRADATION
I
0
SEMI-CONTINUOUS ACTIVATED SLUDGE
>98
30 MINUTES
14 DAYS
\
8
I
16
I
24
TIME (MIIM)
Figure IV.1.2
I
32
I
40
17
48
-------
lit
Birds and mammals can metabolize tetra- and penta-CBs to
hydroxy derivatives at varying speeds, but they have very little
ability to metabolize hexa- or higher CBs (Sections E.4 and E.5).
The principal mechanism of metabolism appears to be via oxida-
tion to arene oxide (epoxide) intermediates, followed by rearrangement
('NIH shift1) to form hydroxy-CBs. Hydroxylation at the 3- or 4-
positions is favored (Section E.6). Less important mechanisms of
metabolism are direct hydroxylation, dechlorination, and isomeriza-
tion. There is evidence for metabolic formation of CDFs in chickens
and rats (Section E.7). Unidentified non-polar metabolites are
stored in invertebrates and fish (Section E.3).
Metabolism does not always represent detoxification, since
CDFs are much more toxic and at least one hydroxy-CB is substantially
more toxic than the parent compound. The formation of arene oxide
intermediates is of much concern because this reactive class of com-
pounds is implicated as causative agents in toxic, carcinogenic, and
mutagenic effects (Section E.8).
IV.1.4. Photodegradation
The photochemical properties of PCBs were summarized in
Section II.8. Photolysis of PCBs has been studied only under
laboratory conditions and it is difficult to use the data to predict
rates of degradation in the environment. In the experiment which
most nearly simulated environmental conditions (61), there was little
overall degradation after 3 weeks in sunlight and the principal net
effect was a shift from higher to lower CBs in the mixture (Table II.8.3).
-------
Photodegradation does not necessarily represent detoxification, since
lower CBs are formed by dechlorination and small quantities of CDFs
are sometimes formed (Sections II.8.2, II.8.3).
IV.1.5. Transport
PCBs are mobile in the environment and may be transported in
solution, by motion of suspended sediments, as vapors, on airborne
particulates, or in the tissues of mobile animals (2, 12, 332, 333,
47, 50, 52, 53, 54, 56, etc.). They are concentrated at the air/water
interface (52, 55) and may be transported across it by several mech-
anisms, including volatilization, solution, dry fallout of particulates,
\
precipitation in rain and snow, or ejection in spray (Section II.8).
Critical measurements are scanty and conflicting (56) and it is still
not possible to construct satisfactory models of transport to and from
the aquatic environment (56, 331).
Within bodies of water, there is evidence that the transport
of PCBs is controlled by the presence and transport of sediments
(Section II.6.5). The presence of sediments or particulates inhibits
of PCBs
volatilization/(41, 42) and is strongly associated with their trans-
port (50, 56, 12). In natural waters with high sediment loads it
may be reasonable to treat PCBs as passively transported on particu-
lates, but it is not known whether this would be valid for the ocean
or for clear lakes. However, it is questionable whether conditions
in aquaria without sediments provide good models for natural environ-
ments .
-------
IV.I.6. Fate
Theoretically, there are three ultimate fates for PCBs released
into the environment: metabolic degradation, photolytic degradation,
and deposition in sediments in lakes or the deep ocean (2). All three
processes are known to occur, but their relative importance in the
natural environment remains to be determined (2, 56, 331).
IV.2. Bio-accumulation and Bio-magnification
IV.2.1. Mechanisms of uptake and accumulation
One of the most important environmental properties of PCBs
is their tendency to be "bio-accumulated" by aquatic organisms --
i.e., to be concentrated into their tissues to levels much higher
than those in the ambient water (1-3). This property results from
the high solubility of PCBs in lipids and their low solubility in
water: Metcalf et al. (45) have shown that the degree of bio-accumu-
lation of a chemical in aquatic animals is closely related to its
partition coefficient between organic solvents and water (Figure II.
6.6). There is a further tendency for PCBs to be concentrated into
the tissues of animals to levels higher than those in their food (1-3)
this phenomenon is sometimes referred to as "bio-magnification".
Within organisms, PCBs are further concentrated into certain organs,
especially the fat (1-3).
The kinetics of organochlorine 'compounds in animals have
recently been reviewed by Moriarty (335). It is necessary to con-
sider "bio-accumulation as a multi-stage process: the chemicals are
taken into the organism via food, water, or air, circulated through
-------
the organism in the blood, transferred into and out of various organs,
and finally metabolized and/or excreted. Each stage of transfer is a
dynamic process whose rate depends on the concentrations of the
chemicals in the various media and body organs. Under conditions of
constant exposure, an organism may eventually reach a quasi-equilib-
rium, in which the concentrations of the chemical in the tissues are
constant. It is then possible to define a storage factor (ppm in
organism/ppm in ambient medium). In principle, storage factors should
be defined separately for each organ in the body, but in practice it
is common to define a single "bio-accumulation factor" (average ppm
in whole body/ppm in ambient water). However, where the time re-
quired to reach equilibrium is long, as it often is for PCBs, the
organism's physiological state may change and a true equilibrium
may never be reached (335).
Aquatic plants take up PCBs directly from water, and tlieir
bio-accumulation factors reflect partitioning across the cell mem-
branes. Animals may be exposed to PCBs in food, in air, or in water.
Aquatic invertebrates and fish have to process so much water in order
to breathe that they usually reach quasi-equilibrium with PCB con-
centrations in water fairly quickly; intake via food is usually
only a minor route o'f intake (336). Accordingly the storage factor
(ppm in whole body/ppm in ambient water) is the most useful measure
of bio-accumulation. However, for air-breathing animals such as
birds and mammals the food is usually the most important route of
intake and the storage factor (ppm in whole body/ppm in food) is
-------
the most useful measure: this factor is sometimes referred to as
the "bio-magnification factor" (336).
Laboratory experiments on bio-accumulation and bio-magnifica-
tion are usually highly simplified, involving constant exposure via
one route only. The situation in the real world is more complex,
since animals are exposed simultaneously via several routes, levels
of exposure fluctuate greatly in time and space, and the animals'
physiological state changes in response to aging and periodic en-
vironmental stresses. Accordingly, while laboratory experiments
provide useful information on mechanisms of uptake and excretion, and
comparative data for the various components of PCBs, they do not
necessarily provide quantitative measures of the degree of bio-
accumulation and bio-magnification to be expected in the field.
Measurements on wild animals in the field are needed to gauge the
extent of bio-accumulation and bio-magnification, and to specify their
variability in time and space.
IV.2.2. Bio-accumulation in Aquatic Invertebrates
In laboratory experiments, Sanders and Chandler (98) found that
uptake and bio-accumulation of Aroc lor 1254 by some aquatic inverte-
brates was very rapid. Bio-accumulation factors for various organisms
ranged from 2,800 in stone-flies to at least 47,000 in Daphnia inagna
(Table IV.2.1). In scud (Gammarus gseudolimnaeus). the tri- and
tetra-CBs in Aroclor 1254 were differentially accumulated by factors
2-8 times higher than the hexa- and hepta-CBs (Table IV.2.2). Nebeker
and Puglisi (93) found bio-magnification factors of 16,000-36,000 for
-------
Table [V.2.1
(from reE. 98)
36 v
Biological magnification of Cl-lqbcled Aroclor" 1254 by aquatic Invertebrates
Organism , Organisms
pec l/r
sample—
Dcphnld
Daphnla magna 60
Phantom midge
Chaoborus punctlpennls 5
Scud
Conniarus pscudollmnaeus 6
Mosquito larvae
Culex tarsalls 10
Glass shrimp
Palacmonctes kadlakensla 3
Stonefly
Pteronarcys dors at a 3
Dobsonfly
Corydalus cornutus 3
Crayfish
Orcor.ectes nals 2
Organism
Water concentration 3/
concentration (4 day exposure) Magnification factor"
ppb x t SE=/ ppm K t SE 1-day 4-day 7-day 14-day 21-day
1. 1 t 0.2 52 4 2.0 24,700 47,000
1.3 t O.I 10 t 1.6 22,000 23,000 23,800 24,800
1.6 t 0.1 19 i 3,0 17,000 \> 24,000 26,000 27,500 27,000
• I
1.5 t 0.3 2742.0 12,600 18,000 20,000
1.3 t 0.1 16 ± 2.6 10,300 12,300 13,700 14,200 16,600
2.8 i 0.8 7.0 t 0.30 2,100 2,500 2,800 2,900 2,800
1.1 t 0.1 5.1 t 0.23 1,400 4,600 5,700 6,600 6,800
1.2 t 0.1 0.2 i 0,20 570 1,700 3,400 4,500 5,100
— Samples were taken In triplicate.
— Samples were taken la triplicate and expressed as mean value t standard error (P".05).
—'Concentration In organism/concentration In water.
-------
Table IV.2.2
(from ref. 98)
Changes in isomer ratios of Aroclor 1254 residues in scud
Peak No.
1
2
'•• • :. 3
..-.-.'•4
• &"5- .
. ..v'6
7 :
8 .
9
, 10
.11
12
13
14 '
15
•16 •
17
Rel. Ret.
Tinei'
0.27
0.37.
0.45
0.50
0.63
0.77
0.98'
1.07 '
1.19
1.31
1.59
1.67
1.79
2.04
2.61
3.22
3.68'
Concentration
2/ Factor—'
No. Cl's~~ Sample . Average
1 2 '
3
4
4
• 4
5
. . 5
5
5
6
- 6
6
6
7
6
6
7
' 7
2.00
. 1.69
1.81
• 1.80
1.31
1.00
1.13
1.07
0.33
0.84
0.55
0.80
0.43
0.56
0.50
0.25
0.25
2.00
1-72 .
1.81.
2.00
1.31
1.00
1.16
1.16 '
0.66
0.85
0.55
0.80
0.57 '
0.60
0.62
0.50
6.25
2.00
1.71
1.81
1.90
1.31
1.00
1.15
1.12
0>49
0.85
0.55
0.80
0.50
0.58
.0.56
0.37
0.25
Aroclor^
1254
R.P.A. ;'.
0.03
0.29
0.11
0.05
0.51
1.00
0.38
0.57
0.03
0.65
0.33
0.30
0.07
0.45
0.08
0.04
0.04
— Retention time relative to £,£* DDE on GLCUcolumn of 2 mm i.d. x
1.8 m 0.3% w/w OV-7 on 80-100 mesh Corning 110 glass beads; 15
. ml/nin. flow of nitrogen carrier gas; column operated at 155° C.
2/ . .
— Number of chlorine atons substituted on biphenyl ring determined
by gas chroraatography-niass spectrometry (9).
— Concentration factor -^ Relative Peak area of sample £ Relative
Peak areas as Aroclor^ 1254.
-------
the same species of scud when exposed to Aroclor 1242, and of 28,000-
108,000 when exposed to Aroclor 1248. In estuarine shrimps, bio-accumu-
lation factors ranged up to 26,000 during chronic exposure to Aroclor
1254 (104: Table IV.2.3). In short-term tests, shrimp accumulated
Aroclor 1016 to levels 2-4,000 times higher than those in the ambient
water within 96 hours (100). Bio-accumulation factors reported in
oysters ranged up to 101,000 (108) and to 165,000 (337).
In a comparative study in a model ecosystem, Metcalf et al.
(45) found higher bio-accumulation factors for representative tetra-
and penta-CBs than for a representative tri-CB (Tables E.4 and E.5).
In snails the bio-accumulation factors (E.M. in Table E.5) recorded
after 33 days were 5,800 for the tri-CB, 39,400 for the tetra.-CB,
and 59,600 for the penta-CB. In mosquito larvae the corresponding
factors were 815, 10,600, and 17,300, but these represented only
6 days' exposure. It should be noted, however, that some of the
unidentified non-polar metabolites were bio-accumulated even more
than the parent CBs (Table E.4). "Unknown I" from the tri-CB, for
example, was bio-accumulated 12,000 times in the snail and 8,000
times in the mosquito.
IV.2.3. Bio-accumulation in Fish
In laboratory experiments in flowing sea water, juvenile
pinfish (Lagodon rhomboides) and spot (Leiostomus xantherus), both
accumulated increasing amounts of Aroclor 1254, up to quasi-equilib-
rium levels, as duration of exposure increased (111). Spot exposed
to 1 ppb Aroclor 1254 for 56 days reached maximum residue levels of
-------
Table IV.2.3
Length of
Exposure
(hr/ days)
0
1
2
3
4
8
12
16
24 / 1 .
. 36 / 1.5.
48/2
72/3
•96/4
154 / 6.5
336 / 14
504 / 21
672 / 28
840 /35
1176 / 49
1512 / 63
ACCUMULATION OF AROCLOR 1254 IN Palaemonetes pugio WITH TIME
AFTER EXPOSURES TO THE CHEMICAL IN WATER AT THREE CONCENTRATIONS
(Each value represents a composite sample of 10 animals)
Control
Body Cone.
Cone. Factor
(mg/kg)
0.1
0.1
0.1
0.14
0.10
0.1
0.15
*
*
*
*
*
*
*
*
*
*
0.04 . .
Body Cone.
Cone. Factor
(mg/kg)
0.09
Body Cone.
Cone. Factor
(mg/kg)
0.62
Body Cone.
Cone-. Factor
(mg/kg)
0.1
0.1
0.1
0.1
0.1
o.i
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.13
0.15
0.17
0.21
PCS -
0.1
0.1
A
A
A
A
A
A
A
A
A
*
A
A
A
1590
3250
3750
4250
5250
STOPPED
A .
A
0:1
0.1
0,1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.10
0.14
Q. 15
0.33
0.43
0.45
1.57
0.75
0.12
0.13
A
A
'A
A ^
A
A
A
A
A
A
1100
1560:
1670
3670^
4780
5000
17400
8330
A
. A
0.1
0.1
0.1.
0.1
0.1
0.12
. • 0.14
0.26
0.20
0.20
0.37
0.58
0.40
1.28
• 7 .'40
6.67
10.82
16.48
3.24
1.64
A
A
A
A
A
190
230
420
320
470
600-
930-
• 650
2060
• 11930
10900
17450
26580
A
*.
* Magnification factor not calculated.
ocj
-------
37,000 times the water concentration in 14-28 days (Figure IV.2.1),
whereas pinfish exposed to Aroclor 1254 accumulated it to 22,000 times
the water concentration (111). Thereafter, the concentration of PCS
(ppm in tissues) remained roughly constant while the total amount
continued to increase as the fish grew. After placing the fish in
clean water the PCBs were gradually eliminated, falling by half in
about 4 weeks (Figure IV.2.1). In a parallel experiment with pinfish
exposed to Aroclor 1016, a bio-accumulation factor of about 20,000
was measured after 42 days (Table IV.2.4, Figure IV.2.1, ref. 100).
Thus the bio-accumulation of Aroclors 1016 and 1254 was similar in
this fish. However, there was some differential uptake of the com-
ponents of Aroclor 1016, since the peaks 1-3 in the chromatogram
(mono- and di-CBs) were proportionately reduced in the PCBs stored
in the fish tissue, whereas the tri- and tetra-CBs were proportionate-
ly increased in the fish tissues (Figure IV.2.2, and Table IV.2.5;
cf. Figure II.3.3).
DeFoe e_t al. (113) found that the bio-accumulation factor for
adult fathead minnows at 25°C is approximately 120,000 for Aroclor
1248 and 270,000 for Aroclor 1260. Female fathead minnows accumu-
lated about twice as much PCBs as the males but the difference is
largely due to the greater amount of lipids in the females. The
residues of PCBs in the fish tissues were directly proportional to
the water concentration (Figure IV.2.3). The storage factor for fish
lipids (ppm in lipids/ppm in water) was between 1 and 2 million
(ibid.). Nebeker et_ al. (112) found that the bio-accumulation factor
-------
BJOACCUMULATIOW AND DEPURATION
OF PCB's BY FISHES
2 46 8
— Exposure * K—
lwg/1 WEEKS
246
— Depuration —
8
Figure IV.2.1
-------
Table IV.2.4
(from ref. 100)
TOXICITV AND UPTAKE OF Aj«>ci.ou 1010 iiv PiNFisii (I.agodon riiinnlnitlca) EXPOSKD
ffH 42 DAYS IN THUKK SKPAIIATK KXPLRIMENTS
Test co n cent r
Nominal
Control
0.1
1.0
10.0
Control
1.0
:-! I'
10 0
:!2.0
Control
10 0
:J2 (K
100.0'
at ion (fig .'liter')
Veasured
N!>
ND
O.S
3.0
ND
O.'l
'J ">
7.0
I::
NO
6 X
.'1
59
AlOPtmltV
36
16
4S
;is
12
16
Hi
23
44*
6
6
SO*
-,()»
Conceni
Fle.h
ND
0.7
.">. 1
60
O.A
4.0
31
0:i
140
ND
2:>
,jO
"S
iralion in fish (jug g,
Flfoh and skin
ND
0.8
6.3
90
0.6
6.0
yj
76
180
ND
49
4S
72
wet weight)
Whole fish
ND •
2.4
11
166
0..1
'17
6">
170
620
ND
111
106
205
" ND, not detectnnle: <0.2 MS liter in water: <0.2 UU/K in tissue.
1 Mortality significaii'ly greater ihan in control fish, a = 0.01.
c Exposure terniiiniied iinii tissues nnnlyxeil when W", of -he fi.sh died: ;J:1 days at .'12
;Mid l.s daj's at ICil /nj.'lirn1.
-------
^CI3
Figure IV.2.2 (from ref. 100)
4
ipiii
*
Chromatograra of 9 peaks of Aroclor 1016 reference standard. Operating con-
ditions: gas flow nitrogen 25 ml/snin; injection and detector temperature 210°C; oven tem-
perature 1900C; *H electron capture detector; 152,4 X 0,32 cm glass column packed with 2S
OV-101 on 100-120 Gas Chrom Q.
Table IV.2.5 (from ref. 100)
PERCENTAGES or THE 9 MEASURED PEAKS FROM CHROMATOGRAMS or AROCLOR 1018
REFERENCE STANDABDS AND FROM TISSUES OF PINJTISH EXPOSED TO 1 M°/MTER OF
ABOCLOR 1016 FOR 56 DAYS AND THEN HEU> IN PCB-PREE WATER FOB 56 DAYS
Percentage of peak" Chro-
1
'— UlttWJ-
23456789 grams
Reference standard 12.4 11.3 10.0 23.5 13.3 6.4 8,1 8,8 6.2 8
All tissues through 14 days 2.4 5.3 1.8 39.6 7.7 10.3 12.1 9.4 11.4 7
of exposure
All tissues, days 21-56 of 2.5 5.0 2.1 33.2 7.8 11,9 11.3 10.3 18.9 12
exposure
All tissues during 58 day 1,0 1,7 0.3 38.2 2.8 15.0 12,4 11,9 16,7 7
depuration
peak height
* Determined as — — X 100.
sum of nine peaks
-------
I
0\
Q female
O-Biale
6000
o
4000
(5 fish sample)
CJ
s
s
Q
M
PM
2000
0.0
Source:
1.0
-•-• 2.0
WATEiTCONCENTRATION
3.0
4.0
DeFoe, D.L., G.D. Veith, and R.W. Carlson, 1975. Effects of Aroclor
1248 and 1260 on the fathead minnow (Pimephales promelas), U.S.
Environmental Protection Agency, National Water Quality Laboratory,
Duluth, Minnesota.
Figure IV.2.3 (ref. 113)
Aroclor 1248 residue in fathead minnows, normalized to lipid
concentration in fish.
-------
for Aroclor 1254 in fathead minnows was between 110,000 and 240,000,
and that for Aroclor 1242 was between 32,000 and 274,000. Although
the results varied somewhat between replications of these experiments
there is no evidence that the bio-accumulation factors in this fish
increase significantly with the degree of chlorination of the mixture.
Veith and Kiwus (338) conducted an experiment with fathead minnows
exposed to Aroclor 1016 and found a bio-accumulation factor of about
50,000, but the concentrations in the fish were still rising after
32 days (Figure IV.2.4). This result for Aroclor 1016 falls well
within the range observed for the same species for Aroclor 1242, and
within a factor of 3 of that observed for Aroclors 1254 and 1248
(112, 113).
Bio-accumulation factors for bluegills exposed to Aroclors
1248 and 1254 were in the range 26,300 to 71,400. No major modifica-
tion of the PCS isomer ratios were observed in the tissue residues,
and no new compounds were identified (95).
Several studies have shown that fish also store PCBs when fed
contaminated food while kept in clean water. In these cases the bio-
magnification factors were quite modest, because the fish were able
to exchange PCBs across their gills with the ambient water; in natural
environments both water and food would contain PCBs and fish would
take in PCBs via both routes.
Coho salmon (Oncorhynchus kisutch) fed Aroclor 1254 for 240
days at dietary concentrations of 0.4 to 580 ppm (14.5 to 14,500
tig/kg body weight per day) accumulated whole body residues which
-------
•09*
e *
in
£
O
,Q
ur>
o
o
o
o
o
o
o
o
cf
o
o
o
~
o o
_
-;-
o
*
Var'ation of the Aroclor 1016 bioconcentration
factor (Cp/Cy) with time of exposure. The CY is derived
from conposites of five fish.
Figure IV.2,4 (ref.338)
-------
2.? 7
were 0.9 to 0.5 times the dietary levels (95). The highest residue
value was 300 ppm.
Accumulation and retention of Aroclor 1254 by rainbow trout
(Salmo gairdnerii) from the diet followed the same pattern as that
i0« for coho salmon (339). The relative concentration of PCB in the
lipid fraction of trout increased rapidly during 8 weeks' exposure
to 15 ppm Aroclor 1254 in the food, then tended to equilibrate at
about 95 ppm (Figure IV.2.5). While the relative amount in the fish
reached quasi-equilibrium, the absolute quantities continued to in-
crease as the trout grew (Figure IV.2.6). The distribution of PCB
among the tissues was dependent on the lipid content of the various
tissues (Table IV.2.6).
The uptake of pure PCB isomers by fish has been studied in
three experiments. Gruger et al. (121) fed 3,4,3',4' tetra-CB and
two hexa-CBs to juvenile coho salmon at a dietary concentration of
3.3 ppm each (total 10 ppm) for 165 days. The material fed during
the first 24 days was retained well in the tissues, but tissue con-
centrations tended to level off and after 28 days the concentration
of the tetra-CB was only about half that of either of the two hexa-
CBs (Tables IV.2.7, IV.2.8). The experiment is complicated by the
fact that the treated fish lost weight and depleted their lipid
reserves, and that equilibrium concentrations in the tissues had not been
reached (Table IV.2.7). As in the case of the trout, most of the
PCBs were concentrated in the lipid-rich tissues, and the average
concentration of PCBs in lipids was similar (about 70 ppm) in all
-------
100
80
•ft60
40
u
20
0_
.0 .- , 4 . ,8 .12 .16 .20 . .24 ,28.. ,32
!TIME"(WEEKS)
iSource: Lieb, A.J., D.D. Bills and R.O. Sinnhuber, 1974. Accumulation
I of dietary polychlorinated biphenyls (Aroclor 1254) by rainbow
i trout (Salmo gairdneri), Journal of Agricultural and Food
Chemistry, 22(4): 638-642.
Figure IV.2.5 (ref. 339)
PCB in lipid fraction of rainbow trout after exposure to
15 ppm Aroclor 1254.
-------
i_j
Cu
CO
o
Cb
o
J.
8 16 2A
TIME (WEEKS)
32
Source: Lieb, A.J., D.D. Bills, and R.O. Sinnhuber, 1974. Accumulation
of dietary polychlorinated biphenyls (Aroclor 1254) by rainbow
trout (Salmo gairdneri), Journal of Agricultural and Food
Chemistry, 22(4): 638-6A2.
Figure IV.2.6 (ref. 339)
Total amount of PCB per fish: (A) fish on diet contain-
t
ing 15 ppm of PCB; (B) fish removed from diet containing 15 ppm of
PCB at end of 16 weeks.
6-77
-------
3oo
Table IV.2.6 DISTRIBUTION OF AROCLOR 1254 IN TISSUE
OF RAINBOW TROUT
Concn Concn
of PCB in of PCB in
% lipid lipid, tissue
Tissue in tissue ppm ppm
Visceral adipose 92.8 111 103
Gill 9.7 113 11.3
Muscle 2.7 104 2.8
Stomach 6.5 104 6.8
Liver 3.5 57 2.3
Whole fish 8.5 96 8.2
Source: Lieb, A.J., D.D. Bills, and R.D. Sinnhuber, 1974.
Accumulation of dietary polychlorinated biphenyls
(Aroclor 1254) by rainbow trout (Salmo gairdneri)
Journal of Agricultural and Food Chemistry 22(4):
638-6A2.
6-83
-------
Table IV.2.7 (ref. 121)
ANALYSES OF WHOLE JUVENILE COHO SALMON WHEN FED FOR 24, 53, AND 108 DAYS1
Group
Body
Days wt, g
3,4,3',4', 2,4,5,2',4',5' 2,4,6,2',4',6'
Lipid content, chlorobiphenyl chlorobiphenyl chlorobiphenyl Total
wt% Wet tissue^ ug/g
Test
Control
o>
I
00
o 1. Thr
24
53
108
24
53
108
ee f is
4.24
5.26
3.06 •
3.79
5.42
7.87
>h per group.
7.60
6.48
3.8
5.83 .
7.38
6.8
. 2. Perce
0.49
(47%)
0.59
(30%)
0.65
(16%)
0.059
0.044
0.107
nt of chlorobiphe
0.73
(70%)
0.93
(47%)
1.41
(35%)
0.090
0.047
0.023
nyl amount found in f
0.66
(63%)
0.90
(45%)
- 1.42
(35%)
0.050
0.053
0.030
ish relatj
1.88
(60%)
2.42
(41%)
3.48
(29%)
0.199
0.144
0.160
Lve to
amount fed«ls given in parentheses.
Source: Gruger, E.H., Jr., N.L. Karrick, A.I. Davidson and T. Hruby. 1975. .Accumulation of
3,4,3',4'-tetrochlorobiphenyl and 2,4,5,2',4',5'-and 2,4,6,2',4',6'-hexachlorobiphenyl
in juvenile coho salmon. Environmental Science and Technology 9(2): 121-127.
-------
Table LV.2.8 (ref. 121 )
CONCENTRATIONS OF CHLOROBLPHENYLS AND LIP ID CONTENT IN TISSUES OF JUVENILE
COHO SALMON FROM TEoT AND CONTROL CROUPS
CO
LLpLd content,
wt%
Tissue specimens
at 117 days
Test group
Brain 7.L
Liver 2.9
White muscle 2.6
Intestines 4.1
Stomach and pylortc caneca 1.3
Spinal column 6.6
Heart
Lateral line muscle 6.1
Spleen .
Adipose 71.0
Control group
Brain 6.6
Liver 3.9
White muscle 5.5
Intestines 6.6
Stomach and pylorlc caneca 4.2
Spinal column 2I./
Heart
Lateral line muscle 11.4
Spleen , -
Adipose 73.5
at 165 days
Test Croup
White muscle
Brain
chloroblpheny L
0.15
0.25
0.29
0.10
0.41
0.92
0.98
0../7
0.85
10.6
0.020
0.014
0,028
01098
0.012
0.096
0.85
0. 10
(2.0)
0.10
0.086
0.26
2, 4, 5, 2', 4', 5'
chlorob Ipheny L
Wet tissue,
0.11
0.35
0.61
0.79
0.76
1.4
L.2
L.8
2.0
19.3
0.009
0.014
O.OL5
0.012
O.OL4
0.026
0.068
0.058
0,11
0.19
0.20
0.37
2, 4, 6, 2', 4', 6'
chloroblphenyl Total
0.38
0.50
0,64
0.82
0.95
1.4
L.5
1.9
2.1
18.8
0.017
0.037
0.025
0.069
0.022
0.012
O.L8
0.077
O.L2
0.36
0.84
l.L
1.6
L.9
2.1
1,7
1.7
4,5
4.9
48. /
0.046
0.085
0.068
0.20
0.069
0.15
1.1
0.24
(2.3)
0.85
0.22
0.56
0.51
1.2
UJ
a
-------
the tissues tested after 117 days (Table IV.2.8). After 48 days'
starvation the concentrations of PCBs in the tissues were depleted
somewhat (to a total of 33 ppm in adipose), but those in the brain
were increased slightly (Table IV.2.8). The tetra-CB was excreted
only slightly faster than the hexa-CBs (121).
Sanborn et al. (307) exposed green sunfish to three represen-
tative chlorobiphenyls in two pulsed exposures (24 hours' exposure to
1 or 3 ppb 9 days apart). Although the tri-CB was rapidly excreted
and was almost eliminated after 15 days, the penta-CB was well re-
tained and there was no evidence of elimination in the 15-day period
of study (Figure IV.2.7). The tetra-CB was taken up and retained
slightly less well than the penta-CB, but the concentrations in the
fish at the end of the 15-day experiment were only 2-3 times smaller
than those of the penta-CB, despite the limited exposure time (Figure
IV.2.7). Thus the major difference in uptake and retention appeared
to be between the tri- and tetra-CBs.
Metcalf et al. (45) exposed mosquito fish to the same three
chlorobiphenyls under model ecosystem conditions (exposure via both
food and water). Although the exposure to the fish was for only 3
days, they nevertheless accumulated the tri-CB to 6,400 times the
water concentration, and the tetra- and penta-CBs to about 12,000
times the water concentration (Table E.5). Thus under these circum-
stances there was no difference in bio-accumulation between the tetra-
and penta-CBs.
To summarise, under laboratory conditions fish bio-accumulate
PCBs to concentrations 30,000 to 300,000 times higher than those in
-------
4.0
cu
0.
V..
10
o
cu
Cu
o
2
o
o
o
3.0
2.0
1.0
£
Cu
Cii
to
O
Cu
(u
O
2
O
8
z
8
4,0
3.0
2.0
1.0
10.0
tit
&
02
tu
O
O
C
8.0
6.0
4.0
8 2.0
Cl
Cl Cl
Cl
10 15
TIME (DAYS)
20
Source: Saibom, J.R., W,F. Chllders, and F.L. Metcalf, le^S. Uptake
of three polycMorinated bipherryls, DDT, and DDE by the green
•urffisV , Lgr°~^s eya-c33vi3, RAF., Bullcti" of EnvlrormeTtal
Copta-inatio- a-d Joylcology. 13(2); 209-217,
Uptake 6f trl-, tetra-, and pentachloroblphenyl by the green sunfish.
Figure IV.2.7
-------
the ambient water (up to 2 million times higher in lipids). There is
evidence that mono-, di-, and tri-CBs are poorly retained in fish
tissues, but the differences in retention between tetra- and higher
CBs are small, no more than a factor of.2-3 in the circumstances of
these experiments.
IV.2.4. Bio-accumulation in Model Aquatic Ecosystems
I
Two studies have been published of the behavior of PCBs in
model aquatic ecosystems, designed to simulate the transport of PCBs
from water through simple food chains. In one study by Metcalf et
al. (45), radiolabelled chlorobiphenyls were applied to a mixed
terrestrial-aquatic system and subsequently traced in water and various
aquatic organisms. The results have already been summarized in the
previous sections and in Appendix E (Tables E.3-E.5). The study
showed how PCBs and their metabolites move from the terrestrial to
the aquatic environment and are taken up there by aquatic organisms,
including plants, insects, fish, and snails. Because the fish were
only introduced into the system for the last few days of the experi-
ment, the results do not indicate the full potential for bio-accumu-
lation in food-webs: the figures of 6,000-60,000 for bio-accumulation
factors in snails (Table.E.5) give the best measure of this potential.
While Metcalf's system is primarily designed to investigate
storage and biodegradability (45), a system designed by SBdergren
was designed to trace the movement of PCBs through a simple food-web
(340). Figure IV.2.8 shows the basic design of the system and
Figure IV.2.9 shows the results of a test with Clophen A50. Most of
-------
NUI1IINI MIDIUM
ASIILUS MICA
AOIMTICU1 ItUVIAIILU
Principle design of
the model aquatic eco- i
system. The organisms not'
mentioned in the text con-
slitute alternative food- ,|
chains viable in the system,
but not included in this
study. I
Figure IV.2.8
(from ref. 340)
-------
Input
28.5
Chi
pyrer
• III
oidota
- W«
Output
16.2
Chloralla
pyrenoidoia
BUDGET
INPUT'OUTPUT+STORAGE IN THE SYSTEM
76.2 • 31.5 + 19.1
LOSS i 34 °/o
Distribution and budget of Clophcn A 50 within the model aquatic ecosystem (ug). n.d. = no substance detected.
Figure IV.2.9
(from ref. 340)
-------
the transport of the material to the first consumer organism (the
cyprinid fish Leucaspius delineatus) took place via the alga Chlorella
pyrenoidosa. There were some changes in the relative proportions of
the components of the Clophen mixture as they passed through the
system (Figure IV.2.10). However, these changes were very minor ex-
cept in the two predatory fish (the pike Esox lucius and the perch
Perca fluviatilis). Even the first component in the Clophen mixture
(2,5,2*,5'-tetraCB) was passed essentially unchanged through the alga
to the first consumer (Figure IV.2.10).
IV.2.5. Storage and Bio-magnification in Birds
Storage and bio-magnification in birds are of interest for
two reasons: (a) to indicate the range of residues likely to be in-
gested by humans eating wild or domestic birds; (b) to indicate the
degree to which passage of residues up the food chain can lead to
toxic effects in the birds themselves or in their predators.
In a study with chickens (149, 150), laying females fed
Aroclor 1248 at 0.5 ppm accumulated 3.1 ppm in their adipose tissues
and 0.22 ppm in their eggs after 8 weeks; correspondingly higher
levels in tissues and eggs were found at higher feeding levels (Table
IV.2.9). Similar results were obtained with Aroclor 1242: hens fed
at 5 ppm laid eggs containing 1.7 ppm after 6 weeks (152). However,
laying hens may be a poor model for other birds because their contin-
uous egg-laying provides them with an important route of excretion
(341) not available to wild birds which lay few eggs. Pheasants
given 12.5 mg Aroclor 1254 weekly (equivalent to about 50 ppm in the
-------
ESOX
LUCIUS
PERCA
FLUVIATILIS
LEUCASPIUS
DELINEATUS
CHIORELLA
PYRENOI003A
NUTRIENT
MEDIUM
•0 30 JO ,0
MIN.
Gas chromatograms obtained from various com-
ponents in a model aquatic ecosystem when testing Clophen
A 50.
Figure IV.2.10
(from ref. 340)
-------
Table IV.2.9
(from ref. 150)
— Transfer of PCBs' from the laying diet to the adipose tissues and eggs of hens
Diet
no.
1 (Diet A)
i
3
4
5
PCBs
in diet
p.p.m.
0.5
1.0
10.0
20.0
PCBs in adipose
1 wk.
p.p.m.
1.54
2.21
10.4
16.3
4 wks.
p.p.
2.16
4.41
22.7
54.7
tissues
8 wks.
T"'
3.10
6.62
37.1
82.7 .
PCBs in eggs
1 wk.
p.p.m.
0
0.10
0.19
1.05
2.19
4 wks.
p.p.m.
0.16
0.33
2.21
4.51
6 wks.
p.p.m.
0.21
0.42
2.83
5.37
7 wks.
p.p.m.
0.20
0.45
3.11
5.72
8 wks.
Pjp.m.
0.22
0.41
3.06
7.04
'Aroclor 1248, Monsanto, Inc., St. Louis, Mo.
-------
diet) for only 16 weeks accumulated an average of 24 ppm in their
whole bodies; this did not decline significantly even after 6 months
on a clean diet (141). Mallards fed 25 ppm Aroclor 1254 laid eggs
containing 33-56 ppm PCBs (wet weight) (131). Ring doves fed 10 ppm
Aroclor 1254 in the diet accumulated 8 ppm in the muscle, 5.5 ppm in
the brain, 15.3 ppm in the liver, 736 ppm in the fat, and 4.8 ppm in
the eggs (342, 161-163); after starvation the PCBs were mobilized from
the fat and the birds died with 293 ppm in the brain (Table IV.2.10).
American Kestrels fed 10 ppm Aroclor 1254 in the diet laid eggs with
average residues of 225 ppm (dry weight, corresponding to about 30
ppm, wet weight) (164).
A number of workers studying the storage of PCBs in birds have
reported that the lower chlorobiphenyls in Aroclor 1254 (tetra-CBs) are
retained less well than the higher components (141, 131, 342, etc.).
Call et al. (343) have provided quantitative data showing that tetra-
and penta-CBs are stored at relatively lower levels and hexa- and
hepta-CBs at relatively higher levels in Japanese quail than in the
Aroclor 1260 with which they were fed.
However, the differential storage of PCBs in birds is not re-
lated simply to the degree of chlorination. DeFreitas and Norstrom
(27), studying the elimination of components of Aroclor 1254 from
pigeons, found that the components which were excreted and/or metab-
olized most rapidly were those with 2,3,- 3,4-, or 2,3,6- substitutions
in at least one ring. Components with 2,4,5-, 2,3,4-, and 2,3,4,5-
substitution patterns were not eliminated. Components with 2,5-
-------
312,
Table IV.2.10
(from ref. 161)
Organ levels, ppm, wet weight basis.
"
Pre-stress (n - 4)
Post-stress (n«*5)
Muscle
8.1±2.3
(4.1-9.9)
172.0±38.3
(120.0-227.0)
Brain
5.5±1.6
(4.8-8.0)
203.0±27.6
(254.0-340.2)
Liver
15.3±12.6
(3.6-27.5)
11 18 ±267
(937.3-1688.0)
Fat
736.1±211.6
(481.2-1069.4)
***
Figures are means, standard deviations, and range.
**• No fat present.
-------
Table IV.2.11
(from ref. 344)
Mean Total PCS Residues (p.p.m.), found in Cuail Tissue
ifttr Fteding 'Afoclor 1242' ana 'Aroclor 1254' at 250 p.p.m. for 20 Days
Tissue
Liver
Heart
Brain
Omental fat
•Aroclor 1242*
17.0 + 2.6*
3.2±0.7
7.8±1.7
I23±17
•Aroclor 1254'
28.1 ±7.9
7.0+1.1
7.7 ±2.3
304 + 31
' All figures are mean of six birds+ s.e.
-------
35
300-
200-
100-
200-
100-
300-
f 200-
'u
1 0
u
'•= -UO-
i 100-
2.800-
1.400-
1.200-
1.000-
800-
600-
400;
3001
200-
100-
5 months after withdrawal | _
of dressed diet
|
.ll.
j
{ -
j
.1 !
2 month > after withdrawal . > .
of dressed diet j
..!..! .. 1., ..
1?
» .,
i
T-
1 month after withdrawal i
ll.l.l,
of dressed diet
{
i
i
t
i
i
i
«. . j
Immediately after withdrawal i
of dressed diet
., ! ll
\
i
i
,...
i. .1
i
f_ Standard - (— -
.. j.
} \ > - \
•' - - ••• -
.-..._
.r:
\ \
Rclative retention time
. . . |.._
1 —
• -• 7 -
' ' M —
1
f
.._...
1
1
4--
1
DDE
Gas-liquid chromatographic "spectra", normalized to a
common peak (stippled column) of 'Arpcior 1242' standard and
mean pigeon liver residues following feeding at 500 p.p.m. in
diet lor 28 days.
Figure IV.2.11
(from ref. 344)
-------
substitutiona were eliminated, but much more slowly than those with
2,3-, or 3,4- substitutions. Bush et al. (155) obtained similar
results for differential elimination of components of Aroclor 1254
from laying hens, and suggested that 4,4' substitution is more im-
o
portant than number of chljrine atoms in determining the degree of
persistence of chlorobiphenyls in hens. This agrees with the find-
ings of Matthews and Anderson (328) in rats.
Finally, Bailey and Bunyan (344) found that although Aroclor
1242 was not accumulated so strongly from the diet by Japanese quail
as Aroclor 1254, the difference was only by a factor of 2-2.5 (Table
IV.2.11). Although the lower components in Aroclor 1242 (di- and
some tri-CBs) were not well retained in pigeon tissues, some tri- and
most tetra-CBs were well retained and were only slowly excreted over
a 2-6 month period (Figure IV.2.11). Of the components well retained
in the pigeon tissues, only one (probably 2,5,3",4'-tetra-CB) is not
present in Aroclor 1016 (Figure II.3.3). Thus, although there is
substantial differentiation of the components of PCB mixtures as they
are taken up, stored, and eliminated by birds, some tetra- and even
tri-CBs are reasonably well retained in tissues and secreted into
eggs.
Very little information is available on bio-magnification of
PCBs by any fish-eating birds, which are of interest as being the
species at greatest risk in the environment. However, cormorants
(Phalacrocorax carbo) dosed with an average of about 300 ppm Clophen
A60 (about 25 mg/kg/day) accumulated 850-2,750 ppm PCB residues in
-------
their whole bodies in 55-125 days, including residues of 10-20,000
ppm in their fat (142). This indicates a somewhat higher degree of
bio-magnification than for any of the other birds listed above.
-------
IV.2.6. Storage and Bio-magnification in Mammals
The storage and kinetics of PCBs in mammals are of interest
(a) to indicate the range of residues likely to be ingested by humans
eating domestic mammals; (b) as models for the storage and kinetics
of PCBs in humans themselves. There is an extensive literature on
the uptake, kinetics, and elimination of PCBs in mammals, but for
this document primary interest is attached to the results of long-
term feeding at low levels.
Absorption of PCBs from the gastrointestinal tract appears
to be very efficient. Albro and Fishbein (345) fed nine individual
chlorobiphenyl isomers ranging from mono- to hexa-CBs to rats and
found that 91-9970 of the dose was retained in the body. After absorp-
tion PCBs are distributed throughout the body: their distribution
tends to parallel the lipid content of the tissues, so that PCB
storage in the tissues occurs in the following order:
fat ?" liver :?- feces -^ kidney ^*- brain j- plasma z*- urine (346) .
The concentration of PCBs in adipose tissue is lO-'lOO times the con-
centration found in other tissues, both early after single doses
(182) and after prolonged intake (346).
Allen et al. (196) fed six adult female rhesus monkeys 25 ppm
of Aroclor 1248 for two months. PCB concentrations in samples of
adipose tissue averaged 127 /ig/g fat for all animals. At that time,
the experimental diet was discontinued. Eight months later the PCB
content was 34 /ag/g fat. PCBs were transferred across the placenta
of one female which gave birth and concentrated at high levels in
the fat and adrenals of the infant (Table IV.2.12). In an infant born
-------
-------
317 4
to a female 29 months following the discontinuation of PCBs, the
levels within the adipose tissue were 3.38 ppm at 4 months of age (69).
Female monkeys given 5.0 ppm PCB in their diets attained maxi-
mum levels of PCBs within their adipose tissue at 6 months (141 to
177 ppm adipose tissue). However, it required approximately 14
months on the 2.5 ppm diet for the monkeys to reach similar maximum
PCB levels in their adipose tissue (126 to 144 ppm). Males which re-
ceived 5.0 ppm PCBs attained levels ranging from 128 to 200 ng per g
adipose tissue at 14 months. Infants born of mothers exposed to
2.5 and 5.0 ppm PCBs within the diet contained concentrations of PCBs
ranging from 1.0 to 4.8 ppm within the skin at birth. While nursing
from mothers consuming PCB diets, the infants continued to accumulate
the compound. At 3 months the levels within the tissues ranged from
86 to 136 ppm. The concentration of PCBs within the milk ranged
from 0.15 to 0.40 ppm. The tissues of the infants which died while
nursing PCB-fed mothers contained high levels of PCBs within the
thymus, ovaries, brain, kidneys, adrenal glands and pancreas (20-48
ppm tissue). Lower levels were found in the liver, lymph nodes and
bone marrow (8-16 ppm) (69).
-------
Table IV.2.12
(from ref. 196)
POLYCHLORl.NATED BlPI IENY1. CONTENT OV TISSUES OBTAINED
FROM MOTHER AND INFANT FOLLOWING CONSUMPTION OF
AROCLOR 1248 BY THK MOTHER PKIOR TO
Weight PCB content
Organ (g) 0/g/g)
Mother
Liver — 56.3
Fat — 50.0
Placenta — 0.9
Infant
Fat — 27.70
Adrenals 0.2 24.40
Liver 11.9 0.01
Muscle . — 0.98
Brain 52.9 0.29
Kidney? 2.8 . 0.10
Large intestine — 0.08
Small intestine - — 0.52
Stomach — 0.55
Luns 6.1 0.21
Skin — 0.31
-------
Curley et al. (346) fed weanling Sherman rats a diet contain-
ing 100 ppm Aroclor 1254 for 58 days and for 240 days. Animals were
sacrificed at various intervals, A steady buildup of PCB in all
tissues was observed over the 58 day period. The rats stored more
PCB in their tissues after 240 days than at the end of 58 days. In
experiments at two dose levels (100 ppm and 500 ppm) for 240 days,
Curley et_ al. (346) observed that PCB in fat after 240 days at diet-
ary levels of 100 and 500 ppm were 1,101 and 10,021 ppm, respectively.
They did not reach a point of equilibrium storage.
Grant jet al. (347) fed male rats a diet containing either 0,
2, 20 or 100 ppm of Aroclor 1254 for 246 days. The residues in the
blood, brain, heart, liver and fat were found to be dose related. •
All components of residues were not metabolized at the same rate.
Burse j2t al. (208) fed rats diets containing 100 ppm of Aro-
clor 1242 or Aroclor 1016 for up to ten months. Rats were sacrificed
at intervals and tissues analyzed. A roughly steady state concentra-
tion of PCBs in adipose tissue was approached in two months and
reached in 4-8 nupnths (115 ppm of Aroclor 1242 and 214 ppm of Aroclor
1016) (Figure IV.2.12). Equilibrium levels of Aroclor 1016 and 1242
seem to be reached sooner than equilibrium levels of Aroclor 1254
and the levels of Aroclors 1016 and 1242 were 5-10 times smaller than
those reached after continuous feeding with Aroclor 1254 (208, 346).
This indicates considerably less bio-magnification of tri- and tetra-
CBs than of penta- and hexa-CBs in rats. After the rats were placed
on a PCB-free diet the residues of Aroclor 1016 were eliminated some-
what faster than those of Aroclor 1242 (Figure IV.2.12). Comparison
-------
0 0.5 1
10
-Residues resulting from a con-
tinuous diet of a 100 ppm concentration of
Aroclor 1016 (•) or Aroclor 1242 (•) for a
period of ten months. Residues following a
continuous diet for only six months and re-
covery for five months for Aroclor 1016
(D) and for six months for Aroclor 1242
(o) are Illustrated by the broken lines.
Each point represents the mean and stan-
dard error (I) of four rats.
Figure IV.2.12
(from ref. 208)
-------
32.(
of chromatograms (Figures IV.2.13, IV.2.14) shows that only the
later eluting components (penta-, tetra-, and some tri-CBs) of
Aroclors 1242 and 1016 were stored in the adipose tissue. The lower
components were largely metabolized, as hydroxylated metabolites were
found in the urine (348).
Storage and dynamics of PCBs have also been studied in domes-
tic animals. Hansen et: al. (216) fed sows with 20 ppm Aroclor 1242
throughout gestation and nursing and found PCBs in many tissues of
the sows and their offspring. PCB levels in the fat and blood of
the sows averaged 14 ppm and 0.25 ppm respectively (Table III.9.9).
The offspring appeared to have somewhat lower concentrations of PCBs
in their fat but higher concentrations in the blood (Figure IV.2.15).
As with other mammals, there was considerable differentiation of the
components of the Aroclor 1242 mixture (Figure IV.2.15): later elut-
ing components (primarily penta- and tetra-CBs) were retained much
better in the fat than the earlier eluting components. One-third to
one-half of the PCBs stored in the fat of the sows consisted of com-
ponents that would not be present in Aroclor 1016.
Fries .et al. (349) fed 200 mg of Aroclor 1254 daily (0.4 rag/kg/
day, equivalent to 12 ppm in the diet) to nine cows. Residues in
the body fat and milk fat built up to 40 and 60 ppm respectively
during a 60-day feeding period, but did not reach equilibrium levels
in that time (Figure IV.2.16). Following discontinuation of dosing,
levels of PCBs in fat and milk fell off steadily, but those in body
fat had fallen only to 30 ppm after 60 days. The cows excreted only
-------
o
V)
c
o
0.
in
40
30
20
10
Aroclor 1242 Standard
Urine
Adipose Tissue
1
I i
I I I I I I I I I
o
•>
I I I
I I I I I
"0 24 6 8 10 12 14 160 2 4 6 8 10 120 2 4 6 8 10 12 14 16 18
Time, min
-Chromatograms of Aroclor 1242: 3.66 ng, an extract of urine: 4.5 mg. and adipose tissue: 0.027 mg from a male rat fed a diet
containing 100 ppm Aroclor 1242 for eight months.
Figure IV.2.13
.(from ref. 208)
-------
-------
o
u
48 70 99 149
Relative Retention Time
—Electron capture gas chromatographs of PCB mixture In stan-
dard and tissue extracts from sows given PCB mixture in the feed
and from their offspring. Back-fat samples were diluted 100-fold.
Figure IV.2.15
(from ref. 208)
-------
60
bt
»
MILK FAT
20
60
DATS
Concentration of PCB in milk fat and body fat of cows
fed 200 mg of PCB per day. Each point is an average of nine
cows ± standard deviation. The curve for body fat is extrapolat-
ed before 30 days.
Figure IV.2.16 (from ref. 349)
TWI minimi)
Typical gas chromatograms of an Aroclor 1254 stan-
dard, a milk fat residue sample, and a body fat residue sample.
Retention times of peaks 1, 2, 4, 6, and 9 were equal to the re-
tention times of the pure compounds 2,5,2'.5'-tetrachlorobi-
phenyl, 2,3,2',5'-tetrachlorobiphenyl, 2,5,3',4'-tetrachlorobi-
phenyl, 2,3,4,2',5'-pentachlorobiphenyl, and 2,4,5,2',4',5'-hexa-
chloroblphenyl, respectively.
Figure IV.2.17 (from ref. 349)
-------
20-25% of the daily dose in their milk, implying that even under con-
ditions of continuous milk production they were still far from equili-
brium after 60 days. There was differential accumulation of the higher
components of the mixture in both body fat and milk (Figure IV.2.17),
but peaks 2 and 3 (both tetra-CBs) were as well represented in the
milk fat as in the original Aroclor mixture. Jan et_ al. (404) found
that cows excreted substantial amounts of 3,5,3",5'-tetraCB in milk
(up to 2 ppm in milk fat after a single oral dose of 0.8 mg/kg).
Frank _et al. (405) reported data on body burdens of PCBs in
captive harp seals (Pagophilus groenlandicus). as shown in the follow-
ing table:
Estimate PCB
Age at Death
and time in
Captivity (months)
12-11
15-14
24-23
27-26
38-35
52-50
The diet of the seals contained an average concentration of about
O.J^-O.J ppm PCBs, but over 4 years' captivity the average whole-body
ar-sa
concentration built up to 12.9 ppm («• uglily fia ppm in fat).
Wt. at Death
(kg)
52.0
68.0
70.0
63.8
65.0
54.0.
Intake last 2-4
Months (mg/day)
0.75
1.14
1.07
1.01
0.75
0.69
PCB
(rag)
163
143
613
659
785
697
PCB
(mg/kg)
. 3.13
2.15
8.75
10.32
12.10
12; 90
-------
IV.2.7. Storage and Bio-magnification in Humans . '
Although extensive surveys have been made of the occurrence of
PCBs in human tissues, there is little systematic information on rates
of uptake or elimination. PCBs are efficiently absorbed through the
gastrointestinal tract: Price et_ al. (350) measured PCBs in diets,
urine and feces of eight preadolescent girls in Virginia, and esti-
mated absorption of the ingested PCBs as 887o. Humans are also ex-
posed via air, water, and dermal contact, but it is generally believ-
ed that the major exposure is via the diet (1-3, 331, 351).
The most extensive data on distribution of PCBs in human
tissues derive from Japan (35, 25). Fujiwara cited mean levels of
3.1 ppb in blood plasma, 4.7 ppm in body fat, and 50 ppb in milk of
persons surveyed in the Kyoto area (25). He also cited a national
survey which showed a mean level of about 34 ppb in 1116 samples of
human milk. Kuratsune (35) cited a national survey which reported
PCB levels in the range 0.04-1.7 ppm in skin, 0.3-6.4 ppm in fat,
and 0.01 to 0.6 in liver (Table III.16.9). Although these figures
do not all refer to the same individuals, they suggest a distribution
in the body tissues paralleling that of lipids, as in other animals.
-------
-------
327
Surveys in Canada show that the majority of Canadians have
residues of 1-2 ppm in their adipose tissue. Human milk of Ontario
residents was found to have average residues of about 1.1 ppm PCBs
on a fat basis (342).
Extensive surveys in the United States have shown that the
median level of PCBs in human adipose tissue is slightly less than
1 ppm (Table IV.2.13) (353). Less information is available on the
occurrence of PCBs in other human tissues. Finklea et_ al. (354)
found mean levels of 2-3 ppb in blood plasma in South Carolina.
Measurements of residues in human milk have ranged from not detect-
able up to 100 ppb; 30 ppb has been suggested as a typical level (331).
The Total Diet Survey of the Food and Drug Administration pro-
vides an estimate of the dietary intake of an average person in the
United States: in recent years this estimate has been close to 9
^ug/person/day (351: Table IV.2.14). The Total Diet Survey is based
upon a high consumption diet which includes 4 kg food/day, almost
twice that consumed by the "average" man (3i5). Hence the average
concentration of PCBs in the food sampled in the Total Diet Survey
is about 2.2 ppb. Comparing this with the median level in adipose
tissue from the Human Monitoring Program (353) , the storage factor
for human fat (ppm in fat/ppm in diet) appears to be at least 400.
This is far higher than that recorded, for any experimental animal:
see Section IV.2.6, where high figures for storage factors in mammal-
ian fat range from 120-180 in seals, through 35-60 in monkeys, 11-20
in rats, and 5 in cows, to 0.7 in pigs. Several explanations are
possible for this discrepancy:
Preceding Page Blank
-------
321
Table IV.2.13 (from ref. 353)
Levels of polychlorinated biphenyls
in human adipose tissue
Data
source
Yobs,
1972
FY 1973
Survey
FY 1974
Survey
Sample Percent .
size nondetected
688
1277
1047
34.2
24.5
9.1
Percent ' Percent
< 1 ppm 1-2 ppm
33.3 27.3
40.2 29.6
50.6 35.4
Percent
> 2 ppm
5.2
5.5
4.9
Table IV.2.14 (from ref. 351)
Fiscal
year
Estimates of daily PCB intakes
Uotal diet study—teenage male)
Average daily intake of PCB'sa
Meat-fish-poultry food class
Total diet
(yg/day)
1971 •
1972
1973
1974
1975 (1st
half)
15.0
12.6
13.1
8.8
8.7
9.5
9.1
8.7
8.8
8.7
Lower limit of quantitative reporting =0.05 ppm with
analytical method employed.
-------
(i) the dietary intake estimated by the Total Diet Survey
may be too low, because of a high frequency of residues near the level
of detectability;
(ii) routes other than the diet may give significant exposures;
(iii) the residues stored in fat may reflect much higher exposures
in the past;
or (iv) humans may store PCBs much more efficiently than other
animals.
Jelinek and Corneliussen considered (i) and attempted to mini-
mize errors by assigning finite residue values to "trace" findings
(351). Although other routes may be locally significant, no quantita-
tive data have been provided that suggest intakes greater than a few
micrograms per day for a typical person (2, 8, 331). The rapid de-
cline of PCBs observed in the Yusho victims (Table III.16.9) makes
it unlikely that present storage levels reflect exposures more than
a few years ago. Hence it seems probable that humans do in fact
store PCBs more efficiently than other animals. Humans are known to
store other chlorinated hydrocarbons, such as dieldrin (335, 356)
much more efficiently than other animals. This is of considerable
importance for- establishing "safe" levels for human intake, because
it implies that for a given dietary concentration, humans will have
tissue levels up to 10 or more times higher than those of experimental
animals.
There is no precise information on the molecular or isomeric
constitution of the PCBs stored in human adipose tissue in the
-------
United States, although Kutz and Strassman state that most consist
of penta-, hexa- and hepta-CBs (353). A detailed study of a pooled
sample of human adipose tissue from Sweden indicated that it contain-
ed 4-67, tetra-CBs, 23-25% penta-CBs, 44-46% hexa-CBs, 21-22% hepta-
CBs, 4% octa-CBs, and 0.6% deca-CB (Table II.4.1). Musial et al.
(357) reported that most samples of human milk analyzed in Canada
had PCBs similar in constitution to Aroclor 1254, but that peaks
corresponding to Aroclor 1242 (i.e. tetra-CBs) were detected in all
samples. Thus it seems likely that tetra-CBs, although minor, are
not negligible constituents of the PCBs in human tissues.
IV.2.8. Bio-accumulation and Bio-magnification in Natural Ecosystems
Several writers have commented that bio-accumulation and bio-
magnification fa"ctors observed in wild animals in the field are often
much greater than those measured under controlled conditions in the
laboratory. Some examples of this phenomenon as it relates to PCBs
are given below,
Escambia Bay, Florida. Hansen (74) and Nimmo (330) have
pointed out that bio-accumulation factors estimated for several
wild species in Escambia Bay are much greater than those measured in
the laboratory (99, 105; see Table IV.2.15). The discrepancies are
especially great for crabs (;>230,000 in the bay, versus a maximum
of 4,600 in the laboratory) and fish (•^670,000 in the bay, versus
a maximum of 37,000 in the laboratory).
-------
Table IV.2.15 (from ref. 330)
BIQAOTllJIATION OF AROCLOR 1254 IN ESTUARINE ORGANISE
CD1CENTRATION FACTORS
ORGANISE
OYSTER
SHRIMP
CRABS
FISHES
LABORATORY
165,000
26,000
A, 600
37,000
ESCAMBIA' BAY
> 100,000
> 470,000
> 230,000
> 670,000
-------
Hudson River, New York. In a field experiment, Veith et al.
