U.S. DEPARTMENT OF COMMERCE
                                       National Technical Information Service


                                       PB-254  023
CRITERIA DOCUMENTS FOR  BENZIDINE
ENVIRONMENTAL  PROTECTION  AGENCY
1 JUNE  1976

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                                  EPA-440/9-76-017
        CRITERIA DOCUMENT:  BENZIDINE



U.S.EPA, Office of Water & Hazardous Materials,



    Office of Water Planning and Standards
                                June 1976

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           HiC DATA   I1- K «?•»-•: No.
           Criteria Documents for Benzidine
        j^rorv/rrous
                                                                        E. Pctioraia* O.-ganLcaclo,, U,,
         U.  S. ErivirorETsntal Protection Agency
         Office of Water Planning and Standards
         401 ?1 Street,' S.W.
                   n/ D.C.  20460
                                                                        10.
                                                                       IK Coatcace/Graat No.
 12. Sp
                          nad
                                ress
         c- J^ C:^.\aiii:ioa N
         Office of V/ater  Planning and Standards
     .  .. U. S.  Enviroa«Rantal Protection Agsncy
         401 M  Street, S.V/.
                 tnnj P. C.   20460 _ _
                                                                        3. Type of-Report & Period
                                                                          CoTtred .
                                                                         Interim
                                                                       14.
               Notes
I'eE^i'S
             OSiis dccrnent surmarizes the physical/cheiracal properties,  toxicological
             infbrnation and environmental fate and. effects of: .Benzidine, with emphasis
             its aquatic behavior;  Fran these data criteria are developed  for the
             protection of aquatic life.
                                                                                         ori
W-
      '-o.-ds and Dcxruasat Anlysis.
        Criteria
       .Toxicity
       Aquatic animals
       J^miatic biology
        Huran ecology
       Safety factor
                               J7o. Descriptor*
                                                                                 /-'i-
       Tcxic. Pollutant: UfluiinL StanJards
      Feuc-val V.'ater i'ollut.ion Control Act
j  •
 17c. C05ATI J.r
                     i-.
                                                             r.-.;.ort)
                                                           _ ____ ?.'NtJ A'j'..;i j; !»
                                                           /«.'. >•. .-i-rity C. !.«*-< ( I t,l
                                                                iix«" I.ASSU irn

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ATTENTION


AS NOTED  IN  THE NTIS ANNOUNCEMENT,
PORTIONS OF  THIS REPORT ARE NOT LEGIBLE,
HOWEVER,  IT  IS THE BEST REPRODUCTION
AVAILABLE  FROM THE COPY SENT TO NTIS;
DIRECT  QUESTIONS RESULTING FROM
ILLEGIBILITY  TO:
Mr. Kent. Valentine
EPA (Williftri)
401. M Sl.rc'ct, P..W.
W.-i 53!iiny ton , D. C.    20460
Thone:  202-245-3030

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            CRITERIA DOCUMENTS FOR TOXIC POLLUTANTS




    Scientific  rationale and criteria developed pursuant to Section :*07(a)


of th<; l-'cderal Water Pollution Control Act.  I1. L. !)2-T>00, 33 U.S. C.  §§ I2.r>l


et seq..  (lf)72). for the development and establishment of effluent limitations


for toxic substances are set forth in the  following chapters.



    Section 307 (a )(2) states inter alia that a proposed effluent standard

"... shall take into account the toxicity of the pollutant, its persistence,
                                                               x
degradability,  the usual or potential presence of the affected organisms in


any water, the importance of the affected organisms and the nature and extent

of the effect of the toxic pollutant on such organisms..." Thereafter, having


considered these factors,  the  Administrator is to set an effluent standard

for toxic pollutants  which  provides an ample margin of safety.



    In the development of criteria which  serve as both the basis and the goal

for the establishment of effluent limits,  reliance was placed on the toxicity

data derived from laboratory studies on  a range of organisms including

invertebrate,  vertebrate,  and mammalian test species. These  studies

provided extensive acute and chronic toxicity data based on feeding experi-

ments for a wide range of aquatic organisms and consumers of aquatic


organisms.  Environmental studies documenting bioaccumulation in the food

v/eb of the toxic material by the food chain organisms and bioconcer.tration

by organisms directly from water provided  an important  component data

base upon which criteria were derived.  Appropriate human toxicity data

and mammalian carcinogenic studies, where available, were used also in

developing criteria.
                                 ii

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    Aquatic toxicity data generally are obtained by one of two basic



methods, the static and flow-through bioassay.  The more traditional



static bioassay employs a tank in which the test organisms are living



and to which a given concentration of toxicant is added.  Any water



loss due to evaporation is made up by the addition of fresh water.  The



flow-through bioassay, which is a more recent development,  reflects



more nearly the natural conditions.  Concentrations of toxic substances



are constantly maintained and provide  a more accurate test of sensitivity



of aquatic  species. Water in a flow-through test is replenished constantly



through flushing. Comparative results using the static and flow-through



bioassays  demonstrate that flow-through data yield lower toxicity values.



for a pollutant than a static bioassay. This fact is demonstrated by -



comparative studies as discussed in the endrin document.  However,



most of the data available were developed using static bioassays.





    Some toxic pollutants are extremely stable and degrade only slowly



or- form persistent degradation products.  Those pollutants which degrade



rapidly pose a less severe long-term hazard unless their entry to



the environment is continuous. A parent compound, e.g.,  aldrin, may



rapidly degrade or be  altered to a more toxic form,  i. e.,  dieldrin.





    Biocoricentration of toxic pollutants is a significant consideration in



the-development of criterion.  The r='.e and degree of accumulation in



an animal and the rate of loss  from  the animal are factors that help



define the potential magnitude of the  pollution load problem.  As an




                               iii

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example,  a pollutant which bioaccumulates presents a hazard both to



aquatic sy a terns and potentially to man or othor carnivores associated



with the <:«-oByntem. To satisfactorily manage a persistent or



non-degradable pollutant requires the maintenance of a ceiling for



ambient levels in water which will afford protection to the food chain



and the consumers of aquatic life (animals including humans).  The



body burden of toxic pollutants in fish or food chain organisms may



have no outward effect  on the species but will affect consumers of that food



level.   As an  example, the brown pelican,  when feeding on endrin-contaminate



fish may die or suffer species depletion through reproductive impairment.






    Data on toxic effects of pollutants are not available for all species



that may be exposed to the  toxic pollutant in these complex societies.



Such data would be necessary to ensure protection of the most sensitive



species.  It is desirable to know the relative sensitivity of a wide



variety of species in order to have a better estimate of the sensitivity



of the:untested. most sensitive species.  Because such data are not



available on all species, the range in sensitivity of a small number of



tested species is used to provide a measure  of the range of sensitivity



of all species.





    The natural aquatic environment includes many kinds and life stages



of plants  and  animals that are intricately interrelated to form communities.



Criteria are developed to protect these interrelationships  and incorporate



aquatic toxicity data for a phylogenetic cross section of organisms as well as



                                iv

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species representative of wide geographic distribution.  Chronic



Mtudies arc an important consideration in establishing criteria nnd require



ntudies of at least one generation,  i.e.,  one reproductive cycle.  Use of




an application factor for persistent and bioaecumulated toxic pollutants



represents consideration of a safety  factor. As discussed in the



National Academy of Science publication  on water quality (p. 185 of



the NAS/NAE Water Quality Criteria -- 1972.  GPO-5501-00520), the



use of an application factor of 0. 01 when  applied to acute toxic values



is thought to provide an ample margin of safety for certain chlorinated



hydrocarbon pesticides.






    Ecological importance of an organism is dependent on the



role the organism plays within the ecosystem and upon its relationship



to the food chain within the aquatic community and to consumers of



aquatic life,  including man.  Thus, toxicity data for the top carnivores



in a given ecosystem, as well as economically important species such




as trout, salmon, menhaden and shrimp  are needed  for the  development



of a protective criteria level. Toxicity data for organisms such as the



stonefly and Daphnia are of equivalent importance since these organisms



are a food base for higher consumers and are  representative of invertebrate



species found in most waters of the United  States.





    Invertebrate species, such as the stonefly  and the Daphnia.  are an



indication of the integrity of the aquatic food chain and their presence



may be the controlling factor for the  abundance of economically and

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recreationally important predators such as trout, bass or pike. While
these fish may not directly consume the Daphnia or stonefly or, in
fact,  even inhabit the same waters,  these lower order organisms are
representative of the food  chain base supporting predators.

    Criteria levels,  by their nature,  are developed  to protect aquatic
organisms and consumers of aquatic life from direct toxic effect when
placed on contact with the  toxic pollutants; and, to protect from a
more insidious and even greater danger, e.g., chronic effects.
Chronic effects take the form of reproductive failures  or  the poisoning
of predators consuming food organisms which have  bioaccumulated levels
of toxic pollutants as in the case of the brown pelican and consuming
endrin. loaded fish (see Attachment D, Endrin), and a variety of other
physiological  effects as discussed in the various documents.   Decreases
in aquatic organisms or consumers  of aquatic life not always are coupled
to point source discharges of toxic pollutants at concentrations below
acute toxic levels; however, the addition of toxic  levels which are not
acutely toxic can achieve  the destruction or at least disruption of aquatic
systems by causing  reproduction of failure.   Hence, the need for application.
factors.  The relationships between discharges of toxic pollutants and
effects on important organisms of economic and environmental importance
and consumers of these organisms are well documented in the criteria
documents.
                              vi

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                           BENZIDIKE
                       Table of Contents
 II.
III.
IV.
 V.
VI.
VII.
 Prearnble	1



 Physical and Chemical Properties	,1


                                                      •»
. Toxicological .Data	3

 A.     Invertebrates	....3

 B.     Fish	 3

 C.   -  Marmials	 6

       1.   Biochemistry of Benzidine ........ 7

       2.   Physiological Effects	  .13

 D.     Humans .  . . , . ^ . .  .  .	;i6



 Environmental Fate and Effect	  .23



 Criteria Formulation	  .33



 References Cited	37



 Appendix I	49

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I. '  PrcMinhL?


