PRELIMINARY ASSESSMENT OF
SUSPECTED CARCINOGENS IN
DRINKING WATER
INTERIM REPORT TO CONGRESS
U.S. ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
JUNE 1975
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INTRODUCTION
For decades most Americans have confidently relied upon their
public drinking water, assuming that the Nation's drinking water was
free of microbiological and other harmful contaminants. In view of
recent findings, however, the assumption that our water is "safe" is
subject to question. Investigations have found that outbreaks of
disease or poisoning attributed to drinking water have riot been com-
pletely eliminated. Also of concern are recent findings that our
drinking water contains substances which are believed to be potentially
carcinogenic or otherwise toxic, such as various organic chemicals,
certain heavy metals, radionuclides, and asbestos.
On December 16, 1974, the Safe Drinking Water Act became law,
requiring the Administrator of the Environmental Protection Agency (EPA)
to promulgate national drinking water standards. While this legislation
was being deliberated by Congress, the discovery of asbestos fibers in
the water supply of Duluth, Minnesota, alerted the nation to the contami-
nation of some water supplies with asbestos, a suspected carcinogen in
drinking water. In November 1974, EPA announced that small quantities of
66 organic chemicals, some of which were suspected carcinogens, were
found in the New Orleans drinking water supply. Partially in response to
these events, Congress passed an amendment which became Section 1442(a)(9)
of the Safe Drinking Water Act. This Section directs the Administrator
to make "a comprehensive study of public water supplies and drinking
water sources to determine the nature, extent, sources of and means of
control of contamination by chemicals or other substances suspected of
being carcinogenic."
This interim Report is in response to that mandate and presents the
current programs of EPA to identify the nature and extent of the contamina-
tion of the Nation's drinking water, to determine the possible health
effects of exposure, and to develop the technically and economically
feasible means of removing those contaminants Of concern. In many cases,
however, the projects discussed are just underway or in various stages of
completion. Therefore, much of this Report is preliminary and may be
considerably revised and expanded at a later date.
While the criteria for predicting the carcinogenic potential of
chemicals have been reviewed extensively during the last decade and many
experts have agreed on certain guidelines, there is no official consensus
on what evidence is required to categorize a substance as "carcinogenic".
Thus, the Report considers a large number of chemicals in addition to
those that may have been rather conclusively established as carcinogens.
Further, there has been no attempt to distinguish between those "suspected
carcinogens" which are generally recognized as carcinogenic and those
with questionable carcinogenic potential.
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Most suspected carcinogens are hazardous because of their chemical
properties. On the other hand, asbestos is believed to be potentially
carcinogenic because of its physical properties. This Report will deal
with the two main groups of chemical carcinogens, organic and inorganic,
and separately with asbestos.
Orqanics, such as pesticides and other petrochemical products, have
lony been a concern of l.he U.S. Public Health Service. A 1970 survey
discovered that the levels of organics in many water supplies exceeded
the Public Health Service's recommended limit for carbon chloroform
extractable organics, which at that time was 200 micrograms per literJ
In 1972, EPA reported that 46 organic chemicals were present in trace
amounts in the raw and finished water supplies of three locations along
the Lower Mississippi;2 a 1974 EPA study identified 66 organics in New
Orleans drinking water.3 These and similar findings led to the initiation
of the National Organics Reconnaissance Survey to help clarify the
extent that organics are present in the Nation's drinking water.
Many inorganic chemicals in drinking water could cause adverse
health effects at certain concentrations. The proposed Interim Primary
Drinking Water Regulations published on March 14, 1975, call for maximum
contaminant levels for 11 inorganics as well as for organics and microbiological
contaminants. While the Regulations call for maximum levels for nine
specific pesticides, there is a maximum contaminant level for the total
concentration of organics, as measured by the carbon chloroform extract
method. The inorganic chemicals limited by the Regulations are: arsenic,
barium, cadmium, chromium, cyanide, fluoride, lead, mercury, nitrate,
selenium, and silver. Arsenic is both toxic and widespread throughout
the environment, finding its way into drinking water from natural deposits
and from its use as a pesticidal agent. Lead is another example of a
toxic substance which is found in food, air, and water. Other standards,
and revision of the present standards, will be proposed as more is
learned about the contaminants in drinking water and their toxicity and
pathways to man.
Radionuclides may present a hazard for which there may be no harm-
less level. A great diversity of sources are associated with radionuclides
and their occurrence in drinking water supplies varies widely. While
man-made sources such as effluent from nuclear facilities may be controllable,
natural sources of radioactivity are not as easily controlled. Certain
water treatment techniques and alternative water supplies may reduce the
exposure to radionuclides from drinking water sources. At this time, proposed
Community Water Supply Study -- Analysis of National Survey Finding.
Bureau of Water Hygiene, U.S. Public Health Service, July 1970.
p
Industrial Pollution of the Lower Mississippi River in Logisiana,
Environmental Protection Agency, April 1972.
o
JNew^Orleans Area Water Supply Study, Environmental Protection
Agency, Draft report released on November 8, 1974.
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maximum contaminant levels for radioactive materials in drinking water
have been prepared and are being circulated for interagency review.'
While inhaled asbestos is considered a carcinogen as the result of
numerous toxicological and epidemiological studies, whether asbestos
ingested in food or water is carcinogenic is unclear. In addition to
industrial discharges of asbestos, other sources of asbestos, such as
naturally occurring asbestos, may also be contaminating drinking water
supplies with potentially hazardous levels of asbestos.
iii
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TABLE OF CONTENTS
PAGE
INTRODUCTION 1
SUMMARY 1
CHARACTER AND EXTENT OF CONTAMINATION OF WATER SUPPLIES 3
National Organics Reconnaissance Survey 3
Survey of Eighty Water Supplies for Selected Contaminants j|
Survey of Ten Water Supplies for Broad Range of Organics *
National Survey of Pesticides in Drinking Water
Analysis for Inorganics in Water Supplies 11
Analysis of Interstate Carrier Water Supplies 11
Contamination of Consumer's Drinking Water 12
Survey of Rural Drinking Water Supplies 12,
Asbestos Fibers in Water Supplies 13
Review of Asbestos in Duluth, Minnesota 13
Investigations of Asbestos from Pipe Erosion 13
Nationwide Asbestos Sampling Program 14
HEALTH EFFECTS OF DRINKING WATER CONTAMINANTS 15
Review of Drinking Water Contaminants by the National Academy
of Sciences 15'
Quality Criteria for Water 15
Other Investigation of the Health Effects of Organics 16
EPA Science Advisory Board Review of Selected Organics 16
Experimental Evaluation of the Toxicity of Organics 18
Health Effects of Organics Occurring 1n Nature (Humlc Substances) 19
Environmental Levels of Organics and Health Effects 19
Estimating Exposure to Organics 19
Health Effects Studies of Inorganics 19L
Assessment of Effects of Oral Ingestion of Asbestos ?T
Effects of Selected Chemicals Found in Industrial Wastes 22
Industrial Correlates of Cancer Mortality 22
SOURCE IDENTIFICATION 25
Sources of Organics ._ 25
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PAGE
Industrial Sources 25
Discharges from Municipal Waste Treatment Facilities 25
Chlorinatior of Water Supplies 28
Contamination by Agricultural Chemicals 29
Other Non-point Sources of Organics 29
Solid Waste Sources 29
Hazardous Waste Management Practices of Major Industries 29
Investigations of Various Land Disposal Practices and Water
Contamination 30
TREATMENT TECHNIQUES FOR CONTROLLING CONTAMINANTS IN DRINKING WATER 31
Removing Organics with Granular Activated Carbon 31
Techniques for Controlling Inorganics 31
Filtration Techniques for Asbestos 32
COSTS AND ECONOMIC IMPACT OF CONTROL TECHNOLOGY 33
APPENDICES (Separate Volume)
I. Inventory of Organics Presently Identified in Drinking Water
II. National Organics Reconnaissance Survey
III. Organic Chemicals Found in Industrial Effluents
IV. Monitoring for Radiation in Drinking Water
V. Analysis of Inorganic Chemicals in Water Supplies
VI. Preliminary Results of Pilot Plants to Remove Water Contaminants
VII. Health Effects Caused by Exposure to Drinking Water Contaminants
vi
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SUMMARY
The Environmental Protection Agency has been conducting an extensive
program to answer the questions being raised by Congress and the Nation
concerning suspected carcinogens in drinking water. An early step ini-
tiated last November is the National Organics Reconnaissance Survey, de-
signed to provide an estimate of the nationwide distribution of organics
in drinking water. The initial results of this survey, included in this
Report, show that small quantities of organics are present in all of the
80 drinking water supplies surveyed. Further analyses of the data collect-
ed and a comprehensive survey of organics in ten water supplies will be
completed by December 1975. Other projects involve surveillance and analy-
sis of drinking water for selected inorganics, pesticides, and asbestos.
Results for many of these studies will be available within the next two
years.