(358) held a number of fish of five species in a live-car (in contact
with river water but isolated from sediments) for 14 days in the Hud-
son River below Fort Edward, N.Y. Whole-body residues of Aroclor
1016 increased to 1.8-3.8 ppm during the 14-day period of exposure.
Veith et_ al. calculated the average concentration of Aroclor 1016 in
the river to be 100-170 ppt, and hence estimated bio-accumulation
factors in their test fish to be 10-40,000, comparable to those ob-
served in the laboratory (358). However: (a) PCB levels in wild fish
in the Hudson River have been up to 100 or more times higher than
those observed in the test fish (Appendix C, 359); (b) Veith et al.
calculated the PCB concentration in the river from the known dis-
charges and the river flow: adsorption to the sediments is likely to
have reduced the actual concentration considerably.
The Great Lakes. Extensive data are available on PCBs in water,
sediments, and biota in the Great Lakes (Appendix C, pp. 31-54; 93,
360-368). Estimates of the degree of bio-accumulation are hampered
by the difficulty of measuring concentrations of PCBs in water in the
low parts per trillion characteristic of the open water of the lakes.
The best set of data obtained by modern sampling techniques (use of
polyurethane foam plugs for extraction from 20 liter samples -- see
ref. 56) is from Lake Superior, where the mean PCB level at Duluth
was estimated at 0.8 parts per trillion (363). Corresponding mean
levels in biota were estimated as 0.1 ppm in zooplankton, 0.25 ppm
in sculpins, and 0.3-3.3 ppm in several other fish species (363).
-------
One of the fish species with the highest residues in this survey was
the lake trout (Salvelinus namaycush), with mean residues of 0.7 to
1.9 ppm at various sampling stations in western Lake Superior (363).
Another survey of lake trout in western and northern Lake Superior
reported residues in the range 2.7-13.8 ppm (jnean 7.0 ppm) in the
whole fish, and 7.6-62.8 ppm (mean 25.6 ppm) in the fat (extracted
oil) (367). Canadian data (360) fall into the same ranges, with the
lake trout showing generally the highest residue levels (Table IV.2.
16). These data indicate bio-accumulation factors in fish in the
range 3 x 10^ to 9 x 10^ (3 x 10? when expressed on a fat basis).
In Lake Michigan the average concentration of PCBs in water
has not been measured precisely but appears to be substantially less
than 10 ppt (362, 368): levels measured in the intake water of munici-
palities along the Michigan shore were all, with one exception, below
10 ppt (368), and even the concentrations reported in major tributary
rivers to the lake have been only in the range 10-65 ppt (Appendix C,
p. 46). PCB levels measured in fish in Lake Michigan have been con-
sistently in the range 2-20 ppm, wet weight (16-200 ppra, lipid weight)
(361, 368; Appendix C, pp. 40-45). These figures indicate bio-accumu-
lation factors ranging up to at least 2 x 10^ in whole fish (2 x 10^
in lipids).
In Lake Ontario concentrations of PCBs in water in the range
35-56 ppt were reported in 1972 (Appendix C, pp. 31-32), but the
method of extraction and analysis was not stated and the reportedly
high levels in water are only partly reflected in high levels in
-------
Table IV.2.16 (from ref. 360)
33?
Polychlorinated biphenyls in commercial fish and fishery products,
(area 3)
Major
Location species
Lake Superior (A) chub
lake herring
lake trout
whitefish
smelt
yellow perch
Lake Huron (B) chub
whitefish
carp
suckers
yellow pickerel
sheepshead (drum)
coho salmon
Landings
(pounds)
306,000
1,611,000
195,000
328,000
788,000
67,000
3,295,000
671,000
950,000
56,000
176,000
269,000
29,000
noncommercial
2,151,000
Lake Erie alewife 332,000
rock bass 49,000
carp 41,000
yellow perch 12,190,000
smelt 15,760,000
yellow pickerel 234,000
white bass 2,346,000
catfish 88,000
bullhead 109,000
sheepshead (drum) 354,000
coho salmon noncommercial
Lake Ontario (D) bullhead
yellow perch
smelt
white perch
sunfish
carp
rock bass
eel
coho salmon
31,503,000
248,000
699,000
103,000
290,000
203,000
395,000
42,000
222,000
noncommercial
2,205,000
PCB
(mean ppm)
0.96 ( 8)
1.17 (10)
2.02 (37)
0.68 (11)
0.35 ( 6)
0.31 ( 5)
2.09 (17)
0.95 ( 8)
1.55 ( 4)
1.33 (12)
0.61 ( 9)
0.75 ( 2)
5.11 ( 6)
1.22 (14)
0.27 ( 2)
1.27 ( 7)
0.19 (10)
0.42 (21)
1.16 ( 9)
1.26 (28)
2.04 ( 8)
0.26 ( 4)
0.74 (15)
3.14 ( 8)
0.73 (12)
1.23 (10)
4.16 (17)
1.84 (22)
0.74 ( 6)
1.69 (10)
1.76 (18)
17.14 (49)
4.97 ( 3)
^Landings less than 25,000 pounds per species are not
included.
-------
biota. Average PCB levels in fish are similar or slightly higher
than those in Lake Michigan, in the range 4-30 ppm (360). Taking
the water data at face value, these indicate bio-accumulation factors
in the range 10^ -10^, somewhat lower than those in the same fish in
Lakes Michigan and Superior.
Data on eggs of fish-eating birds from the Great Lakes indi-
cate further bio-magnification of PCB residues by the birds. Table
IV.2.17 summarizes PCB residues in eggs of Herring Gulls (Larus
argentatus) from the Great Lakes (366). The geographical pattern of
contamination generally parallels that found in the fish (Table
IV.2.17). Taking Lake Superior as an example, the mean PCB level of
60 ppm in gull eggs (roughly 1000 ppm on a lipid basis) is much great-
er than that of 0.3-7 ppm in fish (5-40 ppm in lipids) (363). This
suggests a degree of bio-magnification by the birds much greater than
anything reported in the laboratory (Section IV.2.5).
The California Current. Young et_ al. (12, 369-370) have pre-
sented extensive data on PCB residues in the marine environment off
southern California. Residues in inshore areas are variable because
of localized sources, and hence are difficult to use to derive field
estimates of bio-accumulation. However, the maximum water concentra-
tion measured at the surface above one sewage outfall was 4 ppt (370,
p. 332); corresponding tissue levels in fish, crabs, and mussels
ranged up to 4.3, 3.8 and 1.7 ppm respectively, indicating bio-
accumulation factors of the order of 10 .
Young et al. also presented measurements of the background
concentrations of PCBs in the California Current which flows into
-------
Table IV.2.17 (from ref. 366)
Organochlorine residue levels3 in Herring Gull cggjin the Great Lakes'1
Lake Ontario
Lake Erie
Lake Huron
Lake Superior
Lake Michigan
DDE
n
39 22.6
(8.8-35.1)
42 7.04
(3.8-14.3)
40 13.8
(5.4-41.9)
39 18.6
(8.6-47.1)
10 31.8
- (15.8-145)
ODD '
0.09
(trace-0.83)
0.08
(trace-0.24)
0.10
(trace-0.38)
0.15
(trace-0.4)
0.01
(0.01-0.07)
DDT
0.09
(0.02-1.04)
0.04
(0.01-0.15)
0.08
(0.01-0.32)
0.12
(0.02-0.58)
0.13
(0.07-0.39)
Dieldrin
0.37
(0.08-1.08)
0.30
(0.10-0.69)
0.41
(0.13-0.87)
0.39
(Oil3-1.35)
0.48
(0.3-0.92)
Heptachlor
Epoxide
0.12
(0.01-0.36)
0.14
(0.04-0.28)
0.12
(0.04-0.26)
0.14
(0.07-0.38)
0.16
(0.11-0.60)
Mi rex
5.06
(1.95-18.6)
0.31
(0.14-2.19)
0.56
(0.06-6.92)
0.66
(0.2-5.17)
<0.01
Hexachloro-
benzene
0.19
(0.01-0.72)
0.11
(0.06-0.31)
0.14
(0.05-0.42)
0.11
(0.02-0.33)
0.04
(0.02-0.14)
PCBC
142
• (73.8-261)
65. B
(41.2-110)
51. S
(15.4-118)
60
(33.4-148)
91.3 ••
(55. 1-395) -
Hg
0.51
(0:29-1.47)
0.22
(0.11-0.35)
0.23
(0.11-0.50.
0.39
(0.16-0.63)
n.d.
aHedian Values and ranges (in brackets) in parts per million, wet weight.
bEggs were collected from two colonies in each lake in both 1974 and 197S except from
lake Michigan where they were from a single-colony in 1975.
cPolychlorinated biphonyl \-alucs are based on a 1:1 mixture of Aroclor 1260:1254.
n.d.Not detected.
-------
337
the area from the northwest: these fell into the range 0.27-0.49 ppt
with a mean of 0.40 ppt (369, p. 29). Away from the influence of
local sources of PCBs, mean residues in mussels and dover sole were
in the ranges 14-26 ppb and 40-50 ppb respectively. Referred to the
reported background level in the water these indicate bio-accumulation
factors of the order of 5 x 10^ and 10^ respectively. However, Rise-
brough e_t al. (56, pp. 12-20) have presented evidence that the PCB
levels reported in water by Young et al. are at least 10 times too
high; if so, these estimates of bio-accumulation factors would be
at least 10 times too low.
Reported levels in birds and mammals in the California current
and the outer islands are much higher than those reported in mussels
and fish: 0.15-2 ppm in whole bodies of various fish-eating birds
(371); 10 ppm in the whole bodies (200 ppm in lipids) in plankton-
eating birds (225, 371); 20-400 ppm in the egg-lipids of fish-eating
birds (372, 373); 12-145 ppm in the fat and 0.5-9.7 ppm in the livers
of sea-lions (374). These figures indicate a substantial degree of
bio-magnification by the vertebrates and an overall storage ratio
(ppm in fat/ppm in ocean water) exceeding 10' in some cases.
Despite the variability in residue levels near to major
sources of PCBs, the Southern California studies provide useful in-
formation about differential bio-accumulation of PCB components. At
one of the largest sources, a sewage effluent at Palos Verdes, about
6670 of the PCBs discharged during 1974-75 consisted of components
characteristic of Aroclor 1242 (tetra- and tri-CBs): the remainder
-------
-------
consisted of components characteristic of Aroclor 1254 (penta- and
hexa-CBs) (369: Table 1). The corresponding ratio in the tissues of
fish (dover sole) sampled at the same place was reversed (67% Aroclor
1254) (370: Table 3). This suggests that in these circumstances
penta- and hexa-CBs were accumulated roughly 4 times more efficiently
by fish than tetra- and tri-CBs.
The North Atlantic Ocean. Several authors have published
measurements of the order of 1 ppt or higher for concentrations of
-------
PCBs in seawater in the open Atlantic Ocean (52, 53, 375, 376), but
the problems of sampling without shipboard contamination are very
severe and Risebrough et al. (56) have given evidence that all the
figures are much too high. Certainly 1 ppt is an upper limit for
levels to be expected in ocean water.
Discounting data from locally polluted inshore waters, PCB
residues reported from biota samples from the open Atlantic Ocean
include the following: PCB residues (ppm)
Organism Whole body or muscle Lipid Ref.
Zooplankton
ii
Fish
it
ii
Deep-sea fish
ti
Oceanic birds
Seabird eggs (Iceland)
Seals
0.01
0.1
0.002
0.008
0.07
0.001
0.2
0.4
-0.12
- 0.45
- 2.1
- 0.1
- 2.65
- 0.17
- 21
- 27
0.1
0.3
0.4
0.2
4
0.04
0.25
4
2
- 9.8
- 260
- 31
- 3
- 12.5
- 38
- 74
- 320
- 75
378
379
376
380
360
56
376
387
380
386
Despite the wide variability (and some problems in sampling plank-
ton -- see ref. 56) these data indicate that PCB residues in plank-
ton and fish often reach 0.1 ppm in the whole body and 1 or even 10
ppm in lipids. Even accepting the 1 ppt levels reported in seawater,
these figures indicate bio-accumulation factors of the order of at
least 105 (106- 107 in lipids). Plankton-eating and fish-eating
birds and mammals often have residues an order of magnitude higher
* The first report of levels up to 150 ppt (375) has been questioned
(377) and is inconsistent even with subsequent reports of around
1 ppt, which are themselves questionable.
-------
33,
still. Levels were highest of all in predators (up to 88 ppra in
muscle and 535 ppm in fat in Glaucous Gulls (Larus hyperboreus) at
Bear Island — ref. 38t).
The data cited above show that in natural environments animals
generally bio-accumulate and bio-magnify PCBs by factors substantially
higher than those usually measured in laboratory experiments. Despite
the difficulties in measuring PCBs in water at levels near or below
1 ppt, there is now evidence from several areas that aquatic inverte-
brates and fish can bio-accumulate them by factors as high as several
million fold from ambient water, and that.fish-eating birds and mam-
mals can further bio-magnify these concentrations by factors of 10-
100. Reasons for this enhanced magnification in natural environments
have been discussed by Nisbet (336). One likely reason is that PCB
residues in many organisms increase with age (see Figure IV.2,18 for
an example involving lake trout). Hence long-lived wild animals have
an opportunity to accumulate PCBs to much higher levels than indivi-
duals exposed experimentally for limited periods in the laboratory.*
Other reasons proposed for this field effect include selective ex-
posure in a patchily contaminated environment, and selective preda-
tion on contaminated prey (336). Whatever the explanation for the
phenomenon, the bio-accumulation factors observed in the field are
those that are relevant to assessment of exposure to organisms that
may eat the contaminated fish.
* See also ref. 405 for an example involving seals, whose body bur-
dens were still increasing after 4 years in captivity (see p. 324
above).
-------
24
ffi
£
0 1 2 3 4 5 ? .7 6 9 10 11 I?
Fish 2&9 (years)
The concentration of PCB's in
Caynga Lake trout as a function of agi.
Figure IV.2.18 (from ref. 381)
-------
IV.3. Presence in the Aquatic Environment
A review of PCB levels in the environment is appended to this
document as Appendix G and only a brief summary is included here.
PCBs are widely distributed in the environment of North America.
Data gathered from nationwide monitoring activities by the U.S.
Geological Survey (48) show mean concentrations of PCBs in the range
0.01 to 0.05 /ig/1 (10-50 ppt) in unfiltered water samples and from
0.25 - 218 ppb in bottom sediments. The highest levels were found
in the Southeast (South Atlantic Slope and Eastern Gulf of Mexico
drainage basins) and the Northeast (North Atlantic Slope and St.
Lawrence River drainage basins). (See Appendix-C, pp. 3-15).
In the National Pesticide Monitoring Program, PCBs have been
I* -f;*A
detected/at all of the 100 monitoring stations, although the percen- '
\
tage of composites with detectable residues fell from 100% to 51%
between 1969 and 1973 (Appendix C, p. 27). In the same period the
number of composite samples of fish with residues greater than 5 ppm
fell from 61% to 40% (ibid.). Generally, the higher concentrations
were found in certain river systems with industrial activity, includ-
ing the Allegheny, Kanasha, Cumberland, Tennessee, Ohio, Mississippi
and Missouri Rivers (93) . High residues have also been found in
fish in the Great Lakes, in the Hudson and other northeastern rivers,
and in a number of estuaries and inshore waters (Appendix C, pp. 31-
87; 2, 93, 359-364, 367-370, etc.). PCB residues in fish detected
in monitoring programs include chlorobiphenyls characteristic of
Aroclors 1242 and 1248 (tri- and tetra-CBs) as well as those
-------
characteristic of Aroclors 1254 and 1260 (penta-, hexa-, and hepta-
CBs (93, 370, 367, 382). For example, in the crosscheck samples
*
analyzed for the National Pesticide Monitoring Program, 1970-73, 26
of 131 samples listed contained components characteristic of Aroclors
1232 or 1242, and 70 had components characteristic of Aroclor 1248;
all had components characteristic of Aroclors 1254 and 1260 (382).
In lake trout samples.in Lake Superior, more than half the PCB resi-
due components were listed as matching Aroclors 1242 and 1248 (367).
Similarly, numerous tetrachlorobiphenyls and at least one trichloro-
biphenyl component were identified in lake trout and coho salmon from
Lake Michigan (95). Thus tri- and tetra-CBs as well as higher CBs
are widely stored in fish in the United States.
PCBs are also found very widely and often at high levels in'
fish-eating birds (1, 2, 56, 93, 225, 364-366, 371-373) and fish-
eating mammals (374, 383-386). Levels are particularly high in the
fat (blubber) of marine mammals such as seals, dolphins and polar
bears (383-386; see Table IV.3.1).
PCBs are widely distributed in human tissues, reflecting
general intake in the diet (351-356).
-------
Table IV.3.1 (from ref. 383)
TOTAL DDT PLUS PCBs IN BLUBBER OF HARBOR SEALS COLLECTED IN 1971
LOCATION
Washington:
Puget Sound
California:
San Miguel Island
Oregon:
Columbia River
Alaska:
• Pribilof Islands
NO. OF
SEALS
MONTH
COLLECTED
June-August
June
May
August
AGE,
YEARS
9-30+
2-4
(a.)
TOTAL DDT fie PCBs (mg/kg, wet wt.)
MEAN "• INDIVIDUAL VALUES
862.7 459.4; 1,620.0
610.7 • 380.7; 318.5; 425.5;
518.3; 2,350.0
62.5 27.7; 80/4; 109.9
11.3 6.8; 7.1; 27.8
a. canine teeth lost
£
-------
IV.4. Effects on Biota and Natural Ecosystems
Effects of PCBs on organisms and ecosystems fall into two
categories: (a) effects observed in the laboratory under controlled
conditions of exposure to PCBs; (b) effects observed in natural
systems and associated with PCB exposure by epidemiological or equiv-
alent methods.
Effects of type (a) are relatively easy to extrapolate to
natural ecosystems: if an effect is observed in the laboratory
when test organisms are exposed to a certain level of PCBs, it is
reasonable to assume that similar effects will take place in the
field if the same or comparable species are exposed to the same level
of PCBs. It is often likely that effects will occur at lower levels
in the field, for the following reasons:
(i) natural systems involve many species and it is likely
that some will be more sensitive to PCBs than the species
chosen for testing;
(ii) under natural conditions organisms are exposed inter-
mittently to environmental stresses (temperature, pH,
oxygen depletion, food shortage, predation, etc.) which
generally make them more vulnerable to the effects of an
additional toxic stress;
(iii) natural systems are exposed to other pollutants and it
is known that additive and and synergistic toxic effects
may occur.
-------
Thus It is reasonable to expect adverse effects to occur in the
field at lower exposure levels than in the laboratory, but it is
difficult to predict the lowest hazardous levels without actual
field studies.
Effects of type (b), however, which depend on field studies,
are often difficult to interpret or to establish with reasonable
certainty. When an adverse effect is observed in the field, it is
often associated with exposure to more than one pollutant: it is
difficult to establish whether it is caused by PCBs, by another
pollutant, or by both acting together. Furthermore, PCBs are
patchily distributed in the environment, so without extensive measure-
ments of concentrations in water it is difficult to establish the
• exact degree of exposure of the affected organisms.
Accordingly to judge the effects of PCBs on natural systems
it is necessary to weigh laboratory and field evidence together.
IV.4.1. Effects Observed in the Laboratory
The following effects of PCBs have been observed in control-
led experiments at exposure levels which occur locally in the field:
(i) Change in species composition of phytoplankton communities
(Section III.3). Effects on the growth and rate of cell division of
sensitive species of phytoplankton have been noted at PCB concentra-
tions as low as 0.1 ppb (84, 86) and large effects on the species
composition of mixed cultures took place at this concentration (92).
The effects of lower concentrations have not been studied. The
changes involve replacement of sensitive diatoms by resistant green
-------
algae and are expected to have substantial effects on consumers and
hence on food-webs (83). Synergistic effects with DDE are also in-
volved (90) .
(ii) Change in species composition of marine animal communi-
ties. Effects on species composition and biological diversity of
communities of estuarine animals developing in the laboratory from
planktonic larvae in flowing seawater were noted at PCB concentra-
tions as low as 0.1 ppb, the lowest concentration tested (ref. 109;
Section III.4.2).
The results reported in these experiments (refs. 88. 92. 109)
are of particular importance because they demonstrate that PCBs
affect mixed communities of plants and animals at concentrations much
lower than those required to show effects on single species popula-
tions .
(iii) Effects on aquatic invertebrates (Section III.4).
Reproduction and growth is impaired in aquatic invertebrates at con-
centrations lower than those required to cause mortality. The water-
flea Daphnia magna and the midge Tanytarsus dissimilis are both
affected at levels between 0.4 and 0.5 ppb (93: Table III.4.1).
Synergistic effects with DDT are also involved (94).
(iv) Sublethal effects on fish (Section III.5). Although
there is little evidence that PCBs affect survival of fish at con-
centrations below 1 ppb, adverse effects on reproduction have been
noted at concentrations as low as 0.1 - 0.4 ppb, corresponding to
residues of 5 ppm in eggs (113, 114, 115). Effects were also noted
-------
on thyroid function in fish exposed to a dietary level of 0.48 ppm
PCBs (which corresponds to roughly 0.4 ppm whole-body residue)
(refs. 73, 95; Figure III.5.2).
(v) Effects on reproduction in birds (Section III.6.4).
Marked effects on reproductive success (especially embryonic mortal-
ity) have been noted in chickens at dietary levels as low as 8-10
ppm of PCBs, corresponding to residues of only 1-2 ppm in whole eggs.
It is doubtful whether the chicken is a good model for wild birds,
since other species have proved less sensitive in laboratory tests.
However, second generation effects and synergism with DDE have been
noted in other species at dietary levels of 10 ppm (161, 164).
(vi) Hepatic porphyria in birds (Section IV.6.3). PCBs in-
duced AIA-synthetase and caused porphyria in quail at doses as low
as 1 mg/kg/day and probably at 0.1 mg/kg/day. These effects were
associated with residues as low as 1 ppm in the liver (145: Figure
III.6.1).
(vii) Effects on mink (Section III.9.4). Mortality and total
reproductive failure took place in mink fed a diet containing only
0.64 ppm of PCB residues, the lowest dose tested (201). In another
experiment at a higher dose level, there was evidence of synergistic
effects with DDT and dieldrin (200: Table III.7.5). The mink is the
only fish-eating mammal whose sensitivity to PCBs has been tested.
All these effects have been noted at exposure levels which
occur quite frequently in natural environments. Concentrations of
0.1 ppb are reported not infrequently from polluted fresh waters
-------
svr
(48; Appendix C), and concentrations as high as 0.4 ppb are reported
occasionally. Fish throughout the United States have tissue residues
as high as those associated with thyroid malfunctions (Appendix C;
93). Fish-eating birds often are exposed to fish with PCB residues
as high as 8-10 ppm (Section IV.3); many, perhaps most, fish-eating
birds in the United States have residues in their eggs as high as
the 1-2 ppm that affect hatchability in chickens (Section IV.3.; 1,
2, 56, 225, 364-366, 371-373). Many fish-eating birds, even from
remote parts of the Atlantic Ocean, have PCB residues in the liver as
high as 1 ppm (140, 387, 388). Fish-eating mammals
in the Great Lakes and many other areas of the United States will be
exposed to diets containing 0.64 ppm of PCBs (Section IV.3; 93).
Thus it is reasonable to suppose that at least some of the adverse
effects reported in the laboratory are taking place in natural environ-
ments .
IV.4.2. EffectsObserved in the Field.
Several adverse effects on wild animal populations have been
reported which have been associated reasonably plausibly with ex-
posure to PCBs.
(i) Effects on reproduction in salmon. Swedish investigators
have reported a statistically significant association between hatch-
ing failure in eggs of Atlantic salmon and PCB residues. Concentra-
tions in the range 0.4-1.9 ppm, wet weight (7.7-34 ppm, lipid weight)
were associated with mortalities between 16 and 100 percent (118).
This report was published only as a preliminary note and complete
details are not available.
-------
(ii) Reproductive failure in other fish. Several species of
fish in Lake Michigan have not been reproducing effectively in recent
years (409-410). Despite annual stocking of lake trout since 1965,
for example, no wild-raised young have been collected (409). Eggs of
Atlantic salmon and northern pike have shown very low hatchability in
the laboratory (410). These reproductive failures have been associa-
ted circumstantially with residues of PCBs and other chemicals, but
no clear link has yet been established.
(iii) Fin rot syndrome in marine fish. "Fin rot syndrome" has
been induced in the laboratory in spot exposed to 3-5 wg/1 of Aroclor
1254 (106). The syndrome appears.identical to that observed in wild
fish (croakers and spot) which died under conditions of warm weather
and oxygen depletion in Escambia Bay, Florida (106). Although the
deaths of the wild fish were attributed originally to lack of oxygen
in the water (99), the levels of PCBs in the dying fish (around 10
ppm) were similar to those in fish experimentally poisoned in the
laboratory (99, 111). This suggests that PCBs may have played at
least a contributory role in the incidents.
In independent observations, McDermott et^ all. (370) have
reported that fin erosion has recently become prevalent in dover sole
off Palos Verdes and Orange County, California. Diseased sole have
higher PCB residues than healthy fish (median concentration 2 ppm,
wet weight, versus 1 ppm), but the difference was not quite statisti-
cally significant (P = 0.1). The syndrome was associated with con-
centrations of PCBs in water not greater than 4 ppt (370, p. 32).
-------
(iv) Deaths of fish-eating birds. Koeman (142) reported that
a number of Cormorants (Phalacrocorax carbo) found dead in the Nether-
lands in 1970.contained high residues of PCBs (mean 190 ppm in brain,
320 ppm in liver, wet weight). These concentrations were similar to
those in Cormorants experimentally poisoned with PCBs (76-180 ppm in
brain, 210-290 ppm in liver) and Koeman attributed the deaths of the
wild birds primarily to PCB poisoning (142). However, the correspond-
ing levels of PCBs in the fish and water were not known.
In November 1969, more than 50,000 seabirds, mostly murres
(Uria aalge), were found dead in the Irish Sea. The most consistent
findings at post mortem were emaciation, liver damage, and high resi-
dues of PCBs in the liver (2-880 ppm, wet weight) (389). Birds col-
lected in apparent good health at the same time and place had body
burdens similar to those of the dead birds, but in the healthy birds
the PCBs were stored in the fat, whereas in the dead birds the PCBs
were largely in the liver. It therefore seems likely that food
shortage triggered the incident, but since the liver residues of PCBs
in some birds were well into the lethal range (142) it seems likely
that some of the birds actually died from PCB poisoning. This is an
important example of the interaction of environmental and toxic
stresses. Residues in fish in the same area were in the range 0.01-
2.6 ppm (389).
Glaucous Gulls (Larus hyperboreus) .wV.ich had been feeding on
the eggs of seabirds at Bear Island in the Arctic Ocean had high
levels of PCBs in the liver (mean 24 ppm). One individual found
-------
dying with failure of coordination of the limbs had 311 ppm PCBs in
the liver (388) and is therefore likely to have succumbed to PCB
poisoning (140, 142). The example is important because the PCBs were
apparently acquired through the natural food chains of the North
Atlantic and Arctic Oceans (387, 388).
Two Bald Eagles (Haliaetus leucocephalus) have been reported
dying with high residues of PCBs in the brain. One found dead in
Michigan in 1970 had 235 ppm of PCBs and 385 ppm of DDE in the brain
(390). Another found dead in Michigan in 1972 had 190 ppm of PCBs
and 55 ppm of DDE in the brain and 1200 ppm of PCBs in the whole body:
the immediate cause of death was drowning, as it was seen to fall off
?.
a perch into the water (391). In each case the residues of JMridt PCBs
in the brain were in the lethal range (142, 391) and in the first case
residues of DDE were also: it seems likely that the birds died from
the combined .effects of PCBs and DDE poisoning. The first bird was
from the Lake Michigan area (Grand Traverse county); the second bird
was probably from southeastern Michigan. The Bald Eagle is an endan-
gered species and is subject to the special provisions of the Endan-
gered Species Act of 1973.
(v) Effects on reproduction in fish-eating birds. Herring
Gulls are experiencing low reproductive success at colonies in Lake
Ontario, but appear to be breeding normally at colonies in the other
Great Lakes, including Lake Michigan (366, 392, 393). The breeding
failure is characterized by early embryonic mortality (393) and is
associated with high levels of PCBs in the eggs (Table IV.2.17).
-------
-------
Recent studies have shown that the embryonic mortality is
associated with porphyria and edema (subcutaneous, pericardial, and
abdominal), and that these conditions are statistically associated
with high PCB levels (406). In addition, deformities of the feet,
toes, and eyes have been recorded in chicks of Herring Gulls and three
other fish-eating species in Lake Ontario (407).
In studies of other species of fish-eating birds, reproductive
failure and eggshell-thinning have been associated primarily with
residues of DDE (56, 364, 372, 373, 394) and no other study has sug-
gested an independent effect of PCBs. However, only a few species
have been studied to date.
(vi) Premature births in sea-lions. Premature pupping in sea-
lions has been noted on San Miguel and San Nicholas Islands, Cali-
fornia, since 1968. Most or all of the premature pups die (374).
Residues of PCBs were much higher in the females giving birth to
premature pups than in those of females giving birth at full term
Preceding Page Blank
-------
(means 112 ppm and 17.1 ppm PCBs in blubber, respectively). However,
residues of DDT compounds, primarily DDE, were also elevated in the
females giving birth prematurely (means 824 vs. 103 ppm in blubber).
Fish in this area have residues generally in the range 0.01-2 ppm
PCBs, ranging up to 4-6 ppm in the vicinity of sewage outfalls (370).
In all cases summarized above, the association between PCB
levels and adverse effects in wild animals is somewhat circumstantial:
this is inevitable in an epidemiological type of investigation. How-
ever, in each case the suspected adverse effect can be matched with
adverse effects noted in laboratory animals with comparable residue
levels. In several of the cases the adverse effects were also assoc-
iated with high levels of DDE, and additive or synergistic effects
seem likely. The interaction of environmental and toxic stresses is
also apparent in several cases. Together these examples seem suffi-
cient to show that current levels of environmental contamination
with PCBs are having adverse effects on natural ecosystems, but the
ambient concentrations at which they do so has not been established.
IV.5. Potential Effects in the Human Population.
•
As detailed in Section III, several different toxic effects
have been observed in experimental animals exposed to PCBs in the
diet at levels as low as 0.5-2.5 parts per million. Surveys by the
U.S. Food and Drug Administration suggest that the average level of
PCBs in the human diet in the United States is now about 2.2 parts
per billion (Section IV.2.7 above). There is thus a factor of-200-
1000 between the average level in the human diet and levels known
-------
to cause effects in experimental animals.
In addition, residues of PCBs are sporadically distributed
in the food supply and some individuals ingest much more than the
•average: persons with dietary preference for fresh-water fish and
breast-fed infants have been identified as high-risk groups (2, 331).
It is not yet possible to use epidemiological studies to
estimate safe levels of intake, for the following reasons:
(i) Epidemiological studies in tne general population are
not being conducted, and in any case would be difficult or impossible
because of the widespread exposure of the general public.
(ii) The Yusho incident, although providing some dose-response
information, is confused by the high level of PCDFs in the ingested
PCBs.
(iii) Occupational experience in the past has provided no
quantitative dose-respor.3e information and in any case may be con-
fused by effects of PCDFs in older formulations.
(iv) Current studies of occupationally exposed workers are
still in progress and in any case will provide information only
about adults.
-------
354
V. Criteria Formulation
The criterion level for PCB's is 0.001 ug/1 PCB's. It should
be noted that if all PCB entry into the environment were to stop
immediately, the environmental burden would in some waters still
exceed the ambient water quality criterion. While EPA is
attempting to prevent the continuing discharge of PCB's, or at
least to minimize the continuing discharge of PCB's into the
aquatic environment, the responsiblity for protecting man from
contaminated interstate comiercial food products is with the Food
and Drug Administration of the Department of Health, Education, and
Welfare.
The chronic effects of PCB's in man may occur at extremely low
concentrations. Although it becomes virtually impossible to state
with confidence that any PCB concentration above zero provides an
ample margin of safety for man, the PCB criterion number is
believed to provide protection for the aquatic environment.
The criterion for PCB's is derived with consideration of the
bioaccumulation potential rather than solely upon the more
traditional use of an application or safety factor applied to an
acute toxic value. The reasons for this approach are the
environmental persistence and bioaccurnulation potential of PCB's as
outlined below:
-------
355
The persistence of PCB's in the environment is such that they
present long-term environmental hazards.
The laboratory determination of the bioaccumulation potential
for PCB's in general has been shown to be around 274,000 times
the PCB level in the test water. There have been reports that
certain animals captured from the aquatic environment have
apparently bioaccumulated PCB's in their flesh to levels of
between 3 and 10 million times that of the water concentration
in which the animals were captured. It is important to note,
however, that the level of PCB contamination in the food of the
captured aquatic life, as well as the concentrations of PCB's
in which these organisms resided for the predominance of their
life periods, are unknown. Thus, the actual bioaccumulation
potential of PCB's in the aquatic environment is uncertain.
Therefore, the bioaccumulation potential demonstrated in the
laboratory of 274,000 is the number which is used in
determining a criterion level.
The demonstrated physiological effects of PCB's on fish and
consumers of fish and wildlife, which include reproductive
failures in a broad phylogenetic group of aquatic and
terrestrial animals, liver enlargement, enzyme induction and
skin lesions, require the consideration of parameters beyond
the usual acute toxicity and safety factors.
Data which support a one part per trillion (0.001 ug/1)
criterion are:
0.1 ug/1 will cause population shifts in phytoplankton. It is
important to note that at this level of the food web
bioaccumulation does not play a role in the adverse effect.
However, this concentration is extremely low and does have
significant ecosystem consequences since shifts in population
at this level will have an impact on the food for top
predators.
0.4 to 0.5 ug/1 lowers the reproductive potential of some
invertebrates.
0.1 ug/1 will lower the species diversity index of some
invertebrates.
Bioaccumulation has been demonstrated in the laboratory at
concentrations of around 274,000 times the water level.
-------
356
PCS contaminated fish will cause detrimental effects on
consumers of fish.
At 0.64 ppm (milligrams per kilogram in the food), total
reproductive failure was observed in mink.
At 3.57 ppm (milligrams per kilogram in the food), mink died.
At 2.5 ppm (milligrams per kilogram in the food), reproductive
dysfunctions occurred in the rhesus monkey.
At 3 ppm (milligrams per kilogram in the food), some mortality
was observed in the rhesus monkey.
In rats, 5 ppm (milligrams per kilogram in the food) resulted
in the induction of enzymes in the liver. ^
At levels of between 40 and 300 ppm PCB's in chicken feed,
deaths of chicken occurred. Reproductive failures occurred at
between 8 and 10 ppm PCB's in the food.
Ulceration in the stomachs of dogs occurred after long-term
feeding at 1 ppm PCB in feed.
Based upon the highest bioaccumulation factors demonstrated in
the laboratory, a water criterion of no more than 0.001 ug/1 (1
part per trillion) should provide protection to the aquatic
ecosystem, and should provide a margin of safety to the consumers
of aquatic life.
Adverse effects in man that are due to PCB or polychlorinated
dibenzofurans (PCDF) contamination have included: chlorcacene,
swelling of the eyes, and liver involvement. There was no
quantification of the levels of PCB's ingested by those individuals
affected by PCB's. The carcinogenic threat due to PCB's has not
been conclusively demonstrated, although based upon interpretation
-------
of data, sane researchers have concluded that PCB's have resulted
in cancer in the mouse and thus they represent a threat to man.
Based upon the proven bioaccumulation potential of 274,000
times the ambient water concentration in controlled conditions, the
level of 0.001 ug/1 PCB's should afford protection for consumers
whose sole diet consists of aquatic organisms contaminated at the
worst or maximal level predicted by the laboratory data.
-------
-------
EPA - 560/7-76-001
/x C
REVIEW OF PCB LEVELS IN THE ENVIRONMENT
JANUARY 1976
OFFICE OF Toxic SUBSTANCES
ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D,C, 20460
NOTE: Appendices A and B are copyrighted materials and therefore have been
emitted.
C-i
Preceding Page Blank
-------
1EV1EW OF PCB LEVELS IN THE ENVIRONMENT
Prepared by
Office of Toxic Substances
Environmental Protection Agency
Washington, D,C, 20460
January 1976
C-ii
-------
Table of Contents
1.0 Introduction .
2.0 PCS Levels in the Environment
2.1 Data from National Monitoring Programs .... .. 3
2.1.1 Water 3
2.1.2 Sediment - 9
2.1.3 Soils ....'.. 15
2.1.4 Air ; 18
2.1.5 Fish . . 19
2.1.6 Birds ... f ...'..... 28
References ....... 30
2.2 Data from Localized Monitoring Efforts - Lakes : .'• . 31
2.2.1 Lake Ontario ', ".. 31
2.2.2 Lake Erie /• 35
2.2.3 Lake Superior 37
2.2.4 Lake Michigan '. . 40
2.2.5 Lake Huron . 48
2.2.6 Cayu^a Lake ' 52
References .......... 54
2.3 Data from Localized Monitoring Efforts - Rivers ..'...... 56
2.3.1 Iowa - Mississippi River 56
2.3.2 New York - Hudson 57
2.3.3 Maryland - Chester River 60
2.3.4 Connecticut ' 62
References ............... 64
2.4 Data from Localized Monitoring Efforts - Marine Environment . 65
2.4.1 Atlantic Ocean . . 65
2.4.2 Bay of Fundy 72
2.4.3 Gulf of Mexico - Caribbean Sea 73
2.4.4 California 78
2.4.5 Eacambia Bay, Florida 82
References 86
2.5 Data from Localized Monitoring Efforts - Industrial Plants
Products, Sewage Treatment Facilities and Landfills . . .
2.5.1 Industrial Plants 88
88
92
94
98
2.5.2 Sewage Treatment Facilities 101
101
105
108
112
113
117
C-iii
2.5.1.1
2.5.1.2
2.5.1.3
2.5.1.4
Monsanto Co. , Sauget
Yates Manufacturing
Val,eagt Corp., Troy,
, Illinois
Co. , Chicago, Illinois
General Electric, Hudson Falls -
Sewage Treatment Facilities ......__.__.
2.5.2.1
2.5.2.2
2.5.2.3
2.5.2.4
2.5.2.5
Illinois .
Ohio .
California
References
•
.
-------
2.6 Data from Localized Monitoring Efforts - Cities 118
2.6.1 Jacksonville, Florida 118
References ».. 121
3.0 Behavior of PCB's in the Environment 122
3.1 Composition of Aroclor Products . . . . 122
. 3.2 Water Solubility of PCB's ............ .-•».,-••.--...• 122
3.3 Interaction of PCB's with Soils ........ 123
3.4 Evaporation of PCB's from Water 124
3.5 Environmental Sampling Guidelines .... 124
References ...... 129
4.0 Occurrence of PCB's in Food 130
References 133
5.0 Exposure and Biological Accumulation of PCB's in Man ....... 134
5.1 National Monitoring Programs ,.... 134
5.2 Localized Studies 134
References 136
6.0 Environmental Trends ..... ........... 137
C-iv
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1.0 Introduction
Polychlorinated biphenyls (PCS'a) were first manufactured commer-
cially in 1929. They are currently manufactured in the United States,
Great Britain, France, Germany, USSR, Spain, Italy and Czechoslovakia.
The sole producer of PCB's in the United States is the Monsanto . ...
Industrial Chemicals Company, where products are marketed under the
trade name "Aroclor". Various Aroclor products that have been marketed
include Aroclor 1221, 1232, 1242, 1248, 1254, 1260, 1262 and 1268. The -
latter two digits designate the percent chlorine in each formulation.
Aroclor 1016 is a new product which has 41% chlorine. Since their
introduction, PCB's have been used in a variety of commercial and industrial
products such as transformers, capacitors, paints, inks, paper, plastics,
adhesives, sealants and hydraulic fluids. Through this widening product
usage and their resistance to degradation, PCB's have been identified
in the environment since 1966 with increasing frequency.
On September 1, 1971 an interdepartmental task force was established
in the United States to review the data linking FCB's with adverse . •
health and environmental effects and "to coordinate a governmentwide
investigation into PCB contamination of. food and other products". The
task force concluded in its report of May 1972 that,PCB's. were highly
persistent, could bioaccumulate to relatively high levels in fish and
could have serious adverse effects on human health. It recommended the
discontinuance of all PCB uses except in closed electrical systems.
Since the 1972 Task Force Report, environmental sampling and laboratory '
studies have indicated that PCB's were a more serious and continuing
environmental and health threat than had been originally realized.
These concerns were highlighted this past November at the National
Conference on Polychlorinated Biphenyls held in Chicago, Illinois.
This study reviews the current PCB data base to assess the PCB
levels in the environment on a national level; the full spectrum
of PCB levels reported in man and the environment were of interest.
Data were obtained from a number of national monitoring programs,
the literature and many unpublished reports. The data examined was
inclusive to December 1, 1975.
It should be stressed at the outset, that due to the complexity
and difficulty of PCB identification and measurement, that levels
reported are not really comparable between different investigators.
This aspect could not be compensated .-for or identified in the data
presented. In addition, some of the Aroclor identifications reported
may only have been best'estimates of the pattern observed and may
not have really identified the true Aroclor discharged or the quanti-
tative level of the polychlorinated biphenyl found-in the sample.
However, the levels reported do give an indication of the contamination
levels in different media for a given locality.
-------
Recognizing the faults of combining different data bases, the
sheer mass of data supports the conclusion that there is widespread
contamination of the environment by PCB's. There are regional variations,
but effects are consistent across all media (e.g., water, sediment,
fish, birds), generally showing greater concentrations of PCB's in
highly developed areas and in areas of industrial activity. Over the
years examined, the situation has shown no improvement nationally.
This report is divided Into five major sections:
PCB's in the environment
Behavior in ths environment
Occurrence in food
Bioaccumulation in man
Environmental trends
Wherever possible, the level of data reported has been greatly reduced
over that originally reported, especially for the older studies, however
every effort has been made to indicate the locality and the level of
contamination originally reported. More recent studies are presented
in greater detail. Trend assessments, cross media comparisons and
conclusions are drawn where justified.
-------
2.0 PCS Levels in the Environment
2.1 Data from National Monitoring Programs
2.1.1 Water
PCS monitoring in water ia an activity of the overall National
Pesticides Monitoring Program operated by the U.S. Geological Survey.
Analysis of the PCS data in EPA's STORET water quality file has provided
little information, although scattered whole water measurements have
been taken by a number of states over the years. Those states reporting
nonzero readings are few in relation to the number of states showing zero
concentrations.
At the direction of various local, state and federal agencies,
the USGS collects and analyzes water data, producing a data file of
uniform integrity. Current data from this file8 covering the period
October 1972 to 1975 provides the best available national data and
the basis for the following analyses.
PCB levels, gathered by the USGS during the period January 1971
to June 1972 were reported by Crump-Wiesner, Feltz and Yites2. While
the data suffers from the lack of representative sampling within
states and multiple samples from the same locations, they concluded that
significant concentrations of PCBs were widespread in the water
'resources of the nation. Their published summary of PCB residue data
for surface and ground waters has been updated with the 1972-1975
data and is presented in Table 2.1-1.
The preponderance of zero readings in whole water and the low
levels of scattered non-zero readings could be masking widespread
PCB contamination in the nation's waters. Zero readings are due '••
to the low solubility of PCBs and the analytical procedure commonly
used which limits detection to 0.1 ppb.
There is a disparity between whole water and bottom deposit
measurements. In almost all cases in which samples of both whole water
and bottom sediment were taken simultaneously and the latter reading
was non-zero, the whole-water concentration was measured at zero ppb
This occurred even when the concentration in bottom sediment was as
high as 4000 ppb8. More recent water 'studies3 to the ppt level
have consistently shown measureable PCB levels.
-------
Alabama.
Arizona
Arkansas
California
Colorado
Connecticut
Delaware
D.C.
Florida
Table 2.1-1
Summary of FCB Residue Data for Surface and
Ground Waters, January 1971-(partial) 1975
reai
71
73
73
74
71
72
73
74
75
71
72
73
74
75
71
72
73
74
75
71
72
73
74
71
72
73
NO
NO
72
73
74
75
No. of
: Samples
3
— .
4
2
8
8
38
14
4
32
8
28
22
1
161
27
110
99
42
32
3
6
9
13
16
45
ACTIVITY
ACTIVITY
16
106
60
22
Occurences
0
0
0
0
0
0
0
0
0
1
0
0
2
0
0
2
0
0
0
0
0
6
6
1
0
4
0
0
Concentration
(ppb)
Median
Concentration
(ppb)
0.2
0.1-0.2
0.1
0.1
0.1
0.1
0.1-1.0
0.1
-------
C--
Table 2.1-1 (cont.)
Hawaii
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Year
73
74
71
72
73
74
72
73
74
74
75
74
71
72
73
74
71
72
73
74
71
71
73
74
75
71
72
73
74
71
71
73
74
75
No. of
Samples
1
29
5
I
1
1
1
1
6
1
1
24
1
27
2
10
4
24
3
9
195
147
22
2
1
6
1
5
5
6
5
Occurences
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
1
0
0
0
0
2
0
0
0
0
1
1
1
1
Median
Concentration Concentration
(ppb) (ppb)
O.L
0.2
0.1-0.2
0.1
0.2
0.1
0.1
0.1
-------
C -
Table 2.1-1 (cont.)
State
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nevada
New Hampshire
New Jersey
New Mexico'"
Year
71
72
73
74
75
71
73
74
71
73
74
75
71
72
73
71
72
73
74
71
72
73
74
75
72
73
74
73
74
71
72
73
74
71
72
73
74
No. of
Samples
2
2
6
23
18
3
1
1
8
1
52
60
21
7
19
47
9
32
8
44
3
24
17
2
4
6
5
3
3
11
5
29
29
36
10
5
5
Occurences
0
1
0
0
0
2
0
0
0
0
0
0
0
. 0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
3
1
2
0
0
0
0
0
Median
Concentration Concentration
(ppb) (ppb)
0.1
0.1-0.3
0.1
-------
Table 2.1-1 (cont.)
Year
North Carolina 72
North Dakota
Ohio
Oklahoma
Oregon
Pennsylvania
Rhode Island
South Dakota
73
South Carolina 72
73
74
Tennessee
71
72
73
74
73
74
No. of
Samples
71
73
74
72
73
74
71
72
73
74
72
73
74
71
72
73
74
75
71
72
73
74
75
71
73
74
75
325
32
16
3
1
1
40
3
4
3
14
1
3
19
5
77
37
11
13
2
9
9
1
2
1
25
20
2
2
12
18
1
5
1
1
2
Occurences
52
1
0
0
0
0
0
0
0
0
2
0
0
0
0
2
5
2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Median
Concentration. Concentration
(ppb) (ppb)
0.3
0.1-E.2
0.1-2.9
0.1-0.2
2.0-3.0
0.1
-------
c -
Table 2.1-1 (cont.)
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
Wyoming
Year
71
72
73
74
72
73
74
73
No. of
Samples
660
82
385
297
1
8
16
Puerto Rico
71
72
73
74
71
72
73
74
71
74
71
72
73
74
75
71
72
73
74
73
74
4
12
5
1
25
1
6
6
4
1
3
1
12
30
2
18
1
6
3
34
63
Occurences
12
1
6
4
0
0
0
1
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
1
Median
Concentration Concentration
(ppb) (ppb)
0.1-3.0
0.1
0.1-0.6
0.2-0.7
0.4
MMMiWM
0.3
0.3
0.1
0.1
0.8
E - estimated.
SOURCE: This table is an extension of Table 2 in Crump-Wiesner, J.S.,
H.R. Feltz and M.L. Yates, J. Research USGS, !_, 603-607; (1972)
incorporating the newer data of PCB Data Base, October 1972
to (partial) 1975, The U.S. Geological Survey, Quality of
Water Branch, Reston, VA.
-------
2.1.2 Sediment
Nationwide sampling of bottom sediments have shown PCB concen-
trations to have widespread occurrence. Data from Crump-Wiesner,
et. al. ,2 January 1971-June 1972 are summarized In Table 2.1-2.
The October 1972 to 1975 USGS data are summarized In Table 2.1—3. -
Table 2.1-3 permits distinguishing between those states where the
non-zero PCB readings were from one or a limited number of stations
with multiple readings and those states where the non-zero readings
come from a number of stations within the state. The map in Figure
2.1-1 indicates the distribution of PCB contamination from 1972-1974
based on the figures in the tables.
States which monitored sediment concentrations to any appreciable
extent detected the presence of PCB's in concentrations often higher
than 40 ppb. A greater proportion of states are reporting PCB's in
bottom sediment each year, as displayed in Table 2.1-4.
Although the sediment data is meaningful, some caution is necessary
in interpretation: measurements may be the result of past contamination,
not present discharges; mean readings and ranges are somewhat inadequate
to summarize the data - geographic locations are essential since
readings show patterns only in particular water basins.
-------
Table 2.1-2
Summary of PCS Residue Data for Bottom Sediments
January 1971 - June 1972
Median
State
California
Hawaii
Georgia
Maryland .
Mississippi
South Carolina
Virginia
West Virginia
No. of
Samples
3
23
13
1
4
12
11
8
12
4
'16
11
293
10
10
2
Occur-
rences
0
4
3
1
0
10
5
2
10
2
11
8
23
8
0
1
Concentration
(ppb)
• -•• •
20-2,400
20-190
40
10-1,300
10-1,200
50; 170
8-250
15; 140
10-50
30-200
7.9-29C
5-80
10
Concentration
(ppb)
60
85
300
30
20
20
50
80
40
-
SOURCE: Crump-Wiesner, J.S., H.R. Feltz and M.L. Yates,
J. Research DSGS, 1, 603-607, (1972).
-------
C-ll
Table 2.1-3 .
Summary of PCB Residue Data for Bottom Sediments
Stations measuring///Stations with at least one non zero reading
Range of non-zero readings (mean), in ppb
STATE ;
Alabama
Alaska
Arizona
Arkansas
California
Colorado
Connecticut
Delaware
Florida
Georgia
Hawaii
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nevada
New Hampshire
New Jersey
New Mexico
1972
1/0
1973
1/0
1/0
1/0
6/0
15/0
1/0 1/0
16/8 16/11
<5-E800 (127.5) <5-40 (14.1)
NO ACTIVITY -
64/34
27/7
<5-400 (93.6)
<2-600 (35.8)
1/0
4/0
1/0
3/0
2/2
,<10
3/0
2/0
' 1/0
NO ACTIVITY
3/0
1/0
NO ACTIVITY
NO ACTIVITY
1/0
• i/o-
NO ACTIVITY
'6/0
3/0
3/0
NO ACTIVITY,
20/18
<3-4000 (230.2)*
4/0
1974
2/0
1/0
15/4
<2-29 (12.8)
18/2
<2-65 (33.5)
1/0
40/31
<2-350 (71-5)
68/16
<2-530 (43.3)
9/7
<1-51 (13.6)
1/0
4/2
<9-6l (35)
(partial)
1975
20/2
<140-430 (28!
1/0
13/8
<4-60 (17.6)
1/0
50/13
<3-56 (16.4)
.4/0
1/0
3/0
15/7
<1-800 (172.2)
1/0
4/1 (5)
15/4
<10-58 (29.5)
-------
C-12
Table 2.1-3 (cont.)
STATE 1972 1973 1974 1975
New York 17/5 17/14
<2-1300 (519)* <2-450 (95.8)
North Carolina 1/0
North Dakota 2/0 2/0
Ohio 1/0
Oklahoma 1/0 3/0 1/0
Oregon 1/0 1/0 2/0
Pennsylvania 9/7 5/3 23/16 3/3
<5-E100 (50.7) <5-20 (11.7) <6-700 (105.6) <42-240 (144)
Rhode Island NO ACTIVITY
South Carolina 2/0 . 2/0 5/1 (6)
South Dakota 1/0 1/0 .
Tennessee 1/0 1/0 , ——
Texas 41/3 58/8 58/17
<4-120 (61.7) <3-45 (17.6) <1-153 (45.5)
Utah 3/0 1/0
Vermont " NO ACTIVITY
Virginia NO ACTIVITY •
Washington 1/0 3/0 . 2/0
West Virginia NO ACTIVITY
Wisconsin 9/1 (10) 21/0 2/0
Wyoming —- 3/0 1/0
Puerto Rico '- 6/0 16/5
. . .... <10-640 (242)
E - estimated
*mean figure does not include anomalous values
SOURCE: PCB Data Base* October 1972 to (partial) 1975, U.S.
Geological Survey, Quality of Water Branch, Reston, VA.
-------
C- 13
Table 2.1-4
States Reporting PCB's In Bottom Deposits
1971-72 1973 1974 1975 (partial)
29/15 39/8 " 32/14 6/4
(51.722) (20.512) (43.752) (66.672)
# states measuring FCB's In bottom sediments/# with at least one non-zero readii
SOURCE: PCB Data Base, October 1972 to (partial) 1975, U.S.
Geological Survey, Quality of Water Branch, Reston, VA.
-------
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r^C
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•" u.
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ut <
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S-'
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•i'U.
O 5
<
c
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tu
ec
3
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-------
C-li
2.1.3 Soils
Two national soils monitoring programs are conducted by EPA as
part of its Pesticides Monitoring Program covering both cropland and
urban soils. In 1973, the only year in which PCB's were analyzed in
cropland soils, virtually no occurrences were detected1. -.
The urban soils program is a small one, consisting of 5 different
urban locations each year. In 1973, the only year for which PCS data
In cropland soil are available, virtually no occurrences were detected.
The sampling design recovers one analytical sample per square mile in
the city proper and one per twenty square miles in the suburbs. The
results of the program for the years 1971-1973 are summarized in
Table 2.1-5 and Figure 2.1-21.
Among each year's set of 5 cites, 3 (60%) had at least one
positive PCS site, cities and sites having been randomly selected.
Over the three years an average of 2.68% of the sites in these cities
(roughly corresponding to 2.68% of the total area) showed PCS
concentrations in ranges from 0.9-11.94 ppm. The anomalous reading
of 11.94 was found in a residential lawn in Gadsden, Alabama. Seventeen
of the twenty two positive readings were below 1 ppm.
-------
Table 2,1-5
National Urban Soil Monitoring Program
PCB Detections 19/1 - 1973
1971
Baltimore, MD.
Gadsden, AL.
Hartford, CT.
Macon, GA.
Newport News
1972
Dea Holnes,
Lake Charles
, VA.
IA
, LA.
PLtchburg, HA
Pittsburgh,
Reading, PA,
1973
Evansvllle,
Greenville,
PLttsfield,
Tacoma, WA.
PA.
IN.
SC
HA.
Total No. '
of Sites
156
55
48
41
78
82
70
35
189
49
82
86
45
95
No. of
Positive
Detections
6
1
ND
ND
I
3
1
ND
1
ND
ND
3
ND
6
Percent
Positive
Detections
3.
I.
-
-
1.
3.
1.
-
0.
—
-
3.
-
6.
9
8
„
3
t
7
4
5
5
3
Range of Positive Arithmetic PCB
Detections (ppra) Mean (ppm) Type(s)
0.
11.
3.
0.
1.
1.
0.
•
0,
09 - 0.74
94
30
34 - 0.94
31
01
13 - 1.59
18 - 0.63
0.
0.
0.
0.
0.
0.
0.
0.
02
21
04
03
02
01
02
03
1260 1-lawn,
Not identified
residential
1254 lawn
Not identified
l-waste
1254
Not identified
1254 3-lawn
1-1254, Others
5 waste
,
lawn
, 2-lawn
, lawn
not
Washington, D.C.
116
1.7
0.32 - 0.80
<0.01
Identified, 2 lawn,
4 waste
1-1254, Others not
Identified, 1 lawn,
1 waste
SOURCE: Carey, Ann, 1975, EPA National Soil Monitoring Program, unpublished.
-------
/°"oo^~r J i ' ' I -
/ / i I
/ / 'D^Hol I
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I / * ] W^OMlNQ *——I
fe»^ / / I
' f°^>'^.^ / / I
/^^Oi"*—*.._ ' '
/ . *"»•••» / >—*~-.—-.
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A 1073
• AT LEAST ONE DETECTION
-------
- It
2.1.4 Air
Polychlorlnated biphenyls have not been measured In air on a
nationwide basis.
-------
c-is
2.1.5 Fish
Fish have long been a popular sampling medium for PCS levels
primarily due to the minimal difficulties of sampling and analysis
relative to other media. Data on residue levels in fish, however,
present problems of interpretation: the eating habits, lipid content,
age, sex and size affect PCB levels; residue levels in fish, like
those in sediment indicate past, not necessarily current, exposure}" •
residue levels in fish are slow to reflect changes in levels of
contamination of the water; distinguishing Aroclor 1242 from 1016
is difficult.
The U.S. Fish and Wildlife Service of the Department of the
Interior provides the best national overview with the National Fish and
Wildlife Monitoring Program. One of the elements of this program is the
annual sampling of freshwater fish at 100 stations (as of 1970).
Beginning with the 1969 collections, whole fish samples were analyzed
for PCB's.
The most recent data from this program are the unpublished results
of the 1973 collection. While many species of fish are sampled through-
out the country, a reasonable summary of the data is provided in Table
2.1-6, which concentrates on the four most commonly sampled species of
fish, largemouth bass, channel catfish, carp and yellow perch.
The great number of stations reporting "no detection" for those
four species in 1973 is significant. Generally lower levels were
reported for other species in 1973 also. Furthermore, when sampling
data is totalled, ignoring both species and geographic location, as
in Table 2.1-7, marked declines in both the proportion cf composites
with some PCS residues and the proportion with residues above the
maximum recommended by Fish and Wildlife of 0.5 ppm are exhibited.