     R--?nzidine  is a proven human carcinogen with  the site of


ir.'jmor  i r< Ino1: ion  h^inq the bladder.  Th-^raf ore, in  derivinq


an ambient  water quality criteria considerations beyond the


aquatic toxicity arf! necessary.  As calculated in  Appendix


1, l»velr, of benzidine which could result in a cancer risk •


of no  nor-"1  than  one case per million people exposed,  at the


95 percent confidence limit, during a lifetime, if allowed to reach


man  through water,  are projected to ranqes from  0.05  uq/1 to


1.0  uq/1.   A level  of C.I ug/1 is recommended based en the


calculated  dose/response data, the use of extrapolative


methods to  determine a risk level, and the possible


population  at  risk.





     Benzidine  has not been studied extensively for toxicity


to aquatic  species  since the main concern has been its


carcinogenic activity in man.   However, initial  fcioassays


with benzidine have produced 96 hour TL  's of 2.5 to


areater than 20.0 mq/1 for fish.   A bioaccumulation study


with bonzieline has  shown that edible tissue residues  can


accumulate  Uf*  tiu'ps the. ambient water level.  Use  of  an 0.01


application factor  applied to the 96 hour TL-.. for fish


results in  a level  of 25 uq/1  which would protect  aquatic


life.





TT.  Physical and  Chemical Properties


     Benzidine (4,4'-diaminobiphenyl) is classified as an


aromatic amine.   It has the empirical formula  C  H  N  and a
                                        \-£ \_£. £.

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      molecular weight of  184.24 grams  (1).  BenzifJrie exists as a



      grayish-yellow,  white, or reddish-gray crystalline powder



      with a melting point of 128°C and a boiling point of 400°C



      at 740 mm mercury  (2).  Benzidine's solubilities in water



      range from 0.4 g/1 at 12°C to 9.4 g/1 at 10::C.  Organic



      solvents increase  the solubility of benzidir^ with 20 g/1



      dissolving  in ethyl  ether and 200 g/1 in absolute ethanol



       (3).







          As an aromatic amine, benzidine has an inherent



      basicity.   Although  amines are much weaker bases than



      hydroxide ion or ethoxide ion, they are much stronger bases



      than water.  Aqueous mineral acids or carbon/lie acids



      readily  convert  amines into their salts; aqvieous hydroxide



      ion readily converts the salt back into free amines.  As



      seen in  figure 1,  benzidine is easily converted to and from



      its salt (4).
                                Figure 1
"X C
    .  . /  s  \ \  /  /^^\  \  .,,,   "
I
               Ben/; idine                               Benzidine Salt

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    Benzidine can readily undergo diazotization reactions.


This ability to undergo diazotization makes benzidine suited


as a basic building block for dyes.  Diazotization is the


reaction of a primary aromatic amine with nitrous acid in


the presence of excess mineral acid to produce an azo


(-N=N-) compound  (24) .





    The azo compounds are strongly colored, with the color
                                                           ^

depending upon the exact structure of the molecule.  Because


of their color, the azo compounds are of importance as dyes;


about half of the dyes in industrial use today are azo dyes


CO.





III. Toxicological Data





    A)    Invertebrates





    Benzidine' s toxicity to invertebrates was investigated


by Lerr:
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carcinogenic activity in man.   However, initial  bioansays

with benzicline have shown  that  it  is  r.ct  highly  toxic  to

fish..
    Lemks in 1973  (18) determined  96-hour TL  's  for  five
                                             50
species of fish.  Toxicity  data  for these five  species  are
shown in Table 1.
                       Table  1   (18)
            TL   Values for  Static Biosssay with
              50
                          Benzidine
Species
          TL   Values (mg/1)

24 hr.     US hr.     72 hr.	 96 hr,
Flagfish
(Jordanella 'floridae)

Fathead Minnows
(Pimephales promelas)

Red Shiner
(Not pop is lutrensis)
Lake Trout
(flalve Linus n-i
Rainbow Trout
+ 50


+20


+ 20


 8.7


+ 20
          32.5    .  25
          20
          10
           5.0
          ltt.1
+ 20
  2. 5
  «*.35
 10
         .  16.2
+ 20
  2.5
  4.35

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    The Synthetic Organic Chemical Manufacturer's

Association  (SOCMA) in 1975  (19) determined TI.   values  for

three different species of fish.  Their  results  are  listed

as Table 2.               ;



                       Table  2   (19)
             96-hour TL   Values for  Eenzidine
                       50

                                        96-hour  TL  Value

Species	.__	(mq/1)
Fathead Minnows                              2
  (Pimephales protnelas)

Emerald Shiners                              5
  (Notropis atherinoides)

Bluegills                                   15
  {Lepornis macrochirus)

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    C)
    The history of cancer research  shows that  the
discoveries in man of carcinogenesis  ty  various chemicals
preceded studies of these substances  in  experimental
animals.  Such was the case with  benzidine.  Animal studies
were used to gain more information  about the carcinogenic
action of benzidine.

    As early as 1895 , Rehn  (20) related  certain bladder.
tumors to exposure to aromatic amines.   However, isolation
of the compound or compounds  responsible for bladder  tumors
was difficult since many of the workers  studied were  exposed
to an array of compounds.  Through  selective research the
major suspected carcinogens were  identified by Barsotti and
Vigliani in 1949  (21) as beta naphthylamine and benzidine.

    Early attempts to induce  experimental tumors in animals
with benzidine had been without success  (22, 23) , and it was
*~~-*J- *>*-.*- 4 ~l 1 O C r\ *, U -H *- O *-,-T -*- « ^ i,  -* 1   / *7 \  ~l*-».-ns"knr^*-w-*4-X-«.'3 *. Vx -» JL.
J i W— C* I . w J_ A JL S ^ J Oi 1U O U £JJL V- i. CT I.  CA JL. •  I ^ /  *-»^-"*'»«^itO t-i C4 C, CTVJL i_ 1 1'Ji l_
benzidine was carcinogenic.   Tumors occurred in the liver,
intestine, and the acousti gland  in 20  percent of the test
rats injected with a maximum  cumulated  amount  of 1.28g of
technical-grade benzidine.  Purified  benzidine and benzidine
sulfate were also carcinogenic at a similar dosage level
(total  dose: 0.96 and 0.94g,  respectively). However, no

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tumors occurred in either rabbits or monkeys after injection

of benizidine.  Only one case of bladder cancer was found in

dogs fed a total dose of 325g of benzidine in.five years.

No conclusions concerning the carcinogenicity of benzidine

for dogs was drawn from this single occurrence.


    1)    Biochemistry of Benzidine

                                                           x
    The failure to obtain bladder tumors with benzidine in

previous experiments was thought to be due to the species of

the animals used, the mode of administration of the

chemical, or the degree of dosage.  But, after Spitz's

successful experiment, the importance of the metabolism of

benzidine was recognized.  Studies were conducted to

determine the fate of benzidine upon entering the body.


    Work by Weber and Heideprim in 1928 (9)  and Goldblatt in

1914-7 (8) indicated that benzidine may be oxidized in vivo.

Baker in 1950 (10) demonstrated that oxidation may take

placo to give 3,3'-dihydroxybenzidine.  Further work by

Baker and Deighton in 1953  (11) determined the rate of

recovery of benzidine from tissue and the extent of

conjuqarion of the aromatic amino groups.  Their studies

showed that 93 percent of the injected dose was recovered as

diazotizable material after U hours and 68 percent after 12

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                             8





hours.  Of this, the conjugated forn accounted for 24



percent and 49 percent respectively of the recovered amount.








    Sciarini in 1957 (12) identified free benzidine and the



metabolite 3-hydroxybenzidine in the urine of dogs following



intraperitoneal injection of benzidine.  Troll and Nelson in



1958  (13) found the major metabolites of fcenzidine in  dogs,



rabbits, and guinea pigs to be the sulfate and glucuromide



of 3- hydroxybenzidine.








    Sciarini and Meigs in 1958 (14) verified the metabolites



and quantified the constituents in the dog.  As shown  in



Table 3, only about 2 percent to 9 percent of unmetabolized



benzidine was recovered in dog's urine.

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                          Table 3

Benzidine Recovery from Dog Urine Following Intraperitoneal
            Injection at Different  Dosage  Levels
Dose Administered
(mg/kg Body Wt)
 Percent Free Benzidine
Recovered in 24 hours
    100
     56
     25
      9
      2.0
      1.0
      0.5
      0.25
      0.2
      0.1
      0,05
     6.8
     4.0
     1.7
     3.9
     9.0
     2.7
     3.2
     6.4
     4.0
     7.0
     2.0
    The average  free  benzidine  recovered amounted to about 7
percer.t of the dose administered  while the major metabolite
 (3-hydroxybenzidine)  was  approximately 47 percent of the
dose.  The feces of the dog  were  found to contain about 10

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                             10



percent as much benzidine  and its  metabolite as detected ir.


the urine.