Concurrent with the efforts to determine the presence of contaminants,
EPA has numerous studies to evaluate the health effects of these substances
in drinking water. The National Academy of Sciences is conducting a two-
year study concerning the relationship between various contaminant levels
and health effects. This effort should provide important information for
setting national contaminant levels. EPA's Science Advisory Board recently
reported its findings on the potential carcinogenic effects from exposure
to certain organics in drinking water.4 The report emphasized the great
need for well-designed experimental studies on the effects of lifetime
exposure by ingestion of the compounds found in drinking water. EPA has
been conducting preliminary investigations to evaluate the toxicity of
several individual compounds and mixtures of organics. Other efforts in-
clude examination of the health effects-of naturally occurring organics
(humic substances) and some epidemiological studies of the effects of or-
ganics. In addition, investigations of the health effects of selected
inorganics and of asbestos involve many studies, including a four-year
asbestos feeding study expected to begin shortly.
As part of the strategy to develop the basis for controlling contam-
inants in drinking water, EPA is identifying the possible sources of or-
ganics: industrial effluents and waste management practices, discharge
from municipal waste treatment facilities, chlorination processes, and
runoff of agricultural chemicals. Various treatment techniques such as
the use of granular activated carbon are being tested for removal of
organics and other drinking water contaminants. Finally, EPA is developing
estimates of the possible costs and economic impact of controlling con-
taminants in drinking water.
A Report: Assessment of Health Risk from Organics in Drinking
Water, Hazardous Materials Advisory Committee, Science Advisory
Board, Environmental Protection Agency, May 19, 1975.
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CHARACTER AND EXTENT OF CONTAMINATION OF WATER SUPPLIES
On April 18, 1975, EPA announced the preliminary results of a
nationwide survey for organics in drinking water. This National Or-
ganics Reconnaissance Survey is one of~several efforts underway to
investigate the possible problem of suspected carcinogens in drinking
water. Another investigation is focusing on whether drinking water is
a significant source of three pesticides (aldrin, dieldrin, and DDT).
Previous EPA work uncovered a significant number of people carrying
disturbing traces of dieldrin in their blood and body tissues.
In addition to the studies of organic contaminants, inorganic
chemicals, especially those which are included In the proposed Interim
Primary Drinking Water Regulations, are the subject of monitoring and
analysis efforts. A special assessment of rural drinking water supplies
is being considered and a study of asbestos in drinking water Is underway.
This section discusses these and other programs to determine the nature
and extent of contamination of the Nation's drinking water supplies.
National Organics Reconnaissance Survey
One of the Agency's most significant efforts to delineate the
problem of organics in drinking water is the National Organics Reconnaissance
Survey. Initiated in November 1974, the National Organics Reconnaissance
Survey has three major objectives. One 1s to determine liie extent of
the presence of the four trihalomethanes: chloroform (trlchloromethane),
bromodichloromethane, dibromochloromethane, and bromoform (trlbromomethane)
in finished water, and to determine whether or not these compounds are
formed by chlorination. The second objective is to determine the effects
raw water source and water treatment practices other than chlorination
could have on the formation of these compounds. The third objective 1s
to characterize, as completely as possible using existing analytical
techniques, the organic content of ten finished drinking water supplies.
These ten supplies represent five major categories of raw water sources
1n use in the United States today.
Survey of Eighty Water Supplies for Selected Contaminants
Eighty water supplies were chosen to determine the presence of six
specific organics of particular concern: the four trihalomethanes
(chloroform, bromodichloromethane, dibromochloromethane, and bromoform),
carbon tetrachloride, and 1,2-dichloroethane. Selected in consultation
with State water supply officials, these 80 supplies provide a reasonably
representative sample of the Nation's community drinking water supplies
that chlorinate their water, representing a wide variety of raw water
sources, treatment techniques, and geographical locations. Based on the
survey findings, it appears that chlorination contributes to the formation
of the four trihalomethanes. Results from the analysis of the raw or
untreated water samples showed that none of the samples contained any
dibromochloromethane or bromoform, and only 62 percent of the samples
contain any chloroform or bromodichloromethane. Of these samples, 58.4
percent contained very small concentrations of chloroform, 0.1 to
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0.9 yg/1; the other 3.6 percent contained no chloroform but had low
concentrations of bromodichloromethane, 1,2-dichloromethane, and/or
carbon tetrachloride in various combinations. Table 1 presents results
of the analysis of raw water.
Table 1
RAW WATER ANALYSIS
(Based on 79 samples)
Number of Locations Detected Range of Concentrations
(pg/llter)
None Detected 30
Chloroform 45 <0.1 - 0.9*
Bromodichloromethane 6 <0.2 - 0.8*
Dibromochloromethane 0 *
Bromoform 0
1,2-Dichloroethane 11 ° <0.2 - 3
Carbon Tetrachloride 4 <2 - 4
*0ne additional location received raw water prechlorinated by a nearby
industry. This water contained 16 yg/1 of chloroform, 11 yg/1 bromo-
dichloromethane, and 3 yg/1 dibromochloromethane.
In contrast to these findings for raw water, the presence of the
four trihaloniethanes, although mostly in low concentrations, was wide-
spread throughout the finished water. In all the locations, the finished
water treated or contained chloroform in concentrations ranging from
less than 0.1 yg/1 to 311 yg/1, with 50 percent of the finished waters
containing 25 yg/1 of chloroform or less. Bromodichloromethane was in
97.5 percent of the finished waters in concentrations of 0.3 yg/1 to 115
yg/1, with 62 percent of these containing 10 yg/1 or less. Dibromochloro-
methane appeared in 90 percent of the locations in concentrations from
less than 0.4 yg/1 to 100 yg/1, with 75 percent of these locations
having 5 yg/1 or less. Finally, bromoform was found in 31.6 percent of
the finished waters in concentrations ranging from 0.8 yg/1 to 92
yg/1, with 95 percent of these having 5 yq/1 of bromoform or less.
Only very small amounts of 1,2-dichloroethane and carbon tetrachloride
were found in the finished waters. Of the supplies that contained 1,2-
dichloroethane, 32.9 percent of the total, 6 yg/1 was the highest concentration
found; of the 12.6 percent of the systems with carbon tetrachloride, the
highest level was 3 yg/1. Table 2 shows the distribution and range of
concentrations of the trihalomethanes, 1,2-dichloroethane, and carbon
tetrachloride in finished water. Table 3 presents the results of the
analyses of the finished water for each of the 80 cities.
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Table 2
FINISHED WATER ANALYSIS
(Based on 79 samples)
Cpjnppu_nd_ Number of Locations Delected Kd'uje of Cpricentratipns
(uq/liteF)
Chloroform 79 0.11 — 311
Bromodichloromethane 76 1.8 -- 116
Dibromochloromethane 70 0.4 — 100
Bromoform 25 1.0—92
Carbon Tetrachloride 10 2.0 -- 3
1,2-Dichloroethane 26 0.2— 6
Survey of Ten Water Supplies for Broad Range of Oryanics
The second principal component of the National Organics Reconnaissance'
Survey included ten of the 80 cities as sites representing five major
categories of raw water sources for a more comprehensive survey of the
organic content of finished water. The first five cities investigated
and their raw water sources are: Miami, Florida (ground water); Seattle,
Washington (uncontaminated upland water); Ottumwa, Iowa (raw water
contaminated with agricultural runoff); Philadelphia, Pennsylvania (raw
water contaminated with municipal waste); and Cincinnati, Ohio (raw
water contaminated with industrial discharges).
Preliminary analyses of the drinking water of these five cities
have identified over 85 organics» as indicated in Table 4. More analyses
were performed than are included; however, only those constituents that
were qualitatively or quantitatively determined to be present are included.
Different techniques were used to identify as broad a range of organic
compounds as possible. One technique was designed for the more volatile
organics. Details of all procedures are found in Appendix III.
Within the next six months, the water supplies of the five remaining
cities will be surveyed and the results are expected to be reported
by the end of the year. These five cities and their raw water sources are:
Tucson, Arizona (ground water source); New York, New York' (uncontaminated
upland water); Grand Forks, North Dakota (water contaminated by agricultural
runoff); Terrebonne Parish, Louisiana (water contaminated by municipal
waste); and Lawrence, Massachusetts (water contaminated by industrial
discharges).
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Table 3
•[NISIIIIl WATER DATA FOR EIGIIIY CIIIIS
ALASKA, Douglas
ARIZONA, Phoenix
Tuscon
ARKANSAS, .Camden
CALIFORNIA, Coalinga
Concord
Dos Palos
Los Angele:
San Diego
San Fran-
; Cisco
COLORADO, Denver
Pueblo
COHMECTICUT, Wotcrbury
DELAWARE, Newark 0.5
(Artesian Wa-
ter Co.)
. -Wilmington
'• Sub. 23
Chloroform
JL<9/1
40
9
<0.2
40
16
31
61
; 32
52
41
14
2
93
Brown •
dichloro-
niC'thiiiH!