While there is a downward trend in the number of stations reporting
significant residue levels, those which have reported high concentrations
in the past continue to do so. Walker9 notes that PCB residues have
been found in forty to sixty percent of the samples in residue con-
centrations exceeding 0.5 ppm and that the geographic dispersion shows
that the higher concentrations appear to be associated with certain
river systems having industrial activity: thirty-one of thirty-five
stations in the Mississippi river system reported residues in excess of
0.5 ppm in the 1970-73 sampling program; all stations in the Great
Lakes drainage area reported concentrations exceeding 0.5 ppm. Several
factors related to interpretation of this data must be recognized: the
PCB residues prior to 1973 are reported"as "estimated", while those for
1973 are the result of the analysis for three Aroclors (1242, 1254 and
1260) totalled; a trend cannot be inferred from the data of one year,
regardless of how dramatic it is, although such data may signal a
turning point; analytic protocols for sample analysis, especially
determination of specific Aroclors, are suspect and the results of
cross check analyses show that some laboratories used for the analysis
typically expressed PCB .levels of only 5 to 20 percent of those discovered
by more sophisticated analytic protocols of the Fish Pesticide Research
Laboratory .
-------
c-
20
Table 2.1-6
PCS Residues in Selected Species of Fish
(averages of composite samples, expressed in
ppm, wet weight, whole fish)
State
AL
AZ
AR
CA
CO
Waterway/
Station Location
Alabama R.
Chrysler
Tombigbee R.
Mclntosh
Colorado R.
Imperial Reservoir
Colorado R.
L. Havasu
Colorado R.
L. Powell
Gila R.
San Carlos Res.
Arkansas R.
Pine Bluff
Sacramento R.
Sacramento
San Joaquin R.
Los Banos
Klamath R.
Hornbrook
Rio Grande
Alamosa
Arkansas R.
John Martin Res.
Species
Largemouth bass
Channel catfish
Carp
Largemouth bass
Channel catfish
Largemouth bass
Carp
Channel catfish
Carp
Largemouth bass
Channel catfish
Carp
Largemouth bass
Carp
Largemouth bass
Channel catfish
Carp
Channel catfish
Carp
Largemouth bass
Carp
Channel catfish
Yellow perch
Largemouth bass
Carp
Carp
Channel catfish
1969a
<0.10
0.40
0.25
0.64
• • •
1.69
0.10
<0.10
0.10
0.10
1970a
3.70
0.86 .
1.30
0.11
0.13
0.17
0.17
0.14
. 0.21
0.09
0.09
0.04
0.08
1.25
2.62
0.73
3.74
1.72
0.14 .-
0.24
0.09
0.26
0.09
0.15
1971a
1.35
0.17
0.93
0.03
0.17
0.05
0.14
0.06
0.10
0.08
0.03
0.21
0.52
1.04
0.28
0.12
0.21
0.06
0.12 *•
0.06
0.05
0.11
J972a
6.5
1.5
**
**
N.D.
0.01
N.D.
N.D.
<0.10
0.1-j
**
**
**
**
N.D.
4.35
3.7
**
N.D.
0.05
197
N.I
N.I
N.I
N.E
N.E
N.D
N.D
N.D
N.D
N.D
N.D
N.D
2.5
N.D
N.D
<0.1
.
N.D
N.D
-------
Table 2.1-6 (cont.)
C- 21
Waterway/
State
CT
FL
GA
ID
-
IL
IN .
LA
Station Location
Connecticut R.
Windsor Locks .
St. John's R.
Welaka
lanal
auwanee n..
Old Town
Apalachicola R.
Jim Woodruff Dam
Savannah R.
Savannah
Altamaha R.
Doctortown
Bear R.
Preston
Salmon R.
Riggins
Snake R.
Lewis ton
Ohio R.
Metropolis
Illinois R.
Beards town
Wabash R.
New Harmony
Des Moines R.
Keosauqua
'Mississippi R.
Guttenberg
Species
Yellow perch
Channel catfish
Largemouth bass
Channel catfish
Largemouth bass
Largemouth bass
Channel catfish
Largemouth bass
Carp
Largemouth bass
Channel catfish
Carp
Largemouth bass
Carp
Yellow perch
Carp
Carp
Carp
Channel catfish
Carp
-
Carp
Channel catfish
Carp
Channel catfish
Largemouth bass
Carp
Largemouth bass
1969a
3.40
0.14
0.31
1.25
0.56
0.69
<0.10
<0.10
1.18
0.58
11.3
0.54
1.41
1970a
2.45
0.18
0.37
0,26
0.62
0.31
0.67
0.53
0.70 •
2.92
0.79
0.89
1.29
0.14
0.29
2.01
3.78
0.82
3.10
1.07
0.22
0.40
0.30
1.79
1971a
17.1
0.07
0.28
0.09
0.08
0.5
0.62
0.12
0.14
0.12
0.27
0.82
0.42
0'.06
0.65
3.16
6.07
0.64
1-13 ..
3.95
0.16
0.86
1.21*
1.11
' 1972a
6. 6
N.D.
N.D.
N.D.
N.D.
0.35
2.5
N,D.
0.64
2.30
.
1.20
1.9
1.0
0.11
*
7.1
5.7
2.1
1.6
3.3
1.33
1.60
N.D.
1.0
1.25
1973
5.6
N.D.
N.D.
N.D.
N.D.
0.3
N.D.
N.D.
0.5
3.2
N.D.
0.8
2.35
N.D.
1.4
5.45
1.45
2.1
1.27
1.00
0.90
1.2
0.96
-------
Table 2.1-6 (cont.)
C-22
State
KS
LA
ME
MD
MA.
MI
MN
MS
MO
Waterway/
Station Location
Kansas R.
Bonner Springs
Mississippi R.
Luling
Red R.
Alexandria
Penobscot R.
Old Town
Kennebec R.
Hinckley
Susquehanna R.
Conowingo
Potomac R.
Little Falls
Merrimac R.
Lowell
L. Huron
Bay Port
Red R. (north)
Noyes
Yazoo R.
Redwood
Mississippi R.
Cape Girardeau
Missouri R.
Hermann
Species
Carp •
Channel catfish
Carp
Channel catfish
Channel catfish
Carp
Yellow perch
Yellow perch
Carp
Channel catfish
Yellow 'perch
Carp
Channel catfish
Largemouth bass
Yellow perch
Carp
Channel catfish
Yellow perch
Channel catfish
Carp
Channel catfish
Carp
Largemouth bass
Carp
Channel catfish
1969a
0.46
0.66
0.31
0.69
1.21
1.31
1.04
1.04
1970a
0.55
0.86
0.58
0.33
0.23
2.6
1.77
2.39
0.63
.6.12
2.76
3.80
3.33
0.68
1.95
5.26
3.51
1.29
0.21
1221
1.28
0.77
0.28
1.95
0.30
0.15
0.69
• 0.94
0.95
0.81
21.2
5.50
1.53
2.83
2.29
0.68
1.63
1.89
3.20
7.6
1972*
-1.30
4.5
6.6
N.D.
0.36
0.20
1.9
4.5
1.9
1.1
9.5
0.49
0.17
N.D.
2.42
2.8
2.00
1973C
•r 1.2 •
0.80
0.3
N.D.
0.60
1.2
t
0.5
N.D.
12.0
4.30
• 6.6
4.25
N.D.
N.D.
N.D.
1.9
1.0 .
4.6
-------
Table 2.1-6 (cont.)
C-23
State
MT
NE
NV
nauBLWdy /
Station Location
Big Horn R.
Ear din
Yellowstone R.
Sidney
Missouri R.
Nebraska City
North Platte R.
L. McConaughy
South Platte R.
Brule
Platte R.
Louisville
Colorado R.
L. Mead
Truckee R.
Fernley
Species
Carp
Channel catfish
Channel catfish
Carp
Carp
Channel catfish
Carp
Channel catfish
Carp
Carp
Channel catfish
Carp
Largemouth bass
Channel catfish
Carp
Largemouth bass
1969 a 1970 a
0.42
0.55
0.14
1.38
0.24
0.21
0.08.
0.71
0.62
0.13
0.09
"
0.54 0.51
<0.10 0.73
19713
0.05
0.53
0.06
0.09
0.22
0.23
0.43
1.68
0.09
0.13
• •
1,21
0.42
1972 a
N.D.
0.10
.
0.67
0.50
N.D.
N.D.
1.15
1.50
4.30
*
N.D.
0.26
0.76
1.8
2.1
197j
N.D,1
N.D.
0.20
N.D.
0.30
N.D.
N.D.
0.50
0.33
1.70
0.20
N.D.
0.20
0.83
1.00
NJ
NM
NY
NC
Raritan R.
Highland Park
Rio Grande
Elephant Butte Res
Hudson R.
Poughkeepsie
St. Lawrence R.
Massena
L. Ontario
Port Ontario
Roanoke R.
Roanoke Rapids
Cape Fear R.
Elizabethtown
Largemouth bass
Carp
Channel catfish
Largemouth bass
Largemouth bass
Yellow perch
Yellow perch
Largemouth bass
Carp
Channel catfish
Largemouth bass
4.82
0.10
0.35
0.65
9.37
1.45
2.48
0.89
3.33
0.52
0.30
34.5
2.12
7.34
•
0.37
0.81
4.9
0.92
1.54
13.0
3.15
6.2
1.40
0.65
3.90
2.1
N.D.
N.D.
3.2
1.1
5.2
N.D.
N.D.
N.D.
N.D.
-------
Table 2.1-6 (cont.)
C624
State
ND
OH
OK
OR
PA
SC
Waterway/
Station Location
Missouri R.
Garrison Dam
Ohio R.
Marietta
Ohio R.
Cincinnati
Verdigris R.
Oologah
Canadian R.
Eufaula
White R.
DeValls Bluff
Red R.
Lake Texoma
Arkansas R.
Keystone Res.
Willamette R.
Oregon City
Columbia R.
Bonneville
Rogue R.
Gold Ray Dam
L. Erie
Erie
Allegheny R.
Natrona
Pee Dee R.
Dongola
Cooper R.
Summerton
Species
Carp
Carp
Channel catfish
Largemouth bass
Carp
Channel catfish
Carp
Largemouth bass
Carp
Largemouth bass
Channel catfish
Carp
Channel catfish
•
Carp '
Largemouth bass
»
Carp
Largemouth bass
Channel catfish
Carp
Channel catfish
Carp
Carp
Largemouth bass
Yellow perch
Carp
Largemouth bass
Carp
Largemouth bass
1969a
0.10
8.07
•
0.24
0.66
1970a
0.08
4.82
11.85
24.5
0.61
0.40
0.81
0.14
1.77
1.82
0.25
0.21
0.45
1.25
1971a
5.20
14.5
22.65
25.8
27.3
0.8
0.09
0.31
, 0.36
0.73
2.32
0.26
0.13
0.29
1.28
1972a
•NiD. .
2.5
9.75
19.0
30.0
**
**
1.5
N.D.
N.D.
0.5
**
192
N.E
11;
24.
25.
21.
N.D
N.D
N.D
N.D
N.D
N.D
' N.D.
N.D.
N.D.
N.D.
1.25
<0.10
2.60
0.87
2.40
4.59
0.62
1.04
0.45
0.19
1.11
5.52
0.35
0.18
0.44
1.4
1.65
4.0
3.70
N.D.
3.20
N.D.
5.4
0.75
1.75
0.5
1.5
3.3
-------
Table 2.1-6 (cent.)
C- 25
State
SD
TN
TX
UT
VT
VA
WA
Waterway/
Station Location
James R.
Olivet
Cumberland Rl
Clarksville
Tennessee R.
Savannah
Mississippi R.
Memphis
Pecos R.
Red Bluff Lake
Brazos R.
Richmond
Colorado R.
Wharton
Nueees R.
Mathis
Rio Grande
Brownsville
Utah Lake
Provo
Green R.
Vernal
L. Champlain
Burlington
James R.
Richmond
Snake R.
Ice Harbor
Yakima R.
Granger
Columbua R.
Pasco
Species
Carp
Channel catfish
Carp
Largemouth bass
Carp
Channel catfish
Largemouth bass
Carp
Channel catfish
Channel catfish
Largemouth bass
Channel catfish
Channel catfish
Carp
Channel catfish
Largemouth bass
Channel catfish
Carp
Carp
Channel catfish
Yellow perch
Channel catfish
Largemouth
Channel catfish
Carp
Carp
Largemouth bass
Carp
1969'
1970'
1971
1972a 1973
0.89
3.15
0.29
0.83
•
0.20
1.67
2.92
1.46
4.32
1.20
3.26
1.07
0.06
1.17
0.32
0.03
0.05
0.40
0.18
0.09
0.10
0.78
0.79
0.34
1.00
1.24
0.63
0.17
0.65
0.20
0.69
1.19
0.33
3.18
0.63
1.22
0.19
0.38
3.62
0.10
0.6
0.22
0.74
0.44
• 0.33
0.62
0.19
0.22
0.19
N.D.
•1.20
16.0
5.0
4.65
11.0
10.0
5.4
0.60
0.5
1.1
N.D.
7.70
**
**
**
1.20
1.3
1.70
1.4
N.D.
4.3
5.8
1.5
9.8
3.1
1.5
N.D.
N.D.
-N.D.
N.D.
3.46
0.26
N.D.
N.D.
1.21
1.5
1.5
0.5
N.D.
N.D.
N.D.
-------
Table 2.1-6 (cont.)
C- 26
Waterway/
State Station Location
WV • Kanawha R.
Winfield
WI L. Michigan
Sheboygan
Wisconsin R.
Woodman
Species
Carp
Yellow perch
Carp
Channel catfish
1969
0.31
1970
1.25
7.42
1.15
0.17
1971
0.61
11.45
1.44
1.11
1972
12.0
9.3
197
3.£
7.£
3.6
** - PCB-like compound present
N.D. - Not Detectable
a. estimated PCB levels
V total of Aroclors 1242, 1254 and 1260
SOURCES:
1969 Data - Henderson, C., A. Inglis and W.L. Johnson, Pesticides
Monitoring Journal, 5_, 1-11 (1971).
1970-1973 Data - National Fish and Wildlife Monitoring' Program,
Results of Freshwater Fish Monitoring 1970-1973,
U.S. Fish and Wildlife Service, U.S. Department of
Interior, Washington, DC (unpublished).
-------
C- 27
Table 2.1-7
Summary of PCS Residues Detected in Fish from 1969-1973
National Pesticide Monitoring Program
Number of Composites
Ldues Above 5 ppm
Range (ppm)
<0.10-14.8
0.03-24.8
0.02-41.0
<0.05-30.0
<0.01-25.0
With Residues
Year
1969
1970
1971
1972
1973
Total
147
393
587
401
400
No.
147
390
581
311
202
%
100
99
99
78
51
With Residues Above 5 ppm
No.
89
239
284
215
160
%
61
61
48
54
40
SOURCES:
1969 - Henderson, C., A. Inglis and W. L. Johnson, Pesticides
Monitoring Journal, _5, 1-11 (1971).
1970-1973 Data - National Fish and Wildlife Monitoring Program, Results
of Freshwater Fish Monitoring 1970-1973, U.S. Fish and
Wildlife Service, U.S. Department of Interior,
Washington, DC (unpublished).
-------
2.1.6 Birds
Two of the three elements of the National Fish and Wildlife
Monitoring Program mentioned in the previous section are: mallards
and black ducks; starlings.
PCB's have been found in all of the starling samples taken in
1970, 1972 and 1974. The level of residues appears to be declining
over this period with national arithmetic means of 0.65 ppm, 0.43 ppm
and 0.12 ppm for the three years respectively9.
Results of sampling of mallards in 1970 and 19729 are shown
by flyway on Figure 2.1-3. Residues are highest in the Atlantic
flyways, with average concentrations more than double that of any
other flyway and more than 10 times greater in some cases. Samples
of black ducks were also taken in the Atlantic flyways in 1969 and
1972 and the mean PCS concentration was constant at 1.36 ppm.
In the 1969 mallard study1* not only did mallards from the Atlantic
flyway show the greatest average PCS concentration, but with the
exception of Maryland all of the states in the Atlantic flyway had
averages exceeding 0.5 ppm with the highest residues from New Hampshire
southward through Delaware. In the Mississippi flyway, residue
levels were highest in states bordering the Great Lakes, generally
diminishing as sampling moved southward.
-------
1953 02
19/2 01
1963 -1,24
19/2-1,29
FIGURE 2,1-3 PCB't IN MALLARDS (AVERAGES, WIINTS, PPM, WET WEIGHT BASIS)
vo
-------
U-
REFERENCES, Section-2.1
1. Carey, Ann, 1975, EPA National Soil Monitoring Program, unpublished.
2. Crump-Wiesner, J.S., H.R. Feltz and M.L. Yates, J. Research. TJSGS,
1, 603-607 (1972),
3» Haile, C.L., G.D. Veith, G.F. Lee and W.C. Boyle, Chlorinated
Hydrocarbons in the Lake Ontario Ecosystem (IFYGL 1975), unpublished
EPA report, EPA-660/3-75-022.
4. Heath, R.G. and S.A. Hill, Pesticides Monitoring Journal, ]_,
153-163 (March 1974).
*
5. Henderson, C., A. Inglis and W.L. Johnson, Pesticides Monitoring
Journal, 5_, 1-11 (1971).
6. Martin, W.E. and P.R. Nickerson, Pesticides Monitoring Journal,
£, 33-40 (June 1972).
7. National Fish and Wildlife Monitoring Program, Results of Freshwater
Fish Monitoring 1970-1973, U.S. Fish and Wildlife Service, U.S.
Department of the Interior, Washington, DC (unpublished)..
«. PCS Data Base, October 1972 to (partial) 1975, U.S. Geological
Survey, Quality of Water Branch, Reston, VA.
9. Walker, Charles R., The Occurence of PCB's in the National Fish
and Wildlife Monitoring Program, presented at the National Conference
on Polychlorinated Biphenyls, Chicago, Illinois, November 19-21, 1975.
-------
C -
2.2 Data from Localized Monitoring Efforts - Lakes
Figure 2.2-1 is provided in order to display the relationship of the
different lakes in the Great Lakes region as discussed in 2.2.1 - 2.2.5.
2.2.1 Lake Ontario
Lake Ontario is one of the lesser studied Great Lakes for PCB's. A
thorough study of chlorinated hydrocarbons in the Lake Ontario ecosystem
was performed in 1972 by Haile, Veith, Lee and Boyle.6 Samples of
various media were taken from 19 different locations in Lake Ontario
during the summer of 1972, as indicated in Figure 2.2-2, and significant
concentrations of PCBs were reported in all media. Findings for water,
sediment and net plankton are summarized in Table 2.2-1. Other than the
south shore areas off Oswego (77 ppt) and the north of the Niagara River
(97 ppt), the PCS content of the Lake Ontario water appears relatively
uniform in the range of 35 to 56 ppt, with an average of 45 ppt.
PCS concentrations in sediments around the south shore areas off the
mouths of the Welland Canal and Niagara River and off Oswego averaged
more than twice the concentrations found at the four other sites (means
of 184 ppb vs. 72 ppb). This led the authors to conclude that the
Niagara and Oswego Rivers may be important sources of PCB associated
with settleable particulates. Plankton samples were not ta!ren at the
south shore sites; lake wide levels averaged 7.2 ppm.
Fish samples selected in the same study found mean PCB concentra-
tions on a whole fish basis in smelt (2.65 ppm) similar to those re-
ported in Lake Michigan smelt. Mean PCB levels in alewivo.s (2.35 ppm)
were lower than values reported for Lake Michigan alewives (4.6 ppm).
Bottom feeding slimy sculpin, which are less migratory than the latter
two species, exhibited greater station to station variability in PCB
levels, with a lake wide average of 4.63 ppm. Average concentrations in
Cladophora were 515 ppb and for benthic fauna were 471 ppb. Samples
were not taken consistently across media at stations and the results
suffer accordingly, but the authors do draw one of thii few estimates of
accumulation factors for chlorinated hydrocarbons. They estimate re-
lative concentrations as 1; 2500; 10,000; 150,000; and 300,000 for
water, sediment, benthos, net plankton and fish, respectively.
Kaiser1° shows PCB levels in two 1973 fish samples from northern
Lake Ontario as 5.99 ppm (total PCB, fat, northern longnose gar) and
2.38'ppm (total postanal fins, northern pike), magnitudes considered
comparable to those of other fishes from Lake Ontario. •
-------
KEY fQ RIVERS
1. AU SABLE
2. THUNOEH BAY
3. CHEUOYGAN
4. MANISTEE
6. MUSKEGON
6. GRAND
7. KALAMAZOO
8. BATTLE CREEK
B. PORTAGE CREEK
10. ST. JOSEPH
It. RAISIN
. 12. HURON
13. ROUGE
14. DETROIT
15. CASS
1C. FLINT
17. SHIAWASSEE
18. SAGINAW
10. TITTABAWASSEE
, 20. BAY CITY
21. BOARDMAN
22.ELK
FIGURE 2.2-1 THE GREAT LAKES (AND RIVERS IN MICHIGAN)
-------
C-33
Table 2.2-1
PCS Concentrations, Lake Ontario Ecosystem
Summer 1972
Sample Location Water Sediment Net Plankton
(map reference) (ppt) (ppb dry) (ppm dry)
1 49 3.4
8 35
10 10.6
12 245
13 97 155
30 44 80
36 45 43 7.6
45 3.6
46 79
60 40 84
75 56 11.8
90 77
91 158
96 - 6.0
SOURCE: Haile, C.L., G.D. Veith, G.F. Lee and W.C. Boyle, Chlorinated
Hydrocarbons in the Lake Ontario Ecosystem (IFYGL), EPA
Report. EPA 660/3-75-022 (1975).
-------
• wsp
•vC
12 T^f^vOLCOTT
NIAGRA
FALLS
fb
wb
wfsbpC
KILOMETERS
wts
FIGURE 2.2-2 LAKE ONTARIO SAMPLING SITES FOR CHLORINATED HYDROCARBON
ANALYSIS. NOTATIONS ARE: f-F!SH. w-WATER, s-SEDlMENT, p-NET
PLANKTON, C CLADOPHORA, b BENTHOS. STATION NUMBERS ARE
IFYGL STATION IDENTIFIERS.
-------
C-35
2.2.2 Lake Erie
Several studies of PCS concentrations in fish samples from
Lake Erie are summarized in Table 2.2-2. Levels are generally
lower than those reported from Lake Michigan and Lake Superior, but
are inconclusive other than demonstrating the presence of PCB's in
the lake water. Water measurements in tributaries to Lake Erie3
including the Rouge river, which is tributary to the Detroit River •
are in Table 2.2-3, the Raisin and Rouge Rivers show relatively
high levels of concentration when contrasted to the concentration
levels in fish in the preceding table.
-------
Table 2.2-2
Mean PCB Levels in Fish, Lake Erie
(ppm, whole fish)
C -36-
Species 1970'
Carp 2.0
Catfish 4.4
Drum 1.1
Yellow Perch 0.8
Salmon 2.1
Walleye
White Bass 2.1
Smallmouth Bass
19721
0.25
1.02
0.71
1973*-
9.3
0.9
Trace
0.5
2.5
SOURCES: Carr, R.L., C.E. Finsterwalder and M.J. Schibi, Pesticides
Monitoring Journal, .6, 23-26 (1972).
" Kelso, J.R.M. and R. T"rank, Transactions American Fisheries
Society, 103, 577-581 (1974).
c 1973 Great Lakes Environmental Contaminant Survey - Data
Summary and Analysis, Bureau of Consumer Protection,
Michigan (1973).
Table 2.2-3
PCB Concentrations in Michigan Tributaries
to Lake Erie in 1971-72 and June 1973 in
ppb as Aroclor 1254
River Mean PCB Concentration
Raisin 0.2:0
Huron 0.012
Rouge 0.470
Detroit 0.020
Range (1971-72)
<0.068-0.500
<0.010-0.039
0.058-1.600
. <0.010-0.053
1973
<0.010
<0.010
0.460*
<0.010
* Aroclor 1242
SOURCE: Hesse, J.L., Status Report on Polychlorobiphenyls in Michigan
Waters, Michigan Water Resources Commission, June 1973.
-------
C-37
2.2.3 Lake Superior
The results of several available fish studies are presented in
Table 2.2-4 for different species of fish. Lake trout are in the
highest trophic level within the lake and biological accumulation should
result in this species possessing some of the highest concentrations of
PCB's.
The study by Veith and Glass19 , summarized in the table, drew
samples from three areas in the western portion of the lake. There was
variability in the levels of PCB's in fish caught in different areas,
but no conclusions are drawn in the study. Samples from the Apostle
Island region (Wisconsin) had higher mean concentrations for all species
than those from the other two regions (Minnesota). Parejko and John-
ston1 ** note that the biphenyls containing lower percent concentrations •
of chlorine predominated in the sample. The latter study involved tests
for correlation between factors of age, sex, geographical location and
concentration level; surprisingly, no significant correlations were
discovered.
The geographic distribution of lake trout samples from the 1972-
1974 Great Lakes Environmental Contaminant Survey3 is detailed in Table
2.2-5.. As regards recent screening of fish against the FDA guideline,
Kleinert12 reports that of 64 fish samples collected in the nearshore
waters during 1974, none exceeded the 5 ppm guideline and only two
exceeded a leval of 1 ppm.
-------
C-31
Table 2.2-4
/•
Mean PCS Levels in Fish, Lake Superior
(ppm, whole fish)
Species 1971C 1972* 1973 197&*
Burbot 0.7
Chubs - 0.9
Herring 2.0 *.w .
Lake Trout 7.08 0.8 1.8, 2.64 " 1.55
Long-Nose Sucker
Smelt 0.3
Whitefish
SOURCES: Veith, G,D. and G.E. Glass, PCBs and DOT in Fish from
Western Lake Superior, U.S. EPA National Water Quality
Lab., Duluth, Minnesota (1974).
1973 Great Lakes Environmental Contaminant Survey - Data
Summary and Analysis, Bureau of Consumer Protection,
Michigan (19"3).
c Parejko, R. and R. Johnston, Uptake cf Toxic Water
Pollutants, (PCB) by Lake Trout. Project Completion
Report, D.S. Dept. of the Interior, Office of Water
Resources Research, Contract 14-01-0001-3522 (19"3).
Willford, W.A., Contaminants in Upper Great Lakes Fishes,
Presented at Great Lakes Fishery Commission, Upper Great
Lakes Committee Meetings, Milwaukee, Wisconsin, March
1975.
Hesse, J.L., PCB Situation in Great Lake Fish, Report to
Michigan Water Resources Commission, April 17, 1975.
-------
C-39
Table 2.2-5
Mean PCB Levels in Lake Trout
from Lake Superior (ppm)
Lean Variety
MS 1** 1972
1973
1974
MS 2 1972
1973
1974
MS 3 1972
1973
1974
MS 4 1972
1973
1974
MS 5 1972
1973
1974
MS 6 19/2
1973
1974
Fat or Siscouet
MS 1 1974
MS 2 1974
MS 3 1974
MS 4 1974
<17" 17-20"
2.
•»
^
' 0.
1.
0.
••
0.
_
-
0.
2.
4
•mi»
•^m*m
5
__
6
6
*M^
5
_«.
_
*__
9
2
(4)*
(3)
(12)
(3)
W
(3)
(8)
2.9
—
1.8
_
1.9
0.1
_.
1.0
0.5
...
1.2
1.8
^~m
1.0
0.4
M»
(1)
(3)
•>••
_
(7)
(2)
m^m
(6)
(2)
•••
(3)
(2)
(3)
(2)
20-25"
5.
3.
1.
2.
4.
0.
4.
2.
0.
3.
1.
1.
1.
1.
2.
••••
6
*w
1MBB
A
2
2
5
4
6
0
7
3
2
4
A
5
8
MOB
(3)
•MM)
»•*
(3)
(3)
(6)
(8)
(9)
(3)
(6)
W
(6)
(3)
(4)
(3)
(3)
(7)
>25"
*»
4.
^
5.
5.
2.
4.
2.
5.
4.
1.
2.
1.
1.
1.
2.
•••
8
^•w
2
2
7
8
0
7
7
4
1
9
5
• •
3
6
(4)
i
(2)
(1)
(3)
(11)
(12)
(8)
(9)
(3)
(3)
(3)
(6)
M»
(3)
(5)
Variety
0.
2.
4.
12.
5
5
A
7
(3)
(5)
<,6)
(2)
3.6
6.2
12.6
5.4
(2)
(10)
(2)
(8)
1.
11.
7.
9
3
4
•••
(4)
(6)
(7)
•-••
3.
3.
6.
6.
8
3
8
1
(3)
(2)
(7)
(6)
Concentrations in parts per million (ppm) in fillet; vet weight.
Number of samples in parentheses ( ). '
**Refers to geographic area in Figure 2.2-1.
SOURCE: Hesse, J.L., Contaminants in Great Lakes Fish, Staff Report,
Michigan Water Resources Commission, Department of Natural
Resources, (1975).
-------
2.2.4 Lake Michigan
Lake Michigan is the most heavily studied of the Great Lakes.
It has been established that the lake contains the highest concentrations
of agricultural pesticides due, in part, to the large useage in the
watershed relative to the flushing period for the lake and to the
relatively low biomass density. • There were seizures of Lake Michigan -
fish by the FDA during 1975. Samples from a shipment of Lake Michigan
Chinook and Coho Salmon in May 1975 were found to exceed the 5 ppm
guideline.2 PCB levels in these fish ranged from 7.6-10^9 ppm. Hesse7
reports a February 1975 seizure of large, surplus salmon exceeding the
FDA guideline. In May 19752 a seizure of chubs resulted in analysis
which showed that concentrations aid not exceed the guideline. Such
activities, however, have dramatized the hazards to both the lake and
its fishing industry. In June, 1975, the Secretary of the State of
Wisconsin Department of Natural Resources, based on evidence indicating
that most large trout and salmon contain PCB's at levels exceeding the 5
ppm tolerance level, concluded that most fish over 24 inches in length
appear to have excessive levels.
To provide a broad historical perspective, data from several
studies of Lake Michigan fish are assembled in Table 2.2-6. The question
of trend in the levels of fish contamination has been addressed by
both Hesse8 and Willford21, referring specifically to the data of
Table 2.2-7. Both conclude that the situation has generally remained
static since 1972. Statistical analyses show no significant differences
in the levels of the three species over the three year period 1972-1974.
Data fron the Great Lakes Environmental Contaminant Survey for this
period for lake trout is detailed, by sampling area, in Table 2.2-8.
Ihe sample sizes are generally small and, while not allowing for
rigorous statistical analysis, document the presence of a widespread
PCB problem in lake trout of larger sizes and an intensification of
the problem in southern Lake Michigan. The general conclusions that
larger fish such as brown, lake and rainbow trout and chinook and
coho salmon contain PCB residues at levels exceeding the FDA guideline,
that concentrations increase with the percentage of fat and the size
of the fish, and that levels found in the southern portion of the
lake exceed those in the northern portion are supported by various
studies2.
The results of some earlier (1971-72) fish sampling undertaken
by the Illinois EPA3 found PCB levels in the edible portion of five
species (yellow perch, chub, carp, coho salmon and alewife) generally
below the 5 ppm tolerance limit. This is in apparent contradiction
to the later studies discussed in the preceding paragraph - especially
since the Illinois samples came from the southern portion of the
lake. Data from this study is included in Table 2.2-6. There are,
of course, many variables which impact on the interpretation of data
from fish sampling lipid content, fish size and age, season of capture,
location, etc. Thus, mean readings may not be truly representative
although this statistic is commonly used to provide broad summarization
of an abundance of data.
-------
G-41
Measurements taken on Lake Michigan open waters and sediment
tend to show results which are consistent with reported sediment data . •
from other sections of the country (see section 2.1.3), and somewhat
higher readings for concentrations in whole water. The Illinois EPA
has found tributary sediments with higher concentrations than those
from open waters (1971): averages of 23.06 ppb as Aroclor 1242 and
14.66 ppb Aroclor 1254 for the former contrasted with 95.77 ppb --
Aroclor 1242 and 32.27 ppb Aroclor 1254 for the latter"*. Whole
water concentrations in tributaries analyzed as Aroclor 1242 or 1254
ranged from 0.1 to 4.0 ppb during the period 1971-19742. PCB
concentrations measured by the Illinois State Board of Health in
tributaries to Lake Michigan during 1973-1974 ranged from 0.01 to 0.09 ppb.
The Milwaukee River, a Wisconsin tributary to Lake Michigan
was sampled in August 1969 for PCB's20; concentrations of Aroclors 1260
and 1242 were in the ranges trace to 0.26 ppb and trace to 2.07 ppb,
respectively. The high Aroclor 1242 reading was validated by a repeat
measurement (of 2.80 ppb in February 1970) and attributed to combined
sewer outfalls and contaminated industrial cooling waters. Estimates
of PCB concentrations in sewage treatment plant effluents in H'-irch,
1970, ranged from 0.04 ppb to 0.25 ppb, but the effluent from a chemical
plant had a concentration of 2.50 ppb. This led the authors to conclude
'that PCB's were discharged to natural waters through municipal and
industrial wastes and that PCB's in such large ecosystems as Lake
Michigan have resulted in part, through water transport from metro-
politan areas. This certainly is true; unfortunately no follow-up
studies were performed to estimate the effect of both controls and
increased attention to the PCB problem.
With the exception of a contamination problem in the Lalamazoo
River, most PCB measurements in Lake Michigan tributaries within the
state of Michigan are at levels in whole water of less than 0.1 ppb.
Data showing levels identified in 1971-1972 are in Table 2.2-9.
The Kalamazoo River was the subject of studies in both 1971 and 19728.
Concentration levels were higher downstream from Battle Creek, and
some sources of contamination were identified.
Fifty four fish samples were collected frcm 15 stream sections
on the Kalamazoo River in July 1971u. Measurable concentrations were
found in nearly all fish samples tested with concentrations ranging
from less than 0.01 to 109.9 ppm in edible portions of fish on a
wet weight basis. Those fish from the north and south branches and
the main stream of the river down to Battle Creek had low concentrations
ranging from 0.01 to 0.33 ppm. Downstream' from the Battle Creek
wastewater treatment plant the levels in fish increased ranging from
0.82 to 18.75 ppm and remained high downstream with levels below
Kalamazoo ranging from 1.35 to 109.9 ppm1*.
Settleable solids were only sampled at eight stations in 1971
with levels identified ranging from 0.01 to 0.422 ppm*1. The levels
in the mainstream were 10 to 20 times higher than those in the north
and south branches and gradually Increased downstream. The sample
from the Battle Creek River had the highest concentration in the
watershed indicating that the tributary contributes significantly
-------
C- 4-2
to the total problems in the mainstream.
Since the Kalamazoo River is the most polluted input to Lake
Michigan further sampling to identify possible sources of PCB loss
to the environment was conducted in the vicinity of the City of
Kalamazoo in 19721S. PCB concentrations from the discharge of several
industries and a wastewater treatment plant were below the limit
of detectability. However, Portage Creek, which receives effluents
from several industries including two paper mills, had 0.47 ppb of
Aroclor 1242. Settleable solids that were collected showed concen-
trations ranging from 0.23 to 2.63 ppm at eight of the ten stations.
The two stations that did not have significant concentrations were
upstream from the paper mill ponds. Sediment core samples taken
from the Bryant paper mill ponds had concentrations"up to 368.7 ppm
as deep as six to eight inches.5 . •
Further data collected in the spring of 1973 on settleable solids
are presented in Table 2.2-10 demonstrating considerable sensitivity
of measurements to sampling intervals. The levels detected in 1975
were also generally higher for the Kalamazoo River than were detected
in 1971.
-------
C- 43
Table 2.2-6
Mean PCS Levels in Lake Michigan Fish
(ppm, whole fish)
Species 1971° 1972Q 1973* 1974e
Alewife 2.84a, 4.6 2.4
Brown Trout 7.3
Carp 2.04a, 4.2 3.9
Chub 2.85a, 6.0 7.0, 2.83a 4.48
Chinook Salmon 11.4 12.4 6.4
Coho Salmon 1.68a, 11.5 11.2, 10.93e 4.9, 12.17e 10.45
Lake Trout 13.53C, 15.5 7.4, 12.86e 18.93e 22.91
Perch 5.8 0.4
Rainbow Trout 9.3
Red Sucker 3.0
Smelt 2.7 1.6
White Sucker 3.9
Whitefish 3.0 0.7 0.9
Menominee 1.1 1.0
Suckers 1.0 0.45
Steelhead 6.0
Bloater Chubs 5.66e 5.24e 5.57
Yellow Perch 0.22a 0.3a 0.4
SOURCES:
aU.S. EPA, Pesticide Monitoring Programs: Lake Michigan and Tributaries
in Illinois, EPA 600/3-74-002.
^Veith, G.D., Chlorinated Hydrocarbons in Fish from Lake Michigan,
University of Wisconsin, Madison, Wisconsin, unpublished report on
EPA Project 16020 PBE, (1973).
CU.S. EPA, An Evaluation of DDT and Dieldrin in Lake Michigan, EPA-
R3-72-003, (1972).
^Hesse, J.L., Status Report on Polychlorobiphenyls in Michigan Waters,
Michigan Water Resources Commission, (June 1973).
eBremer, K.E., State of Concerns of the Lake Michigan Toxic Substances
Committee Related to Polychlorinated Biphenyls (draft) U.S.EPA, (1975).
^1973 Great Lakes Environmental Contaminant Survey-Data Summary and Analysis,
Bureau of Consumer Protection, Michigan, (1973).
-------
Table 2.2-7
Concentrations of PCBs In fall collections of Lake Michigan
Bloaters and Lake Trout off Saugatuck, Michigan, and
Coho Salmon from between Ludington and Frankfort, Michigan
Average Total. PCBs
Species and Year Number of Fish Length (mm) (pptn)
Bloaters
1972 120C 255 5.66 (0.95)
1973 160C 250 5.24 (0.37)
1974 110C 257 5.57 (0.31)
Coho salmon
1972 10 693 10.93 (2.12)
1973 29 620 12.17 (0.77)
1974 30 665 10.45 (0.92)
Lake trout
1972 9 648 12.86 (4.75)
1973 30 602 18.y3 (2.08)
1974 30 616 " 22.91 (3.73)
aAnalysis performed by Great Lakes Fishery Laboratory.
Concentrations in whole fish, wet weight with 95% confidence
interval in parentheses.
cComposite samples, 10 fish per sample.
SOURCE: Bremer, K.E., State of Concerns of the Lake Michigan Toxic
Substances Committee Related to Polychlorinated Biphenyls
(draft) U.S. EPA, (1975).
-------
C- 45
Table 2.2-8
Mean PCS Levels In Lake Trout
from Lake Michigan (ppm)
<17" 17-20" 20-25" >25"
MM 1**
MM 2
MM 3
MM 4
MM 5
MM 6
MM 7
MM 8
1972
1973
1974
1972
1973
1974
1972
1973
1974
1972
1973
1974
1972
1973
1974
1972
1973
1974
1972
1973
1974
1972
1973
1974
2.2 (1)*
0.7 (1)
•' ''.-'•
2.6 (3)
2.6 (2;
1.0 (3)
^»^MW«a •
2.4 (1)
1.1 (9)
2.7 (2)
2.4 (9)
5.1 (6)
3.6 (2)
1.6 (2)
•.•I.JIM.
2.4 (3)
1.8 (1)
3.1 (3)
•»—_!»
6.4 (1)
2.5 (16)
| _^
5.8 (2)
8.2 (3)
«•— — —
"'— * * "
5.8 (1)
7.5 (6)
7.1 (2)
5.6 (11)
6.8 (1)
8.9 (8)
6.4 (1)
10.1 (4)
axmJJ-1 —
11.1 (3)
10.6 (3)
6.5 (3)
8.5 (3)
7.3 (2)
9.6 (6)
4.1 (1)
11.0 (3)
9.6 (18)
- 7.3 (3)
11.2 (3)
11.9 (2)
12.4 (3)
12.6 (4)
*Concentrations in parts per million (ppm) in fillet; wet weight.
Number of samples in parentheses ( ).
**Refer to geographic area in Figure 2.2-1.
SOURCE: Hesse,. J.L., Contaminants in Great Lakes Fish, Staff Report,
Michigan Water Resources Commission, Dept. of Natural Resources
(1975).
-------
C- 46
• Table 2.2-9
Mean PCB Concentrations in Michigan Tributaries to the
Lake Michigan Basin, 1971-72 and 1973
(ppb as Aroclor 1254)
1972-72
1973
039 <0.010
097 0.040
080 0.033
037 <0.010
039 0.037
044 0.018
039 <0.010
River
St. Joseph
Kalamazoo
Grand
Muskegon
Manistee
Boardman
Elk
Average
0.013
0.065
0.041
0.010
0.014
0.017
0.012
Range
<0.010-
0.019-
0. Oil-
<0.010-
<0.010-
<0.010-
<0. 010-
SOURCE: Hesse, J.L., Status Report on Polychlorobiphenyls in Michigan
Waters, Michigan Water Resources Commission, (June 1973).
-------
Table 2.2-10
Concentrations of PCB's (polychlorinated biphenyls). in the settleable solids collected from the mouths
of the Grand, Kalamazoo and St. Joseph Rivers; Spring 1973, for comparison of variable sampling periods.
Concentrations in ppra on an oven-dry basis.
Kalamazoo
St. Joseph
Sample
3X
Weekly
Biweekly
Monthly
3X
Weekly
Biweekly
Monthly
3X
Weekly
Biweekly
Monthly
Sample Dates
3/21 3/23 3/30 4/2 4/4 4/6 4/9 4/11 4/13 4/20 4/27 4/30 5/2 5/4 5/11 Means
3.24
1.25
6.7
27.5
6.83
0.94
0.85
3.0
3.77
1.6* 0.95 1.0
1.1
<0.1 0.93
2.08 <0.1 2.52 1.33 3.20 <0.1
3.54
2.13
1.58
1.0 0.55
0.73
1.41
0.1
3.77 3.09
2.54
2.11
0.68
0.85
0.74
0.50
2.98
2.64
•
0.95
0.75
0.67
0.83 3.5 0.53
0.80 0.77
0.60
0.50
Mean ~
3.11 3.50 3.75
2.88 4.87
2.50
3.14
Mean •
0.63 0.82
0.83 1.21
0.95
0.83 .
Mean «
1.43
0.89
0.67
0.96
0.99
4.72
3.87
2.86
2.63
3.52
0.73
1.16
1.24
0.75
0.97
a3X - Sample collected Mon, Wed. and Friday
*Concentration based upon a 1:1 ratio of Aroclor 1242 and 1251.
All other concentrations calculated as Aroclor 1242.
SOURCE: Monitoring for Polychlorinated Biphenyls in the Aquatic Environment, Michigan Water Resources Commission, (May 1973)
o
-------
C-48
2.2.5 Lake Huron
Levels of PCB's in fish samples from Lake Huron are detailed
in Table 2.2-11 from areas as indicated in Figure 2.2-1.
The Saginaw Bay area, designated as MH-4 on the map, has been the
object of detailed analysis, and significant concentrations have been
detected. Water measurements in tributaries to Lake Huron, including
the Saginaw Bay area, are in T^ble 2.2-12. Concentrations in fish
taken from the Saginaw River in 1971 were as high as 165 ppm aa shown
in Table 2.2-13. The waste water treatment plant on the Saginaw
River ij Lhe Bay City facility. During 1971, this plant had an average
effluent concentration of 120 ppb with a high of 340 ppb.
After control measures were initiated by some industrial sources
in October 1972, there was a sharp drop in PCS levels at the mouth
of the river. Levels measured in 1972 ranged from <0.020 to 0.640 ppb
and in 1973 from <0.100 to 0.200 ppb. This is one of the noteworthy
examples of controls effecting a marked change in PCB contamination8.
-------
C- 49
Table 2.2-11
Mean PCS Levels, Whole Fish
in. Lake Huron (ppm)
Species
Brown Trout
Catfish
Menominee
Yellow Perch
Salmon
Ualleye
Smelt
Whitefish
1973
3.6 (MH-2)*
4.9 (MH-4)
0.4 (MH-1)
0.2 (MH-1)
8.4 (MH-1,3)
1.1 (MH-1)
0.6 (MH-3)
0.5 (MH-1)
*Refer to geographic area in Figure 2.2-1
SOURCE: 1973 Great Lakes Environmental Contaminant Survey - Data
Summary and Analysis, Bureau of Consumer Protection, Michigan
(1973).
-------
C-50
Table 2.2-12
Mean PCB Concentrations in Michigan Tributaries
to Lake Huron in 1971-72 and 1973
(ppb as Aroclor 1254)
1971-72
River
Saginav
Cass
Flinta
Shiawassee
Tittabawasseec
Au Sable
Thunder Bay
Cheboygan
Average
1.100
0.014
0.078
0.029
0.140
<0.010
0.023
0.032
0.450-2.900
<0.010-0.048
0.010-0.150
<0.010-0.073
<0.022-0.230
<0.010-0.010
<0.010-0.037
<0.010-0.053
1973
0.2101
<0.010
-------
Table 2.2-13
Concentrations of polychlorinated biphenyls (PCB's)
in Fish from Saginaw River, December 7, 1971
(ppm; wet weight)
C- 51
Species
Perch
Carp
Catfish
Catfish
Carp
Carp
Carp
Carp
Carp
Pike
Pike
Gizzard Shad
Gizzard Shad*
Gizzard Shad*
Gizzard Shad*
Gizzard Shad*
Gizzard Shad*
Gizzard Shad*
Location
Karn Weadock Discharge Channel
n if n it
U.S. Coast Guard Station
ii
ii
it
it
ti
it
it
Zilwaukee Bridge
Length
9.0
21.0
8.0
7.5
23.0
24.0
20.0
24.0
21.0
27.0
23.0
14.0
6.0
4.5
5.0
4.5
5.0
5.0
Percent
fat
1.3
0.9
7.0
4.9
__
10.5
6.5
5.9
4.6
1.6
1.1
17.5
15.3
15.0
17.0
15.7
9.6
8.7
PCB's based
upon 1242
standard
16.3
8.8
37.1
47.9
48.0
20.4
15.5
45.8
30.2
16.6
6.9
165.3
32.5
161.9
77.0
24.1
52.0
10.4
Concentration based upon analysis of whole fish.
upon edible portion only.
All others based
SOURCE: Hesse, J.L., Status Report on Polychlorobiphenyls in Michigan
Waters, Michigan Water Resources Commission, (June 1973).
-------
C- 52
2.2.6 Cayuga Lake
In October 1970 lake trout were collected from Cayuga Lake in
Ithaca, New York. Since these fish are marked each year when they
are stocked in the lake their ages were accurately known. Table
2.2-14-shows the residues of PCB's identified along with the age,
length, weight and sex of each fish. The paak heights of individual
PCB isomers did not vary with the age of the fish indicating that
there is no selective metabolism or storage of specific PCB isomers
as the fish matures. However, the concentration of total PCB's does
increase progressively with maturity. The variation in PCB concen-
trations among individual 11 or 12 year old fish may be due to differences
among foraging, metabolic and excretary capabilities of the older fish.1
-------
C- 53
Table 2.2-14
Residues of PCB's in Cayuga Lake Trout as a function
of maturity; j, juvenile.
Age
(years)
1
1
1
1
2
2
2
3
3
3
4
4
4
5
6
6
6
7
7
7 '
8
8
8
9
11
12
12
12
Sex '
J
. J
J
J
J
J
J
J
J
J
J
J
J
M
M
M
F
M
M
7
M
F
F
M
M
M
F *
Length
(cm)
27.7
28.7
33.5
44.5
44.5
41.1
53.8
50.3
55.1
61.0
63.5
66.4
68.3
63.5
68.9
59.7
75.2
71.6
69.0
71.2
80.3
71.6
75.5
70.6
Weight
(s?)
• .-.
181
226
407
815
725
770
1310
1160
1359
2030
2440-
2850
2310
2260
3300
1990
3390
2805
3300
3390
4200
2535
3120
3440
PCS
(ppm)
0.6
1.6
0.5
1.2
2.0
1.3
2.5
2.2
2.4
1.2
3.5
4.1
5.1
5.7
3.4
9.7
8.6
4.0
5.5
10.5
17.5
13.4
4.5
30.4
12.4
13.4
26.2
7.4
SOURCE: Bache, C.A., F.W.. Serum, W.D. Youngs and D.J. Lisk, Science,
177. 1191-1192, (1972).
-------
REFERENCES, Section 2.2
1. Bache, C.A., F.W. Serum, W.D. Youngs and D.J. Lisk, Science,
177. 1191-1192, (1972).
2., Bremer, K.E., State of Concerns of the Lake Michigan Toxic - ••-
:' ' Substances Committee Related to Polychlorinated Biptienyls (draft)
U.S. EPA, (1975).
3. Carr, R.L., C.E. Finsterwalder and M.J. Schibi, Pesticides
Monitoring Journal, JS, 23-26, (1972).
4. Evaluation of the Aquatic Environment of the Kalamazoo River
Watershed, Part A, Biological Survey, June-August 1971, Michigan
Water Resources Commission, (May 1972).
5. .1973 Great Lakes Environmental Contaminant Survey - Data Summary
and Analysis, Bureau of Consumer Protection, Michigan, (1973).
6. Haile, C.L., G.D. Veith, G.F. Lee and W.C. Boyle, Chlorinated
Hydrocarbons in the Lake Ontario Ecosystem (IFYGL), EPA Report
EPA 660/3-75-022, (1975).
7. Hesse, J.L., Contaminants in Great Lakes Fish, Staff 'Report,
Michigan'Water Resources Commission, Dept. of Natural Resources,
(1975).
8. Hesse, J.L., Status Report on Polychlorobiphenyls in Michigan
Waters, Michigan Water Resources Commission, (June 1973).
9. Hesse, J.L., PCS Situation in'Great Lake Fish, Report to Michigan
Water Resources Commission, April 17, 1975.
10. Kaiser, K.L.E., Science, 185, 523-525, (1974).
11. Kelso, J.R.M. and R. Frank, Transactions American Fisheries
Society, 103, 577-581, (1974). .
12. Kleinert, S.J., Environmental Status of PCBs in Wisconsin, Wisconsin
Dept. of Natural Resources, unpublished, (1975).
13. Monitoring for Polychlorinated Biphenyls in the Aquatic Environment,
Michigan Water Resources Commission,' (May 1973).
14. Parejko, R. and R. Johnston, Uptake of Toxic Water Pollutants
(PCS) by Lake Trout. Project Completion Report; U.S. Dept. of
the Interior, Office of Water Resources Research, Contract
14-01-0001-3522, (1973).
15. Polychlorinated Biphenyl Survey of the Kalamazoo River and Portage
Creek in the Vicinity of the 'City of Kalamazoo, 1972, Michigan
Water Resources Commission, (January 1973).
16. U.S. EPA, An Evaluation of'DDT and Dieldrin in Lake Michigan,
EPA-R3—72-003, (1972).
-------
C- 55
17. U.S. EPA, Pesticide Monitoring Programs: Lake Michigan and
Tributaries in Illinois, EPA 600/3-74-002.
18. Veith, G.D., Chlorinated Hydrocarbons in Fish from Lake Michigan,
University of Wisconsin, Madison, Wisconsin, unpublished report
on EPA Project 16020 PBE, (1973).
19. Veith, G.D. and G.E. Glass, PCBs and DDT in Fish from Western
Lake Superior, U.S. EPA National Water Quality Lab., Duluth,
Minnesota, (1974). ' v
20. Veith, G.D. and G.F. Lee, Water Research, 5., 1107-1115, (1971).
21. Willford, W.A., Contaminants in Upper Great Lakes Fishes, Presented
at Great Lakes Fishery Commission, Upper Great Lakes Committee
Meetings, Milwaukee, Wisconsin, (March 1975).
-------
- 56
2.3 Data from Localized Jfonitoring_ Efforts ^..Rivers
.2.3.JL Iowa_-_Mississippi River
Monitoring Iowa rivers for pesticides concentrations over a period
of years indicated that chlorinated hydrocarbon insecticides used in
row crop agriculture were being carried into the rivers by soil erosion.
Since fish are excellent biological compositors, measurement of trace
elements in their tissues can give a picture of the relative pollution
of a river. Therefore a study of the pesticide levels in the eggs of
some fish from locations in Iowa was undertaken in the spring of 1971.2
Two of the sites had measurable amounts of polychlorinated biphenyls.
The PCS's detected match Aroclor 1254. The concentrations identified
in the roe removed from the fish from these sites on the Mississippi
were as follows:
Date Length of PCB Concentration in
Site Species Collected Fish 15 grams of roe fppm)
Near Northern
border Channel Catfish 06-04-71 23.4 1.5
Largemouch bass 05-20-71 16.4 3.2
Walleye 04-16-71 27.5 4.2
Near Southern
border Channel Catfish 04-16-71 24.0 0.9
Largemouth bass 04-15-71 17.5 2.5
Walleye 04-13-71 24.3 5.5
*
The levels of PCB's found in the same species from the two lo-
cations are approximately the same indicating that the major source of
these industrial chemicals is upstream from both of these sites.
-------
C- 57
2.3.2 New York - Hudson River
The Hudson River In New York State provides an Interesting ecosystem
In which to study PCB's, primarily because it is the receiving water
for effluents from two plants of the General Electric Co., at Hudson Falls
and Fort Edward. These plants use PCB's in the production of transformers
and capacitors. Summaries of extensive sampling during 1975 of the
Hudson River are presented in Figures 2.3-1 and 2.3-2. The GE plants
appear to be the major contributors to the PCB residue levels in the
river. Although trace levels of PCB's are evident above the GE plant
outfall location, levels in water and sediment at Station 1 located
at the outfall of the Fort Edward plant were as high as any levels
measured in the country. In the immediate area downstream from this
outfall, PCB concentrations in water exceed the equilibrium solubility
level by more than a factor of 10. Major effects on the levels in
sediment are noted more than 35 miles downstream from the outfalls.
The data indicate elevated concentrations in aquatic life far from
the outfalls: fish samples approximately 40 and 66 miles downstream
from the outfalls showed PCB levels in excess of 5 ppm vhile the same
jpecies showed only traces of PCB's directly upstream from the outfalls.
Since sediment samples above the plants also show some concentration
there does appear to be some PCB source upstream of the plants.
-------
LLUCERNE
CORINTH
SCHENECTADY*
TROY
ALBANY
KINGSTON •
PDUCHKEEPSIE
;,
MILE
POINT
2188
2140
2031
2048
1999
19/J
1962
1942
IBB 4
IS/6
1249
608
DESCRIPTION
ATL LUiEHNE
ABOVE CORINTH
BELOW CORINTH
ABOVE SHERMAN
ISLAND DAM
ABOVECIEN
FALLS LANDFILL
BFLOWGLEN
FALLS LANDFILL
f PORTLAND
CEMENT CO
STATION 0
ACOVEBAKER
FALLS DAM
BELOW BAKER
FALLS DAM
STATION I
STATION 2
STATION)
STATION 4
ATFT
EDWARD
ABOVE THOMPSON
ISLAND DAM
ABOVE
SCHUYLERVILLE
nBOVE
WATERFORD
NEAR
COXSACKIE
ABOVE
KINGSTON
NEAR BEACON
ESTIMATED PCB S
WAfcR
(.PL)
<-0 I
DIVISION OF FISH AND WILDLIFE, l'l/5, ANALYSES OF PCB'i IN FISH FLESH
OTHIR WATER DATA; NEW YORK STATE DEPARTMENT OF ENVIRONMENTAL CONSERVATION.
01 VISION OF PURE WATERS, PCB MONI TORINO IN THE UPPER HUDSON RIVER BASIN. OCTOBER 18/S
Ul
00
FIGURE 2.3.-1 MAP OF HUDSON RIVER, NEW YORK, SHOWING DEVELOPED AREAS AND SAMPLING STATIONS WITH PCB LEVELS
-------
MI 220
Ml 218,8
C.1M97.3J
\ """ '»
\GLENFALLS '......
Ml 200•""Mi 198.9
J HUDSON
"- FALLS
STATION
FT. EDWARD
. .
SHERMAN Ml 205.7
ISLAND DA'M
THOMPSON ISLAND DAM
FIGURE 2.3-2 DETAILED MAP OF A PORTION OF THE HUDSON RIVER
•cv
i
in
so
-------
C- 60
2.3.3 Maryland - Chester River
This study was conducted in the Upper Chesapeake Bay in 1971-1972j1
the study area is shown in Figure 2.3-3 . The Bay and its tributaries
receive chlorinated hydrocarbons as a result of industrial, agricultural
and waste disposal activities occurring along the shorelines of these
waterways and within the total watershed.
Sediment samples were collected approximately quarterly except
for the last set which was taken early in order to collect data shortly
after tropical storm "Agnes". The PCB's identified were almost
exclusively Aroclor 12A2. The first readings, taken in November 1971
ranged from 0-21 ppb with an average of 83 ppb. By April 1972 the
average had climbed to 110 ppb with a range from 0-300 ppb. By June
the readings taken ranged from 0-150 ppb with the average reduced to
53 ppb. After "Agnes" in July the average had again increased to
96 ppb with readings ranging from 0-180 ppb. .
The explanation given for the variations is that during the early
spring, massive amounts of suspended sediment from the Susquehanna
River entered the Chester River and were carried upstream in the flow
of water along the river bottom. The peak sediment loads from the
Susquehanna generally come at the end of February, decreasing abruptly
after the end of March due to a reduced flow rate of the river. An
equilibrium net transport develops in the Chester River in April.
In May, fine sediments were transported slowly into the Bay. However,
over the year there is a movement of sediment along the river bottom
into the river from the Bay. Thus, the upper Chesapeake Bay, i.e.,
the Susquehanna River is the major source of suspended sediments in
the lower tidal portion of the Chester River.