    Subsequent investigations by Sciarini and Meigs in 1961


(15) identified other  metabolites  in mice and benzidihe


workers.  The recovery and identification of only a portion
  »
of the dose of benzidine administered to the mice was


consistent with the  hypothesis  that additional metabolites


were present.  Through analysis of the urine of workers


engaged in benzidine manufacture,  four substances were


identified in the  following proportions: free benzidine


3.6-5.6 percent; monoacetylbenzidine  1.6-5.4 percent; diacetylbenzidine


5.1-10 percent; and 3-hydroxybenzidine 78.5-89.7%.




    Experiments with substituted benzidines conducted by  .


Sciarini  and Meigs in  1961 (16) were designed to broaden the
                                                    *• _ j

understanding of the behavior  of benzidine.  The three


disubstituted benzidines used  were: dicrthotolidine,


dianisidine, and dichlorobenzidine.  Structures of benzidine


and the disubstituted  benzidines are shown in figure 2.

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                            11
                          Figure 2
                     V.ctf,
                  ,s
                                    NH,
                                         OCH,
,,-•-,. ^\
[c i
x-
f ^
C



/
i
V S

.
-°CW3 V^<
-0/^ ^ ^-
NH^ /x/h^
Benzidine Diorthotolidine Dianisidine Dichlo
    Both dianisidine and dichlorobenzidine were found to



tnet-.abclize in the human body along different pathways than



benzidine.  Diorthotolidine follows a metabolic route



similar to that of benzidine.








    Neumann's study in 1970  (17) of recognized carcinogenic



aromatic amines demonstrated that it is the metabolites or



reactive intermediate stages of benzidine formed during



metabolism whicn are considered to be the carcinogenic



substances.
    Hovever, ev*n products such as azo dyes, which are



derived from benzidine, have been shown to undergo metabolic



reduction to free benzidine.  Rinde and Troll  (63) in 1975,



reportor] on thr metabolic reduction of four benzidine azo

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                            12



dyes in the rhesus monkey.  By comparing the excretion of
                    i
free benzidine after feeding the monkeys either benzidine or

the dyes, it was determined that the metabolic reduction of

the dyes to free benzidine was nearly complete.  Yet,  P.inde

and Troll stipulate that they do not intend to imply that

all azo dyes are biologically reduced to carcinogens,  but

those derived from carcinogenic amines should receive

particular attention.

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                            13





    2)    Physiological Effects








    Concurrent with the investigation of the metabolic



pathways of benzidine, studies were undertaken to



experimentally produce tumors in mammals through exposure to



benzidine.








    Boy land et al., in 1954 (25) fed ferrale Wistar rats a



diet containing 0.017 percent benzidine.  Chlolagiomas and/



liver-cell tumors were reported, but urinary bladder



carcinomas were not found.








    Bonser et al,,  (26) injected benzidine into mice,



subcutaneously at a weekly dose of 6rng for 52 weeks.



Hepatonas and lymphomas occurred in the treated animals,



while lymphomas occurred in one-third of the untreated



control animals.  Nevertheless, the presence of the



hepatomas caused benzidine to be classified as carcinogenic.








    Loumonier and Laquerriere in 1962  (27) studied the



effect of daily applications of benzidine  (3 percent in



benzene) painted to the back skin of Wistar rats.  After 15



days of treatment,  jaundice appeared due to toxic hepatitis.



After a latent period, of 2-1 months, the rats developed



malignant tumors, primarily hepatomata.

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                            m


    In-1964, Pliss  (20) studied the tu:-origenic properties

of ber.zidine in rats.  A total dose of 3GOmg of benzidine

was subcutaneously injected during a  6 rroriths period,

however, there was a considerable loss of animals,

especially females, during the first  few months of the

experiment due to acute toxic effects.  Only 20 rats (40 percent)

including 5 females survived for 5.5  -or.ths.  The deceased

animals showed profound degenerative  changes in the liver
                                                           "•x
with ultimate necrosis.  Hepatomata,  cymbal gland tumors,

and sarcomata in the underlying fat at. the site of injection

of ber.zidine were reported in 70 percent of the surviving

rats.




    Saffiotti et al.,  (29) and Sellakuxar ,et al.,  (30)

investigated the effects of ber.zidine on Syrian golden

hamsters.  Benzidine was administered to hamsters in the

diet at concentrations of 0.1 percent for their lifespan.

Hepatomas, liver-cell and chloangiomatous tumors developed,

but none appeared in the bladder.




    Griswold et al., in 1968  (31) reported that benzidine

produced breast cancer in female Sprarue-Dawley rats after

intraqastric feeding ranging from 12  to 50 mg/rat during a

30 day period.

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                             15

    In 1970, Zabezhinskii  (32) reported  the results  of
benzidine inhalation experiments on  rats.  The  animals  were
exposed to a concentration of benzidine  in the  air of 10-20
mg/cu m for 4 hours 'a day, 5 times per week,  for 20  months.
After inhaling benzidine  for 13 months,  29 percent of the
rats developed tumors consisting of  myeloid leukemia,
fibroadenomata, carcinomata of the mammary gland (male  and
female), and hepatoma.

            s                        •      '       •
    The induction of hepatic tumors  in mice by  benzidine was
reported by Prokofjeva in 1971  (33).  Single  weekly  doses of
6 mq per animal were subcutaneously  injected  into 181 mice
(C3HA line) over a period of 8-13 months (total dose:
210-336 mg) .  Of the 46 mice that survived for  15-28 months,
31 (67.4 percent) had developed hepatomata.  A previous  control
colony of C3HA mice showed a 1 percent hepatoma frequency in
untreated animals.


    A study was conducted by Vesselir.cvitch,  et al.,
reported in 1975  (71), to assess the  carcinogenicity of
benzidine hydrochloride in mice.  In  one carcinogenicity
study, 200 six-week old B6C3F mice were  given benzidine
dihydrochloride intermittently by stomach intubation, twice
weekly, in the amounts of 0.5 or 1.0  mg/mouse at each
intubation for 8'4 weeks.  All animals were killed at 90
weeks of age, at which time  their tumor  incidence was

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                            16


evaluated.  Benzidine-treated mice developed liver tumors,

Harderian gland tumors, lung adenomas, and lymphoreticular

tumors.  A total of 124 of the indicated tumors were

reported for both dose levels.




    D)   Human




    The incidence of bladder tumors resulting from
                                                           •\
occupational exposure to aromatic amines was first described

by Rehn in Germany in 1895  (20).  Between 1905 and 1932,

bladder tumors in dyestuff workers were reported in

Switzerland  (36) , Great Britian  (37) , Russia (38) , and

Austria (39).  The first cases of this condition in the

United States were described by Ferguson in 1934 (40) .

Subsequently the disease has been recognized in Italy  (41) ,

Japan  (42) and France  (43) .




    The noted high occurrence of bladder tumors in the dye

industry was an .established fact, though the etiology of the

disease was still obscure.  Early theories implicated

certain intermediate products used in the manufacture of

dyes  (44).  of those, aniline, benzidine, and alpha and beta

naphthylamines were the most frequently implicated  (45, 46,

47, 48) .

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                            17





    In 1919, Barsotti and Vigliani  (U9) examined 186 workme.n



cystoscopically to follow the evolution of bladder lesions.



Through their study, the following conclusions were made:








    1)   Aniline has no appreciable carcinogenic potential.








    2)   Benzidine and beta-naphthylamine have the highest



         carcinogenic potential among the aromatic amines



         studied.








    Scott in 1952  (5) investigated the incidence of bladder



tumors in an English dyestuffs factory*,  Sixty-six cases of



bladder tumor were reported.  Of the sixty-six cases there



were 30 (23 in the manufacturing section and seven in the



handling section) who were exposed to benzidine, and who had



never been exposed to beta naphthylamine.








    In 1954, Case et al.,  (50) published the results of



their study of workmen engaged in the manufacture and use of



aniline, benzidine, and alpha and beta-r.aphthylamines in the



British chemical industry.  They determined the incidence, of



tumors of the urinary bladder among such workers.  The data



indicates that the incidence of bladder cancer among persons



exposed to benzidine greatly exceeded that among the general



population.  The study also showed bladder cancer to be a

-------
                            18






fatal disease, only 20 percent of all cases having survived more



than 10 years from the first detection of the disease.








    By 1957, based upon the findings cf Case et ajL.,  (50) ,



the manufacture of benzidine had been accepted as an



occupational hazard by the Association of British Chemical



Manufacturers.  That year, plant and operating



recommendations were made by Scott and Williams  (51) to



ensure the safe manufacture and use cf products causing



tumors of the bladder.



    Loriq term retrospective studies were undertaken in order



to assemble additional information on the occurrence a-nd



natural history of malignant tumors ir. workers exposed to



dyes and dye intermediates.








    In 1962, Goldwater et al.  (52) studied the incidence of



urinary bladder tumors in workers exposed to



alpha-naphthylamine, beta-naphthylamina and benzidine, to



determine the average incubation period, the average



survival time, and the incidence of ralignant tumors other



than those of the bladder.  The population studied  consisted.



of 366 male workers in a coal  tar dye.factory employed



bet-ween 1912-1962..  Of the 366 workers studied,  76  were



exposed to benzidine alone.  Bladder car.cer developed in 17,



or 21.3 percent, of the 76 exposed to benzidine.  The



induction of bladder cancer from benzidine had an average

-------
                            19






incubation period of 18.7 years, calculated from the first




exposure to diagnosis of malignancy.   Details of the



calculated incubation periods are given in Table 4.