. un/1
0.8
15
<0.8
19
17
18
53
6
30
15
10
2
10
Dibrqmo
chloro-
methane
uo/1
<0.4
17
2
7
15
6
34
3
19
4
3
<2
0.6
Bronio
form
ug/i
NF
<4
13
NF
2
<1
7
NF
3
<0.8
NF
NF
<1
1 ,j>
Didiloro-
olhdrie
tiij/1
NF
NF
NF
NF
NF
NF
NF
NF
NF
NF
NF
NF
<0.2
r.cu bom
Tetra-
chloride
ug/1
NF
NF
NF
NF
NF
NF
NF
. NF
NF
NF
NF
NF
<2
Non-Vol.itile
lot.il Organic
Carbon
mg/1
2.8
1.0
<0.05
1.5
2.4
1.9
2.9
1.3
2.8
1.6
1.7
1.6
2.9
DISTRICT OF COLUMBIA
Washington
41
0.5
11
NF
NF
<0.2
<0.4
<0.3
NF
<2
NF
0.2
1.8
'1.2
FLORIDA, Jacksonville
Miami
GI.ORG1A, All. in l,i
IDAHO, Idaho Falls
ILLINOIS, Chicago
Clinton
INDIANA, Indianapolis
Whiting
IOWA, Clarinda
Davenport
Ottumwa
Ottumwa
KENTUCKY, Owensboro
KANSAS, Topeka
LOUISIANA, Logansport
Terrebonne
Parish
9
311
36
2
15
4
31
0.5
48
88
0.8
1
13
88
28
134
4
78
10
3
10
0.5
8
0.3
19
8
NF
NF
20
38
39
32
2
35
2
' 3
4
NF
<2
NF
4
<9.6
NF
NF.
17
19
24
8
NF
3
NF
NF
NF
NF
NF
NF
NF
NF
NF
NF
3
5
3
<1
NF
<0.2
NF
NF
<0.4
NF
NF
NF
NF
<0.4
NF
NF
NF
NF
NF
0.2
NF
NF
NF
NF
NF
NF
2
NF
NF
NF
NF
NF
. NF
3
NF
NF
2.3
5.4
0.9
0.3
1.5
6.7
2.6
1.5
3.0
4.4
2.3 (2/17/75)
2-4 (4/7/75)
2.0
2.2
3.5
3.2
NF - None Found
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Table 3 (cont.)
IINISIIII) WAIIIt DATA I Ok I Hill IY CIIIIS
Chloroform
uq/1
MARYLAND, Baltimore 32
MASSACHUSETTS, Boston 4
Lawrence 91
MICHIGAN, Detroit 12
Mt. Clemens 11
Mt. Clemens 6
MINNESOTA, St. Paul 44
MISSISSIPPI, Grecnvillo 17
MISSOURI, Cape
Gir.irdciiu llf.
KiinSiV. City '/A
St. Lour. 'jli
NIBKASKA, Lincoln 4
NEW JERSEY, Passaic
Valley 59
Toms River 0.6
NEW MEXICO, Albuquerque 0.4
NEW YORK, Buffalo 10
New York 22
Rhinebeck 49
NORTH DAKOTA, Grand
Forks 3
OHIO, Cincinnati 45
Cleveland 18
Columbus 134
Dayton 8
Indian Hill Hal.iT-
works 5,
Pi qua T3T-
Youngstov/n 80
OKLAHOMA, Oklahoma City 44
OREGON, Corvallis 26
PENNSYLVANIA, Philadel-
phia 8£
Pittsburgh 8
Strasburg <0.1
PUERTO RICO, San Juan 47
RHODE ISLAND, Newport T03T
SOUTH CAROLINA, Charles-
ton 195.
SOUTH DAKOTA, Huron 309
TENNESSEE, Chattanooqa 30
Memphis 0.9
Nashville 16
Bromo-
dichloro-
me thane
un/1
11
0.8
9
9
6
*
7
6
?}
it
13
6
16
<0.8
T
10
7
11
1
13
- 9
8
8
7
T3
5
28
3
9
2
NF
29
42
9
116
9
2
5
Dibromo
chl cro-
ne thane
ua/1
2
NF
0.6
3
2
2
<2
3
2
?.
3
4
2
3
2
4 '
a.y
i
NF
4
*
<0.4
VI
11
3.
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Table 3 (cont.)
FINISIO WA1TR DATA FOK EIGHTY CI1II.S
TEXAS, l;rown;.ville
lull,-is
Chloroform
uq/1
lie 12
in
iiio 0.2
Bromo-
dichloro-
methanc
tin/1
37
4
0.9
Di bromo
chloro-
methane
UO/1
100
<2
3
Bromo
form
uq/l
92
NF
3
1,2-
Dichloro-
ethane
uq/l
NF
NF
NF
Carbon
Tetra-
chloride
uq/l
NF
NF
NF
Non-Volatile
Total Organic
Carbon
mg/1
3.1
2.9
0.5
111 All, S.ill.
rity
V1RG1NA, Aiinunrlalc
llopewcl I
WASHINGTON, Ilwaco
Seattle
20
07
6
167
15
WEST VIRGINA, Huntington 23
Wheeling 72
WISCONSIN, Milwaukee 9
Oshkosh 26
NF
NF
NF
6
1
35
0.9
16
28
7
4
<0.6
0.8
5
NF
5
17
3
<0.4
NF
<2 ..
NF
NF
NF
NF
NF
NF
NF
NF
NF
NF
<0.4
<0.4
<0.2
<0.2
' NF
NF
NF
NF
3
NF
NF
NF
0.9
2.7
0.2
3.1
0.9 (End of Dist.
System)
l.Q
1.8
1.7
3.3
8
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Table 4
ORGANIC COMPOUNDS DETECTED IN SURVEY OF FIVE CITIES
(Approximate Concentrations, ijg/1)
Miami, Seattle, Ottumwa, Philadelphia, Cincinnati,
Florida Washington Iowa Pennsylvania Ohio
"1. acetaldehyde X 0.1
2. acetone X 1
3. arptophenone
4. acetylenebromide X
5. acetylenechloride - x
6. acetylenedichloride X
7. atrazine
8. benzene X
9. benzole acid
10. bis 2-(chloroethvl lethf-r
11. 1 ,2- bis (2-chloroethoxv)ethane
1? bromodichloromethane 78 0.9
n. bromoform 1.5
14. bromomethane X
15. 2-butanone X
16. t-butyl toluene
17. camphor 0.5 0.5
_jH_ carbon disulf.ide X
ig. carbon tetrachloride X
prj chloral (trichloroacetaldehyde) 3.5
21. chlorobenzene 1-0
22. chloroethane X
23j chloroform 311 15
24. chloromethane X
25. chloropicrin (trichloronitromethane)
26. j3-chlorotoluene 1.5 *""
27. cyanogen chloride
28. cymeme isomer 0.1
29. cyclohexanone X
30. dieldrin 2 1
31. dibromochloromethane is x
32. 2,6-di-tLbutyl)benzoquinone 0.1
33. di-n-butyl phthalate , 5 0.01
34. m-dichlorobenzene 0.5
35. o-dichlorobenzene _j
36. p-dichlorobenzene 0.5
X 0.1
X X
1
x
n i
X X
15
0.5
0.03
X 9
X
X X
0.01
0.1
X X
5.
X-
x
1 86
X X
0.05
0.1
X X
2
X 5
0.1 n n<;
X
X
X
. X .
X
X
x
n
x
x
0.1
x
X
2
X
X
45
X
X
1
a
x
x
x
37. 1,1 dichloroethane X
38. 1 ,2 dichloroethane <0<2
39. 1.1 dichloroethylene (vinyl idine
chloride) x
40. cis-1 ,2 dichloroethylene X
41. trans 1,2 dichloroethylene X
_4_2, dichloromethane X X
43. diethyl malonate
44, diethyl phthalate 1 JL.QJ
45. dimethoxymethane
46. dimethyl disulfide
47. di-n-octyl adipate 20.0
48. di-(2-ethylhexyl) phthalate 30
fi
X
X
X X
x
X
<0 4
v
x
X
0:01
0.1
"•
49. di-n-oropyl phthalate 0.5
50. ethanol X
51. ethyl ether
X X
X
x
x
52. _p-ethyl toluene 0.05
X - organics identified but not quantified.
*"Approximate concentrations" are explained fully in the Appendix. When organics were
quantified by more than one technique or at different times the highest concentration
of organics detected is reported.
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Table 4 (cont.)
ORGANIC COMPOUNDS DETECTED IN SURVEY OF FIVE CITIES
(Approximate Concentrations, ug/t)
Miami, Seattle, Ottumwa, Philadelphia, Cincinnati
Florida Washington Iowa Pennsylvania Ohio
53. hexachloroethane
54. isophorone (3,5,5-trimethyl-2-cycloheren-
55. lindane
56. methanol
57. methyl acetate
58. 3-methyl butanal
59. 3-methyl -2-butanone
60. 2-methyl butyl nitrile
61 . methyl ether
62. methyl formate
63. 3-methyl -3-pentanal
64. 2-methyl propanal
65. 2-methyl propyl nitrile
66. nicotine
67. nitromethane
68. n-pentanal
69. 2-pentanone
70. j>henylacet1c add
71. n-propyl benzene
72. n-Droovlcyclohexanone
73. 6-santalene
74. a-terolneol
75. tetrachloroethylene
76. 1 ,1 ,3,3-tetrachloro-2-propanone
77. tetramethvl benzene isomer
78, tetramethyltetrahydrofuran
79. toluene
Rn tri-n-butvl phosphate
81. 1,1,1 trichloroethane
82. 1,1,2 trichloroethane
83. trichloroethylene
84. trimethyl isocyanurate
85. 1 ,3,5-trimethyl-2,4,6-trioxo-
hexahydrotriazine
86. vinyl chloride (6)
0.5
1-one)
XX X
X
X XX
X
X X
X X
X
1
XXX X
X X
3.3
X
0.5
0.1
4
0.05
0.2
0.01
0.5
0.1 X
0.2 1
0.?