The average values and ranges identified in biota of the Chester
River taking into account variability due to seasonal fluctuations,
distributional differences resulting from sample location, and species
as well as individual upf.ake differences were as follows:
Average (ppb) Range (ppb)
Oysters 55 16-250
Soft shelled clams 58 ' 13-180
Fish 18.5 2-570
Crabs • 20 0.4-51
Based on data collected June 6, 1972 from the nine stations along
the main river course it was determined that concentrations of PCB's
decreased as a function of distance up river from its mouth at Love
Point in its upstream direction at the rate of 4.20 ppb/Nautical mile.
-------
CHESTER
RIVER
LOVE POINT BALTIMORE
WASHINGTON
>- .•»&$&£
"
FIGURE 2.3-3 CHART OF CHESAPEAKE BAY SHOWING MAJOR TRIBUTARIES AND LOCATION
OF THE CHESTER RIVER.
-------
C- 62
2.3.4 Connecticut
In October 1974 the State of Connecticut intensively sampled bottom
sediment in rivers and lakes thoughout the state. The results are
shown in Figure 2.3-4, based on a computer mapping provided by the
Connecticut District Office of the U.S. Geological Survey.6 The data
show PCS contamination to be both widespread and at high levels through-
out the state, particularly around the highly developed areas of Hart-
ford, New Haven, Stanford-Greenwich and all along the Housatonic River
flowing from Massachusetts. The state had sampled mostly whole water
for PCB's prior to 1974, with no appreciable residue levels discovered,
but now has switched to a yearly bed material determination. The readings
for the baseline period of October 1974 are to be updated yearly.
-------
WESTPORT BRIDGEPORT/^
A^ . «_jJ I \ A.*«« **
NORWALK 7FA|-R|S|.ELD
o
i
FIGURE 2.3-4 PCB CONCENTHATIONS IN BOTTOM DEPOSITS
r»p rr.M'MPrTintr r\r-rnncD IOTA tnr>*-, v
-------
C- 64
REFERENCES, SECTION 2.3
1. Clarke, W.D. Ed., Chester River Study, A Joint Investigation by
the State of Maryland Department of Natural Resources and Westing-
house Electric Corporation, Vol. I-III, November 1972. •
2. Johnson, L.G., Morris, R.L., Bulletin of Environmental Contamination
and Toxicology, JEI, 503-510, (1974).
3. Nadeau, R.J. and R.P. Davis, Investigation of Polychlorinated
Biphenyls in the Hudson River, 1974, U.S.E.P.A., Washington, D.C.,
21 pp. .
'4. ''New .York'State Department of Environmental Conservation, Division
of Fish and Wildlife, 1975, Analyses of PCB's in Fish Flesh,
unpublished report.
5. New York State Department of Environmental Conservation, Division
of Pure Waters, PCS Monitoring in the Upper Hudson River Basin,
October 1975, unpublished report.
6. Thomas, Chester E., Assistant District Chief, Connecticut District,
U.S. Geological Survey, Water Resources Division, personal communi-
cation, July, 1975. . •
-------
C - 65
2.4 Data from Localized Monitoring Efforts - Marine Environment
2.4.1 Atlantic Ocean
In addition to the many PCS studies that have been conducted
within the United States, a few studies have been carried out inves- ••
tigating the air, water and fish off the east coast of the United
-States. These studies, conducted between 1971 and 1974 covering
Providence, Rhode Island; Grand Banks; Vineyard Sound; Georges Bank and"
Bermuda show PCB's to be extensively distributed over the Atlantic Ocean.
The general sampling area is shown in Figure 2.4-1.
One of the few air studies that has been, published was carried
out by Harvey and Steinhauer11 in 1973. Table 2.4-1 shows the sampling
locations and Aroclor 1254 concentrations identified. The highest
concentrations were in Vineyard Sound which'is approximately 100-150
miles from the Boston, Hartford, New York, New Jersey complex. Over
1000 miles away at Grand Banks the concentrations were 100 times less
than in Vineyard Sound. Figure 2.4-2 shows the relationship of
atmospheric PCB levels with distance from these industrial areas.'
The.seaward decrease appears to be exponential.
Later studies on PCB's in surface and subsurface waters were
done by Harvey13. Although the concentration range across the northern
North Atlantic is broad, from 1-150 ppt, the average was about 35 ppt
•in surface waters and 10 ppt at 200 meters depth. Looking at the lower
latitudes it appears that the surface waters of the Sargasso Sea have
slightly lower concentrations r.han other parts of the North Atlantic,
averaging 27 ppt. The widespread PCB distribution implicates the
atmosphere as a predominant mode of transport in the Atlantic with
variations due to the seaslicks, localized rainfall or discharges from
ships.
During the period of February-June 1973, PCB concentrations in
the marine atmosphere of the Bermuda - Sargasso Sea and Providence,
Rhode Island area were measured by Bidleman and Olney1. It is interesting
to note that most of the PCB was trapped on the polyurethane foam
collection surface suggesting that PCB's are in the atmosphere mainly
as vapors rather than adsorbed onto particulate matter, or that they
volatilize from the trapped particles collected on the glass fiber pre-
filter. Table 2.4-1 gives the locations and levels identified as
Aroclor 1242 or 1248.
Sargasso Sea surface water was also measured by Bidleman and
Olney1 in 1973. From Table 2.4-2 it can be seen that the concentra-
tions were higher in the surface layer than in the subsurface samples.
Follow-up by Harvey12, et. al., indicated that PCB concentrations
in North Atlantic surface waters declined forty fold from 1972 to
1974 presumably following the cessation of certain industrial uses
of those compounds. However, Longhurst and Radford dispute the
decrease stating that either the analytical methods were inaccurate
or Harvey's original estimate of the total amount of dissolved PCB's
in the upper 200 m was incorrect. Harvey and Steinhauer have agreed17
-------
C- 66
that their extrapolation may well have been improper and planned
more sampling for 1975.
In 1971 a seafood monitoring program18 was conducted on the East
Coast of the United States. It is difficult to make interspecies
comparisons but as can be seen in Table 2*4-3' the highest Aroclor 1260
level was in flounder from Jacksonville, Florida.
-------
Table 2.4-1
PCB Concentrations Over the Western North Atlantic
C- 67
Station
Bermuda
33°20'N, 65°14'W
34°39'N, 66°15'W
38°48'N, 69°14'W
40°32'N, 70°20'W
Georges Bank
(41°40'N, 67°30'W)
Vineyard Sound
(41°20'N, 70°50'W)
Grand Banks
(45°16'N, 52°08'W)
Providence, R.I.
Sample volume (m ) ng/m
560 0.5=
480 0.4=
820 0.16=
500 0.15=
1070 0.59=
1320 0.30=
918 ' 0.65=
1950 0.62=
1740 ' 0.55=
732 0.52=
1300 0.61=
860 0.21=
300 1.6=
267 0.79=
222 0.72=
196 0.83=
105 . . 1.4=
675 0.82=
660 0.58=
655 0.61=
640 0.80=
650 1.60=
105 3.9=
224 5.3=
780 0.05=
960 0.07=
840 0.10=
940 0.16=
540 0.05=
392 4.0=
1071 • ;.!=
744 5.8=
76 . . 9.4=
Calculated as Aroclor 1254
=Calculated as Aroclor 1242 or 1248
SOURCE: Harvey, R.G. and W.G. Steinhauer, Atmospheric Environment,
Nature, 252, 387-388 (November 29, 1974).
-------
C- 68
Table 2.4-2
PCB's Measured in Sargasso Sea Area, 1973
Location Sample* ppt**
29°56'N, 64°40'W SM H.2
SS 3.6
30°45'N, 66°55'W SM ' 4.9
SS <0.9
30°34'N, 66°59'W SM 8.3
SS 1.0
28°53'N, 65°07'W SM 42.6 , 19.3
SS <0.9 , <0.9
29°56'N, 63°00'W SM 3.8
SS <0.9
30°00'N, 64830'W SM 5.6
SS 1.6
31°34'N, 63°49'W SM -5.0 ;
SS . 1.8
31°38'N, 63°57'W SM 8.4
SS 0.9
*SM - sample is surface microlayer
SS - sample is subsurface water
**PCB calculated as Aroclor 1260
SOURCE: Bidleman, T.F., and C.E. Olney, Science, 184, 516-518 (Feb. 8, 1974).
-------
//GRAND
BANKS
NOVA SCOTIA
3 BOSTON
PROVIDENCE
GEORGES BANK1
HARTFORD ,
NEWVOR'K
VINEYARD SOUND
PHILADELPHIA-^
PITTSBoRGHy •
WASHINGTON
\
\
RICHMOND
WILMINGTON
•/
JACKSONVILLE *
BERMUDA
'SARGASSO SEA
MIAMI
FIGURE 2.4-1 ATLANTIC OCEAN SAMPLING SITES
-------
C-70
5.0
V'°
2 3,0
m
2.0
T.C
500
1000
150G 2000
-km"FROM SOURCE
SOURCE:HA°VEV, G.R. AND W.G. STEINHAUER, ATMOSPHERIC ENVIRONMENTS,
777-782,11974).
FIGURE 2.4-2 RELATIONSHIP OF ATVOSPHERIC ^CB LEVELS WITH
DISTANCE FROM INDUSTRIAL AREAS
-------
C-71
Table 2.4-3
PCB Residues In Seafood
Species
Blue crabs
Shrimp
Flounder
Weak fish
Dm:,
Sample Quantity
JACKSONVILLE, FLA.
15
1 kg
3
5
5
Aroclor 1260 fppta)
0.08
0.60
0.65
0.44
0.17
Blue crabs
Shrimp
Pilot shrimp
Oysters
Razorback clams
Squid
Flounder
SAVANNAH,
16
GA.
0.
0.
15
28
5
4
kg
kg
Blue crabs
Shrimp
Oysters
Squid
Croaker
CHARLESTON, S.C.
10
1 kg
0.02
Blue crabs
Shrimp
Oysters
Clams
Scallops
Flounder
Spanish mackerel
Weak fish
Blue fish
Fish meal
Blue crabs
Weak fish
Striped sea bass
Spot
Herring
Blue crabs
Flounder
Weak fish
Striped bass
Mullet
Croaker
MOREHEAD CITY, N.C.
15
- - 1 kg .
24
20
12
3
2
2
2
0.5 kg
CHESAPEAKE BAY
25
3
5
10
DELAWARE BAY
15
2
5
2
5
1
0.02
0.11
0.02
0.49
0.02
0.10
0.13
0.07
0.23
0.07
0.21
0.50
SOU1CE: Markin, G.P., J.c.' Hawthorne, J.L. Collins and J.H. Ford
P.esticides_Homitorin.g..Journal..]_._ 139-143.. (March 1974),
-------
C- 72
2.4.2
Bay of Fundy
As early as 1969, PCB residues were identified in harbour porpoises
from the Bay of Fundy, located in the northeast section of Maine5.
Zitko, et. al.2", identified Aroclor 1254 in a number of different fish-
ranging from 0.07 ppm in the muscle of basking shark and 0.21 ppm in
the muscle of sea raven to 3.55 ppm in Herring Oil and 218 ppm in the
liver of white shark. The species studied and the levels measured
are listed in Table 2.4-4.
Table 2.4-4
PCB and Chlorinated Hydrocarbon Pesticides in Aquatic 'Animals
from the Bay of Fundy - Gulf of Maine Area.
Species
Herring
Mackerel
Plaice
White hake
Ccean perch
Cod
Sea raven
Basking shark
White shark
Bluefin tuna
Herring oil
Fishmeal
Double-crested cormorant
Herring gull
Tissue
whole fish
muscle
muscle
muscle
muscle
muscle
muscle
viscera
muscle
liver
muscle
liver
muscle
eggs
muscle
liver
subcutaneous fat
abdominal fat
eggs
muscle liver
subcutaneous fat
Aroclor 1254, ppm
0.34
0.35
0.38
0.44
0.32
0.55
0.21
0.73
0.07
1.07
0.77
218
1.54
3.55
0.54
43.5
17.2
38
13
38
52
12.6
5.
5.
.54
,06
6.50
75
SOURCE: Zitko, V., 0. Hutzinger and P.M.K. Choi, Environmental Health
Perspectives, 47-50, (April 1972).
-------
C- 73
2.4.3 Gulf of Mexico - Caribbean Sea
Runoff from approximately two-thirds of the United States and
one-half of Mexico enters the Gulf of Mexico and is swept generally
westward to be trapped in the Western Gulf for as much as 100 years.
Therefore a buildup of man-made toxic chemicals is possible in the
Western Gulf especially since there is a heavy concentration of chemical
manufacturers in Louisiana and Texas.
The earliest samples collected in this area were brown Pelicans
collected in 1969 from the Atlantic and Gulf Coast of Florida and in
1970 from Florida Bay. The highest levels, 1.0-7.5 ppm came from
the Atlrntic Coast while those from the Gulf Coast ranged up to
4.2 ppm and those fron the Keys in the Bay only had concentrations
up to 2.5 ppm. The birds represented a wide range of ages and
both sexes, but the Immature and adult birds always had higher residues
than the young.
In 1971 a seafood monitoring program18 for the insecticide mirex
was set up. Three of the stations were located in the Gulf of Mexico
and identified Aroclor 1260 as indicated in Table 2.4-5. Due LO
the different kinds of species involved a comparison of levels is
difficult to prepare. However, it is clear that the levels in samples
from Mobile Bay, Alabama ranging from 0.01 to 0.4Q ppm were higher
than those from the Mississippi Sound where the highest level was
only 0.20 ppm.
Fish and other marine organisms were collected in the Gulf of Mexico
and the Caribbean Sea in May and October 1971 as shown in Figure 2."-3.
While PCB's were detected in nearly all the samples analyze.-1 the levels
were generally low. The samples from coastal waters generally had
higher levels than samples from open waters. This same observation
holds true for sea plankton. Of the six samples containing PCB's
above 100 ppb wet weight four of them were near Coastal areas.9
Groupers were also collected8 since they tend to spend their post
larval life in one locality and should therefore yield data more
representative of a particular area. Figure 2.4-3 shows the sampling
locations. The levels are generally low although the highest levels
do come from the western Gulf. Note also that at Anton Lizardo the
levels in the groupers increase with increasing size as can be expected
since the fat content of the fish increases with increasing size and
age of the specimen. Table 2.4-6 presents some of the levels identified
in 1971.
Giam et. al.s again took measurements from stations in the Gulf of
Mexico in 1973-1974 as indicated in Figure 2.4-3 and Table 2.4-7.
The concentrations in biota are lower than they were in the 1971 survey
with m average according to Giam of about 20 ppb reduced from 60 ppb.
" It must be noted, however, that these stations were all close to the
southern coast of the U.S. with no samples collected in the Western Gulf.
-------
C- 74
Table 2.A-6
Biota and Plankton from the Gulf of Mexico - 1971
Station Biota
1
2
3
4
6
7
9
10
11
12
13
14
15
16
27
28
29
30
31
32
Weight
(Ibs.)
Flounder °°
Flounder <=o
Flounder oo
Flounder oo
Plankton J-
Crustaceanoo
Crustacean oo
Shrimp co
Rock Shrimp «»
Squid oo
King Mackerel muscleoo
Plankton J-
Tuna muscleoo
Tuna muscleoo
Plankton x
Plankton J-
Plankton-1-
Plankton-1-
Plankton-1-
Plankton-^
Plankton-1-
Grouper^ 3.1
2.9
1.9
1.9
0.7
Grouper ft
Grouperfl
Group erft
GrouperQ
Grouper^
2.8
10.0
3.7
2.9
6.0
4.8
1.6
3.0
2.4
3.3
18.0
Standard Length
(mm)
398
378
306
287
222
414
416 ""
338
514
403
354
495
-59
315
385
339
352
681
PCB's
(ppb)
32
36
59
34
678
151
22
167
6
40
34
<3
58
36
100
30
<3
1055
44
42
191
110
32
"14
14
12
33
12
10
7
7
6
5
3
3
14
6
81
220
C.S., A.R. Hanks, R.L. Richardson, W.M. Sackett and M.K. Wong,
Pesticides Monitoring Journal, _6, 139-143, (Dec. 1972).
tGiam, C.S., M.K. Wong, A.R. Hanks, W.M. Sackett and R.L. Richardson,
Bulletin of Environmental Contamination and Toxicology, JJ» 376-382,
(1973).
flGiam, C.S., R.L. Richardson, D. Taylor and M.K. Wong, Bulletin of
Environmental Contamination and Toxicology, 11, 189-192, (1974).
-------
C-75
Table 2.4-5
PCS Residues In Seafood
Species Sample Quantity Aroclor 1260
MISSISSIPPI SOUND
Crabs 15 0.07
Shrimp 1 kg "
Squid 1 kg 0.03
Flounder 3 0.03
Speckled sea trout 3 0,20
Spanish mackerel 3 0.06
Weak fish 5 0.12
Atlantic whiting 5 0.10
Fish oil 1 liter 0.02
Fish meal 1 kg 0.02
Ground fish (unprocessed) 1 kg 0.0*
MOBILE BAT, ALA.
Blue crabs 15 0.12
Shrimp 1.3 kg 0.01
Oysters 20*- 0.03
Squid 10 0.0*
Flounder 3 0.11
Speckled sea trout 1 0.40
Spanish mackerel 2 0.18
Weak fish 5 0.37
Atlantic whiting 5 0.11
Croaker 3 0.33
Red snapper 2 0.1*
Mullet 5 0.11
Anchovy >20 0.08
Shad >10 0.09
TAMPA BAY, FLA.
Crabs 10 0.03
Weak fish 5 0.83
Mullet 5 0.31
SODBCE; Markin, G.P., J.C. Hawthorne, J.L. Collins, and J,H. Ford,
Pesticides Monitoring Journal, 7, 139-1*3, (March 19**).
-------
C- 76
r* v • • i ' i i F i' i '
30rr-COl-l-EGE STATION*
—* j—**« *». L U-
,"*~ — •
WEST FLOWER GARDENS"'
VANTON LIZA°DO, s
-"''1
80"
B BIOTA 1971
e GROUPERS 1971
A. BIOTA, WATEP, SEDIVENT, !973-1974
* PLANKTON 1971
FIGURE 2,4-3 GULF OF MEXICO SAMPLING SITES
-------
C- 77
Table 2.4-7
Concentrations of PCBs in Selected Samples
from the Gulf of Mexico, 1973-74
Station
7
18
19
20
21
22
23
24
25
26
Biota
(ppb)
20
11
22
23
37
14
6
11
94"
68
Water
(ppt)
4.1
2.1
1.7 •
1.7
2.1
2.4
1.3
0.8
2.7
Sediment
(ppb)
<0.2
35.0
33.0
<0.2
<0.2
<0.2
-•_ _JI ILM
SOURCE: Giam, C.S., J.S. Chan, J.P. Kakareka and G.S. Neff, Trace
Analyses of Phthalates and Chlorinated Hydrocarbons in Gulf
of Mexico Samples.
-------
C- 78
2.4.4 California
According to Horn and Risebrough11* PCBs have become a significant
component of the marine food webs of southern California. They have
been associated with a high incidence of premature births among sea
lions and eggshell thinning with consequent reproductive failure in
fish-eating birds.
One study collected different levels of sediment from the Santa
Barbara Basin.1"* The dated and analyzed sediments indicated that the
deposition of PCB's began about 1945 probably as a result of the rapid
increase in PCB use as electrical insulating fluids and paint additives
during World War II. Through 1967 there was no indication of a leveling
off in the rate of PCB deposition. Levels in the 1940-1945 layer
were 31 ppb increasing to 49 ppb in the 1947-1952 layer, 66 ppb in
'the 1955-1960 layer and 103 ppb in the 1962-1967 layer.11*
Risebrough23 has suggested that the observation of PCB's in the sea
indicate that they are dispersed by wind currents. Table 2.4-8 shows
the distribution of PCB residues in several collections of marine fish
collected from the Coastal waters of southern California in late 1965
and early 1966 and in marine birds collected in'late 1966. Note that
the levels in the birds J.08-109 ppm were higher than those in fish,
N.D.-1.2 ppm. Petrels and shearwaters breed on remote islands spending
their entire lives at sea. They do not dive for fish but feed primarily
upon organisms obtained at or near the surface where aerial fallout
could be expected to retain temporally the water-insoluble chlorinated
hydrocarbons components. Two Peregrine Falcons showed PCB levels
ranging from 1.5 ppm, net weight, in the brain of an Immature bird
to 1,980 ppm lipid weight in the carcass of an adult bird.
Analyses of Western gull eggs22 show that eggs from San Francisco
Bay, with levels from 24-950 ppm contained more PCB's than eggs from
the Farallon Islands 27 miles west of the Golden Gate Bridge with
levels from 12-1010 ppm. These were both higher than eggs from Baja
California where the levels were 1.2-471 ppm.
Concern over reproductive failure of the Double Crested Cormorant
led to a study in 1969 of Cormorant eggs from three locations in
southern California. The levels identified ranged from 12-1,100 ppm
in the yolk lipids.1 ° A similar concern also led to a study of Brown
Pelicans on Anacapa Island in May 1969. Fat samples from six adult
birds and one immature bird ranged from 77 to 366 mg/gm.1S
Early data collected by Munson19 in 1970 from San Diego and Orange
Counties showed levels in aquatic biota ranging from <2.0 to 8.8 ppm
lipid weight (N.D. - 1.0 wet weight) in San Diego and 0.62 - 38 ppm
lipid weight (0.008 to 1.4 wet weight) from Orange County. However,
the difference in residue levels may be due to a different type of
uptake mechanism since the samples from Orange County were invertebrates
while those from San Diego were fish.
-------
C- 79
In addition to the studies of Double Crested Cormorants and Brown
Pelicans, Faber et. al.1* studied Common Egrets and Great Blue Herons. The
PCB levels ranged up to 15 ppm in the brain and 93 ppm in the livers of
adult egrets from the Audubon Canyon Ranch. Fish which the birds
might feed on from Bolinas Lagoon showed levels from 0.072-0.079 ppm.
In order to assess the potential contamination from chlorinated
hydrocarbons the U.S. Geological Survey initiated a study in February
1972 of the San Francisco Bay. Bottom material was collected from 26
streams that discharge into San Francisco Bay. The results of the '
analyses are given in Figure 2.4-4 illustrating the widespread
distribution of PCB's in the San Francisco Bay area. The readir.gs
from Steven Creek of 180 ppb and from Alamitos Creek, of 610 ppb
were higher than anticipated since neither area had any apparent
industrial or commercial development. Despite the extreme range up to 1400
ppb there was no significant difference between the average residue of
streams discharging into the Bay south of San Francisco and those
discharging into the Bay north of San Francisco.1S
Studies of Waste Water Treatment Plants in the Southern California
area will be presented in Section 2.5.3.4.
-------
Table 2.4-8
Polychlorinated Biphenyl (PCB) Residues
in Marine Fish and Marine Birds, 1965-1966
C- 80
Species
Locality,
PCB
Northern Anchovy
Terminal Island
Shiner Perch
San Francisco Bay
English Sole
San Francisco Bay
Monterey
Jack Mackerel
Channel Islands
Hake
Puget Sound
Channel Islands
Biuefin Tuna
Body" muscle
Liver
Yellowfin Tuna '
Liver
Skipjack Tuna
Liver
Gassings Auklet
Ancient Murrelet
Fulmar
Fulmar
Red Phalarope
Rhinoceros Auklet
Slender-billed Shearwater
Sooty Shearwater
Sooty Shearwater
Peregrine Falcon
Breast muscle, second year
Female, migrant from Artie
Breast muscle, immature
California
, Breast muscle, adult
female, California
1.0
0.4-1.2
0.05-0.11
0.04
0.02
0.16
0.12
0.04
0.04
0.04
0.1
0.16
0.15
0.08
0.34
0.10
0.36
2.1
1.2
0.9
22
10.5
109
SOURCE: Risebrough, R.W., Chlorinated Hydrocarbons in Marine Ecosystems,
-------
C-81
OF OVEV-D9IED ST^EAV BED
- UNCOD"ECTED =0°
°ECOVEBY
O LOW VALUE Oc
HIGM VALUE OF RANGE
FIGUDE 2,4 4 PCB'S ?M 3/N FRa-JCISCO BAY AREA STREAW BEDS
-------
C- 82
2.4.5 Escambia Bay, Florida , ,
The first detection of Aroclor 1254.residues in Escambia Bay was in-
oysters in April 1969.3 Later sampling also showed residues in water,
sediment, fish, blue crabs and shrimp as indicated in Table 2.4-9.
One source was apparently an industrial outfall which had had accidental
leakage of a heat exchange fluid. Fish, shrimp and crabs contained
higher concentrations than oysters but are also more mobile and therefore
not as useful as monitors for a particular area.
Figure 2.4-5 identifies the sampling locations (stations 1-7).
Less i.han 0.1 ppb occurred in the water at station 2 but it
was not detected in lower bay water. 'Leaching from sediments is presumably
the cause of the continued presence of Aroclor 1254 in the river water.
Sediment samples taken near the outfall.reached 486 ppra in August 1969.3
• .• i.
Pink shrimp collected at the same time from the bay were found to
contain whole body residues of Aroclor 1254 as high as 14 ppra.2 ° Residues
in seven composite samples of at least five shrimp ranged from 0.6 to
120.0 ppm. Fiddler crabs collected in April 1970 from the lower Escambia
River and Upper Escambia Bay had individual whole bod'/ residues of 0.45
to 1.5 ppm.
The largest accumulations were found in the sediments with the
maximum residue of 61 ppm observed in the River at the outfall from the
industry. The maximum in the Bay of 30 ppm was found near the mouth of
the river. Although Aroclor was not detected in sediments collected
above the plant, soil samples from the bank near the mouth of the river
downstream from the source 6.5.km had 1.4 to 1.7 ppm. Subsequent samplings
from three stations in the bay showed little change in the chemical even
after nine months. Table 2.4-9 shows-the levels identified for these
sediment collections as stations 8-20.20
The amount of PCB in sediment samples appeared to decrease after
the initial February 1970 survey.21 . The decrease is especially noticeable
in December 1970 and October 1971. In general, the residues identified
in 1971 were about one-tenth the 1970 values. Cores taken in a 1972
survey generally indicated less PCB than in 1971. Table 2.4-9
identifies the readings taken for these three years as stations 21-23.
. Later surveys of biota from the estuary showed levels to remain
relatively high. Table 2.4-10 compares residues in the same species or
those occupying similar trophic levels captured on the same day in
Escambia and East Bays; the East Bay site being about 35 kilometers from
the original source of the material. Although sand seatrout and Atlantic
cutlassfish could be expected to have the highest residues since they
are predators the highest levels were actually found in silversides
whose diet consists mainly of plankton. Note also that the concentrations
in species from Escambia Bay were 5 to 10' times greater than those found
in East Bay but that Aroclor 1254 was found even in species captured distant
from the original source'of PCB.21
-------
C -83
EAST BAY
FIGURE 2.4-5 ESCAf/BIA BAY SAIVPLIMG STATIONS
-------
C- 84
Table 2.4-9
Residues of Aroclor 1254 in Samples from Escambia Bay and River
Residues of Aroclor 125& (ppm)
3
3
4
4
4
4
4
4
L
4
3
3
3
4
k
1
2
6
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
Sample
Speckled trout
Flounder liver
Menhaden
Menhaden
Menhaden
Flounder liver
Flounder muscle
Flounder gills
Croaker
Pinfish
Shrimp
Blue crab
Blue crab
Shrimp
Blue crab
Sediment
Sediment
Sediment
Sediment
Sediment
Sediment
Sediment
Sediment
Sediment
Sediment
Sediment
Sediment
Sediment
Sediment
Sediment
Sediment
Sediment 0-2 in.
Sediment 2-4 in.
Sediment 4-6 in.
Sediment 6-8 in.
Sedimer : 0-2 in.
Sediment 2-4 in.
Sediment 4-6 in.
Sediment 6-8 in.
Sediment 8-10 in.
Sediment 10-12 in.
Sediment 0-2 in.
Sediment 2-4 in.
Sediment 6—6 in.
Sediment 6-8 in.
1969
20.0
184.0
5.7
11.0
12.0
76.0
4.5
19.0
12.0
10.0
2.5
7.0
6.3
1.5
1.0
486
<.03
1.7
1970 1971
N.D.
61.0
5.7
4.1
1.9
1.8
30.0
4.2
3.3
4.9
0.6
2.5
1.4
78.0 8.1
30.0 0.12
6.1 N.D.
0.4 N.D.
10.0 0.91
11.0 N.D.
'15.0 N.D.
20.0 N.D.
18.0 N.D.
1.2 N.D.
0.19 0.19
0.08 N.D.
0.02 N.D.
N.D. N.D.
1972
0.97
5.8
— __
_____
0.14
N.D.
N.D.
— ... . .
— --
— ... . i.
_____
— _ _ _
.,.-__.
SOURCE: Nimmo, D.R., D.J. Hansen, J.A. Couch, N.R. Cooley, P.R. Parrish
and J.I. Lowe, Toxicity of Aroclor 1254 and its Physiological
Activity in Several Estuarine Organisms, (unpublished).
-------
C- 85
Table 2.4-10
Comparison of Concentrations of Aroclor 1254 Found in
Species Collected in Escambia and East Bays
Escambia Bay East Bay
Species (ppm) (ppm)
Spartina • . - N.D. N.D.
Zostera N.D. N.D.
Olive Nerite 0.49 . N.D.
Rangia N.D. N.D.
Penaeid Shrimp 0.98 Trace
Blue Crabs '6.90 0.46
Bay Anchovy 3.00 0.68
Catfish 3.80 0.58
Tidewater Silversides 10.00 0.95
Silver Perch 4.50 0.48
Sand Seatrout 1.50
Spotted Seatrout 0.12
Spot ' 1.80 Trace
Atlantic Croaker 1.60 Trace
Hogchoker 1.30 N.D.
Atlantic Cutlassfish 2.90 ' 0.72
SOURCE: Nimmo, D.R., D.J. Hansen, J.A. Couch, N.R. Cooley, P.R. Parrish
and J.I. Lowe, Toxicity of Aroclor 1254 and its Physiological
Activity in 'Several Estuarine Organisms, (unpublished).
-------
C- 86
REFERENCES, Section 2.4
1. Bidleman, R.F. and C.E. Olney, Science, 184, 516-518, (Feb. 8, 1974).
2. Blus, L.J., A.A. Belisle and R.M. Proutfy, Pesticides Monitoring
Journal, 7_, 181-194, (March 1974).
3. Duke, R.W., J.J. Lose and A.J. Wilson Jr., Bulletin of Environmental
Contamination and Toxicology, 5^ 171-180, (1970).
4. Faber, R.A., R.W. Risebrough and H.M. Pratt, Environmental Pollution,
3_, 111-122, (1972).
5. Gaskin, D.E., Nature, 233. 499-500, (Oct. 15, 1971).
6. Giam, C.S., J.S. Chan, J.P. Kakareka and G.S. Neff, Trace Analyses
of Phthalates and Chlorinated Hydrocarbons in Gulf of Mexico
Samples.
7. Giam, C.S., A.R. Hanks, R.L. Richardson, W.M. Sackett and M.K. Wong,
Pesticides Monitorirj Journal, 6_, 139-143, (Dec. 1972).
8. Giam, C.S., R.L. Richardson, D. Taylor and M.K. Wong, Bulletin of
Environmental Contamination and Toxicology, 11, 189-192, (1974).
^^^™ *^w
9. "Giam, C.S., M.K. Wong, A.R. Hanks, W.M. Sackett and R.L. Richardson,
Bulletin of Environmental Contamination and Toxicology, _9_,
376-382, (1973).
10. Gress, F., R.W. Risebrough, D.W. Anderson, L.F. Kiff and F.R. Jehl Jr.,
The Wilson Bulletin, 85, 197-208, (June 1973).
11. Harvey, G.R., and W.G. Steinhauer, Atmospheric Environment, _8_,
777-782, (19'4).
12. Harvey, G.R., Steinhauer, W.G. and J.P. Miklos, Nature, 252,
387-388, (Nov. 29, 1974).
13. Harvey, G.R., W.G. Steinhauer and J.M. Teal, Science, 180,
643-644, (May 11, 1973).
14. Horn, W., R.W. Risebrough, A. Soutar and D.R. Young, Science,
184, 1197-1199, (June 14, 1974).
15. Keith, J.O., L.A. Woods Jr., and E.G. Hunt, Transactions of the
North American Wildlife Conference, 35, 56-63, (1970).
16. L.M., Law, and D.F. Goerlitz, Pesticides Monitoring Journal, j[,
33-36, (June 1974).
17. Longhurst, A.R., and P.J. Radford, Nature, 256. 239-240, (July 17, 1975)
-------
C -87
18. Markin, G.P., J.C. Hawthorne, J.L. Collins, and J.H. Ford,
Pesticides Monitoring Journal, 7_, 139-143, (March 1974).
19. Munson, T.O., Bulletin of Environmental Contamination and Toxicology,
7., 223-228 (1972).
20. Nimmo, D.R., P.D..Wilson, R.R. Blacfcman and A.J. Wilson Jr.,
Nature, 231. 50-52, (May 7, 1971).
21. Nimmo, D.R., D.J. Hansen, J.A. Couch, N.R. Cooley, P.R. Parrish
and J.I. Lowe, Toxicity of Aroclor 1254 and its Physiologic?.!
Activity in Several Estuarine Organisms, (unpublished).
22. Risebrough, R.W., Chlorinated Hydrocarbons in Marine Ecosystems.
23. Risebrough, R.W. and V. Brodine, Environment, 12, 16-27,
(January-February 1970).
24. Zitko, V., 0. Hutzinger and P.M.K. Choi, Environmental Health
Perspectives, 47-50, (April 1972).
25. Zitko, V., and P.M.K.,. Bulletin of Environmental Contamination and
Toxicology, 1_, 63-64, (1972).
-------
C - 88
2.5 Data from Localized Monitoring Efforts Industrial Plants,
Products, Sewage Treatment Facilities and Landfills
2.5.1 Industrial Plants
.5.1.1 Monsanto Co., Sauget, Illinois
The only PCS production facility in the United States is the Monsanto
plant at Sauget, Illinois which has produced PCS mixtures ranging from
20 to 68 percent chlorine. Polychlorinated terphenyls have been produced
at this facility, but production was suspended in 1971.
Soil contamination studies7 ™ere initiated in February 1976. The
sampling locations around the Monsanto facility are identified in Figure
2.5-1. The levels of Aroclor 1242, Aroclor 1260 and decachlorobiphenyl
found at these sampling sites are listed in Table 2.5-1. The distri-
bution of all PCBs analyzed appears to be higher near the plant site and
generally decreasing with distance from the site. There is some evidence
that higher concentrations are present in the soils located to the
southeast which corresponds with the predominant wind direction in this
Area.
A typical chromatogram of a soil sample obtained near the plant is
shown in Figure 2.5-2 along with the reference chromatograms of Aroclor
1242 and 1260 run under the same instrument conditions. Using these
reference spectra, this sample contains 11 ppm Aroclor 1242, 9.3 ppm
Aroclor 1260 and 1.0 ppm decachlorobiphenyl.
All PCB measurements were made using a Varian Model 2760 electron
capture gas chromatograph with a 1.8m glass column operated at 200°C.
The column had a 3mm Id and was packed with 1.5/1.95% OV-17/WF-1
on chrom W-HP, 80/100 mesh support. The flow rate was 68 ml/min
with an inlet pressure of N2 at 38psig.
-------
C - 89
Table 2.5-1
PCB Levels in Soils, ppm, Monsanto
Sample Station Aroclor 1260 Aroclor 1242 Decachlorobiphenyl Total PCB
1 0.05 <0.01 0.097 a. 147
2 . 0.12 <0.01 0.61 0.73
3 1.4 <0.01 0.90 2.3
4 0.31 0.68 0.38 1.37
5 0.20 <0.01 0.27 ' 0.47
6 1.3 0.82 1.6 3.72 '
7 2.9 3.0 1.3 7.2
8 9.6 6.1 2.4 ' 18.1
9 0.65 <0.01 0.12 7.7
10 0.28 0.45 0.081 0.811
11 0.10 <0.01 0,049 0.145
12 0.26 <0.01 0.081 0.341
13 9.6 10.0 1.1 20.7
14 0.03 <0.01 0.40 0.43
15 0.39 0.46 0.12 0.97
SOURCE: Unpublished Report, Contract 68-01-2978, USEPA, Office of Toxic
Substances; July 1975
-------
RESIDENTIAL **' t
/"'.
FIGURE 2.5-1 SAMPLING LOCATIONS. MONSANTO
-------
C- 91
'a> APOCLOR 12^
DECACHLCPOBIOMENVL
n
'c)AROCLOP1260
25
50
75 M!N
FIGURE 2,5-2 TYPICAL CHROVA~OG7A vs Oc STAMDASD APOCLORS
DECAC^LOROB D^EMVL A--JD A SO'L SAV^I E TAKEM
IN THE VIC'MITY Oc VOMSAMTQ CO , SAUGE", ILLINOIS
-------
C - 92
2.5.1.2 Yates Manufacturing Co., Chicago, Illinois
The Yates Manufacturing Co. is an investment casting wax manufac-
turer. Prior to 1972, Aroclors 5460, 6090 and 5442, mixtures that
contain both PCBs and polychlorinated terphenyls, "ere used. Subsequent
to 1972, this company has been purchasing decachlorobiphenyl from foreign
sources.
Soil contamination studies7 were initiated in February 1976. The
sampling locations around the Yates facility used to study soil con-
tamination are identified in Figure 2.5-3. The concentration levels of
Aroclor 1242, Aroclor 1260 and decachlorobiphenyl found at these sampling
sites ar°- listed in Table 2.5-2.
Table 2.5-2
PCB Levels in Soils, ppm, Yates Manufacturing
Sample Location Aroclor 1260 Decachlorobiphenyl Total PCB
1 0.22 <0.001 0 22
2 0.24 0.053 0.293
3 0.81 0.033 0.113
4 0.34 0.19 0.53
5 0.51 0.58 1.09
6 0.40 1.2 1.6
7 0.26 - " 0.51 0.77
8 1.5 0.75 2.25
9 0.57 0.040 0.61
10 0.67 0.020 0.69
11 1.6 _ 3.6 - .- _ 5.2
12 0.29 0.001 0.291
13 0.56 0.034 0.594
14 1.8 <0.001 1.8
SOURCE: Unpublished Peport, Contract 68-01T2978, USEPA, Office of
Toxic Substances; July 1975
-------
?YATES MFG.CO.
*C H I C
jl IRP 9 R.'i y A A/ID I IM/7 I no/NTIOMO VATCCR/IAMI 1C AOTI
-------
C- 94
2.5.1.3 Valcast Corp., Troy, Michigan
Valcast Corp. is an investment casting facility located in a small'
industrial park in suburban Detroit, Michigan. PCBs are a constituent
of the wax mold compound used to fashion intricate shapes which are to
be cast.
Soil contamination studies7 were initiated in February 1976. The
sampling locations around the Valcast facility are identified in Figure
2.5-4. The concentration levels of Aroclor 1260 and 1242 found at
these sampling sites are listed in Table 2.5-3.
Figure 2.5-5 is a typical chromatogram of a soil sample extract
taken from this location. Aroclor 1260 was present in many of the soil
samples taken from the Valcast area, but decachlorobiphenyl was absent.
The one observed concentration of 18 ppm of Aroclor 1242 appears to be
anomalously high, however, replicate analysis yielded values of 16 ppm
and 19 ppm, respectively. Aroclor 1242 was not detected in any other
soil samples from this area.
All PCB measurements were made using a Varian Model 2760 electron
capture gas chromatogranh with a 1.8m glass column operated at- 200°C.
The column had a 3mm Id and was packed with 1.5/1.95% OV-17/WF-1
on chrom W-HP, 80/100 mesh support. The flow rate was 68 ml/min
with an inlet pressure of N^ at 38psig.
A small drainage ditch that passes adjacent to the north boundary
of the Valcast facility was sampled. This ditch serves to remove storm-
water runoff in the vicinity and receives discharged cooling water from
Valcast and other local small industies. Analysis of the Valcast cooling
water at the point of discharge and of water in the drainage ditch
failed to detect PCB levels greater than the detection lir.it of 0.1 ppb
Two bottom sediment samples taken from this drainage ditch, however, had
concentrations as follows:
Aroclor 1242 2.3 ppm 9.4 ppm
Aroclor 12CO 6.7 ppm 8.9 ppm
Decachlorobiphenyl 0.09 ppm 0.11 ppm.
-------
C -95
Table 2.5-3
PCB Levels in Soils, ppm, Valcast
Sample Station Aroclor 1260 Aroclor 1242
1 <0.01
2 . <0.01 18.0
3 0.04
4 0.06
5 0.05
6 0.04
7 0.14
8 0.07
9 <0.01
10 0.12
11 <0.01
12 0.12
13 0.03
14 <0.01
15 0.03
16 0.02
SOURCE: Unpublished Report, Contract 68-01-29~8, USEPA, Office of
Toxic Substances; July 19?5
-------
'A5' _ - M*'lt--—__. V
STEHLING HEIGHTS
MADISON HEIGHTS
FIGURE 2.&-4 SAMPtiWG LOCATiOWS. VALCAST
-------
(a)
19 38 5/ 75 WIN.
(b)
o
FIGURE 2,5-c TYPICAL CHROMATOGRAMS OF SOIL SAMPLES TAKEN IN THE ''
VICINITY OF VALCASFCORP., 1 ROY, MICHIGAN -(d)O.OI ppm, 5
(b> 0014 ppm AROCLOR 1260
-------
C- 98
2.5.1.4 General Electric, Hudson Falls - -Ft. Edward, N.Y.
The General Electric Plants at Hudson Falls and Ft. Edward use
large quantities of PCB's for filling capacitors and transformers. Both
plants have chemical waste treatment facilities, but, significant PCS
and oil/grease levels are discharged by the waste" stream. The NPDES
Permit Application lists:
Daily Average
Concentration Average Daily Maximum Daily
Outfall ppm Loading (Ibs.) Loading (Ibs.)
Location Oil/Grease. PCS Oil/Grease PCS ' Oil/Grease PCB
Hudson Falls 13.7 .5 239.8 10.0 250.9 17.6
Hudson Falls 2.1 " 4.9 5.25
Ft. Edward 8.9 5.0 38.27 20.0 44.5 30.0
In the summer of 1974, EPA Region II initiated a sampling program
in the general vicinity of the General Electric plants.2 The five
sampling stations established for this program are shown in Figure 2.5-6.
Station 0 is upstream from the plants and serves as tKa control
station; station 1 is located at the junction of the outfall stream from
the Ft. Edward facility- and the Hudson River, station 2 is located about
0.25 miles downstream from the outfall junction, station 3 is about 0.5
miles downstream from station 1, and station 4 is located about 0.75
miles downstream from station 1.
Samples collected included sediment, water, fish and snails; Ar-
dors identified included 1016, 1254, 1248 and 1242. The levels found
at each sampling location are listed in Table 2.5-4.
PCB's identified as Aroclor 1016 were conclusively identified in
the water samples at detectable concentrations at all sampling locations
except Station 0 (control) and station 4, the furthest downstream.
At all stations the sediments contained higher concentrations of
Aroclor 1016 than the water column resulting from adsorption of PCB's on
suspended or already settled materials.
The biological samples collected at station 0 contained PCB's
characteristic of Aroclor 1254 and Aroclor 1248. Distinctly different
from .the samples ac station 0 were the samples collected in the vicinity
of or below the General Electric discharge. Fish data from these areas
suggests that Aroclor 1242, Aroclor 1016, or a mixture of these two
formulations are present in the Hudson. There are no distinguishing
features which can reliably determine whether the mixture is Aroclor
1016 or 1242 at this time.
-------
C - 99
Table 2.5-A
Environmental PCS Levels from the General Electric,
Hudson Falls - Ft. Edward N.Y. Area
Media
Aroclor
Station
0
-1
2
3
L
Water (ppb)
1016
<1.0
2800
2.2
3.0
<1.0
Sediment (ppm)
1016
6.9
6700
5*0
2980
6.6
Fish (ppm)
1254 1248 1242
4.0 13.0
45a
350b
78C
aSnails (composite)
bRock Bass
cShiner Minnows
27'
SOURCE: Nadeau R.J., and R.P. Davis, Investigation of Polychlorinated
Biphenyls in The Hudson River, USEPA Region II.
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C- 100
STATIQM 0 COM~°OL
VILLAGE OP WUDSOM
FIGURE 2.5 6 VADQ':UUDSOM CALLS-CT. EDWADD MEW VO°K, MQTE LOCATIQM
OP SAVPLIMG STATIQMS RELATIVE TO GEME°AL ELECTRIC
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C- 101
2.5.2 Sewage Treatment Facilities
2.5.2.1 Illinois
An early study8 of discharges into Lake Michigan was conducted by
the state of Illinois in 1970-1972 from locations as shown in Figure
2.5-7. Only two counties in Illinois border on the lake and all
sewage treatment plant effluents and tributary stream sources enter
the lake from Lake County. In most cases, sewage treatment plant
effluents had higher concentrations of PCB's than the tributary streams.
PCB's were not measured in 1970; however, in 1971, 37 sediment
samples were collected from tributary streams and ravines in Lake County
and at stations offshore from Lake and Cook counties and analyzed for
PCB's. The lake samples were collected 4Q to 80 yards offshore from
seven North Shore Sanitary District sewage treatment plants and at
stations approximately one to three miles offshore. Arrclor 1242
±r, tributary sediments ranged up to 553 ppb in an unnamed channel in
Waukegan and Aroclor 1254 ranged from 1.54 to 232.00 ppb in Pettibone
Creek in North Chicago. Samples from open water sediments had
Aroclor 1242 concentrations ranging up to 106.07 ppb. The highest
level was found 4Q-80 yards offshore from the North Shore Sanitary
District sewage treatment plant at North Chicago. Aroclor 1254
concentrations ranged from 2.48 to 46.92 ppb. Selected values are
given in Table 2.5-5.
Water samples were collected in both 1971 and 1972 at the tributary
streams and sewage treatment plants. Aroclor 1242 and 125A ranged from
14.00-1810.0 ppt and 192.0-388.0 ppt in 1971 respectively and up to
653.0 ppt for Aroclor 1242 and 61.0 to 861.0 ppt for Aroclor 1254
in 1972 in tributary streams. However, in samples from sewage
treatment plants Aroclor 1242 concentrations ranged from 268.0-4Q20.0 ppt
in 1971 and up to 21.0 ppt in 1972. Aroclor 1254 concentrations
ranged from 139.0-568.0 ppt in 1971 and from 97.0 to 178.0 ppt in
1972. The highest readings were from the North Shore Sanitary District
at Waukegan in 1971. Table 2.5-6 presents the levels identified in
water samples from Illinois Streams and Sewage Plants Tributary to
Lake Michigan.
-------
C - 102
WISCONSIN
ILLINOIS
• 4 MILE STATION
WINTHROP HARBOR
N
t
,1 NSSO WAUKEGAN STP
WAUKEr)AKAIVER.f
NSSD NORTH_CHtCAOO FTP
• t NORTH CHICAGO WFP
PETTIFONE CREEK »L _____________
•I NSSD LAKE BLUFF SV:'
•5
iSCALE IN MILES
110
',.5
| LAKE MICHIGAN
LAKE FOREST STP
NSSD HIGHLAND PARK @ PARK AVE. STP
HIGHLAND PARK WFP "A NSSD HIGHLAND PARK @ RAVINE DRIVE STP
EPJfUTy *\ NSSD HIGHLAND PARK GARY AVE. STP
COOK COUNTY
••EVANSTONWFP
13
• 14 MILE STATION
ICHICAGO CENTRAL WFP
CHICAGO SOUTH WFP
• '4 MILE STATION
FIGURE 2.5-7 LOCATIONS OF WATER AND SEDIMENT SAMPLING STATIONS
-------
C- 103
Table 2.5-5
Polychlorinated Biphenyls in Sediments from Lake Michigan
and Tributary streams in Illinois 1971
(ppb) dry weight basis
Aroclor
Location 1242 1254
<1 to 3 miles offshores
Cook County I N.D.-18.55 2.48-17.25
2 17.23-83.35 9.38-46.92
3 ' 3.58-13.65 3.15-12.42
Lake County 4 7.43-19.25 • 5.26-17.45
5 4.98-46.11 8.36-34.52
Highland Park STP 11.11 12.42
Lake Forest STP 10.51 7.02
Lake Bluff STP 4A.36 14.45
North Chicago STP 106.07 26.54
Waukegan STP 17.32 11.97 '
10-50 yards upstream from Lake
Lake County 6 N.D.-4.32 1.54-17.90
7 1.31-173.40 2.54-232.00
8 1.77-553.00 2.56-131.00
SOURCE: USEPA, Pesticide Monitoring Programs: Lake Michigan and
Tributaries in Illinois, EPA 600/3-74-002
-------
C- 10A
Table 2.5-6
Polychlorinated Biphenyls in Water Samples from
Illinois Streams and Sewage Plants Tributary to Lake Michigan
1971 - 1972, (ppt)
Afoclor
Location
1971
Waukegan River
Pettibone Creek
Waukegan STP
North Chicago STP
1972
Waukegan River
Pettibone Creek
Waukegan STP
North Chicago STP
1242
1810.0
140.0-187.0
601.0-4020.0
268.0-1070.0
57.0-120.0
N.D.-653.0
N.D.-17.0
N.D.-21.0
1254
388.0
192.0-194.0
139.0-568.0
153.0-260.0
61.0-136.0
107.0-841.0
97.0-139.0
100.0-178.0
SOURCE: USEPA, Pesticide Monitoring Programs: Lake Michigan and
Tributaries in Illinois, EPA 600/3-74-002
-------
C- 105
2.5.2.2 Michigan
Samples collected in 1971 and 1972 from municipal waste water
treatment plant effluents throughout Michigan1* indicated these plants
as a major source of PCB's with an average concentration of 2.55 ppb
for 60 effluents sampled. Only seven of the effluents exceeded 1 ppb
but one, the Bay City treatment plant on the Saginaw River, had an
average effluent concentration of 120 ppb with a high of 340 ppb.
Samples collected from 58 waste water treatment plants in '1973
averaged 0.52 ppb. The Bay City PCS discharge had been greatly reduced
as a result of control measures in industries served by the waste
.water treatment plant.
Sewage Sludge from 57 of the 58 plants tested in 1973 showed Bay
City to have the highest concentration of PCB's in the sludge being
removed by the treatment process averaging 352 ppm compared to a state
wide average of 15.6 ppm.
The range of values for all waste water treatment plants sampled
in 1971-1973 are given in Table 2.5-7. •
-------
C - 106
Table 2.5-7
PCS Levels from Waste Water Treatment Plants, Michigan
City
Adrian
Albion
Ann Arbor
Battle Creek
.Bay City
Benton Harbor
St. Joseph
Brighton
Charlotte
Constantine
Detroit
Dexter
E. Lansing
Escanaba
Essexville '
Flint
Flushing
Gladstone
Grand Haven
Grand Rapids
Holland
Houghton-Hancock
Iron Mountain-
Kingsford
Ironwood
Jackson
Kalamazoo
L'Anse
Lansing
Manistique
Marquette
Marshall
Menominee
Midland
Milford
Monroe
Mt. Clemens
Mt. Pleasant
Muskegon
Muskegon Heights
Niles
Norway
Effluent (1971-72)
CPPb)
Aroclor
1254
0.41-14.00
0.44
<0.10-0.14
• 0.16-0.92
'5.70-340.00
0.31-0.99
0.38
0.61
0.85 .
0.88-3.00
<0.10
0.35-0.69
0.29
0.21-0.28
<0.10-1.30
0.52
0.19
<0.50
0.37-0.68
0.42-0.79
<0.10 •
0.55-1.20
0.16
<0.10
0.1S-1.30
<0.10 •
0.13-0.23
,<0.20
0.35
<0.10
0.35
0.13-0.40
<0.10
0.33-0.60
1.40-10.00
<0.10
0.28
0.37
0.68
0.40
Effluent (1973)
(ppb)
Aroclor
Sludge (1973)
(ppm)
Aroclor
1242
3.20
2.15
0.44
1.05
<0.10
0.18
0.69
<0.10
1.12
0.22
0.63
0.29
0.15
0.57
<0.1jO
<0.10
0.29
0.83
0.18
0.48
1254 1242
0.34
0.25
<0.10
352.0
0.20
0.34
0.46
32.1
0.23 -
0.18
0.10
<0.10
-
<0.10
0.29
23.3
0.31
2.20
2.90 175.0
1254
1.5
1.1
2.8
13.8
6.8
2.1
3.2
4.6
5.9
3.9
6.3
4.1
4.1
11.8
0.8
5.5
9.5
5.2
3.0
4.4
5.3
1.5
2.8
3.9
4.2
2.9
3.3
6.5
12.7
11.0
7.8
<0.10
-------
C -107
Table 2.5-7 (cont.)
Effluent (1971-72)
(ppb)
Aroclor
Ontonagon
Owosso
Parchment
Pontiac (Auburn Rd)
Pontiac (E. Blvd)
Portage
Port Huron
Saginaw
St. Ignace
South Haven
Swartz Creek
Three Rivers
Trenton
Warren
Wayne County
(Wyandotte)
Wyoming
Ypsilanti
Ypsilanti Twp ill
Ypsilanti Twp '>2
Cadillac
Hovell
Sault Ste. Marie
Traverse City
125A
<0.10
<0.10
<0.10
<0.10-0.61
0.15-1.30
1.90
0.28-0.52
0.74-3.80
0.20
O.10
<0.10
<0.30
0.14-1.10
0.10-0.16
0.17-0.6&
O.AA-0.55
0.21-0.22
<0.10-0.12
0.16-0.19
Effluent (1973)
(ppb)
Aroclor
Sludge (1973)
1242
0.12
0.31
<0.10
<0.10
<0.10
0.40
0.22
-------
C-108
2.5.2.3 Wisconsin
, Samples from sewage treatment facilities in Wisconsin were
collected in March 1970. The PCS concentrations identified in the
effluents ranged from 0.04 to 0.25 ppb and are presented in
Table 2.5-S.9
In 1971 11 municipal sewage treatment plants in eleven southeastern
Wisconsin cities were sampled as shown in Figure 2.5-8. Table 2.5-9
shows the results of this study and indicates that six of the eleven
sewage plants had effluents ranging from 0.1 to 0.5 ppb of Aroclor 1254
while two sites were greater than 1.0 ppb for the same Aroclbr.
However Portage had 42 ppb of Aroclor 1248 in the effluent with 5.2 ppm
in the digester sludge.
It is interesting to note that even though Port Washington is
not as highly industrialized as Grafton the effluents from both cities
contained approximately the same concentrations of PCB's ranging from
0.12 to 0.23 ppb.
Since the concentrations for Cedarburg were so high a special
24 hour study was conducted. The concentrations in raw sewage began to
increase at the beginning of the working day from 0.54 ppb to a maximum
of 3.1 ppb at 4:00 p.m. Table 2.5-10 presents the readings taken.
The concentration in the final effluent appears to begin increasing
from 0.33 ppb at midnight to a maximum of 0.77 ppb at 2 p.m. The
concentration of PCB's in the effluent is approximately 30 percent of
that in the influent. The concentration of PCB's in the sludges is
approximately 1,000 times higher than in the fluid wastes. These data
demonstrate that the time of sampling waste effluents is of importance
in mass transport estimates.1
-------
C-109
Table 2.5-8
Concentrations of PCBs in Outfalls into the
Milwaukee River on March 26, 1970
Location , Aroclor
West Bent STP effluent 1254
Fredonia STP effluent 1254
Tributary at Fredonia 1260
Saukville STP effluent 1260 .
Chemical plant effluent,
Saukville 1242
Grafton STP effluent 1254
PCS Concentration (ppb)
0.25
0.12
0.04
0.13
2.50
0.04
SOURCE: Veith, G.D., and G.F. Lee, Water Research, 5_, 1107-1115,
(1971)
Table 2.5-9
PCS Concentrations in the Effluents from 11 Southeastern
Wisconsin Sewage Treatment Plants, 1971
City
Beaver Dam
Port Washington
Grafton
Cedarburg
Racine
Burlington
Lake Geneva
Walworth
Beloit
Ft. Atkinson
Portage
PCB Concentrations
(ppb)
0.05
0.12-0.22
0.07-0.23
0.28-1.1
0.60-0.83
0.08-0.14
.2.2-2.8
0.17-0.34
3.89-11.75
1.24-2.48
32-42
Estimated Mass Transport
(in Ib/day)
0.0002
0.0027
0.0008-0.0015
0.0027-0.018
0.142
0.0017
0.018
0.0038-0.0052
0.0015
SOURCE: Dube, D.J. Polychlorinated Biphenyls in Effluents from Sewage
Treatment Plants in Southeastern Wisconsin
-------
C- 110
FREDONIA
PORTAGE .
.BEAVER DAV —
FORT A-.KINSON
^T——GRAFTON
S CEDARBURG
RACiNE
f
BELOIT
\ BURL NG~ON
LAKE GENEVA
WALWORTH
FIGURE 2,5-8 WISCOMSIM CITIES WHERE MUNICIPAL SEWAGE TREATWENT PLANTS WERE
SAMPLED IN 1971
-------
C -111
Table 2.5-10
A 24-hour Survey of PCB's In the Cedarburg Treatment
Plant on April 15, 1971
PCB Concentrations (in ppb)1
Time
0:00
1:00
2:00
4:00
6:00
8:00
10:00
12:00
14:00
16:00
17:00
20:00
21:00
22:00
Flow
. (in gal/min)
1480
1360
1300
1250
1200
2000
2100
1900
1900
1850
1900
1950
1800
1650
In the
Influent
0.30
'
0.20
0.13
____
0.54
0.40
1.7
1.5
3.1
0.30
0.36
In the In the Primary
Effluent Trickling Filter
0.33
0.19
0.10
0.35
0.16 .