-------
                        20






                      Tnhle '>








          Bladder Tumors Related to Years




                    of Exposure
A)   First suggestive



     genitourinary



     complaints
                                   Years of Benzidine Exposure



                                   Range          Mean
9-30
20.7
3)   First positive



     cystoscopy
H- 31
16.6
C)   First diagnosis



     of papilloma
U-28
18.
D)   First diagnosis



     of malignancy
5-33
18.7

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                            21






    Following diagnosis of bladder malignancy in workers



exposed to benzidine, the longest period of survival was ten



years, the shortest was less than a year.  The mean survival



time between diagnosis of cancer and death was approximately



3 years.








    Among the 366 men studied, there were 11 recorded



malignant tumors other than cancer of the bladder, as



follows:



                   *




                   Lung           3



                   Prostate       3



                   Stomach        2




                   Brain          2



                   Lymphoma       1








There was no evidence of any unusual incidence of



malignancies other than those of the urinary bladder.








    Rye et a1., in 1970  (53) discussed the use of benzidine



and its congeners, (diorthobenzidine, dianisidine, and




diorthotolidine) as curing agents in polyurethane



production.  There was no evidence of cancer developing



among the workers exposed during production of the three



congeners.  However, several bladder tumors had been found

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                            22





in man working in a plant that alternated production of



benzidine and its three congeners.








    In 1973, Zavon et al.  (54) published their findings



associating the manufacture of benzidir.e with a high risk of



developing bladder cancer.  They observed a group of 25



workers engaged in manufacturing benzidine over a 13-year



period.  Of the 25 workers, three had about one year of



exposure to beta-naphthylaminef three had exposure to



orthotoluidine, and seven had been on dichlorobenzidiae



production at some time.  The mean exposure to benzidine was



10.6 years.







    Thirteen of the group (52 percent) developed bladder tumors,




some multiple.  The study group had  an average induction



tine from first exposure to detection of the first tumor of



16.6 years.  This time period agrees with previously



calculated induction times  (50, 52,  55, 56) .








    Ey 197G only one inember of the thirteen bladder cancer



patients had died, which gives a ten-year survival of  92



percent.  However, this survival period was expected to



increase because no recurrences or life-threatening



complications were present at that tire.  A mean survival of



thre« yoars was reported by Goldwater et al. (52) for



bladder cancer and the ten-year survival of less than  20

-------
                            23






percent was reported by Case et a1.   (50).   Increased



survival may be due to a number of causes.   Earlier



diagnosis and improved therapy used in these patients are



possibilities.








    It is important to note that decreasing the potential



exposure by limiting the'duration of employment on the



process only serves to increase the number at risk.
    IV.  Environmental Fate and Effect








    In 1965, Takemura £t 'al_.  (6) published their results of



a survey of the pollution of the Sumida River, in Tokyo,



Japan.  Concentrations of aromatic amines found in the water



ranged between 205 to 562 ug/1.  Concentrations of the



carcinogenic amine, benzidine, identified by chromatography



and determined quantitatively by the chloramine-T method,



ranged from a maximum of 233 ug/1 to a minimum of 82 ug/1.



The source ot these pollutants was suspected to be from



wastes discharged by dye and pigment factories along the



river.  It was considered that the aromatic amines in the



river were not necessarily discharged directly in the



factories' wastewater but possibly were produced by the



reduction of azo-dyes in the wastes by H S or SO  in the



river water.  Laboratory demonstrations showed that if H S

-------
                            24





is bubbled for a few minutes through a pure azo dye



solution, aromatic amines are liberated from the azo dyes.








    To determine whether benzidine persists in natural



waters for long periods of time or degrades relatively



rapidly, the Great Lakes Laboratory experimentally studied



the degradation of benzidine in lake water under laboratory



conditions (31).  Lake Erie water was obtained from the



inlet of the Buffalo city water treatment plant.  Sample



aliquots were spiked with initial benzidine concentrations



of 1, 2 or 5 ug/1.  The samples were treated under several



conditions: 1 or 2 mg/1 available chlorine, stirred, aerated



and undisturbed and all samples were shielded from light.



Results of the degradation of benzidir.e under various



conditions have been tabulated in Table 5.

-------
                             25
                          Table  5

           Degradation of Benzidine  Under Varying
                         Conditions
      BENZIDINE IN CHLORINATED LAKE WATER (1 mg/1 Cl )
(hrs .)
1/2
 u
12
24
48
72
     3KNZ. CONC.
     in SOLN. A
       (ug/1)

       0.84
       0.48
       C.10
       N.D.
BEV'Z. CONG.
in SCLN. B
  ug/1)

  1.90
  1.17
  1.17
  N.C.
BENZ. CONC.
in SOLN. C
  (ug/1)

  4.42
  4.C6
  2.17
  N.D;
      BENZIDINE IN CHLORINATED LAKE WATER (2 mg/1 Cl )
TIK2
(hrs.)
1/2
 4
12
2U-
48
72

where
     BSNZ. CONC.
     in SOLN. A
       0.79
       0. 39
       0.04
       N.D.
BENZ. CONC.
in SOLN. B
  ug/1)

  1.73
  1.09
  0.31
  N.D.
BENZ. CONC,
in SOLN. C
  (ug/1)

  4.37
  4.10
  1.87
  N.D.
Soln. A = Solution with initial  benzidine
          concentration of  1  ug/1.

Soln. B = Solution with initial  tenzidine
          concentration of  2  uq/1.

ooli. C = Solution with irit-ial  benzidine
          concentration of  5  uq/1.
                 = Not detectable  K0.2 ug/1) .

-------
                             26
TIME
 (hrs.)
1/2
 u
12
24
48
72
                       Table 5 (Coat.)

              BENZIDINE IN AERATED LAKE WATER
TIME
(hrs.)

1/2
U
12
24
48
72
BENZ. CONG.
in SOLN. A
(ug/1)
0.83
0.69
0.31
N . D .
-
..
BENZ. CCNC.
in SCL:-J. B
ug/1)
1.9-
l."2
0.72 .
N . D .
-
-
BENZ. (
in SOL;
(ug/
4.61
4.27
2.01
N.D.
—
—
               BENZIDINE IN STIRRED LAKE WATER
TIME
(hrs.)

1/2
4
12
24
48
72
BENZ. CONC,
in SOLN. A
(ug/1)
0.90
0.70
0.48
N.D.
-
-
BENZ, CCNC.
in SCLN. B
ug/1)
1.57
1,37
0.50
N.D.
-
-
BENZ. (
in SOD
(ug/!
4.70
4.21
2.15
N.D.
-
-
             BENZIDINE IN UNDISTURBED  U:XE WATER
BENZ. CONC,
in SOLN. A
  (ug/1)

  0.89
  0.71
  0.47
  0.02
  * • r~»
  u . L/.
BENZ. CONC.
in SCLU. B
  uc/1)

  1,85
 . 1.C5
  0.75
BENZ. CONC.
in SOLN. C
  (ug/1)

  4.81
  4.03
  2.07
  N.D.

-------
                            27



    The results show that the decay of ber.zidine in .lake

water is relatively rapid.  At all three concentrations,

regardless of the system, benzidine was at or below the

detection limits after 2U hours.  However, the experiments

did not indicate the by-products, kinetics and/or mechanisms

of this decay.




  .A further investigation by the Great Lakes Laboratory
                                                          >.
(57)  determined that the rate of degradation of benzidine in

natural waters was near a first-order reaction with a rate

constant of 0.175 per hour.




    To further evaluate the fate of benzidine in the aqueous

environment and to define the role of sunlight, a series of

studies were conducted to determine the photodegradation

effect by light  (58).  The photodegradation effect was

qualitatively determined by comparing the observed and

calculated concentrations at various times during the

reaction.  The calculated values were determined by using

the first-order decay equation and a rate constant of 0.175

per hour as previously determined  (57).  Results of the

experiment have been tabulated in Tatle 6.

-------
                             28
                          Table- 6
           PHOTODEGRADATION  OF 3ENZIDINE IN WATER
Reaction Time
   (hours)

   P
 0.5
 1.5
 4.0
12.G
24.0
27.0
                          Series A

                        Benzidine Concern ration
                   Observed               Calculated
                   1.0 mg/1
                   0.73
                   0.66
                   0.45
                   0.087
                    ND
                    ND
                    1.0 mg/1
                    0. 91
                    0.77
                    C.50
                    0.12
                     ND
                     ND
                           Series B
 0.5
 1.5
 '4.0
12.C
2 4 . C
29
48
53
72
77.0
                   10.00 mq/1
                    8.70
                    0.05
                    6.45
                    4.5
                    2.49
                    1.80
                    0.50
                    C.29
                    0.018
                    0.018
                    10.00 mg/1
                     9.16
                     7.69
                     4 .96
                     1.22
                     1.50
                     C.06
                       ND
                       ND

                       ND
                           Series C
 1.5
 a. 0
12.C
24.0
23.0
56.-?
100.00 mg/1
 91.95.
 86.93
 95.61
 75.41  .
 63.68
 52.13
 31.15
                                        100.00 mg/1
                                         91.62
                                         76.91
                                         ^9. 65
                                         12. 24
                                          1. 50
                                          0.69
                                           ND
                                           ND
MD - Mo-. Detectable
                           ug/1)

-------
                            29






    For series A the observed values were always less than



the calculated values, indicating that photodegradation



enhanced the rate of degradation of benzidine.  For series B



and C, a reddish-brown material precipitated, serving as a



light" screen which diminished the rate of degradation.  For



the preliminary studies presented, the data indicate that



for low concentrations of benzidine  (less than 1 mg/1) ,



photodegradation enhances the rate of degradation of



benzidine in aqueous solutions.