0.5
X X X
0,5
x
x
X X X
5.6 0.?7
0.02
0.01
X
X
\
X
X
X
X
X
0.01
0.1
0.5
X
0.05
X
0.02
0.5
-------
National Survey of Pesticides in Drinking Water
Other investigations of specific organic contaminants include an
intensive nationwide survey of pesticides in drinking water. The
survey's principal focus is on aldrin, dieldrin, and DDT, and the results
of the survey should be useful in assessing the maximum contaminant
levels to be established for these three pesticides.
The program is designed to examine samples of raw and finished
water from ground and surface water supplies in three population density
ranges (less than 5000, 5000 to 49,999, and 50,000 and greater) in each
of the ten EPA regions. 330 supplies were selected from an inventory of
approximately 40,000 community water supplies. Site selection for
sampling these supplies was based on several criteria: population
served, high and low pesticide potential, and treatment technology. The
samples will be analyzed by gas chromatography/ mass spectrometry,
coupled with a computer to identify the compounds. With this technique,
it should be possible to determine what other chlorinated pesticides are
present at significant levels. This analytical methodology can detect
compounds in the parts-per-trillion range. EPA and contractor laboratories
will analyze some duplicate samples to verify the technique and results..
The sampling began March 1, 1975, and is scheduled to be completed
by mid-summer. A final report with an analysis of the significance of
the findings, including populations at risk, should be prepared by early
fall.
Analysis for Inorganics in Water Supplies
Many inorganic chemicals in drinking water are potentially toxic at
certain concentrations. The proposed Interim Primary Drinking Water
Regulations present maximum contaminant levels for 11 inorganics, including
some suspected carcinogens: arsenic, barium, cadmium, chromium, cyanide,
fluoride, lead, mercury, nitrate, selenium, and silver. All the water
supplies sampled in the National Orgam'cs Reconnaissance Survey were
analyzed for these inorganics. In addition, several other EPA projects
are investigating the presence of these and other inorganic chemicals in
drinking water, as discussed below. While extensive efforts have been
directed to asbestos, because of the special nature of the asbestos
problem these activities will be discussed in a separate section:
Analysis of- Interstate Carrier Water Supplies
Until the passage of the Safe Drinking Water Act, the Federal
Government's authority to regulate drinking water was limited to interstate
carrier water supplies. At about three-year intervals, a survey of each
of the 700 supplies is made jointly by the states and the EPA Regional
Offices. At the time of the survey, a water sample is collected and
analyzed for the chemicals limited by the Public Health Service Drinking
Water Standards. Tabulations made of these data are published in the
Chemical Analysis of Interstate Carrier Water Supply Systems. The
11
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results published, in October-1973 indicate that chromium, lead, and
mercury were in some instances found in concentrations that exceed the
Drinking Water Standards. Of these three, mercury most frequently
exceeded the limit, but this occurred in only 1.5 percent of the samples
analyzed.
Con Lamination of Consumer's Drinking Water
While many analyses have been made of community drinking water
supplies, some studies have examined drinking water at the tap. The
first comprehensive data on water quality at the consumer's tap were
collected in the Community Water Supply Survey of 1969. The concentrations
of arsenic, barium, cadmium, chromium, lead, selenium, and fluoride that
were found in public drinking water supplies each exceeded the 1962
Public Health Service Drinking Water Standards in some instances.
However, of the 2,595 distribution samples analyzed, fluoride, which
most frequently exceeded the proposed limits, did so in only 2.2 percent
of the samples; the lead limit was exceeded in only 1=4 percent of the
samples.
Water occasionally is contaminated by metals from corroded plumbing.
This contamination has been of particular concern in some communities.
Special studies of the lead content in drinking water have shown that 65
percent of the homes surveyed in Boston and 24 percent of the homes
surveyed in Seattle have lead in their tap water in amounts exceeding
the 1962 Drinking Water Standard for lead.
In addition, EPA and the National Heart and Lung Institute are
jointly studying the inorganics present in 170 community water supplies
selected to be representative of U.S. water supplies. An attempt will
be made to determine the effects of drinking water quality on health,
especially the correlation between soft drinking water and heart disease
mortality.
As part of the Agency's Environmental Radiation Monitoring System
(ERAMS), measurements of tritium radioactivity are made in drinking
water samples from 77 major population centers and communities near
selected nuclear facilities. Results of the 1974 ERAMS survey are
included in Appendix IV. In 1974, the highest observed concentration of
tritium was less than 20 percent of the EPA maximum contaminant level
for radioactivity in drinking water currently being prepared. The
average concentration was about one percent of the proposed level.
Additional data on radioactivity in community water systems should
become available as States begin to implement monitoring requirements
that will be established under the Interim Primary Drinking Water Regulations.
Survey of Rural Drinking Water Supplies
Section 3 of the Safe Drinking Water Act requires the Administrator
to survey rural water systems to determine the quality, quantity, and
availability of water supplies for rural Americans. EPA has designed a
survey of 5200 randomly selected rural households tc assess among other
things the availability of water, water sources, and quality of drinking
water.
12
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In addition to the usual bacteriological analyses of water samples
to detect the presence of contamination (total coliform, fecal coliform,
fecal streptococci), chemical and radiological analyses of each water
supply will be made. All samples will be analyzed for pH, nitrates,
ammonia, chlorides, calcium, magnesium, sodium, lead, and sulfates.
Every tenth sample will be analyzed for the inorganic chemicals in the
proposed Interim Primary Drinking Water Regulations and for certain
pesticides. Every twenty-fifth sample will be analyzed for gross alpha
and radium 226. The survey is scheduled to be completed in June 1976; a
final report is due in December 1976.
Asbestos Fibers in Water Supplies
Asbestos fibers in the drinking water in Duluth, Minnesota, have
been traced to industrial discharges into Lake Superior. Monitoring
studies in other locations are indicative of non-industrial sources of
asbestos as well, such as asbestos-cement pipe or naturally occurring
asbestos. These findings suggest that asbestos may be quite widely
distributed in drinking water supplies throughout the nation.
Havieii) of Asbestos in Duluth^ Minnesota
A few months after the presence of asbestos fibers in Duluth's
potable water was confirmed in the fall of 1973, the Agency began periodic
asbestos analyses of the raw water. These analyses, for amphibole mass
by x-ray diffraction and for asbestos fibers by electron microscopy,
demonstrated the continuing presence of asbestos fibers. In addition to
these studies, an extensive lake sampling program showed that the concentration
of asbestos fibers was highest near the industrial discharge and declined
steadily at increasing distances from the discharge.
In the process of attempting to develop a procedure for the routine
analysis of asbestos in water, EPA selected some samples from interstate
water carriers. Only nine of the 63 samples (14 percent) had counts
that were in excess of 5 x 10^ fibers per liter. Furthermore, only five
of these cities (8 percent) had counts of 1 x 10" fibers per liter. The
five cities were Duluth, Minnesota; Troy, Vermont; Seattle, Washington;
Skidway Island, Georgia; and San Francisco, California. Eleven (18
percent) had fiber counts below detectable limits. These findings
prompted EPA to develop a nationwide asbestos sampling program now in
progress.
Investigations of Asbestos from Pipe Erosion
Erosion of'asbestos fibers from the walls of asbestos-cement (A/C)
pipe that is used in water distribution systems may be a source of
asbestos in drinking water supplies. Investigations of this possibility
involve a controlled experiment with water of a known chemical quality
circulated through two 100-foot lengths of A/C pipe. Weekly samples of
the effluent are being analyzed by electron microscopy to determine
whether or not asbestos fibers are released from the pipe wall.
13
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Another phase of this project Involves selection of l
water low in asbestos fibers flows sow; dlstoix*? through A/0
to use. Continuing nonthly analyses o1 r.he s^j-x?- c-ud tan
show whether or not an increase in the asbestos fibzr ton^-nt occur-
because of passage through tne £/C pipe. T^vsn "icc-r^or: n->vc benn
selected, and the first samples have been collect?.-.!. ')>!•>•;• r systems >.r:
expected to be tested in the future,
Nationaide Asbestos Scowling Pro-wan
A nationwide asbestos sampling prugran is unrfe.rvi#.y t.) d^ter'n^H; r
environmental levels of asbestos rssu'1 tir»g from discharges fp.v. ./»>»• iou
sources. Thirty-two sampling locati^t:< have been chosen whic.;'. inclunt"
four major categories of asbestos discharges. A P4.t«ral ^;1io category
was selected because of known asbestos rock forrcarvon" which jw
significant amounts of asbestos in run-off or eniss.ior.s due to
weathering processes. Other cateqorisss Include ashves/Tos 'iiirin.-.!
of other ores such as talc and vermiculite which -nay .also be source?, of
asbestos; and asbestos manufacturing. For al'i categories, both a:.- and
water samples are being taken. Over sixty sampling sites r^vo t;o*-jn
chosen, including the water supplies of'several major cities, such -»r.