OOQ m ««•.•-•.
• J «7 ••— »«^-»
0.50
0.23 0.69
0 • 7 7 ~" """™'™""
0.76
0.25
0.22
0.14
0.34
*The Chromatograms of the samples most closely resembled the
chromatogram of Aroclor 1254.
SOURCE: Dube, D.J. Polychlorinated Biphenyls in Effluents from
Sewage Treatment Plants in Southeastern Wisconsin
-------
C-112
2.5.2.4 Ohio
Very little information is available from the Ohio River. The
values reported are given in Table 2.5-11.
Table 2.5-11
PCS Levels from Sewage Treatment Plants, Ohio, 1971
Collection Site Aroclor Petected Concentration (ppb)
Dayton 1254 17
Hamilton 1248 10
Middleton N.D.
SOURCE: Polychlorinated Biphenyls and the Environment, Inter-
departmental Task Force on PCB's, May 1972
-------
C- 113
2.5.2.5 California
In 1970 over a billion gallons of waste water entered the sea
each day from urban sewage systems in California. Since two kilograms
of PCS output per day are equivalent to one ton per year, outfalls of
9 sewage treatment plants discharging waste to the sea in California
were sampled in an effort to identify potential PCB sources. The
samples were all taken from sewage outfalls at sites closest to the
points of entry into the sea as shown in Figure 2.5-9. The highest
output was reported in Los Angeles County which is one of the most
industrialized areas in the state. Table 2.5-12 shows the PCB levels
identified in the samples collected.5
The only other available data were collected in early 1975 on
sludge as part of the California Compliance Monitoring Survey for
Chlorinated Hydrocarbons.6 The results obtained are listed
in Table 2.5-13.
Only one plant was sampled in both studies, the Hyperion Plant
in Los Angeles. The 1970 sludge samples had 78.5 and 98.1 ppb
concentrations while the 1975 readings ranged from 1,000-1,400 ppb.
-------
C- 114
SAN F°ANC'SCO,
JEPPOLD STREET
R!CUVOND
EAST BAY
\
\
\
\
\
\ .
\
\
\
\
\
\
OXNABD
-^^_ _
CITY OF LOS ANGELES, MVPERION }*S
OTV OF LOS ANGELES, TE°MINAL ISLAND
LOS ANGELES COUNT /,
WHITE POINT OU~FALL
0=>ANGE COUNTY,
PLANT NO, 2
SAN DIEGO •> . — —'•
FIGURE 2,5-3 LOCATIONS OF TREATMENT PLANTS SAMPLED, CALIFORNIA
-------
Table 2.5-12
PCB Compounds in Urban Sewage Outfalls in California - 1970
Sampling Station
Richmond
EBMUD East Bay Municipal Utility
District
San Francisco (Southeast Sewage
Treatment Plant)
Oxnard
Hyperion Waste Water (City of
Los Angeles) Sludge
White Point
Terminal Island
Orange County (plant $2)
San Diego
Description . Flow PCB Type
Serves most of Richmond including
one of the most heavily
industrialized re'gions of the
Bay Area. 21.5
Discharges primary treated waste
water and digested sludge into
San Francisco Bay. 155 1260
Serves the industrial area of
San Francisco. 31.5 1260
Serves Oxnard. 10.0
Mostly domestic sources. 340 1254
5 1254
Serves Long Beach, Torrance and
other heavily industrialized areas
of Los Angeles County. 350 1242, 1254
Serves Wilmington and Terminal
Island seas. Processes mostly
industrial waste. 9.3 1242
Serves most of Orange County. 130 1242-
Serves San Diego and surrounding
communities. 80
PCB ppb
N.D
3.1-3.8
3.8-5.8
N.D
0.16-0.37
78.5-92.1
76
5.8-12.8
0.21-0.64
PCB est.
kg/day
2.0
0.6
0.4
1.6
100
0.35
0.18
N.D
SOURCE: Schmidt, T.T., R.W. Rlsebrough and F. Gress, Bulletin of Environmental Contamination and Toxicology £,
235-243, (1971)
-------
C - 116
Table 2.5-13
PCB Levels in Sludge, California, 1975
Location
Description
Polychlorinated Biphenyls (ppm)
Aroclor Aroclor Aroclor
1254 1260 1242
Orange County
Sewage Treatment
Plant
Hyperion
Sewage Treatment
Plant
Fort Ord
Sewage Treatment
Plant
Fountain Valley
Digester Sludge
Los Angeles,
Digester Sludge
Secondary Digester
Sludge
1.0-1.4
0.2-0.4
38-40
Treasure Isle
Sewage Treatment
Plant
Travis Air Force
Base, Sewage Treat-
ment Plant
Mother Air
Force Base
McClellan
Air Force Base
Beale
Air Force Base
Sludge
Digester Sludge
Sacramento
Primary Digester
Sludge
Secondary Sludge
Primary Digester
0.4-0.6 —
0.6-0.8
0.4-0.6
4.5-5.5
0.3-0.5
SOURCE: Unpublished Data, USEPA National Field Investigation Center,
August 1975
-------
C- 117
REFERENCES, Section 2.5 '
1. Dube, D.J. Polychlorinated BIphenyls in Effluents from Sewage
Treatment Plants in Southeastern Wisconsin
2. Nadeau, R.J., and R.P. Davis, Investigation of Polychlorinated
Biphenyls in the Hudson River, USEPA Region II
3. Polychlorinated Biphenyls and the Environment, Interdepartmental
Task Force on PCB's, May 1972
4. Monitoring for Polychlorinated Biphenyls in the Aquatic Environ-
ment, Michigan Water Resources Commission, May 1973
5. Schmidt, T,T., R.W. Risebrough and F. Gress, Bulletin of Environ-
mental Contamination and Toxicology £, 235-243, (1971)
6. Unpublished Data, USEPA National Field Investigation Center,
August 1975
7. Unpublished Report, Contract 65-01-2978, USEPA, Office-of Toxic
Substances; July 1975
8. USEPA, Pesticide Monitoring Programs: Lake Michigan and Tributaries
in Illinois, EPA '600/3-74-002
9. Veith, G.D., and G.F. Lee, Water Research, 5_, 1107-1115, (1971)
-------
C- 118
2.6 Data from Localized Monitoring Efforts - Cities
2.6.1 Jacksonville, Florida
Samples of ambient air, water, soils and bottom sediments were
collected in the vicinity of Jacksonville, Florida, on September 10,
October 6-7 and November 20-21, 1975, for PCS analysis.1
Figure 1 illustrates the sampling locations in the Jacksonville
area. The outlined area on Figure 2.6-1 circumscribes a municipal
sewage sludge disposal site which has been used for the past several
years by the City of Jacksonville.
•AIR DATA
Air samples were collected at the fire station off Fort Caroline
Road using a high-volume sampler equipped with polyurethane foam as the
collection medium. Measured PCB concentrations are reported in Table 2.6-1
for the 24-hour period of November 20-21, 1975, The levels measured
throughout this period ranged from 4 to 9 ng/m , with the lowest levels
being observed during the early morning period. Chromatograms indicated
the presence of the lower substituted PCB components of Aroclors 1221
and 1016. Quantitation of the PCB levels was performed after perchlor-
ination to decachlorobiphenyl.
WATER, BOTTOM SEDIMENT AND SLUDGE DATA
The analytical data for. water, bottom sediment and sludge are sum-
marized in Table 2.6-2 for the sampling points shown on Figure 2.6-1. PCB
content of bottom sediments range from 10 to 572 ppb, surface water con-
centrations ranged from the analytical detection limit of 20 ppt to
285 ppt, expressed as decachlorobiphenyl. The highest sediment concen-
tration (572 ppb) was observed near the cooling water discharge of the
Jacksonville Electric Authority Southside Generating Station. This may
be related to use of PCB-containing materials at the generating station.
Intermediate conr.entrations were observed in sections of the St. John's
River which is surrounded by urban and industrial development. Drainage
creeks from the municipal sewage sludge landfill area had bottom sediments
of lower concentration. Inspection of gas chromatographic elution patterns
indicates the presence of Avoclor 1260 in these sediment samples.
A concentration level of 720 ppb was measured for fresh sludge taken
from the Monterey sewage treatment plant. Two-year-old sludge, taken
from the landfill area, had a concentration level of 119 ppb.
-------
URBAN
JACKSONVILLE
DOWNTOWN
GEN&^TING
STATIO
URBAN-RESIDENTIAL
012
MILES
STP) SEWAGE TREATMENT PLANT
FiniJRF?n-1 SITF MAP OF JACKSONVILLE I'lORIDA VICINITY SHOWING SAMP! F LOCATIONS.
-------
C -120
Table 2.6-1
PCB in Ambient Air in the Vicinity of Jacksonville, Florida
Date
Period
Concentration (ng/m )*
11/20/75
11/20/75
11/20/75
11/20/75
11/21/75
11/21/75
1200-1600
1200-1800
1800-2400
2000-2400
2400-0600
0600-1200
9
8
9
7
4
6
* Reported as decachlorobiphenyl.
Table 2.6-2
PCB Analysis of Environmental Samples
in the Jacksonville, Florida, Area.
Sample
Site
Sample
Type
Site Description
Concentration
(ppb)*
1 Sludge Monterey sewage treatment plant 720
2 Soil SW section of sludge landfill; 119
about two years old
3 Soil Air collection site 68
9 Sediment Unnamed Stream into Mill Cove 10
10 Sediment Ginhouse Creek 21
11 Sediment Arlington River Mouth ' 74
11 Water Arlington River Mouth 0.260
12 Sediment Generating Station Discharge 572
13 Sediment St. John's River 142
14 Sediment Trout River 167
14 Water Trout River 0.020
16 Water Jacksonville College Pier 0.285
17 Water St. Joseph's River 0.103
18 Water Broward River Mouth 0.020
*Reported as decachlorobiphenyl.
SOURCE: Unpublished Report. Contract 68-01-2978, Office of Toxic
Substances, EPA, December 1975.
-------
C -121
i
REFERENCES, Section 2.6 :
1. Unpublished Report. Contract 68-01-2978, Office of Toxic Substances,
EPA, December 1975.
-------
C-122
3~.0 Behavior of PCB's In the Environment
In general, PCS environmental movement is dependent on stability,
solubility and volatility. These properties will control their trans-
port via air, soil, water and/or sediment depending on the partition
coefficient in each phase.
General discussions on the thermal, photochemical and chemical
properties of PCB's have recently been published by Hutzinger, Safe
• and Zitko . Various transport mechanisms have received considerable
attention9'1*. Current air data indicates that the predominant movement
of PCB's in the atmosphere is not attached to particulates as is the
case with DDT, but rather as the free unbound molecular species.
Some of the complexities of the behavior of PCB's in the environment
include the following characteristics which are discussed in subsequent
sections: (a) the complexity of the composition of different Aroclor
products, (b) the difficulty in definition of water solubility and adsorp-
tion properties due to the complexity of the mixtures, and (c) the
variability of the volatilization process depending on the starting
mixture and point of release. By coupling these areas, the focus will
be on those PCB properties that influence environmental sample collection,
control their distribution in environmental samples and present potential
difficulties in environmental sampling.
3.1 Composition of Aroclor Products
PCB's have been manufactured in the United States by the Monsanto
Industrial Chemicals Company, and marketed under the trademark Aroclor
with a numerical designation3. Table 3-1 provides an overview of the
major Aroclors produced with their associated chlorine content. These
Aroclor products are mixtures of different isomers. A typical analysis
of the currently produced products and the associated chlorobiphenyl
composition is shown in Table 3-2. In addition, the number of potential
isomers making up the chlorobiphenyl component are also indicated. From
this chemical analysis, Aroclor 1221 can be considered primarily as a
monochlorobiphenyl and is the only Aroclor with a significant biphenyl
concentration; Aroclor 1016 and 1242 are primarily trichlorobiphenyls,
with the 1016 having a lower penta and hexa content than the 1242 pro-
duct; Aroclor 1254 is primarily a pentachlorobiphenyl product. The
composition of the different isomers could be quite different for each
product.
3.2 Water Solubility of PCB's
The water solubility of various Aroclor products and some chloro-
biphenyl isomers has been measured by different investigators. A
limited set of reported values are shown in Table 3-3. The solubility
for all three monochlorobiphenyl isomers is listed and range from 1190-
5900 ppb. The solubilities for all of the higher chlorobiphenyl isomers
have not been measured and only representative compounds are listed to
-------
C-123
show the range of values possible and the component solubilities for
Aroclor 1221? for the dichlorobiphenyls, the 2,4-, 2,2'-, 2,4'-, 4,4'-
dichloro isomer is listed out of a possible 12 isomers and range in
solubility from 80-1880 ppb; for the trichlorobiphenyls, only the
2,2',5-trichloro is listed out of a possible 24 isomers; for the te-
trachlorobiphenyls only the 2,2',5,5'-tetrachloro is listed out of a
possible 42 isomers. These values indicate that PCB's have low sol-
ubilities and the solubility decreases with the number of chlorine atoms
present in the isomer, i.e., the lower isomers containing chlorine show
the highest solubility. Factors that contribute to the variability of
the results include adsorption to particulate matter or wall surfaces
and the slow equilibration process.
Studies by Haque et. al.,3 show that equilibration of Aroclor 1254
in water required approximately two months to reach complete equilib-
rium, with the major portion being achieved in a week. These studies
also included various types of adsorbent surfaces ranging from sand to
highly organic soil samples. The adsorption increased strongly with
the organic content of the adsorbent studied. Starting with an original
concentration of Aroclor 1254 at 56 ppb, the addition of 100 grams of
sand or silica gel had very little effect on the final PCB concentration.
However, by adding a high organic content soil, the final PCB concentration
was reduced by approximately 85%.
Studies by Eichelberger1 on the behavior of PCB's in river water
over a 16 week period indicated that the levels of recovery of 10 ppb
spiked Aroclor 1242 .samples were 87, 76, 73, 60, 53 and 43 percent for
zero time, 1, 2, 4, 8. and 16 .weeks respectively. Losses were attributed
to irreversible adsorption on either' the walls of the sample container
or the silt contained in "the sample.
3.3 Interactions of PCB's with Soils
The behavior of PCB's in soil is a complex process dependent on a
number of factors which include surface properties and composition.
Soil composition can be identified by characterizing the percentage of
sand, silt, clay and organic carbon. Depending on the surface properties,
soils can act as an effective barrier to PCB migration in landfill sites
and as an effective sink to PCB's deposited via aerial fallout. Once
the PCB's are adsorbed, factors that would influence PCB movement are
leaching when water is added to the soil and re-evaporation under normal
atmospheric conditions.
In a series of experiments directed at understanding the leaching
properties for various soils that could be encountered at different land-
fill sites, different types of soils were studied10. These experiments
percolated water through a column packed with soil coated with Aroclor
1016 and monitored the effluent water. Breakthrough of the PCB's was
.found to be related to the clay content of the soil. Soils with the
higher clay content retained the PCB's. The isomer distribution in the
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C-
effluent reflected the different water solubility and adsorption properties
characteristic of the Aroclor 1016 isomers. The less chlorinated isomers
were more readily leached. Results from these experiments are shown in
Figure 3-1, where an Aroclor 1016 and 1221 standard solution is compared
with the leached mixture. A .32mm id x 50m glass capillary column
coated with OV-101 was used for these separations. The flow rate was
2 ml/min helium and the column temperature was programmed from 150° to
230°C at 2°C/min. The resulting isomer distribution is significantly
changed from the starting Aroclor 1016 and has a closer resemblance^ ..
to the isomer pattern of Aroclor 1221. In the worst case,-less-than-0.05Z
of the total Aroclor 1016 available was leached under conditions equivalent
to forty years of annual rainfall.
Adsorption and evaporation studies3 with Aroclor 1254 on different
soils show that due to the few adsorption sites in sand, sand surfaces
adsorb relatively small amounts when compared to the other types of soils.
Consequently the vaporization loss from a sand surface will be signifi-
cantly higher than soil surfaces where it is more tightly bound. The
less chlorinated isomers show a greater loss than those isomers of high
chlorine content.
3.4 Evaporation of PCB's from Water
The transfer of PCB's from water to the air environment may be
significantly faster than expected when considering that these compounds
have a high molecular" weight, low solubilities and low vapor pressures6'7.
On examination, these compounds exhibit very high activity coefficients
in aqueous solution resulting in high equilibrium vapor partial pressures
and consequently high evaporation rates. The rates are relatively insen-
sitive to temperature. For different Aroclor products, the evaporation
process is complex depending on the chlorobiphenyl isomecs present,
leading to different isomer concentrations in each phase with time. The
calculated half-lives for Aroclor 1242 and 1254 for a water depth of one
meter are 12.1 and 10.3 hours respectively. Using the half-life values,
if a monitoring station is located one hour downstream from a source of
Aroclor 1242, by the time' the water reaches the station, approximately
one twentieth of the initial levels may have been evaporated. Where the
water body is turbulent, the evaporation rate will be increased signifi-
cantly.
3.5 Environmental Sampling Guidelines
Based on these limited studies, the following guidelines and-
precautions are suggested:
(1) laboratory measurements of field samples should be made as
soon as possible;
(2) concentration levels of field samples measured in the laboratory
will be lower than actual concentrations;
(3) concentration levels in water may be much lower in some areas
depending on the type of suspended particulate matter;
(4) samples collected at plant outfalls will be non-equilibrium
samples;
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C -125
4 ' AROCLOR 1016STDSOLN
PCBs FROM RAY SILTY LOAM
1AROCLOR 1221 STD SOLN
I I I I I
0 1 ,2 3 4 5 6 7 8 MINUTES
SOURCE: MIEURE, J.P., 0. HICKS, R.G. KALEY AND V.W. SAEGER, "CHARACTERIZATION
OF POLYCHLORINATED BIPHENYLS," NATIONAL CONFERENCE ON
POIYCHLORINATED BIPHENYLS, CHICAGO, ILL., NOVEMBER 19-21, 1975
iFIGURE3-1
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C- 126
(5) sampling methods should be employed which reduce the problem of
irreversible adsorption on container walls;
' (6) soil samples will have an enriched high chlorobiphenyl isomer
concentration;
(7) leached water and air samples will have an enriched lower
chlorobiphenyl isomer concentration;
(8) true identification of the specific Aroclor released into the
environment becomes more difficult with time.
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Table 3-1
AROCLOR PRODUCTS
Produced by Monsanto
C- 127
Currently in Production
Discontinued
Percent Chlorine
1221
1016
1242
1254
1232
1248
1260
1262
1268
21
32
41
42
48
54
60
62
68
Table 3-2
COMPOSITION OF SOME AROCLORS
Chlorobiphenyl Number of
Chlorobiphenyl Percent Distribution
of some Aroclors
Composition
C12H10
C12H9C1
C12H8C12
C12H7C13
C12H6C14
C12H5C15
C12H4C16
C12H3C1?
C12H2C18
Isomers
3
12
24
42
46
42
24
12
1221
• 11
51
32
4
2
<0.5
ND
ND
ND
1016
<0.1
1
20
57
21
1
<0.1
ND
ND
1242
<0.1
1
16
49
25
8
1
<0.1
ND
1254
<0.1
<0. 1
<0.5
1
21
48
23.
,6
ND
ND - None detected, <0.1%
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C- 128
Table 3-3
SOLUBILITY OF AROCLORS AND CHLOROBIPHENYLS IN WATER
Aroclor Products
Solubility (ppb) Media
.1016 225-250
1221 200
1242 200
1254 . - 300-3000
1254 300-1500
1254 50
1254 ,56
1254 40
Chlorobiphenyl Compounds
2-chlorobiphenyl* 5900
3-chlorobiphenyl 3500
4-chlorobiphenyl* 1190
2,4-dichlorobiphenyl 1400
2,4-dichlorobiphenyl 637
2,2'-dichlorobiphenyl* 1500
2,4'-dichlorobiphenyl* 1880
4,4'-dichlorobiphenyl* 80
2,2',5-trichlorobiphenyl 248
2,2',5,5'-tetrachlorobiphenyl 46
2,2',5,5'-tetrachlorobiphenyl 26
distilled water
distilled water
distilled water
fresh water
salt water
distilled water
distilled water
distilled water
References
10
8
9
12
12
9
3
8
5
5
5
5
2
5
5
5
2
11
2
*These are the major chlorobiphenyl compounds in Aroclor 1221; the other major
constituent is biphenyl which has a solubility in water of 4600 ppb.
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C -129
REFERENCES, Section 3.0
1. Eichelberger, J., unpublished data.
2. Haque, R., and D.W. Schmedding, Bull. Environ. Contamin. Toxicol.
14, 13 (1975).
3. Haque, R., D.W. Schmedding and V.H. Freed, Environ. Sci. Technol.
8., 139 (1974).
4. Harvey, G.R., and W. G. Steinhauer, Atmospheric Environment, 8_,
777 (1974).
5. Hutzinger, 0., S. Safe and V. Zitko, "The Chemistry of PCB's,"
CRC Press, Cleveland, Ohio (1974).
6. Mackay, D., and P.J. Leinonen, Environ. Sci. Technol. £, 1178
(1975).
7. Mackay, D. , and A."J. Wolkoff, Environ. Sci. Technol., 2.» 611 (1973),
8. Mieure, J.P., 0. Hicks, R.G. Kaley and V.W. Saeger, "Characteriza-
tion of polychlorinatecl Biphenyls,'' National Conference on
Polychlorinated Biphenyls, Chicago, 111., November 19-21, 19T5.
9. Nisbet, C.T., and A.B. Sarofin, Environ. Health Perspec. _!, 21
(1972).
10. Tucker, E.W., W.J. Litschgi and W.M. Mees, Bull. Environ. Contam.
Toxicol., 13, 86 (1975).
11. Wallnofer, P.R., N. Koniger and 0. Hutzinger, Analab Res. Notes
33, 14 (1973).
12. Zitko, V., Bull. Environ. Contam. Toxicol. 5, 279 (1970).
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C -130
Occurrence of PCB's in Food
Some of the earliest findings of PCB's in foods occurred during
the fall of 1969 in coho salmon and milk from West Virignia which was
traced back to the misuse of a transformer fluid containing PCB's for
defoliant spraying adjacent to dairy pasturage. In 1971 PCB's were
found in poultry from North Carolina. Contaminated fish meal was
implicated as the causative agent. The contamination was traced back
to a leak in heat exchange equipment using PCB's. The fish meal
samples examined contained from 14 to 30 ppm of PCB's. Followup
sampling of eggs showed that 71 of 224 eggs contained residues in
excess of 0.5 ppm ranging from 0.6 to 4.2 ppm.3
The Food and Drug Administration conducts a comprehensive food
Surveillance program yearly to determine pesticide residues, PCB's,
heavy metals and other contaminants in the dietary intake of consumers
in the United States and to target emerging problems and trends. The
FDA has analyzed all raw agricultural commodities sampled under the
pesticide surveillance program for PCB's since 1969. PCB's have
been encountered most frequently in fish, both freshwater (catfish,
chub, and smelt) and saltwater (porgies, sea trout, bonita and sardines),
with trace levels in shellfish. Table 4-1 presents the results of
this program from July 1970 to September 1971.3
As a result of these findings FDA proposed certain regulations for
PCB concentrations in foods in 1972. These temporary tolerances are:
Commodity PCB Concentration (ppm)
Milk (fat basis) 2.5
Dairy Products (fat basiu) 2.5
Poultry (fat basis) 5.0
Eggs 0.5
Finished Animal Feed 0.2
Animal Feed Components 2.0
Fish (edible -portion) 5.0
Infant and Junior Foods 0.2
Of these commodit-'es, fish is the only food primarily contaminated by
the environment (waterways). The other commodities were contaminated
by industrial and agricultural uses.
In FY 73 and 74 Comprehensive Fish Surveys were carried out. While
the data are valuable in showing which species and which areas are apt
to be of concern, the diversity of the fish sources and reasons for
collecting them make it difficult to determine if there have been any
trends. In the FY 73 program no PCB's were detected in 70" of the
samples; 3% contained over 1 ppm while only 0.5" had over 5 ppm of
PCB's. Those over 1 ppm were generally fresh water fish or those apt
to be near the shore. Carp were the only fish over 5 ppm with a high
of 20.5 ppm. The FY 74 survey, which was not carried to completion,
showed no PCB's in over 80™ of the samples analyzed and no samples
contained more than 2 ppm.2
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C -131
The total diet studies for FY 70 and FY 71 showed composite
samples containing PCB residues up to 0.36 ppm. The positive readings
were found in meat, fish, poultry, dairy and the grain and cereal
composites. The 0.36 ppm value was found to be caused by migration
of PCB's from the grayboard container and dividers to packaged shredded
wheat.3
The FY 73 study included thirty market basket samples from
representative areas of the United States consisting of the total
14-day diet of a 15-20 year old male in the region of collection
including about 117 individual food items.1
These 117 food items are separated after any necessary preparation
into twelve food group composites for analysis:
I Dairy Products
II Meat, Fish and Poultry
III Grain and Cereal Products
IV Potatoes
V Leafy Vegetables
VI Legume Vegetables
VII . Root Vegetables
VIII Garden Fruits
IX Fruits
X Oils, Fats and Shortening
XI Sugar and Adjuncts
XII Beverages (including drinking water)
Most of the PCB levels identified in 1973 were trace amounts
resulting in a daily'intake of only 1 yg/day. The most frequent
occurrences were in the meat-fish-poultry and grain-cereal products
groups with 33% and 17% positive analyses. It has been suggested
that environmental contamination may be the source in the first group
and lingering recycled paper contamination in the second group.
Of 30 composites examined for each commodity group PCB residues
were only determined in five of the groups as follows:
Group Frequency
Dairy Products 3
Meat, Fish and Poultry 10
Grain and Cereal Products 5
Potatoes .1
Oils, Fats and Shortening 1
The range for all 20 positives was trace to 0.073 ppm. In fact 19
of the 20 readings were only trace amounts with the 0.073 ppm composite
appearing in the Grain and Cereal Products group.1
Data for 1974 show that there were positive readings in only two
food groups: sugar and adjuncts; and meat, fish and poultry. While
only 3% of the samples in the first group were positive, 43% of those
in the meat, fish and poultry group were positive. The fish components
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C -132
of these samples were usually the source of the contamination. Preliminary
information indicated that the range of levels measured was trace
to 0.05 ppm. Data for the first half of 1975 have found 40% of the meat,
fish and poultry group to show positive readings for PCB's with no
positives in other food group.
Using the preceding information the FDA has estimated the average
daily intake from all twelve food group composites and the average daily
intake from the meat fish and poultry food class as presented in Table 4-2.
For those levels which were reported as trace the assumption was made
to average them at 1/2 the quantitative lower level of detection; i.e.,
0.025 ppm. It can be seen that there has been a decrease in the.estimated
total intake. This intake should level out and continue at the 1975
level as long as fish remain almost the sole source of PCB's and the
entry of PCB's into waterways is not decreased.2
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C-133
Table 4-1
PCB Residues in Selected Food Commodities
July 1970 - September 1971
Number of Number of
samples samples Percent PCB levels, Average
examined positive positive Low (ppm) high fppm)
Fish 670 363 54 T 35.29 1.87
Cheese 1344 91 6 T 1.0 .25
Milk 9^1 69 7 T 27.8 2.27
Shell eggs 550 161 29 T 3.74 .55
Fish by-products 13 — T 5.0 1.17
Total (excluding
fish by-product)3505 684 19 1.14
SOURCE: Kolbye, A.D. , Jr., Environmental Health Perspectives,
85-88, April 1972.
Table 4-2
Estimates of Daily PCB Intakes
Total Diet Study
Average Daily Intake of PCB"5
Tot a:
Fiscal Year
1971
1972
1973
1974
1975 (1st half)
SOURCE: Jelinek, D.F. and P.E. Corneliussen, National Conference
on Polychlorinated Biphenyls, November 1975.
Total Diet
(ug/day)
15.0
12.6
13.1
8.8
8.7
Meat-Fish-Poultry
Food Class (ug day)
9.5
9.1
8.7
8.8
8.7
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C - 134
REFERENCES, Section 4
1. Food and Drug Administration, Compliance Program Evaluation,
Total Diet Studies: FY 1973, Bureau of Foods, January 9, 1975.
2. Jelinek, C.F. and P.E. Corneliussen, National Conference on
Polychlorinated Biphenyls, November 1975.
3. Kolbye, A.C., Jr., Environmental Health Perspectives, 85-88, April 1972.
4. Unpublished Data, Food and Drug Administration.
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C- 135
5.0 Exposure and Biological Accumulation of PCB's In Man
5.1 National Monitoring Programs
The National Human Monitoring Program for Pesticides is conducted
by the Office of Pesticide Programs, EPA. Small samples of adipose
tissue from postmortem examinations and from specimens submitted
for pathological examination during therapeutic surgery are collected
and analyzed for the presence of chlorinated hydrocarbon insecticides. '
Analysis for PCB's was begun in 1968. Summaries of the data from 1971
are reported in Table 5.1-1 and from 1972 to 1974 in Table 5.1-2.
Note that although classes are different in the two sets of results,
the proportion of samples showing traces of PCB's is increasing: 50.7%,
1971; 73.99%, 1972; 75.49%, 1973; 90.93%, 1974. The increase between
1973 and 1974 is dramatic. However, the percentage of tissues which
contained quantifiable- (greater than 1.0 ppm) of PCBs appears to be re-
maining relatively constant (31.1%, 58.53%, 35.08%, 40.30%, 1971-74).
5.2 Localized Studies
There have been several localized studies showing the presence
of PCB's in both human plasma and milk. A 1968 study in Charleston
County, South Carolina3, reported that of 612 plasma samples
collected from healthy volunteers, 45% showed some PC3 residue. Levels
ranged to a maximum of 29 ppb with a mean plasma residue of 2.12 ppb.
This study also tested for the significance of several factors
on PCS levels, concluding only that residues were more frequent and
higher in whites- and urban residents. A follow-up study conducted
in 19721 in the Charleston area sampled plasma and scalp hair
specimens from 37 refuse burners and 54 controls. PCB residues were
not detected in hair samples, but 81% of the refuse burners (compared
with only 11% of the controls) had detectable PCB residues in plasma.
Median levels for those with detectable amounts in plasma were 2.6 ppb
for the refuse workers and 3.7 ppb for the controls, with maximums
of 14.1 ppb and 20.2 respectively.
A 1971-72 study6-of 40 human milk samples in Colorado discovered
PCB residues in 20% of the samples in ranges from 40 to 100 ppb. A
1971 study of 47 lactating women in Texas reported an absence of PCB
'residues both in milk from all subjects and in serum from 28 subjects.
A minor study of blood samples from nine cachectic patients and 15
healthy nonpatients from Missouri and surrounding states'* reported
detectable PCB residues in all patients (mean 48 ppb, range 10-100 ppb)
and none detectable in the nonpatients. No conclusions were drawn.
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Table 5.1-1
PCS Concentrations in Human Adipose Tissue, 1971
C-136
Absent Trace to Below 1 ppm 1-2 ppm
Sample Size Number % Number * Number
637
314
49.3 125
19.6
2 ppm
Number %
165 25.9 33
5.2
SOURCE: Yobs, Anne R., Environmental Health Perspectives, 1_, 79-81
April 1972.
Table 5.1-2
PCS Concentrations in Human Adipose Tissue, 1972-1974
Sample Size
1972 4102
1973 1277
1974 1047
Absent
Number "
1067 26.01
313 24.51
95 9.07
Below 1 ppm
Number "
634 15.46
513 4Q.17
530 50.62
1-3 ppm
Number "
2079 50.68
378 29.60
371 35.43
73 ppm
Number "
322 7.85
^0 5.48
51 4.87
SOURCE: Kutz, F.W., Pro'ject Officer, National Human Monitoring Program
for Pesticides, Office of Pesticides Programs, U.S. EPA,
Washington, DC.
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C- 137
REFERENCES, Section 5
1. Bumgarner, J.E., D.I. Hammer, A.V. Colucci, J.P. Creason and
J.F. Flnklea, 1973, Polychlorinated Biphenyls Residues in Refuse
Workers, Bioenvironmental Laboratory Branch, Human Studies
Laboratory, National Environmental Research Center, Research
Triangle Park, North Carolina, unpublished report dated June 26,
1973.
2. Dyment, P.G., L.M. Hebertson, E.D. Gomes, J.S. Wiseman and
R.W. Hornabrook, Bulletin of Environmental Contaminants and Toxicology,
512-53A, (1971)
3. Finklea, J., L.E. Priester, J.P. Creason, T. Hauser, T. Hinners,
and D.J. Hammer, Annual Journal of Public Health, 62, 6^5-651, (1972).
A. Hesselberg, R.J. and D.D. Scherr, 1974, Bulletin of Environmental
Contamination and Toxicology, 11, 202-205, (1974)
5. Kutz, F.W., Project Officer, National Human Monitoring P_ogram
for Pesticides, Office of Pesticides Programs, U.S. EPA, Washington,
DC.
6. Savage, E.P., J.D. Tessari, J.W. Malberg, H.W. Wheeler and
J.R. Bagby, Pesticides Monitoring Journal, 7.» 1-3» June 1973
7. Yobs, Anne R., Environmental Health Perspectives, _!, 79-81, April
1972
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C -13)
6.0 Environmental Trends
There are few data bases or environmental studies which provide
an adequate basis for sound analytic determinations of national trends
in environmental levels of PCB's. Such a data base would be a result
of a system of studies involving consistent sampling across media,
i.e., statistical samples taken at the same locations at representative
time periods, analyzed according to standard protocols, taken over
a period of time long enough to establish a trend. Some studies
do show consistent sampling within specific media, e.g., the Great
Lakes Environmental Contaminant Survey, but the literature is full
of snapshot studies with neither predecessor nor successor, and
baseline studies which have not been followed by any further work.
Thus, whether due to funding, modification of priorities or perso-mel
changes, long-term consistency and coordination have not been achieved.
As,a result, the conclusions drawn in this section represent qualitative
Judgements drawn from the large mass of generally uncoordinated
PCS studies analyzed.
Eves recognizing all the faults of the available data base, the
sheer mass of data supports the conclusion that there is widespread
contamination of the environment b^ PCB's. There are regional variations,
but effects are consistent across all media (e.g., water, sediment',
fish, birds), generally showing greater concentrations of PCB's in
highly developed areas and in areas of industrial activity. Over the
past five years of increasing recognition of and attention to the
problems of PCB's, the situation has shown no improvement nationally.
Conscious efforts have, however, resulted in substantial improvement
in some localized instances.
PCB contamination of the nation's waterways was termed widespread
by the USGS over the period 1971-1972; more recent data from the USGS
up to 1975 has shown no reduction in either levels or in geographical
dispersion. Although sampling stations in the USGS data base are not
expected to be representative of the U.S. and the data suffers from
multiple observations at some stations and spot readings at others, over
the period 1971-1975 states which had reported PCB's in sediment continued
to do so while six of the 23 states which had shown no contaminated
samples in 1973 did report some contamination in 1974. Sediment
concentrations are imperfect indicators of current contamination
levels and whole water measurements would be better. However, the
currently practiced analytical protocol for water measurements, which
limits detectability to 0.1 ppv» leads to a preponderance of zero
readings in whole water which mask the very real problem of PCB con-
tamination in the nation's waters. In almost all cases in which
samples of both whole water and bottom sediment were taken simultane-
ously and the sediment had a non-zero PCB level, concentration in
the water was reported as zero ppb. This occurred even when the con-
centration in bottom sediment was as high as 4000 parts per billion!
Were water measurements to be taken at the parts per trillion level
as some recent studies have done, whole water readings would certainly
show PCB contamination, to an extent similar to that shown by sediment
readings.
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C -139
The results of the U.S. Fish and Wildlife Service's fish monitoring
activities show that stations which have reported high concentrations
in the past continue to do so, and that the higher concentrations are
associated with river systems having significant industrial activity.
Such results are consistent with those for water and sediment from
the USGS water quality file. The fish data, however, shows a decline
in both the proportion of composites with some PCB residues and the
proportion with residues in excess of 0.5 ppm in the 1970-73 sampling
program. Levels of detection are generally lower in 1973 than in previous
years. While there are cautionary notes (see section 2.1.5), some
improvement in PCB contamination appears evident, although mostly
at those stations with prior low contamination levels.
Water is recognized as being a major sink and transport mechanism
for PCB's and, therefore, residue levels in water and fish are signi-
ficant. Yet other media confirm the stability and breadth of contamina-
tion over the nation. Data on human adipose tissue show a steady
climb over the years 1971-74 in the percent showing traces of PCB's.
Soil monitoring shows that sixty percent, i.e., 3 of 5 cities sampled
each year since the National Soils Monitoring Program smarted have had
at least one positive PCB sample. Bird monitoring conducted as part
of the U.S. Bureau of Fish and Wildlife's portion of the National
Pesticides Monitoring .Program shows residue levels in black ducks..
and mallards increasing between 1969 and 1972 in the Atlantic and
Mississippi flyways and slightly decreasing in the Central and Pacific
Flyways. PCB residues in starlings for 1970, 1972 and 1974 appear to
be decreasing, yet PCB residues have been found in all samples each
year, underscoring the ubiquitous nature of PCB's throughout the country.
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C -
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO. 2.
EPA - 560/7-76-001
4. TITLE AND SUBTITLE
Review of PCB Levels in the Environment
7. AUTHORisi Doris J. Finlay
Frederick H.. Siff
Vincent J. DeCarlo
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Office of Toxic Substances
Environmental Protection Agency
Washington, DC 20460
12. SPONSORING AGENCY NAME AND ADDRESS
15. SUPPLEMENTARY NOTES
3. RECIPIENT'S ACCESSION' NO.
5. REPORT DATE
January, 1976 (preparation)
6. PERFORMING ORGANIZATION CODE
8. PERFORMING ORGANIZATION REPORT NO.
10. PROGRAM ELEMENT NO.
2LA328
11. CONTRACT/GRANT NO.
N/A
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
16. ABSTRACT
Review of the current PCB data base to assess the PCS levels in the environ-
ment on a national level; the full spectrum of PCB levels reported in man and
the environment were of interest. P-ita were obtained from a number of nattional
monitoring programs, the literature and many unpublished reports up to
December 1, 1975.
17. KEY WOrlDS AND DOCUMENT ANALYSIS
a. DESCRIPTORS b.lDENTIFI
Polychlorinated Biphenyls (PCB's)
Water Great Lakes Behavior
Sediment Human
Soil Marine
Air Industrial Plants
Fish . Sewage Treatment Plants
Birds Food
18. DISTRIBUTION STATEMENT 19. SECURI
unclas
Release Unlimited . ab'.'sEcuRi
unclas
ERS/OPEN ENDED TERMS C. ' COSATI Field/Group
TY CLASS (This Report) 21. NO. OF PAGES
isified 143
TY CLASS (Tills page) 22. PRICE
jsified
EPA Form 2220-1 i».73)
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D-l
APPENDIX D
REVIEW OF CARCINOGENIC AND CO-CARCINOGENIC EFFECTS OF PCBs
D.I. The Experiment of Kimbrough et al. (266) on Female Sherman
Rats.
This experiment followed a sequence of studies of the effects
of PCBs on rats involving exposures lasting up to one year (179, 187,
189, 208). The results of these studies have been summarized in
Sections III.9.1 and III.10.8 above, and were further summarized
by Kimbrough (5) as follows:
Dietary exposure of rats to the PCB's produces
enlargement of the liver cells in some adult rats at a
dietary level of 5 ppm (0.4 mg/kg/day) (ref. 3). Liver
weights were increased in 21-day-old FI male weanlings
when the dams were fed as little as 1 ppm of Aroclor
1254 (ref. 2). At a dietary level of 20 ppm or above of
Aroclor 1254 or 1260, which is equivalent to a dietary
intake of 1.5 mg/kg/body weight per day, for an ex-
tended period of time, the hepatocytes in many rats had
foamy cytoplasm consistent with lipid accumulation. In
addition, hyperchromatic nuclei and binucleation was
observed in many liver cells. Inclusions were present in
the cyptoplasm of the liver cells. These inclusions on
electron microscopic examination were consistent with
concentrically arranged membranes surrounding lipid
vacuoles. Other ultrastructural changes observed at this
, and higher dietary levels in rats consisted of an increase
in smooth endoplasmic reticulum and atypical myto-
chondria. These ultrastructural changes have also been
described in primates (ref. 4) and are known to occur
with a number of other xenobiotics. Similar observations
were made in a study with smaller numbers of animals
where the rats were fed Aroclor 1242 and Aroclor 1016
(ref. 5).
A brown pigment representing ceroid pigment and
uroporphyrin was observed in Kupffer cells and macro-
phages. Particularly at higher dietary levels, livers
-------
D-2
showed pink fluorescence under UV lights.
In addition, exposure of rats and mice to PCB's for
6 months or longer produced grayish white lesions in the
liver. On microscopic examination, these lesions con-
sisted of proliferation of glandular epithelial cells that
formed ducts and were surrounded by very pronounced
fibrosis (refs. 6,7). The ducts often contained cellular
debris. This lesion, called adenofibrosis, was first de-
scribed by Edwards and White (ref. 6) in rats fed the
carcinogen butter yellow (P-dimethylaminoazobenzene).
When rats were exposed for 6 months to a dietary
intake of 500 ppm Aroclor 1254 and then sacrificed first
at monthly and then at bimonthly intervals, the adeno-
fibrosis persisted through a 10-month observation
period. Usually adenofibrosis in rodents occurs con-
comitantly with hepatocellular carcinomas and/or neo-
plastic nodules (hyperplastic nodules). This was true for
the Balb/cJ mouse (ref. 7). •
[kefs. 3-7 in this passage are the same as refs.
179, 267, 208, 268 and 189 respectively in this
document .1
In this experiment (266) 400 weanling Sherman strain COBS
female rats 21-26 days old were divided at random into two groups:
200 were maintained as controls and 200 were fed ad libitum a diet
containing a nominal concentration of 100 ppm Aroclor 1260 (Lot No.
AK-3, which contains 0.8 ppm of PCDFs, according to ref. 32).
Measured concentrations of PCBs ranged from 70-107 ppm in the treated
diet and less than 0.1 ppm in the control diet. Aflatoxins were not
detectable in either diet. Based on measured food consumption, in-
take of PCBs declined from 11.6 mg/kg/day during the first week of
exposure to 6.1 mg/kg/day at 3 months of exposure and to 4.3 mg/kg/
day at 20 months (see Text-Figure 2 below). Exposure was continued
-------
D-3
until the animals were 21.5 months old; after six weeks on an un-
contaminated diet (i.e., at the age of 23 months) all surviving
animals were killed and autopsied. Although the treated rats grew
significantly more slowly than the controls (Text-Figure 1 below),
survival was good in both groups (173/200 controls, 179/200 treated)
The pathological findings were reported and discussed by the
authors as follows:
Pathologic Findings
Control rats (173) and experimental animals (184)
were examined grossly and microscopically. The experi-
mental group included 5 rats that were killed 1-2
months before the final kill. The remaining animals
500-1
400-
.E 300-
o>
'5
>,
T3
O
CD
200-
100-
Control
—^ 100 ppm Aroclor 1260
1 2 3 4 5 6 7 8 9 1011 1213 14 15 1617 18192021 222324
Months
TEXT-FIGURE 1.—Average body weight of control rats and those con-
suming Aroclor 12CO.
-------
D-4
120
110
100
!•«
c 60
i-
40
30
20
Control
100 ppm Aroclor 1260
1 2 3 4 5 6 7 8 9 1011 1213 1415161718192021222324
Months
TEXT-FIGURE 2.—Food intake of control and experimental rats and
consumption of Aroclor 1260 by experimental rats.
were not included because of improper tissue fixation or
because they died early in the experiment.
A consistent difference in the appearance of the livers
was observed between the experimental and control
groups. Almost all (170/184) livers of the experimental
animals had from a few to multiple elevated tan nod-
ules on the surfaces; additional nodules were usually
seen on sectioning. These nodules varied from 0.1 to
several cm in diameter, and in some rats replaced almost
the entire liver. In contrast, the liver of only one con-
trol showed gross abnormalities and was markedly en-
larged, nodular, tan, and firm. In addition, a variety of
tumors of other organs was observed in both the experi-
mental and the control groups. The incidence and type
of tumors are given in table 1.
Histologic examination showed that 26 experimental
animals and 1 control with enlarged, nodular livers had
hepatocellular carcinomas. The additional 144 experi-
mental rats with gross liver nodularity had hepatocellu-
lar nodules characteristic of neoplastic nodules [syn-
onym, "hyperplastic nodules" (9)]. A recent workshop
sponsored by The National Cancer Institute" recom-
mended the term "neoplastic nodules" for these lesions
as a more accurate indication of their biologic signifi-
cance. No nodules were in control animals.
-------
D-5
The hepatocellular carcinomas were well-differen-
tiated trabecular types (figs. 1-3), except for three in the
experimental animals which had a glandular, papillary
pattern (fig. 4). The trabecular tumors showed severe
disruption of normal liver architecture and were usually
easily recognized at low magnification. Liver plates, two
or more cells thick in some areas, were arranged in hap-
hazard linear, branching, or pseudoglandular patterns.
Different patterns were usually present in the same
tumor. Blunt-ended plates, sinusoidal ectasia, and
congestion were frequent. The hepatocytes varied from
a normal appearance to enlarged, acidophilic, or dif-
fusely basophilic cells with large, hyperchromatic nuclei
and prominent nucleoli. The cytoplasm often contained
eosinophilic inclusions within vacuoles. Mitotic figures
were sometimes present. Foci of coagulative necrosis
were occasionally observed in cancerous areas, but there
TABLE 1.—Incidence and type oj liver lesions and
tumors of other organs examined hislologically
Organ or
tissue
Liver
Thyroid gland
Adrenal gland
Pituitary" gland
Uterus
Urinary bladder
Mammary
gland
Salivary gland
Lung
Adipose tissue
Brain
Ovary
Hematopoietic
system
Kidney
Thymus
Parathyroid
gland
Skin
Type of lesion
Hepatocellular
carcinoma
Neoplastic nodules
Foci or areas of cyto-
plasmic alteration
Parafollicular cell tumor
Pheochromocytoma
Chromophobe adenoma
Carcinoma
Endometrial polyp
Adenocarcinoma
Sarcoma of endometrial
stroma
Transitional cell
papilloma
Fibroadenoma
Adenocarcinoma
Fibrosarcoma
Adenoma
Lipoma
Glioma
Granulosa theca cell
tumor
Papillary adenoma
Granulocytic leukemia
Lymphoma
Hemangioma
Thymoma
Adenoma
Fibroma
Incidence
Controls
1/173
0/173
28/173
37/160
1/173
41/153
0/153
18/149
0/149
3/149
1/167
17/173"
5/173"
1/173°
2/173
0/173"
0/173
5/149
1/149
1/173
0/173
0/173
1/173"
0/173
0/173"
Experi-
mental
26/184
144/184
182/184
18/166
1/167
28/139
1/139
25/163
2/163
7/163
0/169
13/184"
1/184"
0/184°
2/184
2/184"
2/184
0/163
2/163
0/184
2/184
1/184
0/184"
2/184
1/184"
• Incidence b&aed on groaa detection with microscopic confirmation.
-------
D-6
was no fibrosis or other evidence of chronic degenerative
changes. Periodic acid-Schiff (PAS) without diastase
stained carcinomas less intensely than uninvolved liver,
which suggested a decrease in glycogen. Most carcinomas
were more basophilic than the normal liver with azure
eosin stain. No definite intravascular invasion or metas-
tases were found.
Neoplastic nodules were generally spherical and well
demarcated, and occupied areas equal to those of several
liver lobules (fig. 5). The cells in these nodules were gen-
erally enlarged, and the cytoplasm was either ground-
glass-appearing, diffusely basophilic, or clear. Enlarged
hyperchromatic nuclei, double nuclei, and mitotic fig-
ures were often present. The cytoplasm frequently con-
tained inclusions similar to those in the carcinomas, ex-
cept they were larger and appeared as whorled,
concentric lamellae. In previous studies (5) these forma-
tions were.shown by electron microscopy to represent ag-
gregates of smooth endoplasmic reticulum. The normal
liver architecture was absent within nodules, and cells
were in sheets or irregular plates. Portal areas and cen-
tral veins were absent and sinusoids were dilated in
some areas. At the periphery of the nodules, the sur-
rounding liver plates were tangentially arranged and
- narrowed, due to compression (figs. 6, 7). Nodules varied
in PAS positivity, but always differed from surrounding
liver. Most nodules were more eosinophilic, and a few
were more basophilic than the normal liver with azure
eosin stain.
In 182 treated and 28 control animals, there were also
foci or areas of hepatocytes with altered cytoplasm (figs.
8-10). In controls, these were mostly collections of cells
with water-clear cytoplasm. In treated animals, most af-
fected cells were enlarged and had eosinophilic, ground-
glass-appearing cytoplasm or were diffusely baser*:'.: lie
and smaller than normal cells. In basophilic areas, binu-
soids were dilated and liver plates somewhat tortuous.
In general, the cells in these areas were like those in
neoplastic nodules, but there were no architectural alter-
ations, and plates of involved liver cells merged with the
• surrounding liver.
No unusual features were noted in tumors of other or-
gans, and there were no apparent differences in inci-
dence between experimental and control animals.
Parafollicular thyroid tumors varied from small circum-
scribed nodules of pale, oval-to-spindle cells to masses
that obliterated the gland and invaded the capsule.
They were similar to those described by Boorman et al.
(10). Other frequent tumors included pituitary chromo-
phobe adenomas, mammary fibroadenomas, and endome-
trial polyps. Endometrial stromal sarcomas were also
present in 10 animals.
-------
D-7
The only bladder tumor observed was in a control an-
imal. Therefore, the occurrence of the bladder tumor in
the previous experiment was apparently unrelated to the
ingestion o£ Aroclor 1260,
A few rats in the experimental group also showed
areas of adenofibrosis (synonym, "cholangiofibrosis") of
the liver, a lesion described previously following the ad-
ministration of Aroclor 1260 (4).
DISCUSSION
The livers of treated animals showed neoplastic le-
sions in 170 of the 184 examined, and in only 1 of 173
controls. Although only 26 of the lesions in treated rats
were clearly carcinomas according to traditional histo-
logic criteria, neoplastic nodules are part of the spec-
trum of response to hepatocarcinogens and must be in-
cluded in the evaluation of tumorigenesis.
In the past, these liver lesions have been interpreted
in various ways, and different names have been used to
report them: nodular hyperplasia, hyperplastic nodules
(/)), hepatomas (12, 13), and hepatic nodules (14). Simi-
lar ambiguity exists in the classification of human liver
lesions of this type (15).
Several studies with known carcinogens have demon-
strated the development of liver nodules, indistin-
guishable from the neoplastic nodules in this study, be-
fore the appearance of carcinoma (//, 16-18). In a
recent review (9), the biology and significance of nodules
and their relationship to hepatoeellular carcinoma were
thoroughly discussed, In our study, Aroclor 1260 in-
duced a spectrum of nodules and cancers in treated ani-
mals as outlined by the Rat Liver Tumor Workshop."
» Rat Liver Tumor Workshop at Silver Spring, Md., D«c I1-1J,
197-1; sponsored by Carcinogenstis, Division of Cancer Cause and
Prevention, National Cancer Institute.
Comments. This was a well-designed and well-conducted study,
deviating from recommended protocols in only one respect: its limi-
tation to female rats. (In earlier studies by the same authors, males
appeared as sensitive or more sensitive than females to 100 ppm Aro-
clor 1260, as measured by the degree of increase in liver weight —
Tables III.9.2 and III.9.3).Two other limitations may be noted; (a)
the rats were not exposed prior to weaning, although the authors'
-------
D-8
own studies (Table III.9.3) had indicated that rats exposed to PCBs
during gestation and nursing show early liver changes at much lower
dietary levels; (b) the rats were killed at 23 months, relatively
early in comparison to the 26-30 month expected life span. Each of
these design features of the experiment, although common practice in
carcinogenesis bioassays, is likely to have reduced its sensitivity
in demonstrating carcinogenic effects; the early termination is likely
to have arrested tumors at a relatively early stage of development.
Survival of the rats was very good; the only gross indication
of toxic effects was the reduced growth rate, although Aroclor 1260
is known to have other physiological and biochemical effects in rats
at 100 ppm. The liver tumors and nodules were well described, well
illustrated, and related to current understanding of liver pathology
in rats (269). Indeed, several of the liver slides from this study
were examined by a panel of expert pathologists at the workshop
where the terminology used in the paper was developed (269). The
only unusual aspect of the study was the finding of one hepatocellular
carcinoma in an untreated rat.
This study thus provides good evidence for the hepatocarcino-
genicity of Aroclor 1260 in female rats. Because only one rather high
dose was used, and because the rats were exposed for less than 21
months, however, the results provide little quantitative information
on dose-response relationships.
Among other tumors listed in the authors' Table 1, the only
type showing a statistically significant change in incidence is the
-------
D-9
parafollicular cell tumor of the thyroid gland, whose incidence was
reduced from 37/160 to 18/166 (P<.0.01). It is not clear whether
this reduction should be attributed to chance occurrence among the
17 organs examined, or whether it should be related to the known
effects of PCBs on thyroid function (Section III.12.3).
D-2 Industrial Bio-Test Experiment with Charles River Rats.
This experiment was described in an unpublished report dated
November 1971 (207) and a brief summary of results was presented at
the National Conference on Polychlorinated Biphenyls in November
1975 (68). One thousand Charles River strain albino rats were
divided into 10 treatment groups. 100 rats (50 male and 50 female)
served as common controls; 100 rats (50 male and 50 female) were in-
cluded in each of nine exposed groups, fed diets containing 1, 10
and 100 ppm of Aroclors 1242, 1254 and 1260 respectively. Dosage
started when the animals were about 4-6 weeks old (mean weights 133-
136 g) and continued for 24 months. However, 5 males and 5 females
were sacrificed from each treatment group for interim studies after
*
3, 6 and 12 months, so that each treatment/sex subgroup contained
only 35 animals at the start of the second year. Mortality was high,
especially in the animals fed 100 ppm (Table Dl), so that only 6-21
animals from each treatment/sex subgroup survived to the terminal
sacrifice at 24 months (i.e., when the animals were about 25 months
old). The original report gives summaries of body weights, food
consumption, clinical chemistry, organ weights, and histopathological
-------
D-10
diagnoses for each of the 20 subgroups. As in the experiment of Kim-
brough e_t ed., the principal effects were noted in the liver and in
tumor incidence: these are summarized from the original report (207)
in Tables Dl and D2.
Table Dl summarizes data on survival, liver weight, and tumor
incidence. Liver weights were significantly increased in the animals
fed 100 ppm (except the males fed Aroclor 1242); the effect was largest
with Aroclor 1254. The incidence of tumors was similar in all groups,
except for chromophobe adenomas of the pituitary, which were not found
in controls but were found in 8 of the 9 treated groups and in 12 of
the 18 subgroups. The number of surviving animals was too small to
compare individual groups with controls, but if all the treated animals
are considered together the increased incidence approaches statistical
significance. Almost all of these pituitary tumors were found in the
animals killed at 24 months, but 3 were found in animals dying at 20-
23 months.
Table D2 summarizes the histopathologic findings reported in
the original report (207) for the livers of control animals and those
treated at 100 ppm. These diagnoses were summarized by the original
pathologist as follows:
Significant liver injury was found in animals fed 100 ppm
Aroclor 1260 (T-III). The compound associated lesions
consisted of vacuolar change, focal hypertrophy and focal
hyperplasia. In addition, there were lesions of inflam-
mation, necrosis, fibrosis and minor degeneration in this
group which, although seen in the controls and lower test
groups, were more severe and frequent in the T-III group.
-------
Table Dl. Industrial Bio-Test Rat Experim,
Basic Results.
Animals with tumors at
Survival to
Group
CONTROL
Aroclor 1242
1 ppm
10 ppm
100 ppm
Aroclor 1254
1 ppm
10 ppm
100 ppm
Aroclor 1260
1 ppm
10 ppm
100 ppm
Sex
M
F
M
F
M
F
M
F
M
F
M
F
M
F
M
F
M
F
M
F
No. at
12 mo.
35
35
35
35
35
35
35
35
35
35
35
35
35
35
35
35
35
35
35
35
month
18
25
26
25
28
25
29
23
27
22
29
26
24
.24
22
22
27
20
26
22
23
21
19
19
18
24
20
24
16
19
14
24
18
20
17
18
17
21
12
21
16
16
24
10
16
10
10
12
19
6
10
5
21
8
13
.8
12
9
16
6
18
6
12
Liver %
of body
wt.24 mo.
3.47 .
3.05
. 2.93
3.00
3.18
3.19
3.95
4.82**
2.99
3.10
3.21
3.84*
4.75**
8.62**
3.40
3.35
2.87*
3.19
4.67**
4.42**
20-24 months
Abdomen &
Mammary
1
6
2
10
2
7
0
1
0
11
0
6
2
10
0
5
0
5
0
4
Pituitary
0
0
0
2
1
2
0
1
1
1
0
2
0
0
1
3
0
3
1
1
Others
1
2
1
2
1
2
1
2
1
2
2
2
0
2
0
1
0
3
2
3
TOTAL
2
7
3
11
3
10
1
4
2
11
2
9
2
12
1
6
0
8
3
8
P "CO.05, ** P<10.01, significant difference from controls.
o
i
o
m
-------
D-lOb
Table D2. Liver pathology reported in Industrial Bio-Test
Rat Experiment: Controls and animals fed 100 ppm PCBs.