    However, in the photodegradation study  (Table 6) , the



dependence of decay on the ambient water temperature was not



studied.  The mean temperature of the samples in the



fadometer was 48°C.  This temperature is atypically high of



natural waters.








    The biodegradation of benzidine was studied by Malaney



et aj..  (35) and Lutin et al_»  (59) using Warburg



respirometers which contained samples of activated sludge



obtrH. r.srl from three different wastewater treatment plants.



The studios conducted used sludge concentrations of 2500 and



5000 m.g/1 mixed liquor suspended solids (MLSS) and a



ber.zidine concentration of 500 mg/1.  The results showed



th'it benzidine was inhibitory to bio-oxidation by each of



the three sludg.es.  The extent of removal of benzidine by



bio-oxidation in an activated sludge aeration tank was found

-------
                            30






to be insignificant at the concentration studied.   It was



postulated that benzidine may be removed partially or



completely by adsorption.  However, this mechanism was not



investigated.








    A similar study was conducted during 1973 by Ryckman et



al.  (60)  using Warburg respirometers and two different types



of sludges: An aniline acclimated sludge and a municipal




wastewater treatment plant sludge.  The sludge samples were




spiked with two different concentration levels of benzidine,



1 and 5 mg/1.  The results showed that benzidine appeared to



be slightly inhibitory to both the aniline acclimated and



non-acclimated municipal sludges.  Still, both of the



sludges showed rather large uptakes of benzidine during the



12-hour studies.  Approximately 78 and 60 percent uptakes




were noted for the acclimated and non-acclimated sludges,




respectively for the samples with a concentration of 1 mg/1



benzidine.  For the samples containing 5 mg/1 benzidine,



uptakes of 64 and 50 percent were observed for the



respective sludges.  It was hypothesized that an adsorption



mechanism was involved in removing the ber.zidine.  However,



no conclusive proof was obtained to edther support or reject



the  hypothesis of an adsorption mechanism.








     An investigation of the bio-oxidation of benzidine was



conducted for SOCWA' by International Hydronics, Inc.  (61).

-------
                            31



Studies were conducted to determine if benzidine car. be


biochemically oxidized at a concentration of 50 ug/i-  The


fate of benzidine was studied through a series of tescs


u'sing acclimated and non-acclimated sludges.  As interpreted


by SOCMA, the tests produced the following results:




    1)   Benzidine can be biologically cxidized at a level


         of 50 ug/1.  Oxidation of about 90 percent of the
                                                          ^> •
         compound is accomplished.




    2)   Air oxidation of benzidine in a sterilized


         activated sludge will occur.  About 30 percent of


         the benzidine concentration, 50 ug/1, can be


         reduced in this manner.



                         '' "    •                  .                "S
    Ho-vever, neither of these experiments demonstrated          '*


oxidation as such  (for example, recovery of 14C carbon


dioxide after treatment of labeled benzidine) , but depended


on measuring the decrease in benzidine across the system.




    During 1975r Aquatic Toxicology Laboratory of Bionomics


(62)  conducted studies to determine the bioconcentration of


14C-benzidine in bluegill populations.  The radiometeric


method employed measured only lie-residues.  These residues


were not identified to determine if the 14C was in the form


of bor.zinine or a metabolite.  During the six week

-------
                            32





observation period following the ir.treduction of bluegill to



the test units, the cumulative mortality was 6 percent for



fish exposed to 14C-benzidine at a mean water concentration



of 191.02 ug/1, 8 percent for fish exccsed to a mean water



concentration of 98.07 ug/1, and 2 percent for the fish in



the control unit.  Bioconcentration factors of 38 times the



mean concentration of 191.02 ug/1 and "U times the mean



concentration of 98.07 ug/1 were four.c! in the edible



portions of the bluegills after the 42 days of exposure.








    Following the 42 days of benzidine exposure there was a



14-day depuration period to determine the rate and extent of



the elimination of the 14C-residues.  within the first week



of-depuration, the edible portions of fcluegill exposed to



the high treatment level  (191.02 ug/1) of 14C-benzidine



eliminated 47 percent of the 14C-residue present at the end



of exposure.  By the end of the depuration period, 70



percent of these residues had been eliminated.  Within seven



days after commencing depuration, the bluegills exposed to



the low treatment level  '98.07 xy/l) or 14C—benzidine



eliminated 42 percent of the 14C-residue present at the end



of exposure.  By the end of the depuration period, 73



percent of these 14C-residues had beer, eliminated from the



edible portions of the exposed bluegills.

-------
                            33






    Biqconcentration stu'dios show the edible portir-s of



fish bioconcentrate 14C-residues from labeled benziciir.e to a



factor of 44 times the water concentration, thus exhibiting



an exposure route to man.  However, following a 14 day



depuration period, 73 percent of the bioccncentrated



   -residues from labeled benzidine had beer, eliminated.
V.  Criteria Formulation








    Benzidine has not been studied extensively for toxicity



to aquatic species since the main concern has been its



carcinogenic activity in man.  However, initial bioassays



with benzidine have produced 96 hour TL  *s of 2 mg/1 for



the fathead minnow and 5.0 for the emerald shiner (19)  and



2.5, 4.35, and 7.4 mg/1 for the red shiner, lake trout and



rainbow trout respectively  (18).  A bioaccumulation study



with benzidine has shown that edible tissue residues



accumulate 44 times the ambient water level.  Use of an 0.01



application factor applied to the 96 hour TL   for the red



shiner results in a level of 25 ug/1 which would provide an



ample margin of safety for aquatic life.                 ,







    However, the principal objective in regulating benzidine



under soction 307 (a) of the Federal Water Pollution Control



Act is to minimize the risk of human exposure to benzidine



which would result from its discharge to the navigable

-------
waters in light of its proven carcincaenicity.   See 38 Fed.

Rag. 243U3  (September 7, 1973).  Accordingly, the

recommended ambient water criterion is to provide adequate

protection for human health as well as for aquatic

organisms.  It must minimize any unreasonable risk of human

exposure.




    Observations of the incidence of human bladder cancer
                                                          v
due to occupational exposure have demonstrated benzidine to

be a human carcinogen, , To date no minimum effect level or

maximum safe level has been established for humans.

Extrapolation through mathematical modeling is one approach

the Agency has used to determine levels of exposure which

are likely to result in a low risk, or incidence, of'cancer.

The two most widely utilized models for this approach are

the "one-hit" method  (70) and the Mantel-Bryan method (64).

In developing and applying these formulae, animal studies
                                                   '  tt
were used to experimentally demonstrate the relationship

between various dose levels and the frequency of resultant

tumors.  Based on these experimental cose/effect data, it is

possible to theoretically extrapolate the dose for low

effect levels when a carcinogen is administered at a given

daily dose over a lifetime.




    There are several caveats which apply in using this type

of mathematical modeling.  First, this type of modeling is

-------
                               35





not  accepted by  some sectors of the scientific community.



It is not sufficiently advanced or proven  as to justify  use



of this approach alone as  the sole basis for establishing



Hsaf eM levels  of exposure.  If one is to have a high degree of



confidence in. predicting the likely dose/effect level,  a larger



statistical data  base than that which is available should



be utilized.  However, the risk extrapolative rr^thods rray



furnish an indication of risk levels  associated with a



particular exposure level or exposure levels which result in



a predetermined level of risk, e.g.,  one cancer in a million of the



exposed population.
     With these  qualifications in mind, each of the two



mathematical models was applied to the three best available



sets of dose/effect data  (7,  33, 71).  The calculations are



set  forth in Appendix 1,  and  are summarized in the following



table.

-------
                             36


     Table 1 shows levels of benzidine which, based on a daily

.exposure over  an  entire lifetime, would produce no more than

one  cancer  in  one million population at risk at the "95

percent confidence limit:



                           Table 1

           •                            .

                              Extrapolative Method
Observed Dose-Pesponse
       Data               One-Hit (7C)           Mantel-Bryan  (64)

Spitz  (7)                   0.056 ug/1            0.608 ug/1
Prokof jeva  (33)             0.048 ug/1            0.2-12 ug/1
Vesselinovitch (71)         0.061 ug/1            0.843 ug/1


     The Agency does not possess data as to the presence of

benzidine in waters at the levels indicated in the above

chart.  Such measuring as has been clone fails to show

benzidine in the  water columns at detectable levels.  As

noted  earlier,  the Agency lacks evidence of" direct human

exposure to benzidine from drinking water on the aquatic

environment.
           these ci re urn stances,  and in light of the

previously expressed caveats concerning use of mathematical

modeling,  the  Agency has concluded that: a level of 0.1 ug/1,

which approximates the low side of the middle range of the

exposure levels reflected in the mathematical modeling

exercises  (0.05-0. 84 ug/1),  should provide the requisite

margin of  safoty for human health as well as for aquatic

organisms.   This level is recommended as the ambient water criterion.

-------
                            37
REFERENCES CITED:
1.  Weast, R.C., editor, 1972.  Handbook cf chemistry and

         Physics, 53rd Ed.