San Francisco, Denver, Chicago, Atlanta, and Dallas- The sanph'n'g has
begun and a report, with the details of the tnalyses, .^hou!d! ie dvs,;*io!
early in 1976.
14
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HEALTH EFFECTS OF DRINKING WATER CONTAMINANTS
With the aid of modern analytical techniques, such as gas chromatog-
raphy, mass spectrometry, and atomic absorption, many types of organic
chemicals and heavy metals have been detected in drinking water for the
first time. Our knowledge of the health effects of most of these contam-
inants, particularly in the minute concentrations which occur in drinking
water, is highly inadequate. Complete analyses of the health risks
involved must include evaluation of human exposure to these chemicals
from all sources including contaminants in food and in the air. While
the efforts described below are extensive, they represent only the
beginning of the research needed to assess confidently the health
effects of drinking water contaminants.
Review of Drinking Water Contaminants by the National Academy of Sciences
In fulfilling its responsibilities under the Safe Drinking Water
Act, EPA has arranged for a study by the National Academy of Sciences
(NAS) to provide a health basis for setting maximum contaminant levels
in drinking water. While the legislation requires NAS to determine
recommended "maximum contaminant levels" based on potential health
effects, NAS is taking a slightly modified approach. NAS will provide
information and scientific judgments concerning the health effects which
might be expected at various ranges of concentrations for the contami-
nants. This information will enable the Administrator to determine
appropriate health goals for these contaminants and then, after consid-
ering technological and economic feasibility, to establish levels for
National Primary Drinking Water Regulations.
For those contaminants for which there is a sufficient data base,
NAS will make recommendations concerning the relationships between
contaminant levels and health effects. Among the factors the Academy
will consider are the margin of safety required to protect particularly
susceptible segments of the population; exposure to the contaminants by
other routes; synergism among contaminants; and the relative risk of
different levels of exposure to the contaminants.
The Academy will also investigate and report those contaminants
which may pose a threat to human health but whose current level in
drinking water cannot be determined. For those contaminants, the Academy
will recommend studies and test protocols for future research. The
project, initiated in April 1975, is scheduled for completion by December
16, 1976. This NAS review of drinking water contaminants should provide
an overview of the drinking water problem that will be essential in
determining future national strategies.
Quality Criteria for Water
In addition to the studies being conducted by the National Academy
of Sciences to recommend maximum contaminant levels, EPA is developing
15
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Quality Criteria for Water pursuant to the Federal Water Pollution
Control Act Amendments of 1972 (Section 304(a)(l) of PL 92-500). These
criteria are being developed to provide a scientific basis for establishing
ambient water quality goals. These goals should be useful as benchmarks
for setting water quality standards including State Water Quality
Standards, Effluent Guidelines, and the 1979 Interim Raw Source Drinking
Water Standards for the Safe Drinking Water Act (Section 1401(1)(D) of
PL 93-523). Included in the list of about 60 constituents are organic
and inorganic materials, including some suspected carcinogens.
Other Investigations of the Health Effects of Organics
EPA Science Advisory Board Review of Selected Organics
EPA has sought the advice of its Science Advisory Board regarding
potential carcinogenic or other adverse health effects resulting from
exposure to organic compounds in drinking water. Though recognizing the
importance of other types of toxic action, because of time constraints
the Board focused on the possible health risks from cancer. Principal
attention was directed to the compounds listed in Table 5, particularly
chloroform, carbon tetrachloride, chloroethers, and benzene.
Table 5
SELECTED CONTAMINANTS IN U.S. DRINKING WATER SUPPLIES
Contaminant(s) Amounts in ug/1 (ppb) Estimated Distribution*
Carbon tetrachloride <2 - 3
Chloroform <0.3 - 311
Other Halogenated C-, and C2 <0.3 - 229
Bis(2-chloroethyl)ether 0.02 - 0.12
B-chloroethylmethylether unknown
Acetylenedichloride <1
Hexachlorobutadiene ^0.2
Benzene (inc. alkylated benzenes
to C6) <10
Octadecane ^0.1
Cg-C3g hydrocarbons <1
Pnthalate esters ^1
Phthalic anhydride <0.1
Polynuclear aromatics 0.001 - 1
10%
100%
100%
low
low
low
low
high
high
high
50%
low
high
*These distributions for drinking water contaminants represent very
rough estimates made by the Ad Hoc Study Group of the
Science Advisory Board.
16
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The Board prefaced its Report^ with the caveat that the chemicals
that have thus far been identified in drinking water account for only a
small fraction of the total organic content. Thus, the possibility
exists that there may be additional substances in drinking water of
equal or greater toxicological significance. The Board also expressed
concern that future studies should take into account possible synergistic
effects of common combinations of contaminants. Further, it recommended
that a complete analysis of the problem consider data from all routes of'
exposure to these substances in addition to drinking water, such as
dietary and occupational exposure. Some of these additional source's of
exposure would likely pose a much greater potential intake than from
consumption of drinking water.
The Board felt that in general for all the compounds reviewed the
carcinogen!city data and experimental designs were either inappropriate
or below the standard of current toxicological practice and protocols
for carcinogenicity testing. Additional well-designed experimental
studies to determine the carcinogenicity of lifetime exposures by
ingestion are sorely needed.
The Board concluded that some human health risk does exist from
exposure through drinking water although this risk is currently un-
quantifiable. This conclusion was based on evidence of widespread
contamination of drinking water supplies, particularly from chloroform.
Laboratory animal studies indicate production of hepatomas by chloro-
form, but it should be emphasized that experimental carcinogenesis data
for chloroform are extremely limited. Carbon tetrachloride, a demonstrated
carcinogen in laboratory studies, occurs in drinking water generally at
much lower levels and is much less widespread than chloroform and
related trihalogenated compounds. Benzene has not been clearly established
to be carcinogenic in experimental animals, although epidemiological and
clinical studies, largely of occupational exposures, suggest its possible
carcinogenicity. Certain haloethers, chloro-olefins, and polynuclear
hydrocarbons have been demonstrated to be carcinogenic in laboratory
animals and have been identified in drinking water. To the very limited
extent that they have been measured, however, the data indicated that
the potential human dosage of these compounds from ingestion of drinking
water would generally be extremely small. However, the Board noted the
possibility of local situations where the dosages might be high enough
to justify some concern.
Data from epidemiological studies on the contaminants of primary
concern to the Board were very limited and the designs of studies were
generally inadequate for a conclusive assessment of health risk. Recent
studies alleging an association of high cancer incidence in New Orleans
with consumption of contaminated drinking water were considered by the
Board to be useful for forming hypotheses for future epidemiological
studies but not Indicative of any clear cancer hazard. Numerous other
variables might explain the apparent associations. Indeed, experimental
5A Report: Assessment of Health Risk from Organics in Drinking
Water, Hazardous Materials Advisory Committee, Science Advisory
Board, Environmental Protection Agency, May 19, 1975.
17
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toxicology studies suggest that, if there were a carcinogenic risk,
increased liver cancer would be a probable finding. In fact, however,
this was not revealed by the epidemiologlcal studies. As part of its
recommendations to EPA, the Board suggested that epidemiological studies
be undertaken to relate drinking water contamination with differences in
cancer incidence or other effects in exposed populations.
Experimental Evaluation of ihe Toxicity of Oiyanics
Currently, several EPA Offices are evaluating the toxic properties
of individual compounds and mixtures of organics extracted from drinking
water. The metabolism and toxicity of several compounds are being
studied in experimental species. These compounds include bis(2-chloro-
ethyl) ether; bis(2-chloroisopropyl) ether; dibromochloromethane; bromo-
dichloromethane; and the homologous series of chlorinated benzenes and
that of brominated benzenes. Comparative metabolic studies seek to
identify the animal models that will be most predictive of the responses
in man. Comparative acute and chronic toxicity studies will investigate
the types and reversibility of pathological lesions, target organs, and
threshold doses associated with each compound. Specialized studies will
examine the possible synergistic role of the halogen-substituted benzenes.
The toxicity of mixtures of organics collected from five U.S.
cities will be analyzed using several bio-assay procedures. Organic
extracts that demonstrate activity that may be carcinogenic, mutagenic,
teratogenic, or seriously toxic, will be chemically fractionated to
isolate the active chemical(s). The compounds that are identified as
the toxic agents will then undergo more definitive toxicity tests.
The long-standing tasks of obtaining, evaluating, and storing the
relevant information on the toxicity of organics are being greatly
expanded. Arrangements have been made with the Mutagenesis Information
Center at Oak Ridge to obtain literature citations on the potential
mutagenicity of the organic chemicals identified to date in drinking
water. In-depth literature searches for-20 organic compounds found in
drinking water will be conducted for information on teratogenicity,
carcinogenicity, and physical, chemical, biological, and environmental
properties.
Two other efforts are focusing on mutagenicity. Presently contractual
arrangements are being made to test the mutagenic properties of 85
chemical compounds. It is anticipated that approximately 20 of these
compounds.will be organics found in drinking water. In vitro mutagenicity
testing will be done on Salmonella, E. coil, and yeast, using metabolic
activating systems derived from mammalian livers. In another study
EPA will develop preliminary information on the potential mutagenicity
of substances which might be produced during the ozonation process. A
number of chemical compounds will be subjected to conditions similar to
those encountered during disinfection processes using ozone. The ozonated
product mixtures will be tested to determine the potential mutagenic
effects on certain microorganisms.