Aroclor 1242
Controls 100 ppm
M F M F
Aroclor 1254
100 ppm
M F
Aroclor 1260
100 ppm
M F
REPORT OF NOVEMBER 1971 (ref. 207)
Animals surviving 24 months
Animals with diagnoses reported
at "final sacrifice":
Focal lymphoid infiltration
Focal degeneration
Necrosis
Vacuolar change (fatty)
Hypertrophy3
Hyperplasiab
Nodular hyperplasia
Hepatoma
Miscellaneous0
10
11
-
1
-
-
-
2
-
-
—
16
14
3
-
-
-
-
2
-
-
1
6
6
-
1
-
3
2
0
-
-
—
10
14
-
3
-
11
5
3
* 1
-
2
8
11
1
2
-
3
3
3
-
-
1
12
15
-
-
-
10
6
3
1
1
-
6
10
-
1
-
2
2
-
-
-
4
12
15
-
-
2
3
5
6
-
-
2
REPORT OF NOVEMBER 1975 (ref. 68)
Animals with diagnoses reported
at "24 month sacrifice":
Nodular hyperplasia
Hepatoma
Cholangiohepatoma
20
8
2
1
27
13
4
2
27
7
5
2
a Includes focal and centrolobular hypertrophy, b Includes ductile and focal hyper-
plasia. c Focai hepatitis 2; focal cholengiohepatitis 1; portal fibrosis 2,
congestion 3, telangiectasis 1, chronic inflammation 1.
-------
D-ll
The vacuolar change was not seen in the control animals
but was observed occasionally in livers from T-I (1 ppm)
and T-II (10 ppm) animals. It was frequent in'the T-III
animals. This lesion is morphologically indicative of
fatty degeneration. Formalin-frozen sections of livers
from representative animals which displayed vacuolar
changes were stained with Oil Red 0 to reveal the presence
of fat. The vacuolar lesion in the cytoplasm of these
cells was positively identified as fat.
The hypertrophic change found in the liver was focal and
often limited to the central lobular area where groups
of cells were swollen to two or three times their nor-
mal size with clear pink homogenous cytoplasm. The
hyperplasia was associated with the same cells and
appeared to be an extension of the hypertrophic lesion.
The hyperplastic cells were also usually hypertrophic,
The most severe examples of hyperplasia appeared as
nodular growths with limited compression of the surround-
ing normal hepatic tissue.
The minor lesions of degeneration, hepatitis, ductule
cell proliferation, necrosis and focal lymphoid infil-
tration seen in the control animals and the T-I and
T-II groups are lesions of.spontaneous disease and are
not related to the Aroclor 1254. This level of liver
disease is not unusual in rats of this age. (207,
pp. 67-68.)
In 1975 the liver slides were re-examined by the original path-
ologist (416). Revised diagnoses are tabulated in Table D2A and sum-
marised in the second part of Table D. Although the 1975 report
states that "in most instances, the spectrum of treatment-related histo-
pathological findings in the liver from this re-evaluation did not dif-
fer significantly from that previously reported in our original report
dated November 12, 1971" (416, p. 2), the diagnoses were in fact mark-
edly different, including 11 hepatomas, 5 cholangio-hepatomas, and 28
examples of nodular hyperplasia in the animals treated with 100 ppm.
-------
-------
D-lla
table D2A. Liver pathology reported in Industrial Bio-Test
rat experiment: 1975 re-diagnosis (ref. 416).
Control
Dose rate (ppm) :
No. of animals
Vacuolar change
Focal hypertrophy
Nodular hyperplasia
Hepatoma
Ductular hyperplasia
Cholangio-hepatoma
Hepatocellular necrosis
23
1
0
1
0
5
0
1
Aroclor
1 10
31
7
2
0
0
3
0
1
30
8
3
2
0
3
0
1
1242
100
20
9
8
8
2
3
1
0
Aroclor
1 10
31
8
3
0
0
6
0
3
26
10
5
3
0
3
0
1
1254
100
27
13
13
13
4
4
2
2
Aroclor
1 10
25
5
3
0
0
6
0
4
23
6
10
9
0
5
0
2
1260
100
27
10
11
7
5
14
2
6
Preceding Page Blank
-------
D-12
Nodular hyperplasia was also reported in 14 animals treated with 10
ppm and in one control. The tumors were described as follows:
"Those lesions classified as hepatomas or cholan-
giohepatomas were larger nodules which showed evi-
dence of confluence or some variation in cell size,
• shape, staining, or a ductular or adenomatous
pattern of growth. In the absence of metastasis,
invasiveness, severe basophilia, mitoses, or other
evidence of anaplasia, these are benign tumors
rather than malignant tumors (carcinomas)." (416, p. 3)
There are substantial discrepancies between the total number
of animals diagnosed and the numbers listed as surviving to 24 months
in the original report (Table D2).
Comment. Although this experiment was continued for a full
24-month period and provides a useful comparison between the three
Aroclors, the experimental groups were too small to provide a sensi-
tive test for carcinogenicity. In particular, the use of only a single
control group, reduced to 70 animals by interim sacrifices and to 26
by mortality in the second year, made the entire experiment very in-
sensitive. The cause of the high mortality was not stated. The
drastic changes in diagnoses between 1971 and 1975 were not explained
and the tumors were inadequately described.
The 1975 report indicates that PCBs at 100 ppm in the diet in-
duced a variety of proliferative lesions, including tumors and hypaf-
plastic nodules, in the livers of exposed rats, and that these effects
welre induced at roughly similar frequency by each of the three Aro-
clors. No further conclusions can be drawn without a complete report
and independent diagnoses of the lesions in the livers and pituitaries.
-------
D-13
D.3 Apparent Conflict Between Results of Kimbrough and Industrial
Bio-Test Experiments.
In presenting the revised results of the Industrial Bio-Test
experiment, Calandra (68) suggested that they conflicted substantially
with those of Kimbrough e£ al. Specifically, he emphasized that no
hepatocellular carcinomas could be diagnosed in the Industrial Bio-
Test experiment, that two consultants (in addition to the original
pathologist) had reviewed the slides in 1975, and that one of these
consultants had also reviewed slides from the Kimbrough, et al. experi-
ment and "does not agree with the reported findings". However, this
consultant also disagreed with the Industrial Bio-Test pathologists,
reporting no tumors or even hyperplastic nodules in that experiment
(417). In his review of the slides from the Kimbrough _et al. experi-
ment, this consultant diagnosed among 184 treated animals 136 hyperplas-
tic nodules and 43 "hyperplastic nodules with atypical structures"
(Table D2B). A review of this report suggests that the dispute is
primarily over terminology, in particular over the severity of the
criteria required for a diagnosis of neoplasia. This is an area in
which the Agency has considerable expertise and has previously accepted
the criteria and diagnoses of the principal pathologist* in the Kim-
brough et al. study (270). Recognizing the terminological dispute,
there does not seem to be substantial qualitative conflict between
these two experiments. Even without the supporting evidence cited
below, the two experiments together would justify a finding that
Aroclor mixtures induce neoplastic transformations in rat livers.
*.Dr. R. A. Squire, Head of the Tumor Pathology Section of the National
Cancer Institute.
-------
-------
D-13a
Table D2B (from ref. 417)
Differences of liver lesions in control and
experimental rats treated with Aroclor 1260
Experimcntals Controls
Vacuolization 155 13
Focal granular alteration 100 31
Single, granular alteration 109 A5
Single cell necrosis 125 17
Group cell necrosis 36 2
Cell enlargement 175 17
Ductal proliferation 52 3
Cholangiomatous lesion 7
Stern cell proliferation 121 87
Hyperplastic nodules:
without atypia 136 9
with atypia 43 1
Preceding Page Blank
-------
D-14
D.4 52-week Study by Ito et al. in Rats.
Ito et al. (190) reported a study involving 290 male Wistar
rats. The sizes of the experimental groups were not precisely re-
ported but it appears that 20 rats were used as a common control and
30 were included in each of 9 experimental groups, dosed with 100, 500,
and 1000 ppm of Kanechlors 300, 400 and 500. Exposure started at 8
weeks of age and the animals were killed after 28 to 52 weeks. The
results of the study are summarized in Tables D3 and D4. There were
marked increases in liver weight in all treated groups and apparently
high mortality in the groups fed 500 to 1000 ppm. Histopathologic
changes included bile duct proliferation, cholangiofibrosis and
nodular hyperplasia (Table D4). The nodular hyperplasia is not des-
cribed in detail but is said to have been similar to that induced by
other carcinogens. The cholangiofibrosis was apparently similar to
that reported by Kimbrough et a_l. (191, 266): its possible relation-
ship to carcinogenesis is discussed above.
Comment. This study was conducted for far too short a period
to serve as an adequate carcinogenicity test: other defects included
the small size of the control groups, the high doses used, high
mortality, and inadequate description of the lesions. However, it
suggests that all three Kanechlors tested induce pre-neoplastic
lesions in rats exposed to high doses.
D.5 The Study of Kimura and Baba on Donryu Rats.
Kimura and Baba (271) conducted a short-term experiment in
rats of the DonrVtt. strain. Starting at 10 weeks of age, 10 males and
-------
D-14a
Tables D3 and D4 (from ref. 190)
N. ITO, ET AL.
Changes in Cody and Liver Weights of Male \Vistar Rats Given Polyclilorinatcd Biphcnyls
PCS in diet Experimental
'ppm) period
(weeks)
Kancch!or-.>00
Kancc!ilor-I00
Kanechlor-SOO
Control
MOOO)
(500)
(100)
(1000)
(500)
(100)
(1000)
(500)
(100)
49.3
52.0
52.0
40.0
27.8
39.6
52.0
52.0
52.0
52.0
Effective
No. of
rats
13
16
25
10
8
16
15
19
22
18
Body weight (g)
Initial Final
126.4-7.6*
122.5-8.4
124.8-8.2
lGS.O-i-7.8
183.0-^6.6
175.0-18.8
128.3-^-9.0
135.4-7.2
125.2 = 8.5
130.6-^-4.6
288.24-65.7
378.44-38.2
469.6J-72.7
199.6-42.8
209.5 ±43 6
401.8±121.9
420.8-56.5
457.5-1-60.7
506.3±G.5.4
553. 3x69.6
Liver weight
(g) % of
body wt.
oo o j_3 3
19.5-2.5
17.3^-2.1
16.7-5.4
12.8-^-2.0
14.4-1-3.4
18.4-3.0
18.8-^-3.3
14.84-2.1
13.0-M.9
8.0-1-1.1
5.2-i-0.r>
3.7-0.6
0.4-2.3
6.2-1.1
3.6-0.7
4.3-0.4
4.1-0.4
2.9-0.2
2.4-0.2
* Values are mean — SD
Histopathological Findings in the Liver of Male \Vistar Rats Given Polychlorinated Biphenyls (PCB)
PCB in diet Oval Bile
(ppm) cell duct
prolifer- prolifer-
ation ation
KancchIor-500 (1000) 4- 4-
(500) 4- +
(100) ± ±
Kancchlor-400 (1000) 4- +
(500) - -i-
(100) ± ~
Kanechlor-300 (1000) 4- 4-
(500) - J-
(100) - ±
Control — —
Histopathology of the liver
Fatty Cell Fibrosis Cholangio-
changes hyper-. fibrosis
trophy (%)
4-
-1.
if
if
~r
"T
~T
- 4/13 (30.8)
- 0/16 -
- 0/25 -
if 2/10 (20.0)
- 0,8 —
- 0/16 —
- 2/15 (13.3)
- 0/19 —
- 0/22 —
- 0/18 —
Xodular
hypcr-
Ainvloidosis
5/13 (33.5)
5/1G (31.3)
3/25 (12.0)
3/10 (30.0)
0/8 —
2/16 (12.5)
0/15 (6.7)
0/19 —
1/22 (4.5)
0/18 —
0'I3 -
0/1G _
025 —
0/10 —
0/c! —
2/1G (12.5)
0/15 —
0/19 —
0 '22 —
0/18 —
-------
-------
D-15
10 females were exposed to Kanechlor-400 at dietary levels varying
from 38.5 to 616 ppm (for dosage regime see foot of Table D5); 5 males
and 5 females served as controls. The treated animals lost weight,
and suffered from lung abscesses, pneumonia, spleen atrophy, and intra-
cranial abscesses, which the authors suggest may have been due to a
treatment-related loss in resistance to infection. "Multiple adeno-
matous nodules", which the authors interpreted as a "benign neoplastic
lesion...still short of malignancy" were found in the treated females
(Table D5).
Comments. In view of the small number of animals used, the
high dosage, the animals' poor condition, and the early termination of
the experiment, this study can be regarded as no more than a prelimin-
ary screening test. However, it did provide evidence of early neo-
plastic changes, but these were not described and cannot be evaluated.
D.6 The Experiment of Kimbrough and Linder on BALB/cJ Mice.
Kimbrough and Linder (191) reported an experiment in which two
groups of 50 BALB/cJ male mice were fed 300 ppm of Aroclor 1254 in the
diet starting at the age of 5-6 weeks. One group was exposed for 11
months; the other was fed for six months, followed by five months on
untreated diet; two groups of 50 male mice served as controls. Mor-
tality was high early in the experiment due to fighting, but there was
still excess mortality in the treated groups after the mice were re-
caged (34/80 versus 19/77 in the two control groups). The results are
summarized in Table D6. The treated mice showed gross enlargement of
the liver, including 11 hepatomas and adenofibrosis in all 22 animals
Preceding Page Blank
-------
-------
D-15a
Table D5 (from ref. 271)
N. T. KIMURA AND T. BABA
Pathological Findings Induced by Long-term Oral Administration of
Kanechlor-400 in Rats
Rat
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Sex
3
3
3
3
£
3
3
3
3
3
9
9
9
9
9
9
9
9
9
9
0
3
3
3
3
9
9
9
9
9
Total
exp.
period
(days)
159
256
323
339
347
353
355
357
373
530
244
357
366
396
402
461
477
482
504
560
255
332
538
538
538
331
448
538
538
538
Approx.
amount
of
KC-400
ingested
450
900
1200
1300
1300
1300
1300
1300
1300
1800
700
1100
1100
1100
1200
1500
1500
1500
1500
1500
Body weight (g)
Initial Final
199
192
201
204 '
200
230
201
185
234
228
158
161
154
165
202
168
178
225
191
209
257
140
190
182
256
192
192
202
201
193
309
273
192
199
328
210
296
226
325
297
137
184
177
125
212
148
165
145
167
253
471
432
426
523
456
198
495
292
320
314
Liver
Ratio Fatty
to body degen-
wt. eration
4.1 4-
5.4 +
6.8 +
6.8 4-
6.2 4-
5.4 4-
5.2 4-
6.3 • 4-
6.5 4-
5.8 -r
5.9 4-
6.2 4-
7.1 4-
7.8 4-
6.7 +
8.4 +
7.8 4-
6.3 4-
6.5 4-
6.4 4-
2.5 -
3.1 -
2.7 -
2.5 -
2.7
4.2 4-
2.6 +
2.9
3.0
2.6
fWinr
Multiple pathological
adeno- findings*
matous
nodules
SA, Pn, LA
—
- SA, Pn, FDAd
- Pn, D, FDAd
- Pn, LA
- SA, Pn, IA
- Pn
- Pn, LA, FDAd
- LA
LA
- LA
- Pn, D
- LA, D
- Pn, LA, D , '
4- LA, D
4- LA, D, IA, FDAd
4- LA, D, IA, SA,
4- LA, IA, SA
+ LA, D, FN
4- D, AAd
- FDAd
- Pn, FDAd
- FDAd
—
- FDAd
- Pn
- Pn '
_
_
—
* SA = spleen atrophy, Pn = pneumonia, LA = lung abscess, FDAd = fatty degeneration
of the adrenal cortex, D = depilation, IA = intracranial abscess, FN = extensive fat necro-
sis in the abdomen, AAd = adenoma of the adrenal cortex.
Schedule of feeding:
Concn. of
Kanechlor-400 38.5 77 154 308 616 462 462 462
(ppm)
Period of Total
feeding (days) 26 57 21 21 56 39 28 98 28 82 400
A pause ( ) in PCB feeding was inserted similarly in experimental and control groups.
during which and after termination of diet feeding, the rats had free access to the con-
ventional diet (CE-2).
Preceding Page Blank
-------
.—Body weights, liver weights, and hcpatoma incidence in surviving mice fed Aroclor IS54 in the diet and in controls fed plain chow
Dietary Final body weight Liver weight Hcpatoma
level Dosage level Time exposed to Total Total of survivors: Liver weight: expressed as incidence*
(ppm) (mg/kg/day) experimental diet mice survivors arithmetic mean (g) arithmetic mean (g) percentage of in survivors
body weight
0 0. .. 0 50 34 30.7 1 77 5.8 0
0 0 0 50 24 30.9 1 78 5.8 0
300 4!(.8 11 months ' 50 22 33 8f 8 62f 25 51 3(0 1-0. 4 cm
:»(0. 5 cm 0)
-1(1 1. 5 cm
300 Not c:hcckiul (i months and 5 50 24 31.5 2. 37f 7. 5f 1(0. 3cm 0)
months'
recovery.
0)
ID
•Determined when mice were 12 months old. B=dlameler.
t/'<0.001. A (-test was used for tliu statistical evaluation.
Table D6 (from ref. 191)
o
i
in
cr
-------
D-16
fed for 11 months. The pathological changes were illustrated (191,
Figures 1-5) and described and discussed as follows:
Microscopic examination of the livers of the 22
survivors in the group receiving the experimental diet
for 11 months (fig. 1) showed markedly enlarged liver
cells. The nuclei of the hepatocytes were enlarged,
hyperchromatic, and atypical. The cytoplasm was
either smooth or vacuolated. Macrophages and
Kupffer's cells contained a brown pigment. Slight,
diffuse interstitial fibrosis and numerous, large extra-
cellular hyaline bodies were also seen. Some livers had
extensive areas of coagulation necrosis and fibrosis
(fig. 2). A general pleomorphism was noted in a
number of livers. Degeneration, necrosis, and atrophy
of individual liver cells were also observed.
A few nuclei showed karyorrhexis. Some smaller
cells and proliferation of the focal nodular type were
also noted. The irregular outer surface of the liver with
areas of retraction indicated that proliferation,
atrophy, and regression had occurred. Occasional
calcareous deposits =5-8ft in diameter were present.
In each of the livers, several areas were seen where the
parenchyma was replaced by glandular formations of
proliferated epithelial cells which formed ducts and
often produced mucus. These epithelial cells were
surrounded by either sparse (fig. 3) or abundant
connective tissue.
In addition to the above findings for all 22 livers of
mice treated for 11 months (table 1), 10 hepatomas
were found (fig. 4); of these, 3 measured 0.1-0.4 cm
in diameter, 3 measured 0.5 cm, and 4 measured
1—1.5 cm. The tumors developed in a total of 9 mice.
On gross inspection, they appeared as tan nodules.
On microscopic examination, they consisted of well-
differentiated hepatocytes that were relatively uniform
and usually smaller than the surrounding liver cells.
The tumors were well circumscribed and surrounded
by compressed hepatic parenchyma or strands of
fibrous tissue. The larger tumors contained areas where
the sinusoids were dilated and filled with a pink-
staining amorphous material. On gross inspection of
the organs at autopsy, metastases were not seen.
However, detailed screening for metastases including
serial sectioning of lungs was not undertaken.
Most livers of the 24 mice surviving 6 months of
dietary exposure to PCB's followed by a 5-month
recovery had enlarged cells; often these liver cells had
enlarged, atypical, hyperchromatic nuclei, although
the livers at autopsy weighed only slightly more than
those of the controls. Necrosis of individual liver cells
was observed and some nuclei showed karyorrhexis.
-------
-------
D-17
The macrophages and Kupffer's cells usually con-
tained a brown pigment. Many liver cells, particularly
those in the periphery of the lobules, had vacuolated
cytoplasm. The livers of about two-thirds of these mice
showed slight-to-moderate diffuse, interstitial fibrosis.
The outer surface of the livers still showed small
indentations but not as pronounced as those in the
group receiving PCB's for 11 months. Numerous
extracellular hyaline bodies were observed in some
livers. In addition, many calcareous deposits, light in
the center and darker in the periphery, were also
seen (fig- 5). They were more frequent in this group
than in the one fed PCB's for 11 months. A few livers
showed bile duct proliferation. Only 1 liver contained
a small hepatoma measuring 0.3 cm in diameter. The
liver cells comprising the hepatoma were well-
differentiated hepatocytes.
Except for the subcutaneous abscess formations in
some mice and 1 sweat gland adenoma, no other
findings of note were made in the mice of any groups.
DISCUSSION
Two significant findings were made in the present
study: adenofibrosis of the liver and hepatomas. Thus
adenofibrosis can also be induced in mice and does
not occur solely in rats where it has been described
previously (1, 3). A similar lesion may occur in
hamsters (8). In the mouse lesion, the epithelial
component was much better differentiated and less
pleomorphic than in the rat lesion (1). The pattern
of the lesions and the interrelationship with fibrosis
were the same. Ducts and cysts formed in areas of
adenofibrosis in both the mouse and rat livers.
Whether adenofibrosis is a precursor of a malignant
lesion or occurs concomitantly with malignant lesions
of the liver is still debated. In an excellent review,
Stewart and Snell (4) concluded that the lesion
showed no convincing evidence of a precancerous
lesion. Reuber (5) postulated that cholangiocarcin-
omas would develop from adenofibrosis in rats as
well as hamsters.
The mouse strain used in this study only rarely
develops hepatomas spontaneously. Peters et al. (5)
observed 6 hepatomas in a group of 2000 BALB/cCr
mice, a subline from the Andervont subline at the Na-
tional Cancer Institute; one would expect incidences
similar to those observed in the BALB/cJ subline.
Madison et al. (6") found 13 (0.62%) hepatomas in
2088 BALB/cCr mice 18 months of age. In the pres-
ent study none of the controls, 1 of 24 mice fed
PCB's for 6 months, and 9 of 22 mice fed PCB's for
11 months developed hepatomas.
Preceding Page Blank
-------
D-18
Although the hepatomas were well differentiated,
according to Andervont and Dunn (9), they represent
potentially malignant lesions, a certain percentage of
which can metastasize and be transplanted. From the
appearance of the lesion, it is impossible to predict
which tumor will be malignant. The size of the liver
tumors cannot be used as a criterion. Quite possibly
the.tumors would have been larger and would have
occurred more often had the mice been allowed to
complete their lifespans.
Comments. This experiment deviated from accepted protocols for
carcinogenesis bioassays primarily in its very early termination, and
in being limited to males. The high mortality and the consequent small
number of treated animals surviving to 11 months makes it further in-
sensitive as more than a preliminary screening test for carcinogeni-
city. However, there was a significant incidence of liver .tumors
which, as the authors point out, are rare in control mice of this
strain and are at least potentially malignant. These tumors were well
described and well illustrated. Thus, despite its limitations, this
experiment gives convincing evidence that Aroclor 1254 induces very
early neoplastic changes in the mouse liver.
D7. The Experiment of Ito et al. with PCBs and BHC in dd Mice.
Ito et al. (192) reported an extensive series of experiments
in which groups of 12-30 male dd mice were exposed to various levels
of PCBs (Kanechlors KC-300, KC-400, KC-500 at 100-500 ppm in the diet)
alone or in combination with one of three isomers of BHC (hexachloro-
cyclohexane). Two control groups contained only 6 and 20 male mice.
Treatment started at the age of 8 weeks and the animals were killed
and examined after 24 or 32 weeks.
-------
D-19
Results of the experiment are summarized in Tables D7 and D8.
Liver weights were markedly increased in all groups fed PCBs at all
dose levels, but were only slightly increased in the groups fed iso-
mers of BHC alone. KC-500 induced nodular hyperplasia and hepatocellu-
lar carcinoma in 12/12 mice within 32 weeks at the highest dose rate
(500 ppm), but did not do so at lower dose levels; nor did KC-400 or
KC-300 even at 500 ppm (Table D7). KC-500 at 250 ppm in the diet also
markedly increased the carcinogenic effects of BHC (Table D8). Whereas
BHC alone did not induce nodular hyperplasia or carcinomas within 24
weeks, except in the group fed o(.-BHC at 250 ppm, the groups fed
C<-BHC and g-BHC together with KC-500 developed both kinds of lesions
" 50 or
within 24 weeks, even at a dietary level of/100 ppm BHC (Table D8).
The hyperplastic nodules and carcinomas induced by PCBs were well
illustrated (199, Figures 4-6) and were described as follows:
Histopathologic findings: The histologic changes and
incidence of nodular hyperplasias and hepatocellular
carcinomas in the livers of animals in the various
groups are given in table 4.
Oval cell infiltration and bile-duct proliferations
were rare in all groups. But hypertrophic changes of
liver parenchymal cells in centrolobular areas were
clear in groups that received a-BHC or /3-BHC plus
PCBs or a-BHC alone. Among the 30 mice in the
group given 250 ppm a-BHC, nodular hyperplasia
was found in 23 (76. 7%) and hepatocellular carci-
noma in 8 mice (26. 7%). No hyperplastic nodules
or hepatocellular carcinomas were seen in any other
group fed a-BHC or 0-BHC only. However, some
mice in the groups that received 100 or 50 ppm
a-BHC or 250 or 100 ppm 0-BHC with PCBs de-
veloped nodular hyperplasias and well-differentiated
hepatocellular carcinomas (fig. 6). The incidence of
hepatocellular carcinoma in mice given 250 ppm
a-BHC increased when the diet was supplemented
with 250 ppm PCBs-5. No neoplastic changes were
seen in groups fed a-BHC. The histologic patterns of
nodular hyperplasias and hepatocellular carcinomas
induced in mice by a-BHC or /3-BHC were not af-
fected by supplementation of the diet with PCBs.
The histopathology of neoplasms induced by a-BHC
or /3-BHC was essentially the same as of that induced
by PCBs in series I.
-------
-------
D-19a
Table D7 (from ref. 199)
PCB'S AND BHC LIVER TUMORS IN MICE
1639
•Hiitopathohgic findings in the livers of male dd mice treated with technical polychlorinated biphenyh (PCBs) for
32 weeks
Histopathology of liver
PCBs* in diet (ppm)
PCB«-5 (500)
(250)
(100)
PCBs-4 (500) '.
(250)
(100)
PCEs-3 (500)
(250)
(100)
Controls.
Oval Bile-duct
cells prolifera-
tion
+ +
4- 4-
+ +
± ±
Cellular
hyper-
trophy
±
±
±
- ±
Amyloid
degenera-
tion (percent)
0/12 —
2/12 ri6. 7)
3/12 (25.0)
0/12 —
3/12 (25.0)
10/12 (S3, 3)
1/12 (3. 3)
4/12 (33. 3)
10/12 (S3. 3)
0/6 —
Liver nodules (percent)
Nodular
hyper-
plasia
7/12 (58.3)
0/12 —
0/12 —
0/12 —
0/12 —
0/12 —
0/12 —
0/12 —
0/12 —
0/6 —
Ilepato-
cellular
carcinoma
5/12 (41.7)
0/12 —
0/12 —
0/12 —
0/12 —
0/12 —
0/12 —
0/12 —
0/12 —
0/6 —
•PCBs-5, KanechlorJOO,- PCBs-», Kanechlor 400; PCBs-3, Kanechlor 300.
Preceding Page Blank
-------
D-19b
Table D8 (from ref. 199)
PCB'S AND BHC LIVER TUMORS IN MICE
1641
-Histopathologic findings in the liver of male dd mice treated with isomeri of benzene hexachloride (BHC) and tech-
nical polychlorinated biphenyla (PCBs) for 2i weeks
BHC or PCBs* in diet (ppm)
Effective
number
of rnicef
Histopathology cf liver
Liver nodules (percent)
Oval Bile-duct Cellular Nodular Hepato-
cells prolif- hypertrophy hyperplasia cellular
eration carcinoma
u-BHC(250) '. 30
a-BHC(250) + PCBs-5(250) 26
o-BHC(lOO) 26
a-BHC(100) + PCBs-5(250) 25
a-BHC (50) 28
a-BHC (50) + PCBs-5(250) 30
<3-BHC(250) 26
(j-BHC(250) + PCBs-5(250) 29
0-BHCUOO) 26
,3-BHCdOO) +PCBs-5(250) 30
0-BHC (50) 28
0-BHC (50) + PCBs-5(250) 29
7-BHC(250) 26
T-BHC(250) + PCBs-5(250) 28
r-BHC(lOO) 28
7-BHC(100) + PCBs-5(250) 30
Y-BHC (50) 28
•y-BHC (50) + PCBs-5(250) 27
PCBs-5(250) 20
Controls . * 20
,±
+
23 (76.7)
21 (80. 8)
0 —
8 (32.0)
0 —
9 (30.0)
16 (55.2)
0 —
5 (16.7)
0 —
0 —
0 —
0 —
0 —
0 —
0 —
0 —
0 —
0 —
8 (26.7)
15 (57.6)
0 —
1 (4. 0)
0 -
2 (6.7)
0 —
6 (20.7)
0
1
0
0
0
0
0
0
0
0
0
0
(3.3)
•PCDs-S, Kanechlor 500.
tMlce dying during the experiment were not Included.
-------
D-20
Histologically, the neoplasms induced in mouse
liver by PCBs were nodular hyperplasia and well-
differentiated hepatocellular carcinomas. They were
similar to those described previously, produced on
administration of the a-isomer of BHC (14-16), and
to those induced by other chemical carcinogens'(77-
Comment. Because of the very short periods of treatment and
the small number of mice involved, especially in the control groups,
this would be unacceptable as a routine carcinogenesis bioassay. No
negative conclusions can be drawn from the failure of KC-400 or KC-300
to induce hyperplastic nodules or carcinomas within 32 weeks in these
small groups of mice. However, their induction by KC-500 within 32
weeks is a striking positive finding. Survival of the mice was very
good and the lesions were well illustrated.
The primary purpose of the experiment was to investigate syner-
gistic effects of PCBs and BHC. The induction of hyperplastic nodules
and carcinomas within 24 weeks by joint feeding of PCBs and BHC, at
levels below those which had no effects in 32 weeks when fed independ-
ently, is a striking case of synergism. Because of the short duration
of the experiment, this effect should probably be regarded as a case
in which each chemical accelerated the action of the other. Lifetime
studies at lower dietary levels would be required to demonstrate •
whether the life total incidence of carcinomas is increased by joint
exposure.
-------
-------
D-21
D.8 Other Experiments on Co-Carcinogenesis in vivo.
Two other experiments have been conducted to investigate
possible co-carcinogenic effects of PCBs in vivo. In an experiment
with mice, PCBs (KC-400) fed in the diet did not appear to accelerate
the development of cervical carcinoma induced by methylcholanthrene.
(272). After 4 weeks of topical application of methylcholanthrene,
dysplastic changes in the cervix did not progress to invasive carcin-
oma in animals fed the control diet or PCBs, although they did so in
animals fed DDT (272).
In another study in rats (273) feeding with PCBs (KC-500 at
500 ppm in the diet) for 24 weeks appeared to delay or inhibit the in-
duction of nodular hyperplasia and. hepatocellular carcinoma by three
other carcinogens, 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB),
N-2-fluorenylacetamide (2-FAA), and diethylnitrosamine (DEN). The
results of this study are summarized in Table D9. The authors specu-
late that the inhibitory effects may have been attributable to metab-
olism of primary carcinogens by PCB-stimulated microsomal enzymes, as
discussed in the next section.
D.9 Activation and De-activation of Primary and Secondary Carcino-
gens by PCB-Stimulated Microsomal Enzymes.
In a related experiment, Reynolds et al. (274) have shown that
pretreatment with PCBs (150-300 ^moles/kg for 7 days) greatly in-
creases the susceptibility of rat livers to acute injury by vinyl-
chloride monomer (VCM). Twenty-four hours after a 6-hour exposure to
Reproduced from
best available copy
-------
-------
D-21a
Table D9 (ref. 273)
•Hislopalhologic changes of the liver in male rats treated with PCB and chemical carcinogens for S4 weekt
Histopathology of liver
Effective Cell Oval
Group « No. of Fatty hyper- cell
rats 6 changes trophy infil-
tration
1
3.
4.
5.
6.
7.
S.
9.
10.
11.
12.
3'-Me-DAB
2-FAA
DENT
PCB
PCB4-3'-Me-DAB
PCB+ 2-FAA
PCB4-DEN
3'-Me-DAB-i-DE\
2-FAA 4-DEN
PCB4-3'-Me-DAB4-DEN.
PCB-S-2-FAA4-DEN-. .
Control
23 +
13 ±
13 +
19 4-4-
23 4-
17 4-
9 4-4-
13 4-
11 4-
13 4-
12 4-
10 -
±
4-
4.
4-
4_
±
4.
4-
X
±
±
±
4-4-
Bile
duct
prolif-
eration
4- '
4-
4-
JL
±
± |
4.
Cholangio-
fibroais «
1
0
0
0
0
1
1
4
0
3
2
0
(4.3)
(5.9)
(11. 1)
(30.8)
(23. 1)
(14.3)
Nodular
hyper-
plasia '
22
13
13
0
0
1
0
13
11
4
3
0
(95. 7)
(100.0)
(100.0)
(5.9)
(100.0)
(100. 0)
(30.8)
(25. 0)
Cancer «
15
7
12
0
0
0
0
12
9
1
0
0
(65. -2)
(53. 8)
(92. 3)
(92.3)
(81. S)
(7. 7)
• Sn footnote o, table 1.
1.?« footnote c, table 1.
' Number (and percent) of rat] with cholangioflbrosls, nodular hyperplasla, or cancer of liver.
Reproduced from
best available copy
-------
D-22
5% VCM, there was extensive vacuolization of the panlobular parenchyma
in livers of PCB-treated rats, but not in livers of controls similarly
exposed to VCM. VCM also caused extensive necrosis in PCB-treated rat
livers, and a marked increase'in serum alanine o<-ketoglutarate trans-
aminase (AKT) activity, a measure of general hepatic injury (Table D10).
Phenobarbital (PBT) had similar effects (274, Table D10). Reynolds et
al. related this injury to the oxidation of VCM to a biologically active
metabolite by the mixed function oxidase system (MFOS) stimulated by
PCBs and PBT. They showed that Aroclor 1254 and PBT have especially
large effects in stimulating several components of the MFOS, especial-
ly cytochrome P-450, NADPH cytochrome c-reductase, and aryl hydrocar-
bon hydroxylase (AHH, as determined by zoxazolamine and 3,4-benzpyrene
hydroxylase activities) (Figure Dl). Correspondingly, Aroclor 1254
and PBT promote especially severe injury by VCM and large releases of
AKT into the serum (Table D10); serum ART is closely correlated with
cytochrome P-450 content (Figure D2). By contrast the toxicity of
1,1-dichloroethylene (DCE, or vinylidene chloride) is sharply reduced
by pretreatment with PCBs and PBT (Table D10 and Figure Dl), indicating
that DCE is metabolized to a less toxic compound. Figure D3 shows
schematically how the MFOS acts to oxidize foreign chemicals, and
demonstrates the key role of cytochrome P-450.
VCM is a known human liver carcinogen and its liver toxicity
appears related to its carcinogenicity (275). Like most carcinogens,
VCM is also a mutagen (276), but both its carcinogenicity and mutagen-
icity appear to depend on metabolism in the liver to an active
-------
D-22a
Table D10 (ref. 274)
. Effect of MFOS Inducers on Serum Enzyme Response Following Vinyl Chloride
and Olchloroethylene
Serum ART activity'
Pretreatment Vinyl chloride! Dichloroethylenet
Control (water)
PBT§
1254(1
HCB§
3-MC§
SNL§
PCN§
0.32 ± 0.03
4.86 ± 2.69
5.55 ±1.14
1.09 ±0.30
0.29 ± 0.06
0.28 ± 0.01
0.26 ±0.01
20.85 ±3.96
11. 85 ±4.34
0.45 ±0.01
26.02 ±7. 86
13. 94 ±3. 17
13.09 ± 1.47
11. 19 ±3.62
* Alanine ketoglutarate trasaminase activity (in milligrams of pyruvate per milliliter per
hour) measured according to the method ol Murphy and Malley1'; the value from unexposed
control animals was 0.38 ± 0.09 mg pyruvate/ml/hr.
t Measured 24 hours after onset of a 6-hour exposure to 50,000 ppm.
1 Measured 6 hours atler onset of a 4-hour exposure to 200 ppm.
-------
D-22b
Figure Dl (ref. 274)
CYTOCHROME
AHH
CYTOCHROME-C
REDUCTASE
• Comparison of the effects of the MFCS inducers, PBT, 1254, HCBf 3-MC, SNL,
and PCN, on specific components of the microsomal multienzyme complex All activities are on a mil-
ligram protein basis. The ordinate is expressed as the ratio of experimental to control values. Thus a
value of one represents no change from control values. For the most part, each value is the average of
the determinations from microsomes of at least 6 animals. Complete details of the assay conditions are
cli'M-ribcd in Moslen et at."
-------
Figure D2 (ref. 274)
D-22C
0 DICHIOROETHYLENE
. -Cor-
relations between micro-
somal cytnchrome P-450
content at the beginning of
exposure and the serum en-
zyme response 24 hours
after exposure to vinyl
chloride and 6 hours after
exposure to dichlnroethy-
Idle in groups of animals
given different \1FOS in-
duccrs: controls, open cir-
rlei; PBT. solid circles:
1254. open squares; HCB,
wM '•quarri. 3-MC. open
mangle',. SNL. so/iJ fn'an-
glev; PCS', open diarnnndf.
Correlations between in-
creusi-d SAKT following
V( Al and c\ti>cl>riimi- P-450
ir = () 91 i ami lirfAci-n de-
creased SAKT folhiwing
Df.'K and increased cytoi.
ehronir I'JoO.r - O'l^'are
significant at the I', level.
2 3
CYTOCHROME P-450 (nmoles/mg)
Reproduced from
best available copy
-------
D-22d
Figure D3 (ref. 274)
NADPH
NAOH
VI f - —
F9. ? ,
y ( P
^
-Schematization of liver multimoleciilar mixed function oxidase (MFOS) system
(adapted from: Estabrook, Concepts in Biochemical Pharmacology, 1971; Gillette et al. Ann Rev
Pharmacol 12:57, 1972; and Coon et al., Drug Metab Disp I;92. 1973) Electrons are transferred to
the central hemoprotein (cytochrome P-450) through either the NADPH or NADH cytochrome P-450
reductase arms. For the monooxygenation process, Estabrook, Gillette, and colleagues have defined a
sequence of reactions. First, the substrate (RH) combines with the oxidized form of cytochrome P-450.
Second, this substrate-P-450 complex is reduced via a one electron transfer from the NADPH arm to
form a reduced substrate P-450 complex. Third, the reduced complex then joins with molecular ox-
ygen and in this triplet the oxygen is considered "active," possibl) as a siiperoxide species with an
electron resonating between the Oj and the heme Fe. A second electron is then transferred in from
either NADH or NADPH via cytnchrome hi: reducing the triplet, which decomposes to product, H,O,
and oxidized P-450 Coon et al." have suggested additional possible roles for superoxide in hydroxyla-
tion reactions, including transfer of either electron or substrate attack with oxygen insertion
-------
D-23
metabolite, probably chloroethylene oxide (277) . The mutagenicity of
VCM has been demonstrated only in the presence of liver microsomal
preparations, including those stimulated by PBT and PCBs (276-278).
This is only one of numerous instances in which PCBs have been
shown to activate mutagens and carcinogens by stimulating the MFCS.
It is known, for example, that polycyclic aromatic hydrocarbons (PAH)
require metabolic activation via the formation of K-region epoxides
and cis-dihydrodiols before they become mutagenically active in
.bacterial and mammalian cell lines (279). The AHH enzyme system
responsible for the initial epoxidation of PAH is stimulated extremely
efficiently by PCBs (274, Figure Dl), and 18 different PAHs have been
shown to be mutagenically active using PCB-stimulated MFOS-activation
(276). Indeed, it has become standard practice to use Aroclor 1254 as
a MFOS-stimulator in bacterial mutagenesis bioassays to screen suspec-
ted carcinogens (276, 280).
Chemical carcinogens may be classified as secondary or primary
carcinogens according to whether or not they require metabolic activa-
tion before they become active carcinogens (and mutagens) (281). VCM,
as stated above, appears to be a secondary carcinogen (277) . Dimethyl-
nitrosamine (DMN) also appears to be a secondary carcinogen and its
activation to a mutagen appears to depend on oxidative demethylation
by the cytochrome P-450 dependent MFCS (282). Both this process and
the mutagenic activity of DMN in the presence of liver microsomes are
enormously enhanced by exposure to single doses of Aroclor 1254 (281,
282) (Figure D4). By contrast N-methyl-N1-nitro-N-nitroso-guanidine
-------
-------
Figure D4 (ref. 282)
D-23a
0 15 30
Incubation Tims (min.)
. Frequency of DMN ilv* revertants of B.
subltih 168 ilv. The complete mixture contained 200
m.tf DMN, 10 m.V/ MgC!., 50 mM DL-isocitrate-Na-,
5 mM NADP, 0..' ing isocitrate dchydrogunase, IS
mg microsomal protein and 3—7 X 10" bacterial cfu
in 2.S ml 0.1 Al phosphate buffer at pH 7.4 and was
incubated at 37°. In control mixtures (•—•)
either microsomcs 01 the NADPH generating system
were omitted. The system with normal microsomcs
(O—O) contained 0.7 nmolc P-450/mg microsomal
protein, that with PCB induced microsomes (• — •)
2.5 nmole P-450/mn microsomal protein. The ac-
tivity of aminopyrine demethylation expressed as
nmolu HCOH formcd/mg protein/min was 10.2 and
25.4 for normal ami PCB induced microsomes, re-
spectively.
Preceding Page Blank
-------
D-24
(MNNG) is a primary carcinogen and its mutagenic activity is reduced
by pretreatment with PCBs (281).
These findings are of profound importance in evaluating the
environmental significance of PCBs, because PCB mixtures, including
both those with high and low percentages of chlorine (Aroclors 1260
and 1242/1016 respectively), have been found to stimulate MFOS at
extremely low doses (219, 243). The significance of these findings
has been enunciated by Popper e_t al. (281, pp. 728-729):
The ability of isolated microsomes to modify the biological
activity of mutagens confirms the suggestion that the
microsomal biotransformation system plays a key role in
chemical mutagenesis. Although there is probably a
relationship between carcinogenesis and mutagenesis,
there are still differences which have not been ex-
plained. The observation that induced microsomes in-
activate the mutagenic activity of primary carcinogens
or activate that of secondary ones to a greater extent
than normal ones suggests that the status of microsom-
al metabolism affects the response of an individual
to carcinogen exposure. If we are permitted to extrap-
olate from mutagenesis to carcinogenesis, we might
understand some old observations. Differences in the
status of the biotransformation system at the time of
exposure may explain why only a limited percentage of
exposed individuals develop cancer. Furthermore,
nutritional disturbances, particularly protein (14) or
riboflavin (15) deficiency, which reduce microsomal
biotransformation, may explain the geographic preva-
lence of certain cancers such as those of the liver
(16), because malnourished populations should be more
susceptible to primary carcinogens. By contrast, in
the well-nourished technologic societies, the bio-
transformation system induced by chemical pollutants,
drugs and pesticides may prove to be the greater hazard.
-------
E-l
APPENDIX E: METABOLISM AND BIODEGRADAIION
E.I. Metabolism by Bacteria
The ability of bacteria to degrade chlorinated biphenyls is de-
pendent upon the degree of chlorination and chlorine substitution
position as well as the stereo-chemistry and electronic structure of
the chlorobiphenyl.
In laboratory investigations using single chlorobiphenyls and
commercial mixtures, there is general agreement that lower chlorinated
compounds can be degraded by microorganisms (see Figures E.2 and E.3;
Tables E.I and E.2), but there is little evidence for significant
metabolism of tetra- and higher chlorobiphenyls. The mono- and
dichlorinated biphenyls are readily degraded (82), as are chlorinated
biphenyls with one unsubstituted ring (300).
The products resulting from microbial degradation of PCBs have
been elucidated by several investigators. The products and inter-
mediates obtained on incubating unchlorinated biphenyl with a number
of microorganisms are shown in Figure E.I. If there are chlorines
substituted, they appear to remain at their original point of attach-
ment. For example, 4-chloro-biphenyl would degrade to A-chlorobenzoic
acid.
Ahmed and Focht (300) showed the preferential degradation of
the unsubstituted ring of dichlorinated biphenyls using Achromobacter
isolated from sewage effluent and grown on A-chlorobiphenyl as the
sole carbon source. Of the dichlorobiphenyls tested (2-3-; 2,4.-;
-------
-------
HO
H'OH
Pceudomonas •
putida
*Beijerinckia HO
species ^ ^
H OH
gram-ne-gative NADH
/ bacteria N.
Achromobacter
pCB
Beijerinckia
' extract
HO
, ' , COOH
'/\W/ ,CHO-
-o '
(^\* CH2CCOOH
\™3' COOH
CH COOH
^0
HO , P.
Metabolic conversion of biphenyl by several microorganisms.
Figure E.I (from refs. 4, 300, 301, 302)
Preceding Page Blank
-------
E-2
3,4-; 3,5-; and 3,3%'-dichlorobiphenyl) , only 3,3' DCB has both rings
substituted. Figure E.2 shows the brief lag associated with oxidation
of 3,3'-DCB while all other DCBs were oxidized without a lag. The
tri-CB, tetra-CB and penta-CB were oxidized slightly with the penta-
CB containing an unsubstituted ring oxidized more than the tetra-CB
with two substituted rings (see Figure E.3). Manometric data were
used to determine the extent of oxidation. Supernatant solutions
indicated no chloride, further suggesting that chlorination renders
the ring resistant to degradation and associated chlorine release.
Another experiment using bacteria (Nocardia spp. and Pseudo-
mo nas spp.) grown on biphenyl supports the proposition that low
chlorinated biphenyls are readily degraded (82). The components of
Aroclor 1242 tend to fall into three groups: (1) mono- or di-CBs
which are degraded in less than 10 days; (2) tri-CBs which are de-
graded rapidly after an induction lag, then are degraded more slowly
as their concentration drops to 10% of the original value; and (3)
tetra-CBs which are degraded most slowly (see Figures E.4 and E.5).
However, there were definite differences in degradation of the same
compound alone or in combination (see Table E.I). For example, 4,4'-
diCB, as a component of Aroclor 1242, was degraded almost completely
in 20 days when exposed to Nocardia spp. (see Figure E.4), yet 4,4'-
aiCB showed no detectable change after 121 days when incubated alone
with Nocardia spp. (see Table E.I). Mutual solubilization may be
one mechanism involved, as supported by the degradation of hexaCB
in combination with two triCBs and biphenyl, but not when the biphenyl
-------
E-3
was eliminated (see Table E.I). Co-metabolism has also been suggest-
ed to account for the microbial transformation of many pesticides in
nature, compounds that do not supply the responsible populations with
energy, carbon, nitrogen, or phosphorous, and may be another mechanism
associated with the action of bacteria on PCBs. A more complete an-
swer to the process of degradation is needed, as 4,4'-diCB could not
be induced to degrade when mixed with 3,4,2'- and 2,3,2'-triCBs (82).
The evidence appears to support adaptation of the organisms.
Thus, mono- and diCBs can probably be degraded with little further
adaptation of the biphenyl-degrading bacteria (82). Increasing
chlorination may require increasing induction time and be dependent
upon the availability of precursors. The PCB degradation times pro-
bably reflect these adaptation periods (see Table E.I).
Wong and Kaiser (76) found that the ability of bacteria (Achro-
mobacter sp. and Pseudomonas sp.), grown on 0.1% Aroclor 1242, to
degrade the chlorinated biphenyl compounds in Aroclor 1242 mixture
decreased with increasing chlorination. Specifically, the rates of
degradation of biphenyl, 2-chlorobiphenyl and 4-chlorobiphenyl de-
creased in that order (see Figure E.6). Further, gas chromatography
and mass spectrometry showed all metabolites to be aliphatic and aro-
matic compounds containing no chlorine. No phenols, alcohols or
other oxidized derivatives of the PCBs were detected, indicating a
rapid reduction of the expected intermediate hydroxylated metabol-
ites to hydrocarbons.
-------
-------
to
1.4
1.2
, _
1.0
O 3,4,2 - TRICHLOROBIPHENYL
• 2,3,2,3' - TETKACHLOROBIPHENYL
A 2,3,4,5,6 - PENTACHLOROBIPHEm
20
60
80 100 120
TIME (MINUTES)
140 160 180 200
Oxidation of tri, tetra, and penta chlorobiphenyls by Achrcmobacter pCB.
Figure E.3 (from ref. 300)
Preceding Page Blank
-------
10
to
_J
o
s
2
U3
O
[3
j
i
4.0
3.5
3.0
2.5
2.0
1.0
0.5
O.OA
O 2,3 - DICHLOROBIPHENYL
• 2,A - DICHLOROBIPHENYL
A 3,A - DICHLOROBIPHENYL
A 3,5 - DICHLOROBIPHENYL
D 3,3'- DICHLOROBIPHENYL
I i i t i I i
I . r t
50
100 150
TIME (MINUTES)
200.
250
Oxidation of dichlorobiphenyls by Achromobacter pCB.
Figure E.2 (from ref. 300)
-------
Table E.I PERCENTAGE LOSS OF PCBs AFTER A GIVEN PERIOD OF TIME
'from ref. 82)
% Degradation'Days
Compound
Nocardia spp. Pseudoronas spp.
2,4'-Dichlorobiphenyl " 70/7
2,4'-Dichlorobiphenyl •*• biphenyl 100/7
4,4'-Dichlorobiphenyl nil/121
4,4'-Dichlorobiphenyl -1- biphenyl nil/121
2,3-Dichlorobiphenyl 67/8
2,3-Dichlorobiphenyl 4- biphenyl 64/8
3,4-Dichlorobiphenyl 80/8
3,4-Dichlorobiphenyl •«• biphenyl 100'8
2,3,2'-Trichlorobiphenyl , 50/7
2,3,2'-Trichlorobiphenyl J- biphenyl 95/7
",3,4'-Trichlorobiphenyl 94/7
-,3,4'-Trichlorobiphenyl 4- biphenyl 100/7
2,5,4'-Trichlorobiphenyl nil/73
2,5,4'-Trichlorobiphenyl •*• biphenyl 60'73
3,4,3"-Trichlorobiphenyl 76/12
3,4,3'-Trichlorobiphenyl -1- biphenyl 70/12
2,4,6-Trichlorobiphenyl nil/12
2,4,6-Trichlorobiphenyl •*• biphenyl nil/12
2,4,2',4-Tetrachlorobiphenyl nil/9
2,4,2' ,4'-Tetrachlorobiphenyl + biphenyl nil/9
2,4,6,2'-Tetrachlorobiphenyl nil/9
2,4,6,2'-Tetrachlorobiphenyl 4- biphenyl nil/9
2,3,4,5,2',3f-Hexachlorobiphenyl 4-
2,3,2'- and 2,3',4'-trichlorobiphenyl nil
2,3,4,5,2',3'-Hexachlorobiphenyl -1-
2,3,2'- and 2,3',4'-trichlorobiphenyl
4-biphenyl 50/11
60'73
100'73
50 15
50/10
15/73
60/73
nil '84
nil/84
-------
Table E.2 PERCENTAGE DEGRADATION
(from ref. 82)
Aroclor 124?. • Aroclor 1016
52
100
88
95
76
85 •
96
>98
91
>96
-------
20 30 .40
TIME (DAYS)
Legend:
O Peak 13 (2 Cl)
A Peaks 15 and 18 (3 Cl)
D Peak 10 (3 Cl)
• Peaks 11 and 17 (3 Cl)
A Peaks 9 and 12 (3 Cl)
Degradation of typical di- and tri-chlorobiphenyl
components of Aroclor 12^2 following exposure to Nocardia spp.
Figure E.4 (from ref. 82)
-------
100
90
80
70
(U
£50
m
o
0)
40
30
20
10
10
20
30
40 50
60
Degradation of typical tetra-chlorobiphenyl components
of Aroclor 1242 following exposure to -Nocardia spp.
Figure E.5 (from ref. 82)
-------
100
o
u
u
d
o
o
lu
O
(A
»-J
X
C
4)
J3
cx
o
C
o
u
80
60
20
Control-
4 Monochloro
Biphenyl
2 Honochloro
Biphenyl
Biphenyl
50.
JOO 150
Hours
200
250
Concentrations of biphenyl, 2-chlorobiphenyl and A-chloro-
biphenyl in the growth medium after bacterial degradation during three
incubation periods.
Figure E.6 (from ref. 76)
-------
E-4
The slower degradation of more highly chlorinated PCBs is il-
lustrated by the observation of Veight as reported in Wong and Kaiser
(76) that Aroclor 1242 concentration decreased at a faster rate than
Aroclor 1260 in lake water, but no data were given. Tucker et al.
(303) found an inverse relationship between degradation rate and
chlorine content in commercial PCBs (see Figure E.7) using super-
natant samples from a semi-continuous activated sludge technique*.
Effluent from a secondary sewage treatment laboratory system
contained relatively small amounts of the seeded Aroclor 1254, with a
considerable PCB accumulation in the sludge (304). By sampling only
the supernatant, Tucker et al. (303) may have mistaken PCB removal
to sludge through fat dissolution, adsorption on particle surfaces,
and microbial ingestion, for degradation.
Other investigations using naturally occurring microorganisms
have produced results indicating no metabolism of chlorinated bi-
phenyls. Fries, as reported in Hutzinger et al. (4), found no pre-
ferential degradation of Aroclor 1254 components in silage after
several months of normal fermentation.
In an experiment using 0.1 ppm Aroclor 1260 added to natural
river and marine waters, Oloffs jet al. (41) could detect no metabolites;
* This procedure consisted of mixing activated sludge cultures from a
sewage treatment plant with synthetic sewage and allowed to accli-
mate for several weeks before adding polychlorinated biphenyl mix-
tures. Aeration was interrupted for sampling and at the end of a
cycle when the sludge was .-allowed to settle before withdrawing
supernatant. After replacement of the fluid with tap water, the
cycle was reinitiated by adding synthetic sewage and PCBs.
-------
100
y\
§
B
D 8°
O
to
td
2
O
O
Ld
Q
K
U
O
3
LJ
60
20
0
"Biphenyl
Aroclor 1221
MCS 1043
Degradation
Biphenyl
Aroclor 1221
MCS 1043
Aroclor 1016
Aroclor 1242
Aroclor 1254
Addition rate 1 mg/48 hrs.
Aroclor 1016
Aroclor 1242
i
Aroclor 1254
10
20
30
40
50
% CHLORINE (W/W)
Semi-continuous activated sludge primary biodegradation
rates of commercial PCBs as a function of the weight percent chloride.
Figure S.7 (from ref. 303)
-------
-------
E-5
but parent compounds were recovered in decreased concentration. Two .
mechanisms were postulated for Aroclor 1260 loss from water: codis-
tillation and evaporation. Although 0.1 ppm Aroclor 1260 evinced a
slight enhancement of bacterial growth, metabolic breakdown probably
would be very slow at the natural temperatures maintained (7 and 16°C),
one possible explanation for the lack of detectable metabolites.
Cultures isolated on biphenyl media can provide both induced
bacteria and greater numbers of the adapted organisms. Wong and
Kaiser (76) found that only 1% of the bacteria from nutrient agar
could grow on 0.01% Aroclor 1221 enriched agar. Baxter et al. (82)
suggested that degradation patterns of Aroclor 1242 could be explain-
ed in terms of adaptation of Nocardia sp. grown on biphenyl. Thus,
little further adaptation was necessary to degrade mono- and diCBs,
but for more highly chlorinated components, increasing adaptation
may be required (see Figures E.4 and E.5).
Soil microorganism metabolism of PCBs appears to depend on
soil type (4, 305). No indication of any metabolism was found in
soil alone or soil enriched with cattle manure in which single chloro-
biphenyls (4,4'-di; 2,5,2',5'-, 2,6,2',6'-, 3,4,3',4'-, and 3,5,3',5'-
tetra; 2,4,5,2',5'-penta; and 2,4,5,2',4',5'-, and 2,4,6,2',4',6'-
hexaCB) were-incubated under flooded conditions in the laboratory for
one month (306). Under the same conditions, p,p'-DDT degrades almost
completely; therefore, the degradation pathways for these compound's
are not the same.
Preceding Page Blank
-------
E-6 •
E.2. Metabolism by Invertebrates
Metcalf _e_t al. (45) studied the metabolism of three representa-.
tive chlorobiphenyls in a model ecosystem which included several in-
vertebrate animals. Their findings in the salt-marsh caterpillar
(Estigmene acrea) are shown in Table E.3. Although 76% of the tri-CB
was metabolized and excreted as polar degradation products, only 4.6% and
2.1% of the tetra- and penta-CBs were so degraded. Similar results
were obtained with a mosquito larva (Culex pipiens) and a snail (Physa)
(Table E.4). Small amounts of non-polar metabolites were found also,
especially in the case of the tri-CB: much of this non-polar material
was retained in the tissues of the organisms and not excreted (Tables
E.3 and E.4).
E.3. Metabolism by Fish
Table E.4 also gives the results of Metcalf £t al.'s study
of metabolism of the same three representative chlorobiphenyls in
mosquito fish (Gambusia). As in the case of the invertebrates, a
substantial fraction of the tri-CB was metabolized, but only insigni-
ficant fractions of the tetra- and penta-CBs. Metcalf £t al. (45)
define a "biodegradability index": the ratio of polar to non-polar
metabolites. This index ranged from 0.17 to 0.60 for the tri-CB,
indicating substantial metabolism to polar products, but was less
than 0.082 for all organisms for the tetra- and penta-CBs, indicating
negligible biodegradation (Table E.5).
-------
HTa K 1 o K "^ *
, „ v Metabolism of l4C radiolabeled compounds by salt marsh caterpillar*
(from ref. 45)
A.
B.
C.
D.