2.  Standen, A., editor, 1972.  Kirk-Cthmer Encyclopedia of

         Chemical Technology.  3:108.
                 •                              .           ."*• x

3.  Stecher, P.G., editor, 1968.  The Merck Indes, 8th Ed.


tt.  Morrison, R.T. and R.M. Boyd, 1972.  Organic Chemistry,

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5.  Scott, T.S., 1952.  The incidence of bladder tumours in
                                                               4
         a dyestuffs factory.  Brit. J. Industr. Med.,         f1
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6.  Takemura, N., T, Akiyamo, and C. Nakajima, 1965.  A

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         Int. J. Air Wat. Poll., 9:665-670.


7.  Spitz, S., W.H. Kaguigan, and K. Cofcriner, 1950.  The

         carcinogenic action of benzidine.  Cancer,

         3:789-80*4.

-------
                            38





8.  Goldblatt, H.W., 1947.  Occupational cancer of the



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9.  Weber, H., and C. Heiderprim, 1923.  Zur Kenntnis 'des



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         Zeritralblf Gewerbehyg, 5:269-272.








10. Baker, R.K., 1950.  The carcinogenic activity of



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11. Baker, R.K., and J.G. Deighton, 1953.  The metabolism of



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12. Sciarini, L.J., 1957.   3-Hydroxyber.zidine, a metabolite



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13. Troll, W., and N. Nelson, 1958.  Sruaies on aromatic



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         19:499-503.

-------
                            39





14. Sciarini, L.J., and J.W. Meigs, 1958.  The



         biotransformation of benzidine,  (4,



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         the dog.  A.M.A. Arch. Indust. Health, 18:521-530.








15. Sciarini, L.J. and J.W. Meigs, 1961.  The



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         and man.  Arch. Environ. Health, 2:423-428.








16. Sciarini, L.J., and J.W. Meigs, 1961.  Biotransformation



         of the benzidines in.  studies  en diorthotolidiner



         dianisidine, and dichlorobenzidine: 3,



         3 *-disubstituted congeners of henzidine.  Arch.



         Environ. Health, 2:108-112.








17. Neumann, H.G., 1970.  Uber die a ktiverung



         krebserzuegender aromatischer amine im



         stoffwechsel.  Klin. Wschr., 48:959-966.








IS. LemkG, A.E., 1973.  Static bioassays  v?ith benzidino,



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         Laboratory.








19. 3OCMA, 1975.  Acute fish toxicity.  Second Submission by



         SOCMA Benzidine Task Force to Environmental



         Protection Agency.

-------
                            no





20. Rehn, L., 1895..  Arch. Klin. Chir., 50:588.








21. Barsotti, M., and E.G. Vigliani, 19U9.  Bladder^lesions



         from aromatic amines.  Med. Lavoro, 40:129-138.








22. Brenblum, I. and GnM. Bonser, 1937.  xperimental



         investigation of "aniline cancer".  J. Indust.



         Hygiene and Toxicol., 19:86-92.








23, Hartwell, J.L., 1941.  Survey of compounds which have



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24. Hawley, G.G., editor, 1971.  The condensed chemical



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25. Boyland, E., J. Harris, and E.S. Horning, 195U.  The



         induction of carcinoma of the bladder in rats with



         acetamidoflurene.  Brit. J. Cancer, 8:617-654.








26. Bonser, G.H., D.B. Clayson, and J.'-J. Jull, 1956.  The



         induction of tumours of the subcutaneous tissues,



         liver and intestine  in the rrcuse by certain



         dyestuffs and their  intermediates.  Brit. J.



         Cancer, 10:653-667.

-------
27. Laumonier, R., and R. Laguerriere, 1962.  Changes in DNA


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         experimental data.  Rev. Int. Hepat, 12:633-654.




28. Pliss, G.,B., 1964.  Carcinogenic properties of


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29. Saffiotti, U., F. Cefis, R, Montesano, and A.R.
                                                           v
         Sellakumar, 1967.  Induction of bladder cancer in '

         hamsters fed aromatic amines.  In: Bladder Cancer,


         A Symposium.  Edited by K.F. Lampe.




30. Sellakumar, A.R., R. Montesano, and U. Saffiotti, 1969.

         Aromatic amines carcinogenicity in hamster.  Proc,


         Am. Assoc. Cancer Res., 10:78.            •




31. Griswold, D.P., A.E. Casey, E.K. Weisturger, and J.H.


         Weisburger, 1968.  The carcinogenicity of multiple


         intragastric doses of aromatic and heterocyclic

         nitro or amino derivatives in young female'


         sprague-dawley rats.  Cancer Research, 28:924-933.




32. Zabezhinski, M.A., 1970.  Effectiveness of inhalation.as
                 •
         a method of administration of atomized carcinogens.

         Byull EKsp Biol.  Med., 69:72-74.

-------
                            42



33. Prokofjeva, O.G., 1971.  Inducticr. of hepatic tumors in

         mice by benzidine.  Vop Onkol., 17:61-64.




34. SOCMA, 1975.  Exhibit III, Benzidine degradation.

         Submission by SOC.MA Benzidine Task Force to

         Environmental Protection Agency.




35. Malaney, G.W. , P. A. Latin, J.J. Citulka, and L.H.

         Hickerson, 1967.  Resistance of carcinogenic

         organic compounds to oxidation by activated sludge.
                                                        *
         J. Water Poll. Control Fed., 12:2020-2029.




36. Schedler, R., 1905.  Zur Kasuistik der blasentumoren bei

         f acharbeitern.  Inaug. diss., Easel.




37. Ross, H.C., 1918.  Occupational Cancer.  J. Cancer

         Research, 3:321-356.                           .




38. Rosenbauin, N., and J. Gottlich, 1926.  Neubildungen der
arnbleise be: textilarbeiterr.. Gigiona trudn,
                                                        30
39. Sch'.iellar, H., 1932.  Blasentumoren bei anilinarbeitern

         Ztschr. Urol., 26:284-286.

-------
                            43


40. Ferguson, R,5., G.H. Gehrman, D.I-'.. Gay, L. Anderson, and

         V. Washburn, 1934.  Symposium on aniline tu.--.ors of

         the bladder.  J. Urol., 31:121-126.




41. di Maio, G., .1936.  Tumore della vesica tfa amine, detti

         da anilina. Urologia, 3:239-242.




42. Nagayo, M., and R. Kinosita, 1940.  Seme significant
                                                           -»
         features of cancer incidence in Japan.' Yale J.

         Biol. and Med., 12:301-303.




43. Billiard-Duchesne, J.L., 1946.  Les amine-tumeurs de la

         vessie.  J. d'durol., 53:401-422.




44. Leuenberger, S.G., 1912.  Die unter dem einfluss der

         synthetischen farbenindustric. beobachtete

         geschwulstent-wicklung. Beitr. Klin. Chir., 80:208.




45. Curchmann, F., 1920.  Statistische erhebungen uber

         blasenrumoren bei arbeitern in der chemischen

         Industrie.  Gewerbehyg, 8:145-169.


               i

46. Nassauer, M., 1919.  Uber bosartige blasengeschwulste

         bei arbeitern der organisch-chemischen.

         grosindustric. Atsch.f. Pathol., 22:353.

-------
                            44




47. Oppenheimer, R., 1927.  Uber die bei arbeitern


         chemischer betriebe beobachtetian erkrankungen des


         harnapparates. Atch.f. urol . Chir., 21:336.






48. Schwerin, 1920.  Blasengeschwulste fcei arbeitern in


         chemischen betrieben. Abl. f. Gewerbehyg., 8:64.






49. Barsotti, M. ,- and E.G. Vigliani, 1952.  Bladder lesion^
                                                   i       » V

         from aromatic amines.  Statistical considerations


         and prevention.  Arch. Indust. Hyg. Occup. Med.,
50. Case, R.A.M., M.E. Hasker, D,B. McDonald, and J.T.


         Pearson, 1954.  Tumors of the urinary bladder in


         workmen engaged in manufacture and use of certain


         dyestuff intermediates in the British chemical


         industry.  Part I.  The role of aniline, benzidine,


         alpha-naphthylainine, and beta-naphthylamine.  Brit.


         J.  Ind. Med., 11:75-104.





51. Scott, T.S., and M.H.C. Williams, 1957.  The control of


         industrial bladder tumours.  Brit. J. Industr.


         Med., 14:150-163.

-------
52. Goldwater, L.J., A.J. Rosso, and M. Kleinfeld, lr:>5.



         Bladder tumors in a coal tar dye plant*  Arch.



         Environ. Health, 11:814-817.







53. Rye, W.A., P.P. Woolrich, and R.F. Zanes, 1970.  Facts



         and myths concerning aromatic diamine curing



         agents.  J. Occupt. Med. , 12:211-215.




                                                          x.
                                                           ^ x


54. Zavon, M.R., U. Goegg, and E. Bingham, 1973.  Benzidine



         exposure as a cause of bladder tumors.  Arch.



         Environ. Health, 27:1-7.







55. Ehrlicher, H., 1958.  Benzidine in arbeitsmedizinischer



         sicht. Zentrabl Arbeitsmed, 8:201-207.
                               j




                                                       '

56. Scott, T.S., 1962.  Carcinogenic and Chronic Toxic



         Hazards of Aromatic Amines.







57. SCCMA, 1975.  Determination of degration rate for



         benzidine under different laboratory conditions.



         Second submission by SOCMA Benzidine Task Force for



         the Environmental Protection Agency.

-------
                            46





58. SOCMA, 1975.  Degradation of benzidine by exposure to



       •  simulated. June sunlight.  Second Submission by



         SOCMA Benzidine Task Force for the Environmental



         Protection Agency.