-------
In addition to these studies, it is important to note the Nat,*..
Cancer Institute's study of chloroform. This study is an attempt l.o
assess the health effects of ingesting chloroform and should provide
much needed data for evaluating the health risks, if any, associated
with the presence of chloroform in drinking water. The study, which
involves both rats and mice in a two-year experiment, is expected to be
completed by early fall 1975.
Health Effects of Organics Occurring in Nature (Humic Substances)
The organics thus far identified in drinking water are believed to
represent only a small percentage of the total organic concentrate
recovered from drinking water. The remaining fraction is quite heterogeneous
and includes mixtures of high molecular weight organics not susceptible
to rigorous chemical definition.
When subjected to chlorine or ozone treatments, humic substances
might produce either halogenated organic compounds or oxidized forms,
including peroxides or epoxides, which may be hazardous to man. An
animal feeding study concerning the carcinogenic potential of humic
substances that occur naturally in water is planned. The study will
test the effects of subjecting these substances to chlorination, or
ozonation, or to sequential treatment with ozone and chlorine. This
investigation will follow the testing guidelines of the National Cancer
Institute.
Environmental Levels of Organics and Health Effects
An investigation scheduled to begin shortly will seek to identify
and measure environmental levels of selected halogenated organic compounds
and to determine the correlations of various levels with health effects
observed in the exposed population. This study will focus on areas
suspected of having high levels of these organics in the environment and
areas known to have a high incidence of cancer. Comparative analyses
will be made of other areas with moderate and low environmental levels
of the substances. The project should be completed in the spring of
1976.
Estimating Exposure to Organics
EPA plans to explore the correlations between levels of organics
that have been measured in each water supply and the number of users of
each supply. Extrapolations from these data to national exposure
curves will be attempted. The estimate of national exposure to organics,
in conjunction with the various local exposure levels, will assist in
providing a basis for estimating health risks.
Health Effects Studies of Inorganics
Some of the inorganic chemicals which investigators have suggested
may be potentially carcinogenic in drinking water under certain circumstances
19
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are arsenic, beryllium, cadmium, chromium, nickel, selenium, and nitrates.
All the metals are being tested for mutagenicity; those which show
mutagenic effects may be subsequently tested for carcinogenicity. Some
studies and brief assessments of the carcinogenicity of these inorganics
are described below.
While arsenic has been associated with the occurrence of cancer,
its exact role as a carcinogen has not been determined. Exposure apparently
must be quite high and occur over an extended period of time before skin
cancer develops. However, at certain exposure levels arsenic is generally
recognized to be acutely and chronically toxic to man. In view of the
recent reduction in permissible arsenic concentrations set by the Occupational
Safety and Health Administration for the workplace, EPA is reviewing the
concentrations allowed in drinking water.
In addition, EPA is currently considering two studies on arsenic to
help clarify risks associated with exposure to arsenic. The first, part
of a larger study on various selected toxic substances, involves the
relationship between environmental exposure to inorganic arsenic and
health effects. Populations exposed to significant amounts of arsenic
would be the subject of epidemiological studies to assist in determining
the health effects of arsenic exposure. The second study under consideration
would determine the body burden of arsenic in humans who consume drinking
water containing arsenic at or exceeding the current limit of 0.05 mg
per liter.
Nitrate concentrations in drinking water have been limited because
of the possibility that infants who ingest water high in nitrates may
develop methemoglobinemia. There is also a possibility that the nitrogen
might combine with amines in the environment to form nitrosamines; some
nitrosamines are recognized .carcinogens. However, this reaction was
demonstrated at much higher concentrations of nitrates than would normally
occur in water. The exposure associated with the use of nitrates and
nitrites as meat preservatives, for example, is believed to be at least
an order of magnitude greater than the exposure associated with the
presence of nitrates in drinking water.
Existing health effects evidence does not conclusively show whether
selenium is carcinogenic. After a complete review of its health effects,
the Food and Drug Administration last year concluded that selenium could
be safely used as an additive to animal feed. Very low levels of selenium
are apparently necessary for red blood cell integrity. On the other
hand, some FDA critics assert there is cause for concern because several
animal studies show that tumors were developed from exposure to selenium.
It should be noted, however, that doses used in those experiments were
very high.
Radionuclides are recognized carcinogens. Following the recommendation
made by the National Academy of Sciences, EPA bases its estimates of
20
-------
the health effects of radiation exposure through ingestion of drinking
water on the assumption that there is no harmless dose level and that
any health effects produced will be proportional to the radiation dose
delivered by drinking water.
Assessment of Effects of Oral Ingestion of Asbestos
While the development of cancer from exposure to airborne asbestos
has been documented by epidemiological studies, the effects of ingested
asbestos have not been determined. Several current projects are studying
various aspects of this problem, including asbestos absorption in the
gastrointestinal tract, the possible correlation between cancer incidence
and asbestos in drinking water, and the toxicology of ingested asbestos
in rats.
Research on the problem of ingested asbestos in man has revealed
that an excess of gastrointestinal cancer and of peritoneal (abdominal)
mesotheliomas (neoplasms of the lining cells) may occur in workers
exposed to airborne asbestos. Scientists believe that the workers under
study ingested asbestos particles which were in their mouths and respiratory
tracts and that this ingestion of asbestos is related to the incidence
of cancer.
EPA is studying the passage of asbestos fibers through the gastrointestinal
tract in an effort to evaluate this aspect of ingestion exposure. One
study involves labelling asbestos with tritium to elucidate the mechanism
of asbestos absorption.
Several studies have focused on the possible correlation between
asbestos in drinking water and the incidence of cancer. Two studies of
the population of Duluth, Minnesota, where the concentrations of asbestos
fibers in drinking water were very nigh, have recorded no unusually high
incidence of cancer. However, because of the long latency period between
exposure and the development of the disease, these studies may have been
too premature for the detection of carcinogenic effects of ingested
asbestos. In one study, risk ratios were calculated for Duluth in
comparison to the State of Minnesota and Hennepin County (Minneapolis).
Of 21 cancer sites in the body, only cancer of the rectum had an excess
that was significant and highest in the latest 5-year period of the
comparison. The study concluded that this was probably not related to
asbestos exposure. While cancers of the esophagus and stomach had commonly
resulted from occupational exposures to asbestos, these cancers were not
notably high in Duluth.
The second study was based on cancer incidence data instead of
mortality and compared Duluth with the Twin Cities. There was no clear
pattern of difference in gastrointestinal cancer incidence among the
three cities in 1969-1971. However, there is a long lag period between
initial asbestos exposure and diagnosis of asbestos-associated cancers.
21
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A third study planned for next fiscal year would involve the efforts
of the Center for Disease Control. Using the tumor registries of Connecticut
and California, the investigation would identify populations exposed to
asbestos in drinking water and compare their tumor incidence, especially '
gastrointestinal cancers, ovarian cancers, and mesotheliomas, with that
of populations with smaller amounts of or without asbestos in their
water.
In a very important project the National Institute of Environmental
Health Sciences is funding a toxicological study of the ingestion of
various asbestiform types. This four-year study, expected to begin
shortly, is divided into four parts. First, about one ton each of
chrysotile, crocidolite, amosite, and tremolite will be characterized
and prepared. Second, lifetime feeding studies of each of the fibers
(one percent of the diet) will be performed with a single strain of
rats, including a positive carcinogen and other controls. For each type
of fiber there will be 500 rats in the experimental group and 1000 in
the controls. The third part of the study will be similar to the second
part except that hamsters will be used and only chrysotile and one other
fiber type will be used. The last part of the study will attempt to
determine if orally ingested asbestos is carcinogenic under a particular
set of physiological circumstances.
The various studies described above should contribute significantly
to our understanding of asbestos and of the correlation between its
physical properties, including those which are common to other substances,
and potential carcinogenic effects in man.
Effects of Selected Chemicals Found in Industrial Wastes
As part of an ongoing hazardous waste management program, extensive
literature surveys and evaluations of the health and environmental
effects of selected hazardous materials, including some recognized or
potential carcinogens, are being conducted. Effects Reports will be
issued on at least 18 hazardous substances in the following sequence:
mercury, asbestos, cadmium, arsenic, chromium, cyanides, PCB's, fluorides,.
methyl parathion, benzidine, toxaphene, selenium, copper, zinc, beryllium,
and endrin. Almost all of these chemicals have been found in drinking
water at various levels. To provide useful information for health risk
determinations, dose-response information will be presented where, data
are available. Most of this work is being performed for EPA by the Oak
Ridge National Laboratory. The first of the Reports considers mercury
and is expected to be issued in the fall of 1975; the last of the series,
endrin, is anticipated by the end of 1976.
Industrial Correlates of Cancer Mortality
This effort, being carried out in cooperation with the National
Cancer Institute, involves the statistical analysis and correlation of
indices of cancer incidence with indices of the concentration of selected
industries on a county-by-county basis. To the extent possible, the
22
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study will assess the relationships between each specific industry identified
arid increases in particular types of cancer. Consideration will be
given to whether such increases are due to the effluents and emissions
from these industrial plants, to occupational exposure, or to other
factors, including such demographic variables as age, income, sex, race,
and population density.