2,5,2'-trich!orobiphenyl total 14C(%)
Unknown I (Rf0.53>)
trichlorobiphenyl (Rf 0.43)
Unknown II (Rf 0.31)
Unknown III (Rf 0.1 3)
Unknown IV (Rf 0.05)
Unknown V (Rf 0.02)
Polar (Rf 0.0)
2,5,2',5'-tetrachlorobiphenyl total 14C (%)
tetrachlorobiphenyl (Rf 0.50a)
Unknown I (Rf 0.41)
Unknown II (Rf 0.05)
Unknown IiI(Rf 0.03)
Polar (Rf 0.0)
2,5,2',4',5'-pentachlorobiphenyl total >4C(%)
pentachlorobiphenyl (Rf 0.53a)
' Unknown I (Rf 0.46)
Unknown II (Rf 0.39)
Unknown III (Rf 0.03)
Polar (Rf 0.0)
2,2-6w-(p-chlorophenyl)-l,l-dichloroethylene (DDE)
total 14C(%)
DDE (Rf 0.49")
Polar (Rf 0.0)
Body
8.66
0.64
5.84
0.27
0.05
0.10
0.11
1.65
78.68
75.60
0.99
0.13
trace
1.96
75.86
74.00
0.74
0.62
0.08
0.42
80.59
76.88
3.71
Feces
91.34
-
8.91
0.37
0.12
4.67
0.92
76.35
21.32
15.08
1.36
-
0.20
4.64
24.14
20.70
0.74
0.56
0.08
2.06
19.41
19.37
0.04
tf
»TLC with hexane (Skellysolve B, bp 60-68°C).
-------
Table .4 Distribution of chlorinated biphenyls and their degradation
Qrer. o; • pro^ucts jn tfie moejei ecosystem
Chlorinated biphenyl equivalents (ppm)
I. 2,5,2'-trichloro-
biphenyl total I4C
Unknown I
(Rf 0.66")
trichlorobiphenyl
(Rf 0.56)
Unknown II
(Rf 0.23)
Unknown III
(Rf 0.10)
Unknown IV
(Rf 0.06)
Unknown V
(Rf 0.04)
Unknown VI
(Rf 0.03)
Polar (Rf 0.0)
Unextractable
II. 2,5,2',5'-tetrachloro
biphenyl totaP4C
tetrachlorobipnenyl
(Rf 0.48*)
Unknown I
(RfO.23)
Unknown II
(Rf 0.04)
Polar (Rf 0.0)
Unextractable
IH. 2,5,2' ,4',S'-penta-
chlorobiphenyl
total 14C
pentachloro-
biphenyl
(Rf 0.55»)
Unknown I
(Rf 0.46)
Unknown II
(Rf 0.39)
Unknown III
(Rf 0.21)
Unknown IV
(Rf 0.04)
Unknown V
(Rf 0.02)
Polar (Rf 0.0)
Unextractable
H20
0.03845
0.00015
0.00020
0.00005
-
0.00055
0.00040
0.00040
0.02265
0.01405
0.02065
0.00120
0.00005
0.00155
0.01225
0.00560
0.04340
0.00985
—
0.00020
0.00015
0.00030
0.00385
0.02055
0.00850
Oedogonium
(alga)
73.2155
15.9575
1.4630
0.0520
-
-
-
0.0685
0.5185
5.1560
23.6845
21.5975
0.3220
0.1030
0.3275
1.3345
62.4660.
53.8440
0.6850
0.5080
0.1425
—
0.2570
1.6265
5.4330
Physa
(snail)
31.2015
18.9720
1.1590
0.6480
0.9735
0.5460
0.2205
0.4410
3.9315
4.3100
53.7465
47.3275
0.7560
0.4360
3.9850
1.2420
633.0165
587.3545
8.6210
2.2490
1.9365"
0.5000
7.4965
16.5550
8.3040
Culex
(mosquito)
2.7030
1.1995
0.1630
+
.
-
-
-
0.4795
0.8610
14.5335
12.6745
-
0.1070
—
0.9670
0.7850
181.4565
170.8480
2.4070
1.3195
1.0520
—
—
2.6745
3.1555
Gambit sia
(fish)
3.2055
0.2085
1.2800
0.1595
-
-
-
—
0.9985
0.5590
15.5685
14.2360
0.0890
—
0.8545
0.3900
127,6945
119.7060
2.5380
0.5810
0.3285
_
0.7450
2.3610
1.4350
»TLC with hexane (Skellysolve B,bp 60-68 C).
-------
Table E.5
(ref. 45)
Ecological magnification (E.M.) and BiodegraJability index (B.I.) ofPCB's and DDE
compared with water solubility and partition coefficient
H2O solubility Partition
Chemical (ppb) coefficient
tri-ri-PCB
tetrn-CI-ITB
penta-Cl-PCB
DDF.
16 7.803
16 8,126
19 ' 16,037
1.3 18,893
Ecological magnification (E.M.) Biodegradability index (B.I.)
Alga Snail Mosquito Fish Alga Snail Mosquito Fish
7,315 5,795 815 6,400 0.30 0.17 0.35 0.60
17,997 39,439 10,562 11,863 0.015 0.082 0.076 0.060
5,464 59,629 17,345 12,152 0.029 0.027 0.0134 0.019
11,251 36,342 59,390 12,037 0.069 0.049 0.033 0.050
-------
-------
E-7
Sanborn et al. (307) obtained similar results with the green
sunfish (Lepomis cyanellus) which was able to metabolise about 8070
of the tri-CB, but almost none of the tetra- or penta-CB.
By contrast, Hutzinger et al. (308) were unable to detect any
metabolites formed by brook trout dosed with representative mono-, di-,
tetra- and penta-CBs. There was little, if any, metabolism of a penta-
CB by the dogfish (309).
E.4. Metabolism by Birds
Hutzinger e£ al. (308) reported that pigeons were able to metab-
olize mono-, di- and tetra-CBs, but not a hexa-CB. The metabolites
identified were.mono-hydroxy -CBs; unlike rats, pigeons did not pro-
duce detectable quantities of di-hydroxy-CBs. De Freitas and Nor-
strom (27) reported a relation between ease of "metabolism" in pigeons
and chlorine substitution patterns, but their measurements were based
on differential retention and did not in fact distinguish between
metabolism and excretion.
McKinney et al. (29, 310) have recently studied the metabolism
of five symmetrical isomers of hexa-CB in chickens, with some novel
and important results. In addition to the hydroxylated metabolites
identified by others as the major metabolites in birds and mammals,
they found evidence of isomerization (rearrangement of chlorine sub-
stitutions) , dechlorination, and formation of CDFs. The metabolites
of 2,4,5,2',4",5'-hexaCB included a penta-CB, a mono-hydroxy deriva-
tive, together with the 3,6-quinol and 3,6-quinone derivatives of the
Preceding Page Blank
-------
E-8
hexa-CB. The metabolites of 2,4,6,2',4',6'-hexaCB included a re-
arrangement product (2,4,6,2*,3',4'-hexaCB), a penta-CB, a hexa-CDF
and a penta-CDF. The other three hexaCBs studied (2,3,6,2',3',6'-;
2,3,4,2',3',4'-; and 3,4,5,3',4',5'-) showed little or no metabolism
except in the first case, in which a mono-hydroxy derivative was
formed. The formation of the two CDFs by metabolism of chlorobi-
phenyls appears to be well established by gas chromatography--mass
spectrometric techniques (310).
The hexa-CDF was the most abundant chlorinated compound
present in the.feces of the chicks, indicating that it was formed
in significant quantities. The authors (210) suggest that it is
formed via ortho-hydroxylation in association with chlorine migra-
tion, and hence suggest that it ma'y have a 1,2,3,7,8,9 substitution
pattern. This newly-discovered phenomenon is of potentially great
toxicological significance.
E.5. Metabolism in Mammals
Metabolism of chlorobiphenyls has been extensively studied
in mammals. A concise summary of recent work on metabolism in the
rat has been published by Goto e_t al. (311: Figure E.9,) ; as shown
in this section, metabolism in the other mammalian species studied
to date appears to be generally similar.
The liver appears to be the main site of metabolism of PCBs.
The hypothesis that PCBs are metabolically degraded by the liver is
supported by studies showing that the biotransformation of PCBs is
-------
E-9
markedly retarded when livers are damaged by administration of carbon
tetrachloride. Grant et al. (182) found that residues of Aroclor
1254 in rat tissues were higher in rats simultaneously treated with
carbon tetrachloride than in rats dosed only with Aroclor 1254. The
residue pattern in fat of animals treated with carbon tetrachloride
was similar to that of standard Aroclor 1254, indicating little metab-
olism.
Hydroxylation appears to be the main metabolic route for chloro-
biphenyls (4, 28, 308-314). Generally, dechlorination does not seem
to take place. Hutzinger et al. (4) did find traces of substances in
rat feces whose mass spectra indicated loss of a chlorine atom. The
spectra indicated a trichlorinated metabolite of 3,4,3',4'-tetraCB
and a hep'tachlorinated metabolite of 2,3,4,5,2',3',4',5'-octaCB.
Hutzinger et al. have also identified a dechlorinated metabolite of
2,4,5,2',4',5'-hexaCB in rabbits (315).
Hutzinger et al.(4) studied metabolic behavior of 11 chloro-
biphenyls in rats after intraperitoneal injection. Extracts of
urine and feces were analyzed by thin layer chromatography and mass
spectrometry. The identities of many metabolites were confirmed by
NMR spectroscopy and synthesis. The results of this study are sum-
marized in Table E.6. They did not find metabolites for hexa and
octachlorobiphenyls. Decachlorobiphenyl was not soluble enough in
oil for injection into rats.
Work has been done on metabolism of individual chlorobi-
phenyls.
-------
-------
PvlULI HSTABOLtTEJ OP CHLOROB tPUENYLS FOUND [N DlfF°.REKt «C IKAL SPCCLES
Table E,6 (from ref, 4) r-etcboiu. Found
Vo, N'«B«
t 4'CMoroSlphenyl.
Cilorob Iph n>-L AinU liteced
Formula
tt 4,4' JlchlocoblphenyL
Ctl i,i' OtchlorobLplienyL
/Lnbcal
Spec tea
U«.|
r&t
plt>,eoa
t rout,
r ibb 1C
i it
trout
rat
Koro'yuro' -Cetrachloro-
bl^henyl
VCt J.I'.'.'' tEtrdchloro-
Slphenyl
VCIC I, i' ,<,,<>',*, >' He««-
cUcroolphenyl
UC i,i'.4,4'.6.6' lltjca-
chloroSIphfenyI
S i,!1. I, I',i,1"' "c«a
chloroblphenyl
ICt 1,1' , I, l',4,«' .1,^' Octi
cliiorob Iphe-^yl
rat
pigeon
trout
raSblt
rat
plg»OQ
trout
rabb It
tetcachloroblpheoyl
HfdrocYpentBchloroblpheafI
hydro Ry^iethoicrpeatft*
chlorob LpheafL
« IncludUtg cor|u,i
** Dececccd b/ daa^/
procedure,
f
-------
E-10
Monochlorobiphenyls. Hutzinger e_t al. (308) found that 4-
chlorobiphenyl in rat urine metabolized to mono- and dihydroxychloro-
biphenyl. Very little starting material could be recovered from the
feces. No starting material could be recovered from the urine.
These observations indicate extensive metabolic degradation.
Safe _e_t al. (316) in studies of male Wistar rats, employed
NMR spectroscopy to establish the hydroxylation of 4-chlorobiphenyl
»
at the 4" position.
Pi- and Trichlorobiphenyls. Greb et_ al. (317) found that
mono and dihydroxylated derivatives were the major urinary metabol-
ites of 2,4'-dichlorobiphenyl and 2,2",5-trichlorobiphenyl in the
rhesus monkey. They found similar metabolites of these two com-
pounds to be produced by rat liver microsomes (318) .
• Hutzinger et al. (308) reported that large quantities of un-
changed 4,4'-dichlorobiphenyl could be extracted from rat feces, but
only its monohydroxy metabolites could be found in rat urine.
Hutzinger et al. (4) present a number of monohydroxy deriva-
tives observed as metabolic products from specific CBs in- rats
(Figure E.J). They also observed dihydroxy metabolites of 2,2'- and
4,4'-diCBs.
Safe _e_t- al. (316) used NMR spectroscopy to elucidate the
structure of the major hydroxylated metabolite of 4,4'-dichloro-
phenyl fed to rats. They found that hydroxylation occurred at the
3 position to produce 4,4"-dichloro-3-hydroxybiphenyl. A similar
result was obtained in goats and cows (324).
-------
•*- ci
Cl Cl
Cl
/?\w-/\^
Monohydroxy-dferivatives observed as metabolic
products from dichlorobiphenyls in rats.
Figure E.8 (from ref. 4)
-------
-------
E-ll
Tetrachlorobiphenyls. Yoshimura and Yamamoto (313) studied
the metabolic fate of 3,4,3',4'-tetrachlorobiphenyl in rats. They
found 64% of the dose excreted unchanged in the feces. They felt
that most of this unchanged material had not been absorbed from the
gastrointestinal tract. At least three metabolites were also ex-
creted in the feces. The major metabolite, a mono-hydroxy derivative,
excreted during 14 days accounted for only about 3.3% of the dose
administered.
The metabolic fate of 2,4,3',4'-tetraCB was also investigated.
At least four metabolites of phenolic nature were excreted exclusive-
ly into the feces along with a large amount of 2,4,3',4'-tetraCB.
The major metabolite was identified as 5-hydroxy-2,4,3',4'-tetraCB .
(312).
Yoshimura et al. (314) found that the metabolic rate for
2,4,3',4'-tetraCB seemed different from that of 3,4,3',4'-tetraCB
despite the fact that all tetraCB metabolites they found in rat
feces were monohydroxylated derivatives.
Gardner et_ al. (319) used infrared and mass spectra to identi-
fy the urinary metabolites of 2,5,2',5'-tetraCB in rabbits. Three
hydroxylated metabolites were excreted. They were:
3-hydroxy-2,5,2',5'-tetraCB
4-hydroxy-2,5,2',5'-tetraCB
trans-3.4-dihydro-3.4-dihvdroxv-2,5,2',5'-tetraCB
The first two compounds are phenols, but the third is a di-
hydrodiol with the vicinal hydroxy groups in the trans conformation.
Preceding Page Blank
-------
E-12
Van Miller et al. (320) studied the metabolic fate of the
same tetra-CB in rats and found that it was rapidly metabolized to
one or more hydroxylated metabolites and excreted. The principal
metabolite identified was 3-hydroxy-2,5,2',5'-tetraCB. Little of
the material was stored in the fat.
. Hsu _et al. (321) found distinct differences in the metabolism
of the same tetra-CB in infant rhesus monkeys. The 3-hydroxy deriva-
tive was not found: one of two metabolites was unidentified; the
other was identified as the trans-3,4-dihydroxy derivative. Hsu _et
al. suggest that the mechanisms of metabolism in rats and monkeys
must differ (see below).
Pentachlorobiphenyls. Berlin eJC al. (322) treated mice with
2,4,5,2',5'-pentaCB and found that 80% was excreted within 19. days,
mostly in the form of a mono-hydroxy metabolite.
Hexachlorobiphenyls. Metabolic dechlorination of 2,4,5,2',4',
5'-hexachlorobiphenyl was found by Hutzinger et
-------
E-13
Jensen and Sundstrb*ra (323) also found a mono-hydroxy deriva-
tive of this Hexa-CB, probably the 3-hydroxy derivative, in the feces
of rats. This is an important finding because 2,4,5,2',5',5'-hexaCB
has no adjacent unsubstituted carbon atoms, so that its hydroxylation
must take place directly (323).
Summary of metabolism in the rat. Goto jit al. (311) have
summarized their own work and that of others on the metabolism of
chlorobiphenyls<£s shown in Figure E.^). These results show that
hydroxylation usually takes place at the 3- and 4- positions, rarely
at the 2-position. With a few exceptions, hydroxylation usually
occurs at one of two adjacent unsubstituted positions.
E.6. The Mechanisms of Metabolism
Gardner at al. (319) gave evidence that the principal mechan-
ism of metabolism of chlorobiphenyls was via the formation of an
arene oxide (epoxide) intermediate. This has been confirmed for 4-
chlorobiphenyl by Safe et al. (325). They used material labelled
with deuterium at the 4'-position to show that metabolism in rabbits
proceeded via the 3',4'-epoxide, followed by rearrangement to form
the 4'-hydroxy- (or to a smaller extent the 3'-hydroxy) derivative.
The general importance of arene oxides as intermediates in the metab-
olism of aromatic compounds has been reviewed by Jerina and Daly (326).
One of their examples, the metabolism of chlorobenzene, is shown in
Figure E.tD. Arene oxides appear to be formed directly by microsomal
enzymatic oxidation and then to be rearranged (the "NjH" shift'yto
-------
-------
Monohydroxylated Compounds
Dihydroxylated Compounds
(OHO)
-------
Mammalian metabolism of chlorobenzene (50) to phenols, dihydrodiols, cate-
chols, and gliitaihione conjugates. Oxides are proposed as intermediates in the forma-
tion of 2- and 4-chIorophenol, while the formation of 3-chlorophenol is proposed to
occur directly. The structure of the glutathione conjugate derived from 8 is a tentative
formulation. Evidence for formation of the oxide 10 has not been obtained. On
isomerization. it would be expected lo yield 2-chlorophenol.
Figure E.10 (from ref. 326)
-------
Table D8 (from ref. .199)
PCB'S AND BHC LIVER TUMORS IN MICE
1641
'..—Histopalhologic findings in the liver of male dd mice treated with isomeri of benzene hexachloride (BHC) and tech-
nical polychlorinated biphenyls (PCBs) for 2i veeks
BHC or PCBs* in diet (ppm)
Effective
number
of micef
Histopathology of liver
Liver nodules (percent)
Oval Bile-duct Cellular Nodular Hepato-
cells prolif-. hypertrophy hyperplasia cellular
eration carcinoma
a-BHC(250) 30
«.BHC(250) + PCBs-5(250) 26
o-BHC(lOO) •. 26
a-BHC(100) + PCBs-5(250) 25
a-BHC (50) 28
a-BHC (50) + PCBs-5(250) 30
(3-BHC(250) 26
,3-BHC(250) + PCBs-5(250) 29
0-BHCdOO) 26
3-BHC(100) + PCBs-5(250) 30
0-BHC (50) '_ 28
0-BHC (50)+PCBs-5(250) 29
VBHC(250) 26
•y-BHC(250)+PCBs-5(250) 28
•y-BHC(lOO) 28
7-BHC(100) + PCBs-5(250) 30
•x-BHC (50) 28
T-BHC (50) + PCBs-5(250) 27
PCBs-5(250) 20
Controls , 20
±
+
±
+
+ +
+
23 (76.7)
21 (80. 8)
0 —
8 (32.0)
0 —
9 (30.0)
0 —
16 (55.2)
0 —
5 (16.7)
0 —
0 —
0 —
0 —
0 —
0 —
0 —
0 —
0 —
0 —
8 (26. 7)
15 (57.6)
0 —
1 (4.0)
0 -
2 (6.7)
0 —
6 (20.7)
0 —
1 (3.3)
0 —
0 —
0 —
0 —
0 —
0 —
0 —
0 —
0 —
0 —
•PCDs-5, Kanechlor 500.
tMico dying during the experiment were not Included.
-------
E-14
form phenols, or to be hydrated to form dihydrodiols (326). In the
case of chlorobiphenyls, the data in Figure E.fl suggest that arene
oxides tend to form preferentially in the 3,4-position where possible.
The formation of arene oxides requires the presence of adja-
cent unsubstituted carbon atoms and is therefore more favored for
the less chlorinated mixtures. Isomers without adjacent unsubstitu-
ted positions can be hydroxylated directly (323), although more
slowly. Safe et al. (325) showed that the formation of the dihydroxy
derivative proceeded by hydroxylation of the monohydroxy derivative,
rather than directly from the arene oxide. Other pathways of metab-
olism for hexachlorobiphenyls without adjacent unsubstituted posi-
tions are shown by the work of McKinney et al. in chickens (29, 310).
E.7. Formation of CDFs by Metabolism
In addition to the demonstration by McKinney ej: al. (29, 310)
that penta- and hexa-CDFs can be produced by metabolism in chickens,
Curley et al. (327) gave evidence that tetra-CDFs may be formed by
metabolism in rats. They isolated a substance from the urine of rats
exposed to Aroclor 1254 in the diet with a molecular weight of 304
and an isotopic cluster of 4 chlorine atoms. This matches tetra-CDF
but was not positively identified as such.. They found evidence of
small quantities of the same material in the Aroclor mixture fed to
the rats, but the material was much more prominent in the urine of
the rats (327).
-------
E-15
E.8. Toxicity of Metabolites
Metabolism of PCBs has often been regarded as detoxification,
and indeed ultimately is so when the metabolites are conjugated and
excreted. However, some of the primary metabolites may be more
toxicologically significant than the parent materials. The CDFs are
potentially much more toxic than the parent chlorobiphenyls, even if
their production is only a minor metabolic pathway (2). Yamamoto and
Yoshimura (312) reported that the acute toxicity of the primary metab-
olite of 2,4,3',4'-tetraCB is 5 times higher than that of the parent
c omp ound.
The formation of arene oxides as intermediates in metabolism
is of even greater significance. Arene oxides are chemically active
compounds which "react
readily with a variety of nucleophiles, including
such cellular macromolecules as DNA, RNA, and
protein. Thus, arene oxides have become prime
candidates for the 'bioactivated intermediates'
responsible for the binding of aromatic compounds
to biopolymers within the cell. Since the toxic,
carcinogenic, and mutagenic effects of aromatic
compounds often correlate with the extent of
this binding, arene oxides are now strongly
implicated as causative agents in producing
these effects." (326).
Thus, for example, the K-region epoxides of polycyclic aromatic hy-
drocarbons are believed to be the active primary mutagenic and carcino-
genic agents (279, 326). The same is likely to be true for PCBs .
(325, 319, 310, 29, 328). Indeed, Allen and Norback have shown
that PCBs are strongly associated with protein and nucleic acid frac-
tions of cells, and that 20% of the metabolites of a tetra-CB are
bound to microsomal protein and RNA in a non-extractable form (69).
In the words of Matthews and Anderson (328):
-------
E-16
"Thus, we are given a dilemma. Those PCBs which can
be metabolized and excreted may be metabolized via'a
carcinogenic intermediate and those PCBs which are
not readily metabolized have an extremely long biolo-
gical half-life. Several researchers have provided
evidence that the PCBs may be carcinogenic (ref. 14-
16). On the other hand, Vos et_ al. (ref. 17) have
shown the very slowly metabolized hexachlorobiphenyl
used in this study to be acnegenic, to cause liver
damage, and to induce hepatic porphyria. It is not
yet known if it is the parent PCBs or their metabo-
lites which account for the primate reproductive
failures described by Allen (ref. 18). The only
way that we are going to establish which of the
PCBs or their metabolites are carcinogenic or are
going to cause any of the other toxicological prob-
lems and at what levels of exposure the problems are
likely to arise is through systematic pharmacokinetic
studies which will allow us to extrapolate the results
of chronic low dose environmental exposures from
laboratory animals to man. Until such data is avail-
able it is my opinion that every effort should be
made to avoid environmental contamination by any type
of PCBs" (328).
-------
R-l
REFERENCES
1. Interdepartmental Task Force on PCBs. 1972. Poly-
chlorinated Biphenyls and the Environment. Washing-
ton, B.C., May 1972. COM-72-10419.
2. Panel on Hazardous Trace Substances (P.B. Hammond,
I.C.T. Nisbet, and A.F. Sarofim). 1972. Polychlori-
nated Biphenyls—environmental impact. Environmental
Research 5(3):249-362.
3. U.S. Environmental Protection Agency, Office of
Research and Development. Scientific and Technical
Assessment Report on polychlorinated biphenyls.
UnDublished draft report. September 1974. Washing-
ton, D.C. 109 pp.
4. Hutzinger, 0., S..Safe, and V. Zitko. 1974. The
Chemistry of PCB's. CRC Press, Cleveland, Ohio.
77 po.
5. Kimbroueh, R.D. 1974. The toxicity of polychlori-
nated polycyclic compounds and related chemicals.
CRC Critical Reviews in Toxicology 2(4): 4'45-498.
6. U.S. Environmental Protection Agency, Office of
Toxic Substances. 1976. Review of PCB levels in
the environment. Unpublished draft report, January
1976. Washington, D.C.
7. VERSAR, Inc. 1976. Final Report. PCBs in the
United States: Industrial use and environmental
distribution. Report to U.S. Environmental Pro-
tection Agency. Task I: Contract No. 68-01-3259.
8. [Papers presented at a Conference on PCBs, Quail
Roost Conference Center, Rougemont, North Carolina,
December 20-21, 1971.] 1972. Environmental Health
Perspectives 1:1-185.
9. Proceedings of the National Conference on Polychlori-
nated Biphenyls, Chicago, Illinois, 19-21 November,
1975 (F.A. Ayer, editor). 1976. Research Triangle
Institute, North Carolina, Report to U.S. Environ-
mental Protection Agency under Contract No. 68-91-
2928. March 1976.
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R-2
10. Kleinert, S.J. 1976. Sources of polychlorinated
biphenyls in Wisconsin. Proceedings of the National
Conference on Polvchlorinated Siphenvls;141-143.
11. Hesse, J.L. 1976. Polychlorinated biphenyl usage
and sources of loss to the environment in Michigan.
Proceedings of the National Conference on Poly-
chlorinated BiTDhenyls"!145-151.
12. Young, D.R., D.J. McDermott, and T.C. Heesen. 1976.
Marine inputs of polychlorinated biphenyls off
southern California. Proceedings of the National
Conference on Polychlorinated Biphenyls;197-209.
13. Mieure, J.P., 0. Hicks, R.G. Kaley, and V.W. Saeger.
1976. Characterization of polychiorinated biphenyls.
Proceedings of the National Conference on Poly-
chlorinated Biphenyls: 112-12$.
14. Webb, R.G,, and A.C. McCall. 1973. Quantitative PCB
standards for 'electron capture gas chromatography.
Journal of Chromatographic Science 11:366-373.
15. Hirwe, S.N., R.E. Borchard, L
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R-3
20. Webb, R.G., and A.C. McCall. 1972. Identities of
polychlorinated biphenyl isomers in Aroclors.
Journal of the Association of Official Analytical
Chemists 55(4); 746-752 . -
21. Cook, J.W. 1972. Some chemical aspects of poly-
chlorinated biphenyls (PCBs). Environmental Health
Perspectives 1:1-13.
22. Tas, A.C., and de Vos, R.H. 1971. Characterization
of four major components in a technical polychlori-
nated biphenyl mixture. Environmental Science and
Technology 5(12):1216-1218 .
23. Jensen, S., and G. Sundstrom. 1974-b. Structures
and levels of most chlorobiphenyls in two technical
PCS products and in human adipose tissue. Ambio
3(2)*:70-76. "
24. Tas, A.C., and R.J.C, Kleioool. 1972. Characteri-
zation of the components of technically polychlori-
nated biphenyl mixtures--!!.. Bulletin of Environ-
mental Contamination and Toxicology 8(1);32-37,
25. Fujiwara, K. 1974. Environmental and food contamina-
tion with PCBs in Japan. Department of Hvgienic
Chemistry, Kyoto City Institute of Public Hygiene,
Kyoto, Japan, 1974, 9.10. 45 pp.
26. Ito, N., H. Nagasaki, M. Arai, S. Makiura, S. Sugi-
hara, and K. Hirao. 1973. Histopathologic studies
on liver tumorigenesis induced in mice by technical
polychlorinated biphenyls and its promoting effect
on liver tumors induced by benzene hexachloride.
Journal of the National Cancer Institute 51(5):1637-
1646.:
27. deFreitas, A.S., and R.J. Norstrom. 1974, Turnover
and metabolism of polychlorinated biphenyls in relation
to their chemical structure and the movement of lipids
in the pigeon. Canadian Journal of Physiology and
Pharmacology 52(6):1080-1094.
28. Safe, S., 0. Hutzinger, and D. Jones. 1975. The
mechanism of chlorobiphenyl metabolism. Journal of
Agricultural and Food'Chemistry 28(5):851-853 .
29. McKinney, J.D. 1976. Toxicology of selected symmetri-
cal hexachlorobiphenyl isomers: correlating biological
effects with chemical structure, Proceedings of the
National Conference on Polychlorinated Biphenyls: 91T-104.
-------
R-4
30. McKinney, J.D., K. Chae, B.N.. Gupta, J.A. Moore, and
S.A. Goldstein. 1976a. Toxicology of hexachlorobi-
phenyl isomers and 2,3,7,8-tetrachlorodibenzofuran in
chicks. I. Relationship of chemical parameters.
Toxicology and Applied Pharmacology, in press.
31. Vos, J.G., J.H, Koeman, H.L. van der Maas, M.C, ten
Noever de Brauw, and R.H. de Vos, 1970. Identification
and toxicological evaluation of chlorinated dibenzo-
furans and chlorinated naphthalene in two commercial
polychlorinated biphenyls. Food and Cosmetics Toxi-
cology 8:625-633.
32, Bowes, G.W., M'.J. Mulvihill, B.R.T. Simoneit, A.L.
Burlingame, and R.W. Risebrough, 1975a, Identifica-
tion of chlorinated dibenzofurans in American poly-
chlorinated biphenyls. Nature 256:305-307.
33. Roach, J.A.G. and I.H. Pomerantz. 1974, The finding
of chlorinated dibenzofurans in a Japanese polychlori-
nated biphenyl sample. Bulletin Environmental Contami-
nation and Toxicology 12(3):338-342.
34. Nagayama, J., M. Kuratsune, and Y. Masuda. 1976.
Determination of chlorinated dibenzofurans in Kanechlors
and "Yusho Oil"'. 1976. Bulletin of Environmental
Contamination and Toxicology 15(1);9-13.
35. Kuratsune, M., Y. Masuda and J. Nagayama. 1976. Some
of the recent findings concerning Yusho. Proceedings
of the National Conference on Polychlorinated Biphenyls:
15-37.'':
36. Bowes, S.W., M.J. Mulvihill, M.R. DeCamp, and A.S. Kende.
1975b. Gas chromatographic characteristics of authentic
chlorinated dibenzofurans; identification of two isomers
in American and Japanese polychlorinated biphenyls.
Journal of Agricultural and Food Chemistry 23(6):1222-
1223."~
37. Haque, R., D.W. Schmedding, and V.H. Freed. 1974.
Aqueous solubility, adsorption, and vapor behavior of
polychlorinated biphenyl Aroclor 1254. Environmental
Science and Technology 8(2):139-142.
38. Freed, V.H. 1971. Preliminary notes on the study of
physical-chemical properties of polychlorinated bi-
phenyl: Aroclor 1254 as related to its environmental
behavior. Unpublished Ms. (cited in refs. 2, 4).
-------
R-5
39. Mackav, D., and A.W. Wolkoff. 1973. Rate of evapo-
ration of low-solubility contaminants from water
bodies to atmosphere. Environmental Science and
Technology 7 (7 )~: 611-614 .
40. Uhlken, L.D., R.W. Carlson, and R.M. Tyo. 1973.
Apparent volatility of PCB's as used in continuous
flow bioassays. PC3 Newsletter 5:4-8,
41. Oloffs, P.C., L.J. Albright, and S.Y. Szeto. 1972.
Fate and behavior of five chlorinated hydrocarbons
in three natural waters. Canadian Journal of Micro-
biology 18(9):1393-1398.
42. Oloffs, P.C., L.J. Albright, S.Y. Szeto, and J. Lau.
1973. Factors affecting the behavior of five chlori-
nated hydrocarbons in two natural waters and their
sediments. Journal of the Fisheries Research Board
of Canada 30(11):1619-1623.
43. Wollnofer, P.R., M. Koniger, and 0. Hutzinger. 1973.
The solubilities of twenty-one chlorobiphenyls in
water. Analabs Research Notes 13:14-16.
.44. Haque, R., and D. Schmedding. 1975. A method of
measuring the water solubility of hydrophobic chemi-
cals: solubility of five polychlorinated biphenyls.
Bulletin of Environmental Contamination and Toxicology
14:13-18.
45. Metcalf, R.L., J.R. Sanborn, P.Y. Lu, and D. Nye.
1975. Laboratory model ecosystem studies of the
degradation and fate of radiolabeled tri-, tetra-,
and pentachlorobiphenyl compared with DDE. Archives
of Environmental Contamination and Toxicology 3(2);
151-165 . *~
46. Schoor, W.P., 1975, Problems associated with low-solu-
bility compounds in aquatic toxicity tests: theoretical
model and solubility characteristics of Aroclor 1254
in water. Water Research 9(11):937-944.
47. Tucker, E.S., W.J. Litschgi, and W.M. Mees. 1975.
Migration of polychlorinated biphenyls in soil induced
by percolating water. Bulletin of Environmental Con-
tamination and Toxicology 13(1);86-93.
-------
R-6
"48. Crump-Wiesner, H.J., H.R. Feltz, and M.L. Yates.
1974. Pesticides in water: a study of the distri-
bution of polychlorinated biphenyls in the aquatic
environment. Pesticides Monitoring Journal 8(3);
157-161.
49. Dennis, D.S. 1976. Polychlorinated biphenyls in
the surface waters and bottom sediments of the major
basins of the United States. Proceedings of the
National Conference on Polychlorinated Biphenyls:
193-196.
50. Munson, T.O., H.D. Palmer, and J.M. Forns. 1976.
Transport of chlorinated hydrocarbons in the Upper
Chesapeake Bay. Proceedings or the National Con-
ference on Polychlorinated Biphenyls; 223-235.
51. Pfister, R.M., P.R. Dugan, and J.I. Frea. 1969.
Microparticulates: isolation from water and identi-
fication of associated chlorinated pesticides.
Science 166;878-879.
52. Bidleman, T.F., and C.E. Olney. 197Ha. 'Chlorinated
hydrocarbons in the Sargasso Sea atmosphere and sur-
face water. Science 183 (4124):516-518.
53. Harvey, G.R., and W.G. Steinhauer. 1974. Atmospheric
transport of polychlorobiphenyls to the North Atlantic.
Atmospheric Environment 8(8):777-782.
54. Sodergren, A. 1972. Chlorinated hydrocarbon residues
in airborne fallout. Nature 236 (5347);395-397.
55. Duce, R.A., J.G, Quinn, C.E. Olney, S.R. Piotrowicz,
B.J. Ray, and T.L. Wade. 1972. Enrichment of heavy
metals and organic compounds in the surface microlayer
of Narragansett Bay, Rhode Island. Science 176 (4031):
161-163. -
56. Riseborough, R.W., B.W. deLappe, and W. Walker II. •
1976. Pollutant transfer to the marine environment:
synthetic organics. Proceedings of a workshop spon-
sored by the International Decade of Ocean Exploration
and the National Science Foundation, Skidaway Institute
of Oceanography, January 7-9, 1976, in press.
57. Ruzo, L.O., M.J. Zabik, and R.D, Schuetz. 1972.
Polychlorinated biphenyls: photolysis of 3,4,3',4'-
tetrachlorobiphenyl and 4,4'-dichlorobiphenyl in
solution. Bulletin of Environmental Contamination and
Toxicology 8(4):217-218.
-------
R-7
58. Ruzo, L.O., M.J. Zabik, and R.D. Schuetz. 1974a.
Photochemistry of bioactive compounds: photoproducts
and kinetics of polychlorinated biphenyls. Journal
of Agricultural and Food Chemistry'22(2):199-202.
59. Ruzo, L.O., and M.J. Zabik. 1975. Polyhalogenated
biphenyls: photolysis of hexabromo and hexachlorobi-
phenyls in methanol solution. Bulletin of Environ-
mental Contamination and Toxicology 13(Z):181-182.
60. Hutzinger, 0., S. Safe, and V. Zitko. 1972c. Photo-
chemical degradation of chlorobiphenyls (PCBs).
Environmental Health Perspectives 1:15-20.
61. Herring, J.L., E.J. Hannan, and D.D. Bills. 1972.
LJV irradiation of Aroclor 1254. Bulletin of Environ-
mental Contamination and Toxicology '8(3 ); 153-157.
62. Crosby, D.G., K.W. Moilanen, and A.S. Wong. 1973.
Environmental generation and degradation of dibenzo-
dioxins and dibenzofurans. Environmental Health
Perspectives 5:259-266.
63. Crosby, D.G., and K.W. Moilanen. 1973. Photodecompo-
sition of chlorinated biphenyls and dibenzofurans.
Bulletin of Environmental Contamination and Toxicology
10(6) :372-377.
64. Hutzinger, 0., S. Safe, B.R. Wentzell, and V. Zitko.
1973. Photochemical degradation of di- and octa-
chlorodibenzofuran. Environmental Health Perspectives
5:267-270. :
65. Harris, J.R., L. Rose. 1972, Toxicity of Polychlori-
nated biphenyls in poultry. Journal of the American
Veterinary Medical Association 161C13J :1584-1586.
66. Broadhurst, M.G. 1972. Use and replaceability of
polychlorinated biphenyls. Environmental Health Per-
spectives 2:81-102".
67. Kimbrough, R.D. 1976. Pathological findings associated
with chronic experimental exposure to PCB's. Proceedings
of the National Conference on Polychlorinated Biphenyls;
39-41.
68. Calandra, J.C. 1976. Summary of toxicological studies
on commercial PCB's. Proceedings of the National Con-
ference on Polvchlorinated Biohenyls:43-54.
-------
R-8
69. Allen, J.R., and D.H. Norback. 1976. Pathobiologi-
cal responses of primates to polychlorinated biphenyl
exposure. Proceedings of the National Conference on
Polvchlorinated Biphenyls; 57'-64'.
70. Biocca, M., J.A. Moore, B.N. Gupta, and J.D. McKin-
ney. 1976. Toxicology of selected symmetrical
hexachlorobiphenyl isomers: 1. Biological responses in
chicks and mice. Proceedings of the National Con-
ference on Polvchlorinated Biphenyls;89-103.
71. Moore, J.A., B.N. Gupta, and J.G. Vos. 1976. Toxi-
city of 2,3,7,8- tetrachlorodibenzofuran--preliminary
results. Proceedings of the National Conference on
Polvchlorinated Biphenvls:105-107.
72. Stendell, R.C. 1976. Summary of recent information
regarding effects of PCB's on birds and mammals.
Proceedings of the National Conference on Polychlori-
nated Biphenvls; 255-256.
73. Walker, C.R. 1976. Pre-1972 knowledge of nonhuman
effects of polychlorinated biphenyls. -Proceedings of
'the National Conference on Polvchlorinated Biphenvls:
257-258 .
74. Hansen, D.J. 1976. PCB's: effects on and accumula-
tion by estuarine organisms. Proceedings of the
National Conference on PolychlorinatedBiohenvls:
259-260.
75. Nebeker, A.V. 1976. Summary of recent information
regarding effects of PCB's on freshwater organisms.
Proceedings of the National Conference on Polychlori-
nated Biphenvls: 261-269.
76. Wong, P.T.S., and K.L.E. Kaiser, 1975. Bacterial
degradation of polvchlorinated biphenyls. II. Rate
Studies, Bulletin of Environmental Contamination
and Toxicology 13(2 );249-256.•
77. Bourquin, A.W. and S. Cassidy, 1975. Effect of Poly-
chlorinated biphenyl formulations on the growth of
estuarine bacteria. Applied Microbiology 29(1): 125-
127. ~" "*"
78. Bourquin, A.W., L.A. Kiefer, N.H. Berner, S. Crow,
and D. G. Ahearn. 1975. Inhibition of estuarine
microorganisms by Dolychlorinated biphenyls. Develop-
ment in Industrial Microbiolosv 16(25):256-261.
-------
R-9
79. Keil, J.E., S.H. Sandifer, C.D. Graber, and L.E.
Priester. 197 2a. DDT and polychlorinated biphenyl
(Aroclor 1242) effects of uptake on E-»coli growth,
Water Research 6(7 ): 837-841".
80. Greer, D.E., J.E. Keil, L.W. Stillway, and S.H.
Sandifer, 1974. The effects of DDT and PCB on
lipid metabolism in E_. coli and B. fragilis.
Bulletin of Environmental ContamTnation and Toxi-
cology 12(3);295-300.
81. Walsh, F. and R. Mitchell. 1974. Inhibition of
inter-microbial predation by chlorinated hydrocar-
bons. Nature 249(5458);673-674.
82. Baxter, R.A., D.E. 'Gilbert, R.A. Lidgett, J.H,
Mainprize and H.A. Vodden, 1975. The degradation
of polychlorinated biphenyls by micro-organisms.
The'Science of the Total Environment 4(1):53-61.
83. Fisher, N.S. 1975. Chlorinated hydrocarbon pol-
lutants and photosynthesis of marine phytoplankton:
a reassessment. Science 189(4201):463-464.
84. Luard, E.J. 1973. Sensitivity of dunaliella and
scenedesmus (chlorophyceae) to chlorinated hydro-
carbons. Phycologia 12(1/2);29-33.
85, Keil, J.E., L.E. Priester, and S.H. Sandifer. 1971.
Polychlorinated biphenyl (Aroclor 1242R): effects
of uptake on growth, nucleic acids, and chlorophyll
of a marine diatom. Bulletin of Environmental Con-
tamination and Toxicology 6(2):156-159.
86. Fisher, N.S. and C.F. Wurster. 1973. Individual
and combined effects of temperature and polychlori-
nated biphenyls on the growth of three species of
phytoplankton. Environmental Pollution 5(3):205-
212.
87. Mosser, J.L., N.S. Fisher and C.F. Wurster. 1972b.
Polychlorinated biphenyls and DDT alter species com-
position in mixed cultures of algae. Science 176
(4034):533-535.
88. Mosser, J.L., N.S. Fisher, T.C. Teng, and C.F. Wur-
ster. 1972a. Polychlorinated biphenyls: toxicity
to certain phytoplankters. Science 175(4018):191-192.
-------
R-.10
89. Fisher, N.S., L.B. Graham, E
-------
R-ll
101. Wildish, D. J. 1970. The toxicity of polychlorinated biphenyls
(PCBs) in sea water to Gammarus oceanicus. Bulletin of Environ-
mental Contamination and Toxicology 5(3): 202-204.
102. Nimmo, D. R., R. R. Blackman, A. J. Wilson, Jr., and J. Forester.
1971. Toxicity and distribution of AroclorR 1254 in the Pink
Shrimp Penaeus duorarum. Marine Biology 11(3): 191-197.
103. Nimmo, D. R. and L. H. Bahner. 1974. Some physiological conse-
quences of polychlorinated biphenyl and salinity-stress in
Penaeid shrimp. In Pollution and Physiology of Marine Organisms.
Eds. F. J. Vernberg and W. B. Vernberg. Academic Press, NY: 427-443.
104. Nimmo, D. R., J. Forester, P. T. Heitmuller, and G. H. Cook. 1974.
Accumulation of Aroclor 1254 in Grass Shrimp (Palaemonetes pugio)
in laboratory and field exposures. Bulletin of Environmental
Contamination & Toxicology 11(4): 303-308.
105. Nimmo, D. R., D. J. Hansen, J. A. Couch, N. R. Cooley, P. R.
Parrish, and J. I. Lowe. 1975. Toxicity of Aroclor(R) 1254
and its physiological activity in several estuarine organisms.
Arch. Environ. Contam. Toxicol. 3(1): 22-39.
106. Couch, J. A., and D..R. Nimmo. 1974. Detection of interactions
between natural pathogens and pollutants in aquatic animals. In
Diseases of Aquatic Animals, pp. 261-268.
107. Couch, J. A. and D. R. Nimmo. 1974. Ultrastructural studies of
shrimp exposed to the pollutant chemical polychlorinated biphenyl
(Aroclor 1254). Bulletin of the Society of Pharmacological and
Environmental Pathologists 11(2): 17-20.
108. Lowe, J. I., P. R. Parrish, J. M. Patrick, Jr., and J. Forester.
1972. Effects of the polychlorinated biphenyl AroclorR 1254 on
the American Oyster Crassostrea virginica. Marine Biology 17(3):
209-214.
109. Hansen, D. J. 1974. Aroclor^ 1254: Effect on composition of
developing estuarine animal communities in the laboratory. Con-
tributions in Marine Science 18: 19-33.
110. Industrial Bio-Test Laboratories, Inc. 1972. Report to Monsanto
Company: Four-day static fish toxicity studies with Aroclor 1221,
Aroclor 5432, Aroclor 5442, Aroclor 5460 and MCS 1016 in Bluegills
and channel catfish. Unpublished report no. A9380, Jan. 12, 1972.
111. Hansen, D. J., P. R. Parrish, J. I. Lowe, A. J. Wilson, Jr., and
P. D. Wilson. 1971. Chronic toxicity, uptake, and retention of
Aroclor" 1254 in two estuarine fishes. Bulletin of Environmental
Contamination & Toxicology 6(2): 113-119.
112. Nebeker, A. W., F. A. Puglisi, and D. L. DeFoe. 1974. Effect of
polychlorinated biphenyl compounds on survival and reproduction of
the Fathead Minnow and Flagfish. Reprinted from Transactions of the
American Fisheries Society 103(3): 562-568.
-------
R-12
113. De Foe, D. L., G. D. Veith, and R. W. Carlson. 1976. Effects of
Aroclor 1248 and 1260 on the fathead minnow. Journal of the
Fisheries Research Board of Canada, in press.
114. Hansen, D. J., S, C. Schimmel, and J. Forester. 1974. Aroclor
1254 in eggs of sheepshead minnows: effect on fertilization success
and survival of embryos and fry. Proceedings of the 27th Annual
Conference of the Southeastern Association of Game and Fish
Commissioners: 420-426.
115. Schimmel, S. C., D. J. Hansen, and J. Forester. 1974. Effects
of Aroclor 1254 on laboratory-reared embryos and fry of sheeps-
head minnows (Cyprinodon variegatus). Transactions of the American
Fisheries Society 103(3): 582-586.
116. Hansen, D. J., S. C. Schimmel, and J. Forester. 1975. Effects of
Aroclor 1016 on embryo, fry, juvenile and adult sheepshead minnows
(Cyprinodon variegatus). Transactions of the American Fisheries
Society 104(3): 582-586.
117. Hogan, J. W., and J. L. Brauhn. 1974. Abnormal rainbow trout fry
from eggs containing high residues of a PCB (Aroclor 1242). JPro-
gressive Fish Culturist, 1974.
118. Jensen, S., N. Johansson, and M. Olsson. 1970. PCB — indications
of effects on salmon. Swedish Salmon Research Institute Report
LFI medd 7/1970.
119. Halter, M. T. and H. E. Johnson. 1974. Acute toxicities of a
polychlorinated biphenyl (PCB) and DDT alone and in combination to
early life stages of Coho Salmon (Oncorhynchus kisutch). Journal
of the Fisheries Research Board of Canada 31(9): 1543-1547.
120. Sharski, V. M. and F. A. Puglisi. 1975. Effects of Aroclor 1254
on brook trout, Salvelinus fontinalis, Final Report. Unpublished
report, Environmental Research Laboratory, Environmental Protection
Agency, Duluth, Minnesota-.
121. Gruger, E. J., Jr., N. L. Karrick, A. I. Davidson, and T. Hruby.
1975. Accumulation of 3,4,3',4',5' and 2,4,6,2',4',6'-hexachloro-
biphenyl in juvenile Coho Salmon. Environmental Science and
Technology 9(2): 121-127.
122. Johansson, N.-, A. Larsson, and K. Lewander. "1972. Metabolic effects
of PCB (Polychlorinated Biphenyls) on the Brown Trout (Salmo trutta).
Comparative and General Pharmacology 3(11); 310-314.
123. Yap, H. H., D. Desaiah, and K. L. Cutkomp. 1971. Sensitivity of
fish ATPases to polychlorinated biphenyls. Nature 233(5314): 61-62.
124. Cutkomp, L. K., H. H. Yap, D. Desaiah, and R. B. Koch. 1972. The
sensitivity of fish ATPases to polychlorinated biphenyls. Environ-
mental Health Perspectives 1: 165-168.
-------
R-13
125. Desaiah, D., L. K. Cutkomp, H. H. Yap, and R. B. Koch. 1972.
Inhibition of oligomycin-sensitive and insensitive magnesium
adenosine triphosphatase activity in fish by polychlorinated
biphenyls. Biochemical Pharmacology 21(6): 857-865.
126. Koch, R. B., D. Desaiah, H. H. Yap, and L. K. Cutkomp. 1972.
Polychlorinated biphenyls: effect of longterm exposure on
ATPase activity in fish, Pimephales promelag. Bulletin of
Environmental Contamination & Toxicology 7(2/3): 87-92.
127. Kinter, W. B., L. S. Merkens, R. H. Janicki, and A. M. Guarino.
1972. Studies on the mechanism of toxicity of DDT and polychlorin-
ated biphenyls (PCBs): Disruption of osmoregulation in marine
fish. Environmental Health Perspectives 1: 169-173.
128. Zitko, V. and P. M. K. Choi. 1973. Oral toxicity of chlorinated
dibenzofurans to juvenile Atlantic Salmon. Bulletin of Environ-
mental Contamination & Toxicology 10(2): 120-122.
129. Vos, J. G. 1972. Toxicology of PCB's for mammals and for birds.
Environmental Health Perspectives, Experimental Issue 1: 105-117.
130. Stendell, R. C. 1976. Summary of recent information regarding
effects of PCB's on birds and mammals. Proceedings of the National
Conference on PCBs; 255-256.
131. Heath, R. G., J. W. Spann, J. F. Kreitzer, and C. Vance. 1970.
Effects of polychlorinated biphenyls on birds. Proceedings of
the XVth International Ornithological Congress; 475-485.
132. McCune, E. L., J. E. Savage, and B. L. O'Dell.' 1962. Hydroperi-
cardium and ascites in chicks fed a chlorinated hydrocarbon.
Poultry Science 41(1): 295-299.
133. Flick, D. F., R. G. O'Dell and V. A. Childs. 1965. Studies of the
chick edema disease 3. Similarity of symptoms produced by feeding
chlorinated biphenyl. Poultry Science 44(6); 1460-1465.
134. Kohanawa, M., S. Shoya, T. Yonemura, K. Nishimura, and Y. Tsushio.
1969. Poisoning due to an oily by-product of rice-bran similar to
chick edema disease. II. Tetrachlorodiphenyl as toxic substance.
National Institute of Animal Health Quarterly 9(4): 220-228.
135. Rehfeld, B. M., R. L. Bradley, Jr., and M. L. Sunde. 1971. Toxicity
studies on polychlorinated biphenyls in the chick. (1). Toxicity
and symptoms. Poultry Science 50(4); 1090-1096.
136. Platonow, N. S. and H. S. Funnell. 1972. The distribution and some
effects of polychlorinated biphenyls (Aroclor 1254) in cockerels
during prolonged feeding trial. Canadian Journal of Comparative
Medicine 36(2): 89-93.
-------
R-14
137. Vos, J. G. and J. H. Koeman. 1970. Comparative toxicologic study
with polychlorinated biphenyls in chickens with special reference
to porphyria, edema formation, liver necrosis, and tissue residues.
Toxicology and Applied Pharmacology 17(3): 656-668.
138. Rehfeld, B. M., R. L. Bradley, Jr., and M. L. Sunde. 1972. Toxicity
studies on polychlorinated biphenyls in the chick. (2). Biochemical
effects and accumulations. Poultry Science 51(2): 488-493.
139. Koeman, J. H., M. C. TenNoever DeBrauw, and R. H. DeVos. 1969.
Chlorinated biphenyls in fish, mussels and birds from the River
Rhine and the Netherlands coastal area. Nature 221(5186): 1126-1128.
140. Prestt, I., D. J. Jefferies, and N. W. Moore. 1970. Polychlorinated
biphenyls in wild birds in Britain and their avian toxicity. Environ-
mental Pollution 1(1): 3-25.
141. Dahlgren, R. B., R. L. Linder, and C. W. Carlson. 1972. Polychlorina-
ted biphenyls: Their effects on penned pheasants. Environmental
Health Perspectives Exp. 1: 89-101.
142. Koeman, J. H., H.C.W. Van Velzen-Blad, R. DeVries, and J. G. Vos.
1973. Effects of FCB and DDE in cormorants and evaluation of PCB
residues from an experimental study. Journal of Reproduction and
Fertility 19(Suppl.): 353-364.
143. Firestone, D. 1972. Etiology of chick edema disease. Environmental
Health Perspectives 5: 59-66.
144. Kohanawa, M., S. Shoya, Y. Ogura, M. Moriwaki, and M. Kawasaki. 1969a.
Poisoning due to an oily by-product of rice-bran similar to chick
edema disease. I. Occurrence and toxicity test. National Institute
of Animal Health Quarterly 9(4); 213-219.
145. Vos, J. G., J.J.T.W.A. Strik, C.W.M. Van Holsteijn, and J. H. Pennings.
1971. Polychlorinated biphenyls as inducers of hepatic porphyria in
Japanese Quail, with special reference to £-aminolevulinic acid
synthetase activity, fluorescence, and residues in the liver. Toxicol-
ogy and Applied Pharmacology 20(2); 232-240.
146. Goldstein, J. A., J. D. McKinney, G. W. Lucier, J. A. Moore, P.
Hickman, and H. Bergman. 1974. Effects of hexachlorobiphenyl isomers
and 2,3,7,8-tetrachlorodibenzofuran (TCDF) on hepatic drug metabolism
and porphyrin accumulation (Abstract). Pharmacologist 16: 239.
147. Goldstein, J. A., J. D. McKinney, G. W. Lucier, P. Hickman, H. Barg-
man, and J. A. Moore. 1976. Toxicology of hexachlorobiphenyl isomers
and 2,3,7,8-tetrachlordibenzofuran in chicks. II. Effects on drug
metabolism and porphyrin accumulation. Toxicology and Applied Pharma-
cology. In press.
148. Poland A. and E. Glover. 1973. Studies on the mechanism of toxicity
o£ the chlorinatei dihenzQ-p--dioxins-^ Environmental Health Perspec-
tives 5: 245-251.
-------
R-15
149. Scott, M. L., D. V. Vadehra, P. A. Mullenhoff, G. L. Rumsey, and
R. W. Rice. 1971. Results of experiments on the effects of PCB's
on laying hen performance. Proceedings Cornell Nutrition Confer-
ence for Feed Manufacturers, pp. 56-64.
150. Scott, M. L., J. R. Zimmermann, S. Marinsky, P. A. Mullenhoff, G. L.
Rumsey, and R. W. Rice. 1975. Effects of PCBs, DDT, and mercury
compounds upon egg production, hatchability and shell quality in
chickens and Japanese quail. Poultry Science 54(2): 350-368.
151. Briggs, D. M. and J. R. Harris. 1973. Polychlorinated biphenyls
influence on hatchability. Poultry Science 52(4); 1291-1294.
152. Britton, W. M. and T. M. Huston. 1973. Influence of polychlorinated
biphenyls in the laying hen. Poultry Science 52(4): 1620-1624.
153. Platonow, N. S. and B. S. Reinhart. 1973. The effects of poly-
chlorinated biphenyls (Aroclor 1254) on chicken egg production,
fertility and hatchability. Canadian Journal of Comparative Medi-
cine 37(4): 341-346.
154. Tumasonis, C. F., B. Bush, and F. D. Baker. 1973. PCB levels in
egg yolks associated with embryonic mortality and deformity of
hatched chicks. Archives of Environmental Contamination and Toxi-
cology 1: 312-324.
155. Bush, B., C. F. Tumasonis, and F. D. Baker, 1974. Toxicity and
persistence of PCB homologs and isomers in the avian system.
Archives of Environmental Contamination and Toxicology )2(3): 195-212.
156. Mclaughlin, J., Jr., J.-P. Marliac, M. J. Verrett, M. K. Mutchler,
and 0. G. Fitzhugh. 1963. The injection of chemicals into the yolk
sac of fertile eggs prior to incubation as a toxicity test. Toxicology
and Applied Pharmacology 5: 760-771.
157. Lillie, R. J., H. C. Cecil, J. Bitman, G. F. Fries, and J. Verrett.
1975. Toxicity of certain polychlorinated and polybrominated bi-
phenyls on reproductive efficiency of caged chickens. Poultry
Science 54(5): 1550-1555.
158. Cecil, H. C., J. Bitman, R. J. Lillie, G. F. Fries, and J. Verrett.
1974. Embryotoxic and teratogenic effects in unhatched fertile eggs
from hens fed polychlorinated biphenyls (PCBs). Bulletin of Environ-
mental Contamination & Toxicology 11(6): 489-495.
159. Dahlgren, R. B. and R. L. Linder. 1971. Effects of polychlorinated
biphenyls on pheasant reproduction, behavior, and survival. Journal
of Wildlife Management 35(2): 315-319.
160. Risebrough, R. W. and D. W. Anderson. 1975. Some effects of DDE
and PCB on mallards and their eggs. Journal of Wildlife Management
39(3): 508-513.
161. Peakall, D. B., J. L. Lincer, and S. E. Bloom. 1972. Embryonic
mortality and chromosomal alter ations caused by Aroclor 1254 in
Ring Doves. Environmental Health Perspectives 1: 103-104.
-------
R-16
162. Peakall, D. B. 1971. Effect of polychlorinated biphenyls (PCBs)
on the eggshell of Ring Doves. Bulletin of Environmental Contamin-
ation & Toxicology 6(2); 100-101.
163. Peakall, D. B. and M. L. Peakall. 1973. Effects of a polychlorin-
ated biphenyl on the reproduction of artificially and naturally
incubated dove eggs. Journal of Applied Ecology 10(3): 863-868.
164. Lincer, J. L. 1972. The effects of organochlorines on the American
Kestrel (Falco sparverius Linn.). Ph.D. thesis, Cornell University.
165. Call, D. J. and B. E. Harrell. 1974. Effects of Dieldrin and PCBs
upon the production and morphology of Japanese Quail eggs. Bulle-
tin of Environmental Contamination & Toxicology 11(1): 70-77.