59. Lutin, P.A., J.J. Cibulka, and G.W. Malaney, 1966.



         Oxidation of selected carcinogenic compounds by



         activated sludge.  Proc. 21st Ind. Waste Conf.,



         Purdue Univ.








60. Ryckman, Edgerley, Tomlinson and Associated, Inc., 1974.



         Fate of benzidine in the aquatic environment: A



         scoping study.








61. SOCMA, 1975.  Biological treatability of benzidine.



         Third Submission by SOCMA Benzidine Task Force; for



         the Environmental Protection Agency.








62. SOCMA, 1975.  Exposure of fish to lUC-benzidine:



         Accumulation; distribution, and elimination of



         14C-residues.  Third Submission by SOCMA Benzidine



         Task Force  for the Environmental protection Agency.








63. Rinde, E. and W. Troll, 1975.  Metabolic reduction of



         benzidine azo dyes to benzidine in the rhesus



         monkey.  J. Nat. Cancer Inst., 55:181-182.

-------
                            47





64. Mantel, N., and W.R. Bryan, 1961.  "Safety" testing of



         carcinogenic agents.  J. Nat. Cancer Inst., 27:455*



         470.







65. Freireich, E.J., E.A. Gehan, D.P. Rail, L.H. Schmidt,



         and H.E. Skipper, 1966.  Quantitative comparison of



         toxicity of anticancer agents in mouse, rat,



         hamster, dog, monkey, and man.  Cancer Chemotherapy



         Reports, 50:219-244.








66. Huggins, C., G. Briziarelli, and H. Sutton, Jr., 1959



         Rapid induction of mammary carcinoma in the rat and



         the influence of hormones on the tumors.  J.  Exptl.



         Med., 109:25-41.








67. Shay, H., E.A. Aegerter, M. Grunenstein, and S.A.



         Komarov, 1949.  Development of adenocarcinoma of



         the breast in the wistar rat following gastric



         instillation of methylcholanthrene.  J. Natl.



         Cancer Inst., 10:255-266.







68. Altraan, P.L. and D..S. Dittmer, editors, 1971.  Section



         III - development and growth.  Biology Data Book,



         2nd Ed.

-------
69.  U.S. Environmental Protection Agency.   Statement .of



         Basis and Purpose  for the national Interim Primary



         Drinking Water Regulations.








70. Hoel, D.G., D.W. Gaylor,  R. L.  Krischstein,  U. Saffiotti,



         and M.A. Scheiderman, 1975.   Estimation of risks of



         irreversible, delayed toxicity.  J. Toxicology and



         Environ. Health, 1:133-151.








71. Vesselinovitch, S.D., K.V.N.  Rao, and N. Mihailovich,



         1975.  Factors modulating benzidine carcinogenicity



         bioassay.  Cancer  Research,  35:2814-2819.








72. Earnest, R.  1970.  Effects of pesticides on aquatic



         animals in the estuarine and irarine environment.



         Unpublished data.   In:  Annual Progress Report.



         Bureau of Sport  Fisheries and wildlife.  U.S. Dept.



         of the Interior.
 7"^  VT*-»--»   M    IQ^T    A /•»! »-f-£> •f-/~\-VT/1>->4-tr r\f Cr/-\rv/i /->>~rT=»r^Ty-»
 -^ » i \ »-* — <^ ^  t. * •   ^. ^ \J *. *   *»Vxi^.v-v^ «^«^«*^_VU.u.J' »_»*. •*•*•*.* t \ • \~, VX.A-^-flAllJ.V'





          insecticides to three species of salmonids and the





          threespine  stickleback.  Trans. Amer. Fish. ,Soc.,





          90 (3) :26H-268.

-------
                            U9





                         Appendix 1








    Various mathematical models can be used for deriving  a



level from the experimental dose/effect data which will



ensure a limit of no more than one cancer in one million



(1x10  ) of the human population at risk at a 95 percent



confidence level.  The mathematical models employed to



calculate this level for benzidine were the Mantel-Bryan



probit model  (64) and the one-hit model (70).







    The Mantel-Bryan probit model is based on the assumption



that the susceptibility to the carcinogenic effect of a



chemical is distributed log normally among the population,



and that the incidence of cancer will decrease with



decreasing dose at a rate of no less than one normal



deviation  (probit) per 10-fold decrease in dose.








    The one-hit model assumes that a single molecule can



cause cancer.  If the molecules are distributed at random,



the probaoility of inducing ccmccr, as corrected for



repeated cancer production, is proportional to the dose.

-------
                            50
The relationship of an observed response, P, at a h:.u

dose, d, is expressed by the equation:
         P=l-e-kd
where:
         P=observed response
         d=dose
         k=ccnstant, calculated from experimental
           dose-response data.

With the calculated constant, the dose level at the limit of

one cancer per one million at risk can then be calculated, i
    The dose-carcinogenic response studies reviewed for

extrapolation to calculate human dose levels at the limit of

no more than one cancer per one million at risk were

reported by Griswold, et a 1«,  (31) using  Sprague-Dawley

rats; Spitz, et a1.,  (7) using Sherman rats; Prokofjeva  (33)

using C3HA mice; the  experiment conducted by Spitz, et al.,

 (7) with dogs as reported in  Bonser, et 
-------
                            51


test animals employed.  Because of the defined sensitivity

of the female Sprague-Dawley rats and the statistically

insignificant total of ten test animals used,  the Griswold

data was rejected for mathematical extrapolation.



    Spitz's published conclusion  (7)  concerning their

experiment with dogs was that no conclusion concerning the

carcinogenicity of benzidine could be drawn from their
                                                          •<.
reported one case of papillary carcinoma from seven test

dogs.  Six years after the publication of the test results

from Spitz's experiment, Bonser, et al., in 1956 .(26)

reported a personal communication frorr. Spitz stating that a

total of three dogs developed papillorr.as and carcinomas of

the bladder.  However, because the necessary specific data

has not been published, this experiment could not be used in

the extrapolative methods.



    The experiments reported by:   Spitz, et al,,  (7) ;

Prokofjeva  (33); and Vesselinovitch  (71), although not using

random populations,- are the best available data for

calculation of human dose levels corresponding to no more

than one cancer per one million at risk.



    The dose administered to the experimental animals is

first converted to an equivalent human dose.  A conversion

method is base-1 upon the observation that for acute toxicity

-------
                            52


of a number of anti-cancer agents, parameters such as the ID

and the maximum tolerated dose are quantitatively

proportional in mice, rats, hamsters, dogs, monkeys and man

(65 >.  This proportionality is based on a weight

relationship, which is calculated by:


          human dose = Average human weight \ 2/3   ^^
                       [Average animal weight)    x amlnaj- dose

    In the work reported by Spitz, et al.,  (7) a total of

385 Sheman strain rats were injected subcutaneously in the

bac< with a weekly dose of 15 mg of benzidine throughout the

lif a of ';he animals until grossly obvious tumors appeared.

DOS-SB were not administered if the animals  suffered loss of

weirht or obvious illness.  Due to the high mortality of

botl  the control and experimental series in the first 200

day  of the experiment, only those animals  which survived

200 or more days were counted as "at risk." Out of the

ori< inal 385 animals injected with benzidire, a total of 206

sur-'ived 20( days or more.  There were three tumor types in

the test an.mals caused by the benzidine.   These tumor  types

wer*:  hepa-; omas; carcinomas arising in the specialized

auditory sebaceous glands; and adenocarcir.crra of the colon.

A total of 100 test animals produced turners of the three

ind .cated types with an average incubaticr.  time of 222 days.




    The administered dose of benzidine was  15 mg per week or

2.1  mg/day.  The average weight of the experimental animals

-------
                             53
was 265 gm, while the reported average weight  of a human is

70kg (68) .  Calculating the equivalent human dose according

to the 2/3 power of the weight ratio, as previously

described/ is demonstrated in the following equation:

'   sexvalent  h^an a,se . feg ^ff f* x dose Ja anin*ls

       human dose       = ^_2yi_y/3 x 2.14 ng/day

        human dose       =  88.16 mg/day

     Assuming  no sources of benzidine intake other than the

average intake  of two liters of water per person per day

 (69) ,  this dose corresponds to a  concentration of 44.08 rag/1

in water.



     The :jicidence of tumors from  benzidine was 0.4JO  (48%) ,

with the upper  95 percent confidence limit bei ig 0. 543

 (54.3%) .  According to the one hit model, with a dose (d) of

44.08  mg/1, a response (P)  of 0.543 (54.3%) at the upper 95

percent confidence limit,  the constant k is calculated as?

   P =  1 - e~kd
  k =  -ln(l - P)  = -ln(0.457)  = 0.7831
            d         44.08       44.08

  k =  1.78  x 10~2

    Deriving a concentration which, at the  95% confidence

 1 jrdt, will result in no more  than one cancer per million of
                             - 6
 t le population at risk  (1x10  ) yields:

  d =  -ln(l - P)  _ -In (0.999999)       10"6
          k         1.78 x 10~2    1.78  x 10~2

  d =  5.62  x 10~5 mg/1

-------
                            54



    At a 95 percent confidence level, the limit of one


cancer per million at risk corresponds to a concentration Of


0.056 ug/1, as extrapolated from the Spitz data calculated


by the one-hit model.





    Using the Mantel-Bryan method, a risk level of one in


one million at risk is equivalent to a probit of -4.75.