The study should provide a much needed broad perspective in assessing
the relationships among industrial concentrations, pollutant levels
(including drinking water contaminants), and cancer. A report of the
initial results should be available by the end of 1975.
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SOURCE IDENTIFICATION
Investigations of sources of contaminants address a variety of
suspected sources such as industrial effluents, agricultural run-off,
municipal waste treatment facilities, chlorination and other treatment
processes, and landfills. These investigations are discussed below.
Sources of Organics
EPA is identifying substances remaining in municipal and industrial
wastes and sludges after various treatment processes. This effort will
provide information on the presence of substances which are potentially
damaging to man and the environment; provide data on the effectiveness
of various treatments; and allow identification of the sources of organ-
ics in water at the microgram per liter or greater concentrations.
Industrial Dour<:>'.u
Several studies of industrial effluents have produced an extensive
inventory of oryanics which suggests that industrial sources may be
major contributors to the organics found in drinking water. Two of the
substances in drinking water that have been rather clearly identified as
suspected carcinogens, chloroform and bis(2-chloroethyl) ether, appear in
industrial wastes and not in domestic sewage, an alternate possible
source. However, there is also the possibility that these compounds are
formed by chlorination during^the treatment of drinking water.
Extensive studies will be required to establish a direct relationship
between industrial discharges and appearance of organics in drinking
water. Systematic studies of the composition of industrial effluents
are on-going. EPA also is considering a program that will help identify
the industrial sources of discharge of organics into river basins which
feed a number of public drinking water supplies. The goal of this
program would be to correlate the organics appearing in particular water
supplies with specific industrial discharges.
Over 200 organics identified in various drinking water supplies
have been examined to determine possible point source discharges during
manufacture and use; possible non-point sources; persistence; methods of
removal; and gross estimates of total discharge. Some data have been
collected on industrial discharges to the Potomac River Basin. A report
describing these efforts, along with preliminary recommendations, should
be available in the fall of 1975.
Discharges from Municipal Waste Treatment Facilities
Efforts are underway to determine to what extent municipal waste
treatment practices and effluents contribute to the presence of organic
chemicals in drinking water supplies.
Under contract to EPA, the Oak Ridge National Laboratory developed
a procedure for the separation and tentative identification of refractory
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organics from municipal waste treatment facilities. The procedure which
is capable of detecting organics at the microgram-per-liter level was
applied to the study of primary and secondary effluents at the Oak Ridge
facility. In primary effluents, 55 compounds were identified with an
additional 30 or more detected but not identified. The identified
substances include simple carbohydrates, amino acids, and other components
apparently of metabolic origin. These same substances were found in
both chlorinated and unchlorinated effluents. Table 6 provides a list
of the identified compounds.
Table 6
ORGANIC CHEMICALS IDENTIFIED IN PRIMARY WASTE TREATMENT EFFLUENT
Ethylene glycol
Glucose
Erythritol
Phenylalanine
5-Acetylamino-6-amino-3-
methyluracil
Theobromine
Hypoxanthine
Adenosine
3-Methylxanthine
2-Deoxyglyceric acid
Quinic acid
2-Deoxytetronic acid
3-Deoxyerythropentonic acid
Ribonic acid
Uric acid
3-Hydroxyphenylhydra-
ylic acid
4-Hydroxybenzoic acid
4-Hydroxyindole
Maltose
Glycerine
Urea
Uracil
N-Methyl-2-pyridone-5-
carboxamide
7-Methylxanthine
Xanthine
1,7-Dimethylxanthine
Caffeine
3-Hydroxybutyric acid
1-Methylxanthine
Glyceric acid
2,5-dideoxypentonic acid
Oxalic acid
Succinic acid
Phenylacetic acid
Benzoic acid
4-Hydroxybenzoic acid
o-Phthalic acid
Galactose
Galacitol
N-Methyl-4-pyridone-3-
carboxamide
Tyrosine
Thymine
Inosine
Copper (II) acetate
(binuclear)
Guanosine
3-Deoxyarabinohexonic acid
1-methylxanthine
4-Deoxytetronic acid
3,4-Dideoxypentonic acid
2-Hydroxyisobutyric acid
Phenol
4-Hydroxyphenylacetic acid
2-Hydroxybenzoic acid
Indican
£-Cresol
In unchlorinated secondary effluents 33 compounds were detected.
Thirteen were identified. Ten of these were also identified in primary
effluents. The 13 substances are listed in Table 7.
Table 7
ORGANIC COMPOUNDS IDENTIFIED IN SECONDARY WASTE TREATMENT EFFLUENT
Glycerin
5-Acety1 ami no-6-ami no-3-
methyluracil
7-Methylxanthine
1,7-Dimethylxanthine
Catechol
3-Hydroxindole
Uracil
1-Methylinosine
Inosine
1-Methylxanthine
Succinic acid
Indole-3-acetic acid
£-Cresol
Samples of both primary and secondary effluents were chlorinated
under conditions simulating plant conditions and analyzed for chlorinated
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compounds. Of 62 chlorinated compounds which were detected, 15 have been
identified and are listed in Table 8. In addition to the Oak Ridge study,
work being done at North Texas State University has identified 12 poly-
chlorinated compounds in superchlorinated domestic wastes (Table 9) and
detected 16 other chlorinated compounds which have not yet been identified.
Table 10 identifies acid fractions of domestic wastes.
Table 8
COMPOUNDS IDENTIFIED IN CHLORINATED PRIMARY AND SECONDARY EFFLUENTS
5-Chlorouracil 5-Chlorouridine
8-Chlorocaffeine 6-Chloro-2-aminopurine
8-Chloroxanthine 2-Chlorobenzoic acid
5-Chlorosalicylic acid 4-Chloromandelic acid
2-Chlorophenol 4-Chlorophenylacetic acid
4-Chlorobenzoic acid 4-Chlorophenol
3-Chlorobenzoic acid 4-Chlororesorcinol
and/or 3-Chlorophenol
4-Chloro-3-methylphenol
Table 9
COMPOUNDS IDENTIFIED IN SUPERCHLORINATED MUNICIPAL WASTEWATERS
Trichlorotoluene
Hexachloroethane
1,1,1,3,3-Pentachloro-2-propanone
2,4-Di chloroethy1 benzene
o- and £-Chloroethyl benzene
2,4,5-Trichloropitenetole (3 isomers)
1,2-Dichloropropane
o- and jD-Dichlorobenzene
TChloromethyl)butene (2 isomers)
Table 10
ORGANIC SUBSTANCES FOUND IN THE ACID FRACTION OF DOMESTIC SEWAGE
TREATMENT EFFLUENTS
Butyric acid Isobutyric acid
Isovaleric acid Enanthic acid
Caprylic acid (Co) Capric acid (Co)
Laurie acid (C-^T Myristic acid
Pentadecanoic acid (Cis) Palmitic acid ie
Margaric acid (Cig) Stearic acid (Cig)
Nonadecanoic acid (Cig) Arachidic acid (C2Q)
Behenic acid (C22) Palmitoleic acid
Oleic acid Anteisopentadecanoic acid
Anteisomargaric acid Hydroxymyristic acid
Hydroxypalmitic acid Hydroxystearic acid
Phenylacetic acid Salicylic acid
Phenylpropionic acid 2-(4-chlorophenoxy)-2-methyl
Pentachlorophenol propionic acid
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As part of the industrial source program described earlier, a
preliminary literature search has been conducted to determine which
organics have been identified in municipal waste treatment effluents and
which are likely lo be present either from industrial discharge or as a
result of biological treatment or chlorination. The preliminary results
show that 23 of the organics identified in drinking water have been
positively identified in municipal waste treatment effluents; an additional
27 may be found as intermediates or final products of biological treatment;
and 42 could be produced during chlorination of treatment effluents.
In addition to determining whether municipal waste treatment practices
and effluents are a significant source of organics in water supplies,
investigations are also directed to whether control can be achieved by
regulating industrial discharges to sewer systems or whether further
treatment of municipal waste treatment effluents is required. A preliminary
report describing these efforts, along with recommendations of near-term
steps that could be taken to minimize the problem, will be completed in
the fall of 1975.
Chlorination of Water Supplier,
As yet, there is no acceptable substitute for chlorination as a
residual disinfectant, and'the health hazards of foregoing chlorination
would be severe. At the same time, concern is increasing over the
effect of chlorination on organic materials found in natural and waste
waters. In 1973, the following compounds were identified as formed by
chlorination of water supplies: chloroform, bromodichloromethane,
dibromochloromethane, and bromoform. At that time naturally occurring
humic substances were postulated to be precursors to the .formation of
these trihalomethanes. The maximum concentrations found were: chloroform,
54.0 yg/1; bromodichloromethane, 20.0 yg/1; dibromochloromethane, 13.3
yg/1; and bromoform, 10.0 yg/1.
A later study confirmed the presence of these trihalomethanes in a
variety of finished drinking waters from Ohio, Indiana, and Alabama. It
prompted studies to determine which factors influence the rate and
quantity of the formation of trihalomethanes during chlorination, and
which other halogenated compounds might be formed at the same time.