166. Bitman, J., H. C. Cecil, and S. J. Harris. 1972. Biological
effects of polychlorinated biphenyls in rats and quail. Environ-
mental Health Perspectives Exp. 1: 145-149.
167. Chang, E. S. and E.L.R. Stokstad. 1975. Effect of chlorinated
hydrocarbons on shell gland carbonic anhydrase and egg shell
thickness in Japanese Quail. Poultry Science 54: 3-10.
168. Hurst, J. G., W. S. Newcomer, and J. A. Morrison. 1974. Some
effects of DDT, toxaphene and polychlorinated biphenyl on thyroid
function in Bobwhite Quail. Poultry Science 53(1): 125-133.
169. Lincer, J. L. and D. B. Peakall. 1970. Metabolic effects of
polychlorinated biphenyls in the American Kestrel. Nature 228(5273):
783-784.
170. Bailey, S. and P. J. Bunyan. 1972. Interpretation of persistence
and effects of polychlorinated biphenyls in birds. Nature 236(3/3):
34-36.
171. Nowicki, H. G. and A. W. Norman. 1972. Enhanced hepatic metabolism
of testosterone, 4-androstene-3, 17-dione, and estradiol-17-beta
in chickens pretreated with DDT or PCB. Steroids 19(1): 85-99.
172. Dieter, M. P. 1974. Plasma enzyme activities in Coturnix quail
fed graded doses of DDE, polychlorinated biphenyl, Malathion and
mercuric chloride. Toxicology and Applied Pharmacology 27(1): 86-98.
173. Jefferies, D. J. and J.L.F. Parslow. 1972. Effect of one poly-
chlorinated biphenyl on size and activity of the gull thyroid.
Bulletin of Environmental Contamination & Toxicology 8(5): 306-310.
174. Jefferies, D. J. 1975. The role of the thyroid in the production
of sublethal effects by organochlorine insecticides and polychlorin-
ated biphenyls. In Organochlorine Insecticides; Persistent Organic
Pollutants (Ed., F. Moriarty), pp. 131-230. Academic Press, London
and New York.
-------
R-17
175. Iturri, S. J., E. A. Cogger, and R. K. Ringer. 1974. Cardiovascu-
lar and hematological parameters affected by feeding various poly-
chlorinated biphenyls to the single comb White Leghorn cockerel.
Archives of Environmental Contamination and Toxicology 2(2): 130-142,
176. Ulfstrand, S., A. SBdergren, and J. Rabbi. 1971. Effect of PCB
on nocturnal activity in caged Robins, Erithacus rubecula L.
Nature 231(5303)-.467-468.
177. Harris, S. J., H. C. Cecil, J. Bitman, and R. S. Lillie. 1976.
Antibody response and reduction in bursa of Febricius and spleen
weights of progeny of chickens fed PCBs. MS., in press.
178. Friend, M. and D. 0. Trainer. 1970. Polychlorinated biphenyl:
interaction with duck hepatitis virus. Science 170: 1314-1316.
179. Linder, R. E., T. B. Gaines, and R. D. Kimbrough. 1974.
effect of polychlorinated biphenyls on rat reproduction.
and Cosmetics Toxicology 12: 63-77.
180. Grant, D. L. and W.E.J. Phillips. 1974. The effect of age and sex
on'the toxicity of Aroclor .(R) 1254, a polychlorinated biphenyl in
the'rat. Bulletin of Environmental Contamination and Toxicology
12(2): 145-152.
181. Tanaka, K., S. Fujita, F. Komatsu, and N. Tamura. 1969. Experi-
mental subacute poisoning of chlorobiphenyls, especially the in-
fluence on the serum lipids in rats. Fukuoka Acta Medica 60(6):
544-547.
182. Grant, D. L., W.E.J. Phillips, and D. C. Villeneuve. 1971a.
Metabolism of a polychlorinated biphenyl (Aroclor (R) 1254)
mixture in the rat. Bulletin of Environmental Contamination and
Toxicology 6(2): 102-112.
183. Tucker, R. K. and D. G. Crabtree. 1970. Handbook of Toxicity of
Pesticides to Wildlife. U. S. Department of Interior, Bureau of
Sport Fisheries and Wildlife, Resources Publication No. 84. Pp. 119.
Washington, B.C.
184. Miller, J. W. 1944. Pathologic changes in animals exposed to a
commercial chlorinated diphenyl. U. S. Public Health Reports 59:
1085-1093.
185. Bennett, G. A., C. K. Drinker, and M. F. Warren. 1938. Morpholo-
gical changes in the livers of rats resulting from exposure to
certain chlorinated hydrocarbons. Journal of Industrial Hygiene
and Toxicology 20(2); 97-123.
186. Wedel, H. von, W. A. Holla, and J. Denton. 1943. Observations on
the toxic effects resulting from exposure to chlorinated naphtha-
lenes and chlorinated phenyls with suggestions for prevention.
Rubber Age 53: 419-426.
-------
R-18
187. Kimbrough, R. D., R. E. Linder, and T. B. Gaines. 1972.
Morphological changes in livers of rats fed polychlorinated
biphenyls. Archives of Environmental Health 25(5): 354-364.
188. Allen, J. R. and L. J. Abrahamson. 1973. Morphological
and biochemical changes in the liver of rats fed poly-
chlorinated biphenyls. Archives of Environmental Con-
tamination & Toxicology 1(3): 265-280.
189. Kimbrough, R. D., R. E. Linder, V. W. Burse, and R. W.
Jennings. 1973. Adenofibrosis in the rat liver, with per-
sistence of polychlorinated biphenyls in adipose tissue.
Archives of Environmental Health 27: 390-395.
190. Ito, N., H. Nagasaki, S. Makiura, and M. Arai. 1974. Histo-
pathological studies on liver tumorigenesis in rats treated
with polychlorinated biphenyls. GANN 65: 544-549.
191. Kimbrough, R. D. and R. E. Linder. 1974. The induction of
adenofibrosis and hepatomas of the liver in mice of the
BALB/cJ strain by polychlorinated biphenyls (Aroclor 1254).
Journal of the National Cancer Institute 53(2): 547-552.
192. Ito, N., H. Nagasaki, M. Arai, S. Makiura, S. Sugihara, and
K. Hirao. 1973. Histopathologic studies on liver tumori-
genesis induced in mice by technical polychlorinated bi-
phenyls and its promoting effect on liver tumors induced by
benzene hexachloride. Journal of the National Cancer Insti-
tute 51(5): 1637-1646.
193. Anon. 1975. Comparative toxicity of three hexachlorobi-
phenyl isomers in male mice. Unpublished manuscript.
National Institute of Environmental Health Sciences.
194. Allen, J. R. and D. H. Norback. 1973. Polychlorinated bi-
phenyl- and triphenyl-induced gastric mucosal hyperplasia
in primates. Science 179(4072): 498-499.
195. Allen, J. R., L. J. Abrahamson, and D. H. Norback. 1973.
Biological effects of polychlorinated biphenyls and triphenyls
on subhuman primates. Environmental Research 6: 344-354.
196. Allen, J. R., L. A. Carstens, and D. A. Barsotti. 1974.
Residual effects of short-term, low-level exposure of non-
human primates to polychlorinated biphenyls. Toxicology
and Applied Pharmacology 30(3); 440-451.
197. McNulty, W. P. 1976. jUse of the rhesus monkey as a model
for human toxicity with polychlorinated biphenyls.3 Pro-
ceedings of the National Conference on Polychlorinated
Biphenyls: 332-333.
-------
R-19
198. Bell, M. 1976. {"stomach and lip lesions in rhesus monkeys
exposed to Aroclor 1242.] Proceedings of the National
Conference on Polychlorinated Biphenyls: 334-335.
199. Aulerich, R. J., R. K. Ringer, and S. Iwamoto. 1973.
Reproductive failure and mortality in mink fed on Great
Lakes fish. Journal of Reproduction and Fertility 19
(Suppl.): 365-376.
200. Ringer, R. K., R. J. Aulerich and M. Zabik. 1972. Effect
of dietary polychlorinated biphenyls on growth and reproduc-
tion of mink. Proceedings of the American Chemical Society
12(1): 149-154.
201. Platonow, N. S. and L. H. Karstad. 1973. Dietary effects
of polychlorinated biphenyls on mink. Canadian Journal of
Comparative Medicine 37(4): 391-400.
202. Gupta, B. N., J. G. Vos, J..A. Moore, J. G. Zinkl, and
B. C. Bullock. 1973. Pathologic effects of 2,3,7,8-tetra-
chlorodibenzo-p-dioxin in laboratory animals. Environmental
Health Perspectives 5: 125-140.
203. Vos, J. G., J. A. Moore, and J. G. Zinkl. 1974. Toxicity
of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in C57B1/6
mice. Toxicology and Applied Pharmacology 29: 229-241.
204. Vos, J. G. and R. B. Beems. 1971. Dermal toxicity studies
of technical polychlorinated biphenyls and fractions thereof
in rabbits. Toxicology and Applied Pharmacology 19(4): 617-
633.
205. Vos, J. G. and E. Notenboom-Ram. 1973. Comparative toxicity
studies of 2,4,5,2',4",5'-hexachlorobiphenyl and a poly-
chlorinated biphenyl mixture in rabbits. Toxicology and
Applied Pharmacology 23: 563-578.
206. Moron, M., G. SundstrBm, and C. A. Wachmeister. 1973. Poly-
chlorinated biphenyls. VI. 2,3,7,8-tetrachlorodibenzofuran,
a critical by-product in the synthesis of 2,2',4,4',5,5'-
hexachlorobiphenyl by the Ullmann reaction. Acta Chemica
Scandinavica 27(8): 3121-3122.
207. Industrial Bio-Test Laboratories, Inc. 1971b. Reports to
Monsanto Company. Two-year chronic toxicity with Aroclor
1242, 1254 and 1260 in albino rats. Unpublished reports,
November 12, 1971. IBT No. B7298.
208. Burse, V. W., R. D. Kimbrough, E. C. Villanueva, R. W. Jennings,
R. E. Linder, and G. W. Sovocool. 1974. Polychlorinated bi-
phenyls. Storage, distribution, excretion, and recovery: Liver
morphology after prolonged dietary ingestion. Archives of
Environmental Hea-lth 29(6): 301-307.
-------
R-20
209. Industrial Bio-Test Laboratories, Inc. 1972. Report to
Monsanto Company. 90-day subacute oral toxicity study
with MCS 1016 in albino rats. Unpublished report,
April 28, 1972. 1ST No. B9888.
210. Nishizumi, M. 1970. Light and electron microscope study
of chlorobiphenyl poisoning, in mouse and monkey liver.
Archives of Environmental Health 21: 620-625.
211. ftrberg, J., N. Johansson, J. E. KihlstrBm, and C. Lundberg.
Administration of DDT and PCB prolongs oestrous cycle in
mice. Ambio 1(4): 148-149.
212. Industrial Bio-Test Laboratories, Inc. 1971c. Report to
Monsanto Company: Two-year chronic oral toxicity study
with Aroclors 1242, 1254, and 1260 in beagle dogs. Un-
published reports, November 17, 1971. IBT No. C7299.
213. Barsotti, D. A., R. J. Marlar, and J. R. Allen. 1976.
Reproductive Dysfunctions in rhesus monkeys exposed to
low levels of polychlorinated biphenyls (Aroclor 1248).
Food and Cosmetics Toxicology, in press.
214. Barsotti, D. A. and J. R. Allen. 1975. Effects of poly-
chlorinated biphenyls on reproduction in the primate.
Federation Proceedings 34: 338.
215. Allen, J. R., D. H. Norback, and I. C. Hsu. 1974. Tissue
modifications in monkeys as related to absorption, distri-
bution, and excretion of polychlorinated biphenyls.
Archives of Environmental Contamination and Toxicology 2(1):
86-95.
216. Hansen, L. G., C. S. Byerly, R. L. Metcalf, and R. F. Bevill.
1975. Effect of a polychlorinated biphenyl mixture on swine
reproduction and tissue residues. American Journal of
Veterinary Research 36(1); 23-26.
217. Villeneuve, D. C., D. L. Grant, W.E.J. Phillips, M. L. Clark,
and D. J. Clegg. 1971. Effects of PCB administration on
microsomal enzyme activity in pregnant rabbits. Bulletin of
Environmental Contamination and Toxicology 6(2): 120-128.
218. Villeneuve, D. C., D. L. Grant, K. Khera, D. J. Clegg, H.
Baer, and W.E.J. Phillips. 1971b. The fetotoxicity of a
polychlorinated biphenyl mixture (Aroclor 1254) in the
rabbit and in the rat. Environmental Physiology 1(2): 67-71.
-------
R-21
219. Litterst, C. L., T. M. Farber, A. M. Baker, and E. J. van Loon.
1972. Effect of polychlorinated biphenyls on hepatic microsomal
enzymes in the rat. Toxicology and Applied Pharmacology 23(1): 112-
122.
220. Kappas, A. and A. P. Alvares. 1975. How the liver metabolizes
foreign substances. Scientific American 232(6): 22-31.
221. Norback, D. H. and J. R. Allen. 1972. Chlorinated aromatic
hydrocarbon induced modifications of the hepatic endoplasmic
reticulum: concentric membrane arrays. Environmental Health
Perspectives Exp 1: 137-143.
222. Alvares, A. P., D. R. Bickers, and A. Kappas. 1974. Induction
of drug-metabolizing enzymes and aryl hydrocarbon hydroxylase by
microscope immersion oil. Life Science 14(5): 853-860.
223. Alvares, A. P., D. R. Bickers, and A. Kappas. 1973. Polychlorin-
ated biphenyls: A new type of inducer of cytochrome P-448 in the
liver. Proceedings National Academy of Sciences 70(5); 1321-1325.
224. Chen, R. P., H. M. Mehendale, and L. Fishbein. 1973. Effect of
two isomeric tetrachlorobiphenyls on rats and their hepatic en-
xymes. Archives of Environmental Contamination and Toxicology 1
(1): 36-47.
225. Risebrough, R. W., P. Rieche, D. B. Peakall, S. G. Herman, and
M. N. Kirven. 1968. Polychlorinated biphenyls in the global
ecosystem. Nature 220(12/14): 1098-1102.
226. Platonow, N. S., R. M. Liptrap, and H. D. Geissinger. 1972. The
distribution and excretion of polychlorinated biphenyls (Aroclor
1254) and their effect on urinary gonadal steroid levels in the
boar. Bulletin of Environmental Contamination and Toxicology 7
(6): 358-365.
227. Lincer, J. L. and D. B. Peakall. 1970. Metabolic effects of
polychlorinated biphenyls in the American Kestrel. Nature 228;
783-784.
228. Litterst, C. L. and E. J. van Loon. 1974. Time-course of in-
duction of microsomal enzymes following treatment with poly-
chlorinated biphenyl. Bulletin of Environmental Contamination
and Toxicology 11(3): 206-212.
229. Chen, T. S. and K. P. DuBois. 1973. Studies on the enxyme in-
ducing effect of polychlorinated biphenyls. Toxicology and
Applied Pharmacology 26(4): 504-512.
230. Vaino, H. 1974. Enhancement of microsomal drug oxidation and
Glucuronidation in rat liver by an environmental chemical, poly-
chlorinated biphenyl. Chemical and .Biological Interactions 9(5):
379-387.
-------
R-22
231. Wilson, D. W. and L. G. Hansen. 1975. Changes in kinetic
characteristics of sheep liver microsomes following induction
and dietary stress. Toxicology and Applied Pharmacology 31(1):
114-119.
232. Villeneuve, D. C., D. L. Grant, and W.E.J. Phillips. 1972.
Modification of pentobarbital sleeping times in rats following
chronic PCB ingestion. Bulletin of Environmental Contamination
and. Toxicology 7(5) ; 264-269.
233. Komatsu, F. and K. Tanaka. 1971. Shortening of hexobarbital
sleeping time and change of serum triglyceride level in chloro-
biphenyls-intoxicated rats. Fukuoka Acta Medica 62: 35.
234. Sanders, 0. T., R. L. Zepp, and R. L. Kirkpatrick. 1974.
Effect of PCB ingestion on sleeping times, organ weights, food
consumption, serum corticosterone and survival of albino mice.
Bulletin of Environmental Contamination and Toxicology ||:
394-399.
235. Zepp, R. L., Jr., 0. T. Sanders, and R. L. Kirkpatrick. 1974.
Reduction of pentobarbital-induced sleeping times in PCB-treated
cottontail rabbits. Bulletin of Environmental Contamination and
Toxicology 12(5): 518-521.
236. Bickers, D. R., L. C. Harber, A. Kappas, and A. P. Alvares. 1972.
Polychlorinated biphenyls: comparative effects of high and low
chlorine containing Aroclors on hepatic mixed function oxidase.
Research Communications in Chemical Pathology and Pharmacology
3(3): 505-512.
237. Alvares, A. P. and P. Siekevitz. 1973. Gel electrophoresis of
partially purified cytochromes P45Q from liver microsomes of
variously-treated rats. Biochemical and biophysical Research
Communications 54(3): 923-929.
238. Johnstone, G, J., D. J. Ecobichon, and 0, Hutzinger. 1974. The
influence of pure polychlorinated biphenyl compounds on hepatic
function in the rat. Toxicology and Applied Pharmacology 28(1):
66-81.
239. Fujita, S., H. Tsuji, K. Kato, S. Saeki, and H. Tsukamoto. 1971.
Effect of biphenyl chlorides on rat liver microsomes. Fukuoka
Acta Medica 62(1): 30-34.
240. Hansell, M. M. and D. J. Ecobichon. 1974. Effects of chemically
pure chlorobiphenyls on the morphology of rat liver. Toxicology
and Applied Pharmacology 28(4): 418-427.
-------
R-23
241. Ecobichon, D. J. and A. M. Comeau. 1975. Isomerically pure
chlorobiphenyl congeners and hepatic function in the rat: in-
fluence of position and degree of chlorination. Toxicology and
Applied Pharmacology 33: 94-102.
242. Ecobichon, D. J. 1976. Enzymatic and other biochemical responses
to selected PCB's. ' Proceedings of the National Conference on
Polychlorinated Biphenyls: 75-87.
243. Iverson, F., D. C. Villeneuve, D. L. Grant, and G. V. Hatina.
1975. Effect of Aroclor 1016 and 1242 on selected enzyme systems
in the rat. Bulletin of Environmental Contamination and Toxicol-
ogy 13(4): 456-463.
244. Bickers, D. R., L. C. Harber, A. Kappas, and A. P. Alvares. 1972.
Polychlorinated biphenyls: Comparative effects of high and low
chlorine containing Aroclors on hepatic mixed function oxidase.
Research Communications in Chemical Pathology and Pharmacology
3(3): 505-512.
245. Goldstein, J. A., P. Hickman, V. W. Burse, and H. Bergman. 1975.
A comparative study of two polychlorinated biphenyl mixtures
(Aroclors 1242 and 1016) containing 42% chlorine on induction of
hepatic porphyria and drug metabolizing enzymes. Toxicology and
Applied Pharmacology 32: 461-473.
246. Araki, Y. and K. Tanaka. 1974. Potentiation of enzyme-indueing
activity of PCB by DDT or BHC. Fukuoka Acta Medica 65(1): 65-68.
247. Kimbrough, R. D. 1973. Pancreatic-type tissue in livers of rats
fed polychlorinated biphenyls. Journal of the National Cancer
Institute 51(2): 679-681.
248. Berdanier, C. D., R. B. Tobin, R. C. Nielsen, M. A. Nehlman, and
R. L. Veech. 1975. Effect of polychlorinated biphenyls and
thiamin deficiency on liver metabolism in growing rats. Journal
of Toxicology and Environmental Health 1(1): 91-105.
249. Strik, J.J.T.W.A. and J. G. Wit. 1972. Hepatic porphyria in
birds and mammals. TNO-Nieuws 27: 604-610.
250. Goldstein, J. A., P. Hickman, and D. L. Jue. 1974a. Experi-
mental hepatic porphyria induced by polychlorinated biphenyls.
Toxicology and Applied^ Pharmacology 27(2): 437-448.
251. Sinclair, P. R. and S. Granick. 1974. Uroporphyrin formation
induced by chlorinated hydrocarbons (lindane, polychlorinated
biphenyls, tetrachlorodibenzo-p-dioxin). Requirements for en-
dogenous iron, protein synthesis and drug-metabolizing activity.
Biochemical and Biophysical Research Communications 61(1): 124-133.
-------
R-24
252. Woods, J. S. 1973. Studies of the effects of 2,3,7,8-tetrachloro-
p-dioxin on mammalian hepatic o-aminolevulinic acid synthetase.
Environmental Health Perspective^ 5: 125-140.
253. Nagai, J., M. Furukawa, Y. Yae, and K. Higuchi. 1971. The in-
fluence of chlorobiphenyl (Kanechlor) administration on the organ
lipids of rats. Fukuoka Acta Medica 62(1): 42-47.
254. Uzawa, H., Y. Ito, A. Notomi, and S. Katsuki. 1969. Hyperglycer-
idemia resulting from intake of rice oil contaminated with chlor-
inated biphenyls. Fukuoka Acta Medica 60(6): 449-454.
255. Uzawa, H., Y. Ito, A. Notomi, S. Hori, Y. Ikeura, and S. Katsuki.
1971. Clinical and experimental studies on the hyperglyceridemia .
induced by oral ingestion of chlorinated biphenyls. Fukuoka Acta
Medica 62(1): 66-73.
256. Ito, Y., H. Uzawa, and A. Notomi. 1971. Lipid composition of the
rabbit liver poisoned with chlorobiphenyls. Fukuoka Acta Medica
62(1): 48-50.
257. Wassermann, D., M. Wassermann, S. Cucos, and M. Djavaherian. 1973.
Function of adrenal gland-zona fasciculata in rats receiving poly-
chlorinated biphenyls. Environmental Research 6(3): 334-338.
258. Bastomsky, C. H. 1974. Effects of a polychlorinated biphenyl
mixture (Aroclor 1254) and DDT on biliary thyroxine excretion in
rats. Endocrinology 95(4); 1150-1155.
259. Bruckner, J. V., K. L, Khanna, and H. H. Cornish. 1974. Poly-
chlorinated biphenyl induced alteration of biologic parameters
in the rat. Toxicology and Applied Pharmacology 28(2) 189-199.
260. Hendrickson, C. M. and J. A. Bowden. 1973. The j.n vitro inhibi-
tion of lactic dehydrogenase by selected polychlorinated pesti-
cides. Federation Proceedings 32 (3 Part 1): 235.
261. Sharp, C. W., D. G. Hunt, S. T. Clements, and W. E. Wilson. 1974.
The influence of dichlorodiphenyltrichloroethane, polychlorinated
biphenyls and anionic amphiphilic compounds on stabilization of
sodium- and potassium-activated adenosine triphosphatases by
acidic phospholipids. Molecular Pharmacology 10(1): 119-129.
262. Wilson, W. E. and C. W. Sharp. 1972. Chlorinated biphenyl inter-
action with beef brain (Na+ + K*") ATP-ase. .Federation Proceed-
ings 31(2): 591.
-------
R-25
263. Vos, J. G. and T. DeRoij. 1972. Immunosuppressive activity of a
polychlorinated biphenyl preparation on the humoral immune
response in guinea pigs. Toxicology and Applied Pharmacology
21(4): 549-555.
264. Vos, J. G. and L. van Driel-Grootenhuis. 1972. PCB-induced
suppression of the humoral and cell-mediated immunity in guinea
pigs. The Science of the Total Environment 1(3): 289-302.
265. Koller, L. D. and J. E. Thigpen. 1973. Biphenyl-exposed rabbits.
American Journal of Veterinary Research 34(12): 1605-1606.
266. Kimbrough, R. D., R. A. Squire, R. E. Linder, J. D. Strandberg,
R. J. Montali, and V. W. Burse. 1975. Induction of liver tumors
in Sherman strain female rats by polychlorinated biphenyl Aroclor
1260. Journal of the National Cancer Institute 55(6): 1453-1459.
267. Allen, J. R. 1975. Response of the nonhuman primate to poly-
chlorinated biphenyl exposure. Federation Proceedings 34(8):
1675-1679.
268. Edwards, J. E. and J. White. 1941. Pathologic changes, with
special reference to pigmentation and classification of hepatic
tumors in rats fed -dimethylaminoazobenzene (butter yellow).
Journal of the _Nation_al Cancer Institute 2: 157-183.
269. Squire, R. A. and M. H. Levitt. 1975. Classification of specific
hepatocellular lesions in rats: report of a workshop. Cancer
Research 'i* j»*.ss.
270. Train, R. E. 1975. Decision of the Administration on the Sus-
pension of Heptachlor-Chlordane. Ln r_e Velsicol Chemical Corpo-
ration, e£ a_l., FIFRA Docket No. 384. U. S. Environmental Pro-
tection Agency, Washington, D.C., December 24, 1975.
271. Kimura, N. T. and T. Baba. 1973. Neoplastic changes in the rat
liver induced by polychlorinated biphenyl. GANN 64: 105-108.
272. Uchiyama, M., T. Chiba, and K. Noda. 1974. Co-carcinogenic
effect of DDT and PCB feedings on methylchloanthrene-induced
chemical carcinogenesis. Bulletin of Environmental Contamination
and Toxicology 12(6); 687-693.
273. Makiura, D., H. Aoe, S. Sugihara, K. Hirao, M. Arai, and N. Ito.
1974. Inhibitory effects of polychlorinated biphenyls on liver
tumorigenesis in rats treated with 3'-methyl-4-dimethylaminoazo-
benzene, N-2-fluorenylacetamide, and diethylnitrosamine. Journal
of the National Cancer Institute, 53(5): 1253-1257.
-------
R-26
274. Reynolds, E. S., M. T. Moslen, S. Szabo, R. J. Jaeger, and S. D.
Murphy. 1975. Hepatotoxicity of vinyl chloride and 1,1-dichloro-
ethylene. American Journal of Pathology 81(1); 219-231.
275. Thomas, L. B., H. Popper, P. D. Berk, I. Selikoff, and H. Falk.
1975. Vinyl chloride-induced liver disease from idiopathic
portal hypertension (Banti's Syndrome) to angiosarcomas. New
England Journal of Medicine 292: 17-22.
276. McCann, J., E. Choi, E. Yamasaki, and B. N. Ames. 1975. Detec-
tion of carcinogens as mutagens in the Salmonella/microsome test:
assay of 300 chemicals. Proceedings of the National Academy of
Sciences 72(12); 5135-5139.
277. Rannug, U., A. Johansson, C. Rand, and C. A. Wachtmeister. 1974.
The mutagenicity of vinyl chloride after metabolic activation.
Ambio 3(5): 194-197.
278.
279. Grover, P. L., P. Sims, E. Huberman, H. Marquardt, T. Kuroki,
and C. Heidelberger. 1971. In vitro transformation of rodent
cells by K-region derivatives of polycyclic hydrocarbons.
Proceedings of the National Academy of Sciences 68(6): 1098-1101.
280. Ames, B. N., J. McCann, and E. Yamasaki. 1975.
281. Popper, H., P. Czygan, H. Greim, F. Schaffner, and A. J. Garro.
1973. -Mutagenicity of primary and secondary carcinogens altered
by normal and induced hepatic microsomes. Society for Experi-
mental Biology and Medicine Proceedings 142(2): 727-729.
282. Czygan, P., H. Grein, A. J. Garro, F. Hutterer, F. F. Schaffner,
H. Popper, 0. Rosenthal, and D. Y. Cooper. 1973. Microsomal •
metabolism of dimethylnitrosamine and the cytochrome P-450
dependency of its activation to a mutagen. Cancer Research 33(11)
2983-2986.
283. Reuber, M. D. 1968. Histogenesis of cholangiofibrosis and well
differentiated cholangiocarcinoma in Syrian hamsters given 2-
acetoamidofluorene or 2-diacetoamidofluorene. GANN 59: 239-246.
-------
R-27
284. Stewart, H. L. and K. C. Snell. 1957. The histopathology of
experimental tumors of the liver of the rat. A critical review
of the histopathogenesis. Acta Unionis Intgrnationalis Contra
Cancrum 13: 770-803.
285. Green, S., J. V. Carr, Ku A. Palmer, and E. J. Oswald. 1975.
Lack of cytogenetic effects in bone marrow and spermatagonial
cells in rats treated with polychlorinated biphenyls (Aroclors
1242 and 1254). Bulletin of Environmental Contamination and
Toxicology 13(1): 14-22.
286. Schulz, K. H. 1968. (clinical and etiological aspects of chlor-
acne.] Arbeitsmedizinej Sozialmedizine, Arbeitshygiene 3: 25-29.
[In German: English translation in: Effects of 2,4,5-T on Man
and the Environment. Hearings before the Subcommittee on Energy,
Natural Resources and the Environment. U.S. Senate 91-60 (1970.]
287. Crow, K. D. 1970. Chloracne. Transactions of St. John's
Hospital Dermatological Society 56: 79-99.
288. Kimmig, J. and K. H. Schulz. 1957. Berttfliche Akne (sog. Chlor-
akne) durch chlorierte aromatische Zyklische Ather. Dermatologica
115: 540. •
289. Meigs, J. W., J. J. Alborn, and B. L. Kastin. 1954. Chloracne
from an unusual exposure to Aroclor. Journal of the American
Medical Association 154: 1417-1418.
290. Rhoden, R. A. 1976. U.S. federal agency roles and actions:
National Institute of Occupational Safety and Health. P.N.C.PCB;
411.
291. Kuratsune, M., T. Yoshimura, J. Matsuzaka, and A. Yamagucki. 1972.
Edpidemiologic study on Yusho, a poisoning caused by ingestion of
rice oil contaminated with a commercial brand of polychlorinated
biphenyls. Environmental Health Perspectives Exp 1: 119-128.
292. Kuratsune, M. 1972. An abstract of results of laboratory exam-
inations of patients with Yusho and of animal experiments. Environ-
mental Health Perspectives 1: 129-136.
293. Kltratsune, M., T. Yoshimura, J. Matsuzaka, and A. Yamaguchi. 1971.
Yusho, a poisoning caused by rice oil contaminated with polychlor-
inated biphenyls. HSMHA Health Reports 86(12): 1083-1091.
294. Goto, M. and K. Higuchi. 1969. The symptomatology of Yusho
(chlorobiphenyls poisoning) in dermatology. Fukuoka Acta Medica
60(6): 409-431.
295. Funutsu, L., F. Yamashita, T. Yoshikane, £t a_l. 1971. A chloro-
biphenyl induced fetopathy. Fukuoka Acta Medica 62(1): 139-149.
-------
R-28
296. Yoshimura, T. 1974. Epidemiological study of Yusho babies who
had consumed oil contaminated by PCB. Fukuoka Acta Medica 65(1):
74-80.
297. Urabe, H. 1974. Foreword, the Fourth Report of the Study on
Yusho and PCB. Fukuoka Acta Medica 65(1): 1-4.
298. Vos, J. G., J. S. Reinders, J. Krpneman, and J. H. Pennings. 1971.
(jlyperkeratosis in cattle due to contamination of rubber mats
with chlorinated naphthalenes and polychlorobiphenylsj . Tijdschr.
Diergeneesk. 96: 1577-1586.
299. langami, K., T. Koga, M. Kikuchi, M. Hashimoto, H. Takahashi, and
K. Wada. 1969. Experimental study of hairless mice following ad-
ministration of rice oil used by a "Yusho" patient. Fukuoka Acta
Medica 60(6):'548-553.
300. Ahmed, M. and D. D. Focht. 1973a. Oxidation of polychlorinated
biphenyls by Achromobacter pCB. Bulletin of Environmental Con-
tamination _and Toxicology 10(2): 70-72.
301. Catelani, D., A. Colombi, C. Sorlini, V. Treccani. 1973. Metab-
olism of biphenyl. Biochemical Journal 134: 1063-1066.
302. Gibson, D. T., R. L. Roberts, M. C. Wells and V. M. Kobal. 1973.
Oxidation of biphenyl by a Beilerinckia species. Biochemical and
Biophysical Research Communications 50(2); 211-219.
303. Tucker, E. S., V. W. Saeger, and 0. Hicks. 1975. Activated sludge
primary degradation of polychlorinated biphenyls. Bulletin of
Environmental Contamination and Toxicology 14(6): 705-713.
304. Choi, P.S.K., H. Nack, and J. E. Flinn. 1974. Distribution of
polychlorinated biphenyls in an aerated biological oxidation
wastewater treatment system. Bulletin of Environmental Contamina-
tion and Toxicology 11(1): 12-17.
305. Iwata, Y., W. E. Westlake, and F. A. Gunther. 1974. Varying per-
sistence of polychlorinated biphenyls in six California soils under
laboratory conditions. Bulletin of Environmental Contamination and
Toxicology 11(6): 523-528.
306. Johnsen, R. E. 1973. PCB Newsletter No. 5, p. 14. U.S. Environ-
mental Protection Agency, Duluth, Minnesota.
-------
R-29
307. Sanborn, J. R., W. F. Childers, and R. L. Metcalf. 1975. Uptake
of three polychlorinated biphenyls, DDT, and DDE by the Green
Sunfish, Lepomis cyanellus Raf. Bulletin of Environmental Con-
tamination and Toxicology 13(2): 209-217.
308. Hutzinger, 0., D. M. Nash, S. Safe, A.S.W. DeFreitas, R. J.
Norstrom, D. J. Wildish, and V. Zitko. 1972a. Polychlorinated
biphenyls: Metabolic behavior of pure isomers in pigeons, rats,
and Brook Trout. Science 178(4058): 312-314.
309. Bend, J, R., L. G. Hart, A. M. Guarino, D. P. Rail, and J. R.
Fouts. 1976. Distribution and excretion of ^C -2,4,5,2",5'
pentachlorobiphenyl in the lobster (Homarus americanus) and the
dogfish shark.(Squalus acanthias). P.N.C. PCB: 271-284.
310. McKinney, J. D., J. R. Hass, and K. Chae. 1976. Metabolism of
pure' hexachlorobiphenyl isomers in chickens. Dechlorination,
isomerization, hydroxylation, and dibenzofuran formation. MS.,
in press.
311. Goto, M., M. Hattori, and K. Sugiura. 1975. Metabolism of
pentachloro- and hexachlorobiphenyls in the rat. Chemosphere 3:
177-180.
312. Yamamoto, H. and H. Yoshimura. 1973. Metabolic studies on poly-
chlorinated biphenyls. III. Complete structure and acute toxicity
of the metabolites of 2,4,3',4"-tetrachlorobiphenyl. Chemical
and Pharmaceutical Bulletin 21(10); 2237-2242.
313. Yoshimura, H. and H. Yamanoto. 1973. Metabolic studies on poly-
chlorinated biphenyls. I. Metabolic fate of 3,4,3',4'-tetra-
chlorobiphenyl in rats. Chemical and Pharmaceutical Bulletin 21
(5): 1168-1169.
314. Yoshimura, H., H. Yamamoto, and S. Saeki. 1973. Metabolic
studies on polychlorinated bi-phenyls. II. Metabolic fate of
2,4,3',4'-tetrachlorobiphenyl in rats. Chemical Pharmaceutical
Bulletin 21(10): 2231-2236.
315. Hutzinger, 0., W. D. Jamieson, S. Safe, L. Paulmann, and R. Ammon.
1974a. Identification of metabolic dechlorination of highly
chlorinated biphenyl in rabbit. Nature 252(12/20-27): 698-699.
316. Safe, S., 0. Hutzinger, and D. Ecobichon. 1974. Identification
of 4-chloro-4'-hydroxybiphenyl as metabolites of 4-chloro- and
4,4'- dichlorobiphenyl fed to rats. Experientia 30(7): 720-721.
317. Greb, W., W. Klein, F. Coulston, L. Golberg, and F. Korte. 1974.
BeitrBge zur bkologischen Chemie LXXXIV. Metabolism of lower poly-
chlorinated biphenyls -^C in the rhesus monkey. Bulletin of En-
vironmental Contamination and Toxicology 12: 471-476.
-------
R-30
318. Greb, W., W. Klein, F. Coulston, L. Goldberg, and F. Korte.
1974b. In vitro metabolism of polychlorinated biphenyls-14C.
Bulletin of Environmental Contamination and Toxicology 11(4) ;424-432.
319. Gardner, A. M., J. T. Chen, J.A.G. Roach, and E. P. Ragelis. 1973.
Polychlorinated biphenyls: Hydroxylated urinary metabolites of
2,5,2',5'-tetrachlorobiphenyl identified in rabbits. Biochemical
and Biophysical Research Communications 55(4): 1377-3184.
320. Van Miller, J. P.; I. C, Hsu, and J. R. Allen. 1975. Distribu-
tion and metabolism of -%-2,5,2',5'-tetrachlorobiphenyl in rats.
Proceedings of the Society for Experimental Biology and Medicine
148: 682-687.
321. Hsu, I. C., J. P. Van Miller, and J. fl. Allen. 1975. Metabolic
fate of 3H2,5,2',5'-tetrachlorobiphenyl in infant nonhuman pri-
mates. Bulletin of Environmental Contamination and Toxicology
14(2): 233-240.
322. Berlin, M., J. Gage, and S. Holm. 1975. Distribution and metab-
olism of 2,4,5,2',5'-pentachlorobiphenyl. Archives of Environ-
mental Health 30(3): 141-147.
323. Jensen, S. and G. Sundstroem. 1974. Metabolic hydroxylation of
a chlorobiphenyl containing only isolated unsubstituted positions --
2,2',4,4',5,5'-hexachlorobiphenyl. Nature 251(9/20): 219-220.
324. Safe, S., N. Platonow, and 0. Hutzinger. 1975c. Metabolism of
chlorobiphenyls in the goat and cow. Journal of Agricultural and
Food Chemistry 23(2): 259-261.
325. Safe, S., 0. Hutzinger, and D. Jones. 1975. The mechanism of
chlorobiphenyl metabolism. Journal of Agricultural and Food
Chemistry 23(5): 851-853.
326. Jerina, D. M. and J. W. Daly. 1974. Arene oxides: a new aspect
of drug metabolism. Science 185: 573-582.
327. Curley, A., V. W. Burse, R. W. Jennings, E. C. Villanueva, and R. D.
Kimbrough. 1975. Evidence of tetrachlorobibenzofuran (TCDF) in
Aroclor 1254, and the urine of rats following dietary exposure to
Aroclor 1254. Bulletin of Environmental Contamination and Toxicol-
ogy 14(2): 153-158.
328. Matthews, H. B. and A. Anderson. 1976. PCB chlorination versus
PCB distribution and excretion. P.N.C. PCB; 65-74.
329. Horn, W., R. W. Risebrough, A. Soutar, and D. R. Young. 1974.
Deposition of DDE and polychlorinated biphenyls in dated sediments
of the Santa Barbara Basin. Science 184(4142): 1197-1199.
-------
R-31
330. Nimmo, D. R. 1976. Statement before the Subcommittee on Oceanog-
raphy, Subcommittee on Fisheries and Wildlife Conservation and
the Environment, Committee on Merchant Marine and Fisheries, U.S.
House of Representatives, January 29, 1976.
331. Nisbet, I.C.T. 1976. Environmental transport and occurrence of
PCB's in 1975, P.N.C. PCS; 245-247.
332. Nisbet, I.C.T. and A. F. Sarofim. 1972. Rates and routes of
transport of PCB's in the environment. Environmental Health
Perspectives 1: 21-38.
333. Veith, G. D. and G. F. Lee. 1971. Chlorobiphenyls (PCBs) in the
Milwaukee River. Water Research 5(11): 1107-1115.
334. Veith, G. D. and C. F. Lee. 1971. PCBs in fish from the Milwau-
kee region. Proceedings 14th Conference Great Lakes Research:
157-169.
335. Moriarty, F. 1975. Exposure and residues. Pp. 29-72 in Organo-
chlorine Insecticides; Persistent Organic Pollutants (ed. F.
Moriarty). Academic Press, London, New York & San Francisco.
336. Nisbet, I.C.T. 1975. Ecological magnification. Technology
Review 77(5): 6, 7, & 68.
337. Parrish, P. R. 1974. Aroclor(R) 1254, DDT and DDD, and dieldrin:
accumulation and loss by American oysters (Crassostrea virginica)
exposed continuously for 56 weeks. Proceedings of the National
Shellfish Association 64: 7-12.
338. Veith, G. D. and L. Kiwus. 1975. Uptake of Aroclor 1016 by fish.
I. Laboratory bioaccumulation studies with fathead minnows. Un-
published report, U.S. Environmental Protection Agency, Environ-
mental Research Laboratory, Duluth, Minnesota.
339. Lieb, A. J., D. D. Bills, and R. 0. Sinnhuber. 1975. Accumula-
tion of dietary polychlorinated biphenyls (Aroclor 1254) by
Rainbow Trout (Salmo gairdneri). Journal of Agricultural and
Food Chemistry 22(4): 638-642.
340. SBdergren, A. 1973. Transport, distribution,and degradation of
chlorinated hydrocarbon residues in aquatic model ecosystems.
OIKOS 24(1): 30-40.
341. Dahlgren, R. B., Y. A. Greichus, and R. L. Linder, 1971. Storage
and excretion of polychlorinated biphenyls in the pheasant.
Journal of Wildlife Management 35(4): 823-828.
-------
R-32
342. Lincer, J. L. and D. B. Peakall. 1973. PCB pharmacodynamics in
the Ring Dove and early gas chromatographic peak diminution.
Environmental Pollution 4(1): 59-68.
343. Call, D. J., Y. A. Greichus, and J. J. Worman. 1974. A gas
chromatographic-mass spectrometric comparison of polychlorinated
biphenyl residues in the Japanese Quail brain to an Aroclor
standard. Bulletin of Environmental Contamination and Toxicology
11(4): 333-338.
344. Baileys S. and P. J. Bunyan. 1972. Interpretation of persistence
and effects of polychlorinated biphenyls in birds. Nature 236
3/3): 34-36.
345. Albro, P. W. and L. Fishbein. 1972a. Intestinal absorption of
polychlorinated biphenyls in rats. Bulletin of Environmental
Contamination and Toxicology 8(1): 26-31.
346. Curley, A., V. W. Burse, M. E. Grim, R. W. Jennings, and R. E.
Linder. 1971. Polychlorinated biphenyls: Distribution and
storage in body fluids and tissues of Sherman rats. Environment-
al Research 4(6); 481-495.
347. Grant, D. L., C. A. Hoodie, and W.E.J. Phillips. 1972. Toxico-
dynamics of Aroclor (R) 1254 in the male rat. Transactions of
the American Chemical Society 12(1): 92-95.
348. Burse, V. W;, R. F. Moreman, G. W. Sorocool, and E. C. Villanueva.
1976. PCB metabolism in rats following prolonged exposure to
Aroclor 1242 and Aroclor 1016. Bulletin of Environmental Contam-
ination and Toxicology 15(1): 122-128.
349. Fries, G. F., G, S. Marrow, Jr., and C. H. Gordon. 1973. Long-
term studies of residue retention and excretion by cows fed a
polychlorinated biphenyl (Aroclor 1254). Journal of Agricultural
and Food Chemistry 21(1): 117-121.
-------
R-33
350. Price, N. 0., R. W. Young, and J. K. Dickinson. 1972. Pesti-
cide residues and polychlorinated biphenyl levels in diets,
urine, and fecal matter of preadolescent girls. Proceedings
of the Society for Experimental Biology and Medicine 139(4):
1280-.J.283.
\
351. Jelinek, C. F. and P. E. Corneliussen. 1976. Levels of PCB's
in the U.S. food supply. Proceedings of the National Conference
on Polychlorinated Biphenyls: 167-175.
352. Grant, D. L., J. Mes, and R. Frank. 1976. PCB residues in
human adipose tissue and milk. Proceedings of the National Con-
Conference on Polychlorinated Biphenyls; 163-165.
353. Kutz, F. W. and S. C. Strassman. 1976. Residues of poly-
chlorinated biphenyls in the general population of the United
States. Proceedings of the National Conference on Polychlorin-
biphenvls; 159-162.
354. Finklea, J., L. E. Priester, J. P. Creason, T. Hauser, T.
Himmers, and D. I. Hammer. 1972. Polychlorinated biphenyl
residues in human plasma expose a major urban pollution prob-
lem. American Journal of Public Health 62(5): 645-651.
355. Duggan, R. 1969. Pesticide residues in foods. Annals of the
New York Academy of Sciences 160(1): 173-182.
356. Hunter, C. G. and J. Robinson. 1967. Pharmacodynamics of
Dieldrin (HEOD). 1. Ingestion by human subjects for 18 months.
Archives of Environmental Health 15: 614-626.
357. Musial, C. J., 0. Hutzinger, V. Zitko, and J. Crocker. 1974.
Presence of PCB, DDE, and DDT in human milk in the Provinces
of New Brunswick and Nova Scotia, Canada. Bulletin of Environ-
mental Contamination and Toxicology 12(3): 258-267.
358. Vei-th, G. D., J. J. Spagnoli, and J. C. Skea. 1975. Uptake of
Aroclor 1016 by fish. II. Field bioaccumulation studies. Un-
published report, U.S. Environmental Protection Agency, Environ-
mental Research Laboratory, Duluth, Minnesota.
359. ^ ! ,,{ Mc.vi VC-V,
360. Graham, J. M. 1976. Levels of PCBs in Canadian commercial
fish species. Proceedings of the National Conference on Poly-
chlorinated Biphenyls: 177-178.
-------
R-34
361. Willford, W. A., R. J. Hesselberg, and L. W. Nicholson. 1976.
Trends of PCB's in Lake Michigan fishes. Proceedings of the
National Conference on Polychlorinated Biphenyls; 183-186.
I
362. Veith, G. D. 1975. Baseline concentrations of polychlorinated
biphenyls and DDT in Lake Michigan fish, 1971. Pesticides Moni-
toring Journal 9(1): 21-29.
363. Veith, G. D., D. W. Kuehl, F. A. Puglisi, G. E. Glass, and J. G.
Eaton. 1976. Residues of PCBs and DDT in the Western Lake
Superior ecosystem. Unpublished report, U.S. Environmental
Protection Agency, National Water Quality Laboratory, Duluth,
Minnesota.
364. Faber, R. A. and J. J. Rickey. 1973. Eggshell thinning, chlor-
inated hydrocarbons, and mercury in inland aquatic bird eggs,
1969 and 1970. Pesticides Monitoring Journal 7(1): 27-36.
365. [Rickey, J. J.3 1975. Present contamination in the Green Bay
ecosystem. In Progress Report, July 1, 1975. Research on
Polychlorinated Biphenyls and Phthalate esters as environmental
pollutants. Department of Wildlife Ecology, University of Wis-
consin, Madison, Wisconsin.
366. Gilman, A. P., G. A. Fox, D. B. Peakall, S. M. Teeple, T. R.
Carroll, and G. Haymes. 1976. Studies of Herring Gulls of the
Great Lakes. I. Reproductive success and levels of organochlor-
ine in eggs. Unpublished MS., Canadian Wildlife Service.
.367. Parejko, R., R. Johnston, and R. Keller. 1975. Chlorohydro-
carbons in Lake Superior lake trout (Salvelinus namaycush).
Bulletin of Environmental Contamination and Toxicology 14(4):
480-488.
368. Veith, G. D. 1975. Statement of Gilman D. Veith. Wisconsin
DNR Hearings, August 1975.
369. Young, D. R., D. J. McDermott, and T. C. Heesen. 1975. Poly-
chlorinated biphenyl inputs to the Southern California Bight.
Southern California Coastal Water Research Project, El Segundo,
California, TM 224. Pp. 50.
370. McDermott, D. J., D. R. Young, and T. C. Heesen. 1975. Poly-
chlorinated biphenyls in marine organisms off Southern Cali-
fornia. Southern California Coastal Water Research Project,
El Segundo, California, TM 223. Pp. 45.
371. Coulter, M. C. and R. W. Risebrough. 1973. Shell-thinning in
eggs of the Ashy Petrel (Oceanodroma homochroa) from the Faral-.
Ion Islands. Condor 75(2): 254-255,
-------
R-25
372. Gress, F., R. W. Risebrough, D. W. Anderson, L. F. Klff, and
J. R. Jehl. 1973. Reproductive failures of Double-crested
Cormorants in Southern California and-Baja California.
Wilson Bulletin 85(2); 197-208.
373. Gress, F., R. W. Risebrough, and F. C. Sibley. 1971. Shell
thinning in eggs of the Common Murre, Uria aalge, from the
Farallon Islands, California. Condor 73: 368-369.
374. DeLong, R. L., W. G. Gilmartin,. and J. G. Simpson. 1973.
Premature births in California Sea Lions: Association with
high organochlorine pollutant residue levels. Science 181(4105):
1168-1170.
375. Harvey, G. R., W. G. Steinhauer, and J. M. Teal. 1973. Poly-
chlorobiphenyls in North Atlantic ocean water. Science 180
(4086): 643-644.
376. Harvey, G. R., H. P. Miklas, V. T. Bowen, and W. G. Steinhauer.
1974. Observations on the distribution of chlorinated hydro-
carbons in Atlantic Ocean organisms. Journal of Marine Research
32(2): 103-118.
377. Longhurst, A. R. and P. J. Radford. 1975. PCB concentrations
in North Atlantic surface water. Nature 256(7/17): 239-240.
378. Williams, R. and A. V. Holden. 1973. Organochlorine residues
from plankton. Marine Pollution Bulletin 4(7); 109-111.
379. Risebrough, R. W., V. Vreeland, G. R. Harvey, H. P. Miklas and
G. M. Carmignani. 1972. PCB residues in Atlantic zooplankton.
Bulletin of Environmental Contamination and Toxicology 8(6):
345-355.
380. plickey, J. jj 1975. Environmental contamination in.Icelandic
marine birds. In Progress Report, July 1, 1975. Research on
Polychlorinated Biphenyls and Phthalate esters as environmental
pollutants. Department of Wildlife Ecology, University of
Wisconsin, Madison, Wisconsin.
381. Bache, C. H., J. W. Serum, W. D. Youngs, and D. J. Lisk. 1972.
Polychlorinated biphenyl residues: accumulation in Cayuga Lake
trout with age. Science 177: 1191-1192.
382. Stalling, D. L. 1975. PCB residues in fish from the National
Pesticide Monitoring Program (NPMP) collections. Unpublished
report, Fish-Pesticide Research Laboratory, U.S. Department of
the Interior, Columbia, Missouri.
-------
R-36
383. Anas,. R. E. 1974. DDT plus PCB's in blubber of Harbor Seals.
Pesticides Monitoring Journal 8(1): 12-14.
384. Gaskin, D. E., R. Frank, M. Holdrinet, K. Ishida, C. J. Walton,
and M. Smith. 1973. Mercury, DDT, and PCB in Harbour Seals
(Phoca vitulina) from the Bay of Fundy and Gulf of Maine.
Journal of Fisheries Research Board of Canada 30(3); 471-475.
385. Frank, R., K. Ronald, and H. E. Braun. 1973. Organochlorine
residues in Harp Seals (Pagophilas groenlandicus) caught in
eastern Canadian waters. Journal of the Fisheries Research
Board of Canada 30(8); 1053-1063.
386. Holden, A. V. 1972. Monitoring organochlorine contamination of
the marine environment by the analysis of residues in seals.
In Marine Pollution and Sea Life, Fishing News (Books) Ltd.,.
West Byfleet, England.
387. Bourne, W.R.P. and J. A. Bogan. 1972. Polychlorinated biphen-
yls in North Atlantic seabirds. Marine Pollution Bulletin 3
(11): 171-175.
388. Bogan, J. A. and W.R.P. Bourne. 1972. Organochlorine levels
in Atlantic seabirds. Nature 240: 358.
389. Natural Environment Research Council. 1971. The sea bird
wreck in the Irish Sea Autumn 1969. Publication Series C,
No. 4, 'London.
390. Belisle, A. A., W. L. Reichel, L. N. Locke, T. G. Lamont, B. M.
Mulhern, R. M. Prouty, R. B. DeWolf, and E. Cromartie. 1972.
Residues of organochlorine pesticides, polychlorinated biphenyls,
and mercury, and autopsy data for Bald Eagles, 1969 and 1970.
Pesticides Monitoring Journal 6(3): 133-138.
391. Cromartie, E., W. L. Reichel, L. N. Locke, A. A. Belisle, T. E.
Kaiser, T. G. Lamont, B. M. Mulhern, R. M. Prouty, and D. M.
Swineford. 1975. Residues of organochlorine pesticides and
polychlorinated biphenyls, and autopsy data for Bald Eagles,
1971-72. Pesticides Monitoring Journal 9(1); 11-14.
392. Gilbertson, M. 1974. Pollutants in breeding Herring Gulls in
the Lower Great Lakes. Canadian Field-Naturalist 88(3): 273-280.
393. Gilbertson, M. and R. Hale. 1974. Characteristics of the breed-
ing failure of a colony of Herring Gulls on Lake Ontario.
Canadian Field-Naturalist 88: 356-358.
394. Blus, L. J., B. S. Neely, Jr., A. A. Belisle and R. M. Prouty.
1974. Organochlorine residues in Brown Pelican eggs: relation
to reproductive success. Environmental Pollution 7(2): 81-91.
-------
R-37
395. Saeki, S., A. Tsutsui, K. Oguri, H. Yoshimura and M. Hamana, 1971.
The isolation and structure elucidation of the main components
of Kanechlor-400 (chlorobiphenyls). Fukuoka Acta Medica 62(1):
20-24.
396. Thomas. G. H. 1976. Some additional comments with respect to
ambient air sampling for PCBs. Proceedings of the National Con-
ference on Polychlorinated Biphenyls; 373.
397. Combs, G. F., Jr., A. H. Cantor, and M. L. Scott. 1975. Effects
of dietary polychlorinated biphenyls on vitamin E and selenium
nutrition in the chick. Poultry Science 54: 1143-1152.
398. Combs, G. F., Jr., and M. L. Scott. 1975. Polychlorinated bi-
phenyl-stimulated selenium deficiency in the chick. Poultry
Science 52: 1152-1158.
399. Ax, R. L. and L. G. Hansen. 1975. Effects of purified poly-
chlorinated biphenyl analogs on chicken reproduction. Poultry
Science 54(3): 895-900.
400. Bayer, R. C. and F. H. Bird. 1974. Surface changes in the epi-
cardium of chickens fed polychlorinated biphenyls. Poultry
Science 53(2): 737-741.
401. Kikuchi, M., Y. Mikagi, M. Hashimoto', and T. Kojima. 1971. Two
autopsy cases of chlorobiphenyls poisoning. Fukuoka Acta Medica
62: 89-103.
402. TZOU, K.T.S. 1975. Hydrology and meteorology. Chapter 5 in
Upper Bay Survey, Vol. II. Final report to Maryland Department
of Natural Resources. Westinghouse Electric Corporation, Oceanic
Division, Annapolis, Maryland.
403. Takeuchi, T., N. Tomio, K. Eto, H. Matsumoto, A. Fujisaki, M.
Kodama, and S. Suko. 1969. Experimental study on poisoning by
rice oil mixed with Kanechlor (chlorinated biphenyl compound)
43: 63-86.
404. Jan, J., M. Komar, and M. Milohnoja. 1975. Excretion of some
pure PCB isomers in milk of cows. Bulletin of Environmental
Contamination and Toxicology 13(3): 313-315.
405..Frank, R., K. Ronald, and H. E. Braun. 1973. Organochlorine
residues in harp seals (Pagophilus groenlandicus) caught in
eastern Canadian waters. Journal of the Fisheries Research
Board of Canada 30(8): 1053-1063.
406. Gilbertson, M. and G. A. Fox. 1976.
-------
R-38
407. Gilbertson, M., R, D. Morris, and, R. A. Hunter. 1976. Incidence
of abnormal chicks and residue levels of PCB in eggs of colonial
bird species on the lower Great Lakes (1971-1973). Auk 93, in
press.
408. Ringer, R. K. 1975. Testimony before the New York State Depart-
ment of Environmental Conservation, In the Matter of Alleged
Violations of Sections 17-0501, 17-05011, and 11-0503 of the
Environmental Conservation Law of the State of New York, by
General Electric Company, Respondent.
409. U.S. Department of the Interior, Fish & Wildlife Service. 1975.
Sport Fishery and Wildlife Research 1973-74. Combined Annual
Report. Washington, D.C.
410.
411. FAO/WHO. 1967. High food consumption figures based on USA
survey. Annex to Report of Working Group on Pesticide Residues
in Food. WHO Technical Report Series 370.
412. Sigiura, K., M. Hattori, M. Baba, and M. Goto. 1975. Accumula-
tion and excretion of PCBs in the mouse. Chemosphere 3: 181-187.
413. Hoel, D. G., D. W. Gaylor, R. L. Kirschstein, U. Saffiotti, and
M. A. Schneiderman. 1975. Estimation of risks of irreversible,
delayed toxicity. Journal of Toxicology and Environmental Health
1: 133-151.
414. Mantel, N. and M. A. Schneiderman,, 1975. Estimating "safe"
levels, a hazardous undertaking. Cancer Research 35: 1379-1386.
415. Schneiderman, M. A., N. Mantel, and C. C. Brown. 1975. From
mouse to man -- or how to get from the laboratory to Park Avenue
and 59th Street. Annals of the New York Academy of Sciences 246:
237-248.
416. Monsanto. 1975. Industrial Bio-Test Laboratories, Inc. Reports.
Histopathological evaluation of additional liver sections. March
24, 1975. Unpublished reports, Monsanto Co., St. Louis, Missouri.
417. Monsanto. 1975. The Eppley Institute Reports. Report on histo-
pathological re-evaluation of tissues from female Sherman rats
fed Aroclor 1260. Report on histopathological re-evaluation of
livers from rats treated with Aroclor. Unpublished reports,
Monsanto Co., St. Louis, Missouri.
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