One study compared the rate and extent of chloroform formation when .
chlorine was added to raw river water, dual-media filtered water, and
water treated by granular activated carbon. These experiments were
carried out at constant pH and at 25°C. When sufficient chlorine was
added to satisfy the chlorine demand for the duration of the experiment,
chlorination of raw river water yielded approximately seven times as
much chloroform as did chlorination of the dual-media filtered water,
and approximately 80 times as much as did chlorination of the fresh
granular activated carbon filter effluent (207 yg/1, 32 yg/1, and 2.7
yg/1, respectively, in 7+ days). The rate of chloroform formation in
the river water was approximately 10-15 yg/hr for the first six hours.
Researchers have not yet determined which substances are removed from
the raw river water during alum coagulation, settling, and dual-media
filtration that reduces the rate and extent of chloroform formation upon
chlorination.
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Other studies investigated the chlorination of approximately 50
ng/1 of nitromethane, benzene, toluene, and m-xylene. Under the conditions
of Lhe test, nine days of storage at 25°C, nitromethane was readily
converted to chloropicrin, and m-xylene was readily converted to chloroxylene.
Bcnzono did not react with the chlorine under these conditions, and
toluene produced chlorotoluene rather slowly. These studies indicate
that other chlorination by-products can occur during the chlorination
process and should not be overlooked in future studies.
Controlled studies of this type will continue in an attempt to
define specific precursors of the trihalomethanes, and the conditions
under which the formation of these substances is enhanced or retarded.
Investigations dealing with the formation of other halogenated organics
by chlorination of water supplies will also continue.
Contamination by Agricultural Chemicals
Two projects address the contamination of drinking water by agricultural
chemicals. One is an assessment of the magnitude and scope of the
impact on drinking water supplies of intensive application of pesticides
and fertilizers in underground water recharge areas. On the basis of
very limited data now available, no significant problems have been identified
resulting from potassium or phosphorus nutrients. Problems related to
nitrogen seem to be localized. Ground water data on contamination from
pesticides or their residues are too limited for comment at this time.
The initial phase of the study should be completed in November 1976. A
second project is an attempt to determine whether various water treatment
techniques effectively remove pesticides found in raw water supplies. An
analysis of the pesticides present in raw and finished water should
indicate whether there are statistically significant differences in
treatment efficiency.
Other Non-point Sources of Organics
EPA is attempting to estimate the contribution of non-point sources
to the total organic compounds found in river basins which feed drinking
water supplies. The purpose of this activity is to help determine whether
significant abatement can be achieved by regulation of point source
discharges or whether direct treatment of drinking water supplies is
necessary.
A total of 154 organic chemicals identified in various drinking
water supplies have been studied preliminarily to determine possible
non-point sources of discharge, persistence, and methods of removal. A
report describing these efforts should be available in the fall of 1975.
Solid Waste Sources
Hazardous Waste Management Practices of Major Industries
The generation, treatment, and disposal of hazardous wastes of the
following 13 industry categories are currently under investigation:
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Pharmaceuticals; Paint and Allied Products; Storage and Primary Battery
Manufacturing; Inorganic Chemicals; Petroleum Refining; Primary Metals;
Metals Mining; Electroplating and Metal Finishing; Organic Chemicals;
Pesticides, and Explosives; Textiles; Rubber and Plastics; Leather
Tanning and Finishing; and Machinery (except Electrical). These industry
studies relate to the problem of carcinogens in drinking water insofar
as they clarify the types and quantities of recognized and potential
carcinogens that are disposed on land and subsequently might be trans-
mitted to nearby surface and ground waters. The first studies (storage
and primary battery manufacturers) have been completed; the last in the
series is expected to be issued by the summer of 1976.
Investigations of Various Land Disposal Practices and Water Contamination
EPA has several investigations underway to clarify the possible
correlation between disposal practices and contamination of water supplies.
Monitoring of surface and ground waters at dumps and sanitary landfills
is being conducted to determine whfl.her the waters have been contaminated
by material;. preterit in the dumps or landfills. As a result of tho
contamination of surface arid ground waters, drinking water may be con-
taminated. Monitoring has begun at seven of the 11 sites selected and
should be completed by December 1975. Preliminary results from one
dump indicate that the ground water below the site has been polluted.
The results from other sites will probably vary depending on climato-
logical and physical parameters.
Another project is entitled "Development.of a Data Base for Determining
the Prevalence of Migration of Hazardous Chemical Substances into the
Groundwater at Industrial Waste Land Disposal Sites." This study is
expected to document the migration of hazardous substances, including
some suspected carcinogens, from approximately 75 industrial land dis-
posal sites, including dumps, landfills, lagoons, pits, and basins, into
the Nation's groundwaters. The primary objective of this effort is
to provide data for developing future land disposal guidelines and
standards. This investigation is expected to begin in the fall of 1975
and to conclude in the summer of 1977.
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TREATMENT TECHNIQUES FOR CONTROLLING CONTAMINANTS IN DRINKING WATER
Removing Organics with Granular Activated Carbon
To date, the major treatment technique investigated for the removal
of general and specific organics from drinking water has been granular
activated carbon. About ten years ago, partially exhausted granular
activated carbon was shown to remove dieldrin, lindane, 2,4,5-T, DDT,
and parathion to below detectable limits. About the same time, fresh
granular activated carbon used to treat Kanawha River water was shown to
remove bis(2-chloroethyl) ether, 2-ethyl hexanol, bis(2-chloroisopropyl)
ether, a-methylbenzyl alcohol, acetophenone, isophorone, and tetralin.
More recent studies have shown that fresh granular activated carbon
receiving finished water from Evansville, Indiana, removed all detectable
bis(2-chloroethyl) ether and b1s(2-chloroisopropyl) ether.
For about seven months, a coal-base granular activated carbon
column, 28 inches deep, has been receiving Cincinnati tap water spiked
with approximately 30 pg/1 of naphthalene. After this time period, the
50 percent removal point for naphthalene was only approximately two
inches down the column. Two 28-inch deep columns of granular activated
carbon, one coal-based and the other lignite-based, have been receiving
Cincinnati tap water. The purpose of this test has been to determine
the effectiveness of the two types of granular activated carbon for the
removal of trihalomethanes. Both columns removed all of the trihalomethanes
for about one month of operation, and then some chloroform began appearing
in the effluent. The current experience indicates that the effective
life of carbon in removal of organics may be somewhat limited.
At the present time, a pilot plant made of stainless steel and
glass is treating 400 ml/min of unchlorinated Ohio River water in an
attempt to demonstrate how to remove effectively trihalomethane precursors
from water so that chlorine can be used as a disinfectant without the
formation of trihalomethane. Ozone is also being evaluated as a possible
alternative to chlorine for post-treatment disinfection.
Future plans include pilot and full scale research designed to
indicate the effectiveness of granular activated carbon and other organic
removal unit processes for the removal of specific raw water contaminants
of concern.
Techniques for Controlling Inorganics
Techniques for the control of concentrations of various inorganics
have been studied by EPA. Of the substances studied thus far, only
arsenic, asbestiform fibers, and radium 226 have been considered as
suspected carcinogens in drinking water. Treatment technology studies
for these substances have been conducted. Arsenic was studied in bench
and pilot scale investigations by spiking Ohio River water and ground
water from Glendale, Ohio, with concentrations of arsenic from two to
ten times the limits in the proposed Interim Primary Drinking Water
Regulations.
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Information on the treatment potential of various techniques for radium
226 removal was obtained by monitoring several water treatment plants in
Iowa that are treating water that is naturally high in radium 226.
Studies on mercury, cadmium, selenium, and chromium were similar to
those described above for arsenic. For the barium removal studies, both
bench-scale and pilot plants will be used. In all the studies, the
techniques that were found to be among the most effective for removing
the inorganic contaminants included excess lime softening, ion exchanget
and ferric sulfate coagulation.
Filtration Techniques for Asbestos
The methods being studied for the removal of asbestiform fibers are
mixed media and diatomite filtration employing alum and polyelectrolytes.
Pilot plant research conducted in 1974 at Duluth, Minnesota, demonstrated
that asbestiform fiber counts in Lake Superior water could be effectively
reduced by these filtration techniques. During the study, engineering
data were also obtained for making cost esimates for construction and
operation of both granular media and diatomaceous earth filtration
plants ranging in capacity from 0.03 to 30 million gallons per day.
Both amphibole and chrysotile can be markedly reduced by both filtration
techniques.
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COSTS AND ECONOMIC IMPACT OF CONTROL TECHNOLOGY
EPA has begun to evaluate the potential costs associated with
alternative treatment technologies used for removing drinking water
contaminants. The cost estimates from various studies now underway or
proposed will be issued as they become available. Estimates of the cost
impact of the Interim Primary Drinking Water Regulations proposed on
March 14, 1975, will be included in the promulgated Regulations to be
published in the near future. These estimates are based on economic
analyses of the costs associated with limiting bacterial, inorganic, and
organic contaminants at the levels specified in the Regulations.
•& U.S. GOVERNMENT PRINTING OFFICE: 1975— 210^810/12
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