While the upper 95 percent confidence limit of the observed


response corresponds to a probit of  0.108.  Therefore,


extrapolating from the experimental  response of 0.543


(54.3%) to a response of no more than one cancer per million


at risk corresponds to a probit change from 0.108 to -4.75


equal to -4.86.





    According to the ten-fold reduction in dose per one


probit, a probit change of -4.86 corresponds to a


concentration of benzidine which will produce no more than


one cancer per million in the population at risk of: .



    concentration   =   44.08 mq/1 x 10~4-86
                    —   /i n no ^r, /•»-.  n 10 v "in — 5\
                    —   -»T»\/»-»III-^'J-/V  ij_*jyiyvJL\//        ••

                         6.08 x 10~4 mq/1
                         0.6C8 ug/1


    At the 95 percent confidence limit, the concentration


which will result in no more than one cancer per million at


risk is equal to 0.608 ug/1, as extrapolated.by the Mantel-


Bryan method using the Spitz data.

-------
                            55
    In the experiment reported by Prokofjeva, a total of 181



C2 iA mice were given subcutaneous injections of benzidine at



a  single weekly dose of 6 mg per mouse over a pericxl of 8-13



mciths.  Hepatomas appeared in 31 of 46 surviving test mice



v;i^±i the first occurence being within 15 to 16 months.  In a



deiined control population, a one percent hepatoma frequency



wa; observed.  The administered dose of benzidine



(6 mg/week) was equal to 0.856 mg/day.  Calculating the



eq ivalent human dose, assuming the average weights of 30



gr ms for an adult C3HA. mouse  (68) and 70 Kg for  an adult



hu an (68), the following dose is:




   quivalent human dose = (j^*^   x  0.856 mg/day




       human dose      =   150.48 mg/day







    Assuming no sources of benzidine intake other than the



average intake of two liters of water per person per day



(69), this dose corresponds to a concentration of 75.24 mg/1



in water.







    The incidence of tumors from benzidine v.-as 0.674  (67.4%)



with the upper1 95 percent confidence limit equal  to 0.788



(7c .8%).  Calculating the dose corresponding to the level of

-------
                             56
no more than one cancer per one million at risk using the

one-hit model, the rfollowing level is calculated:

   Solving for k according to the Prokof jeva data:
        P=l-e-kd
        k = -ln(l  -  0.788) _ 1.55117
              75.24 mg/1     75.24
        k = 2.06 x 10~2

   Solving for the dose  (d) when the response  (P) is no more
   •chan one cancer per million at risk  (10  ) :
        d = -ln(l  -  10"6X _    10"6  _,
              2.06 x 10 ^ " 2.06 x 10"^
        d = 4.85 x 10~5  mg/1
    At the 95 percent confidence level a limit of no more

than one cancer in one million at risk corresponds to a

concentration level of 0.048 ug/1 as calculated by the one-

hit theory based upon the Prokof jeva data..
    The corresponding probit for 0.788  (78.8%), which is the

95 percent confidence limit of the observed response, equals

0.80 probits.  The probit change from an observed incidence

of 0.788  (78.8%) to one in one million at risk equals -5.55,

a probit change from 0.80 to -4.75.



    According b> the ten-fold reduction in dose pir one

probit change,  i probit change of -5.55 corresponds to a

concen -.ration o: benzidine which will produce no nore than

one cc.-icer per :iillion in the population at risk of:

    concentration  =    75.25 mg/1 x 10~5*55
                        75.24 mg/1 x (2.82 x 10~6)
                         2.12 x 10~4 mg/1
    concentration  =     0.212 ug/1

-------
                                 57




    At the 95 percent confidence limit, the concentration



which will result in no more than one cancer per million at




risk is equal to 0.212 ug/1, as.extrapolated by the Mantel-



Bryan method using the Prokofjeva data.








    The study by Vesselinovitch, et_ al.  (71), consisted of



tin integrated series of studies  to  assess the



carcinogenicity of benzidine dihydrochloride in mice.  In



one carcinogianicity study, 200 six-week old B6C3F mice were



given benzid-'me dihydrochloride  intermittently by stomach



intubation, rwice weekly, in the amounts of 0.5 or 1.0



mg/mouse at oach intubation for  84  weeks.  All animals were



killed at 90 weeks of age, at which time their tumor



incidence was evaluated.  Benzidine-treated mice developed



liver t\mors, Harderian gland tumors, lun : adenomas, and



lymphoreticular tumors.  A total of ]24 of  the indicated



tumors were reported for both dose  levels.  The average dose



level is calculated to be 0.428  mg/day/mcuse.  Calculating



the equivalent hu nan dose, assuming the cverage weights of



30 grams for an adult B6C3F mouse (f8) ar.3 70 kg for an



adult human (68) , the following  dose is:



   equivalent  hurrvm dose =^™_|2.J   x 0.428 mg/day




        human dose       = 75.24 irg/day







    Assuming no sources of benzidine inta:e other than the



average intaVe of two liters of water per person per day

-------
                              58


 (69), this dose corresponds to a concentration of 37.62 mg/1

in water.



    The incidence of tumors from benzLdine was 0.413  (41.3%)

with the upper 95 percent confidence .Limit equal to 0.460. .

The dose corresponding to a level of no more than one cancer

per one million at risk, using the one-hit modal, is

calculated as follows:

  Solving for k according to  the Vesseilinovitch data:

       v _ -ln(l - P) = -ln(0.540) = 0.61619
               d          37.62       37.62

       k = 1.64 x 10~2

  Solving for the dose  (d) when the response  (P) is no more than
  one cancer per million at risk  (10~^):

       d = -Ind - 10"*) _    10"6    .,
            1.64 x 10"?  ~ 1.64 x 10 '•

       d = 6.10 >: 10~5 mg/1

    A ; the 95 percent confidence level a limit of no more

than one cancer in one million at risk corresponds to a

concentration level of 0.061  uc/1 as calculated by the one-

hit tieory based upon the Vesselinovitch data.



    Tie corresponding probit  for 0.460 (46.0%), which is the

upper 95 percent confidence limit of the observed response,

equal.1- -0.100.  The probit change frcrr an observed incidence

of 0.--60 (46.0%) to one in one million at risk equals -4.65,

a proi it change from -1.00 to -4.75.

-------
                            59


    According to the ten-fold reduction, in dose per one

probit change, a probit change of -4.65 corresponds to a

concentration of benzidine which will produce no more than

one cancer per million in the population at risk of:
    concentration  = 37.62 mg/1 x 10~4'65
                   = 37.62 mg/1 x  (2.24 x 10~5)
                   =  8.43 x 1CT4  mg/1
    concentration  =  0.8U3 ug/1
    At the upper 95 percent confidence limit, the

concentration which will result in no more than one cancer

per one million at risk is equal to 0.843 ug/1, as

extrapolated by the Mantel-Bryan method using the

Vesselinovicch data.



    Table 7 presents a summary of the calculated

concentrations which will result in nc more than one cancer

per million at the upper 95 percent confidence limit as

extrapolated by the Mantel-Bryan and the one-hit methods,

from dose-response data as reported by Spitz, et a1.,  (7),

Prokofjcv-a (33), arid Veaaeiiriovitch, et _al.  (71).

-------
                            60


                          Table 7

            Summary of Calculated Concentrations

                              Extrapolative Method
Observed Dose-Response
       Data      *        One-Hit  (70)           Mantel-Bryan  (64)

Spitz (7)                  0.056 ug/1            0.608 ug/1
Prokofjeva  (33)            0.048 ug/1            0.212 ug/1
Vesselinovitch  (71)        0.061 ug/1            0.843 uq/1

-------
                             GLOSSARY



Acutely toxic:  Causing death or severe damage to an organism by


    poisoning during a brief exposure period, normally ninety-six


    hours or less.



Anadromous fishes:  Irishes thai spend a part of their lives in seas


    or lakes, but as<-end rivers and streams al. certain intervals to .


    spawn.  Kxamples are sturgeon, shad, salmon. Lroul,  and

                                                            '^
    striped bass.                                     •       „•       -



Application  factor: The ratio of the safe concentration to the lethal


    concentration as determined for potential aquatic pollutants


    administered to species of interest.



Bioaccumulation (Bioconcentration): The phenomenon wherein elements


    or compounds are stored in living organisms because elimination .
                                                                   E1
                                                          •   •'   .  fc
    fails to match intake.                                           r



('urcinogenic :  Producing < 'anci-r.



Catadromous fishes;  Fishes that Iced and grow in fresh water, but


    return to the sea to 'spawn.  The best example is the American


    eel.



Chronically toxic;  Causing death or damage to an organism by


    poisoning during prolonged exposure, which, depending on the


    organism tested and the test  conditions and purposes, may range


    from several days,  to v/eeks, months, or years, or through a


    reproductive cycle.

-------
EC50; The concentration at which a specified effect is observed

    under the  It-si conditions in a specified time in fifty percent of

    1.1 ie. organisms tested.   lOxamples of specified effects arc hcmor--

    rhaging, decreased feeding, dilation of pupils,  and altcr"d

    swimming patterns.


Epilimnion:  That region of a body of \vater that extends from the

    surface to the top of the thermocline and  does not have a permanent

    temperature stratification.                           .    ".


(•'low-through bioassay:  An assay system in  which aquatic species

    arc: exposed to toxicants in a constantly flowing system,  and where

    th<: toxicant is replenished continuously or dise.ontinuously.


Hardness (Water): The  concentration of the polyvalent metallic ions

    dissolved in water.  Unually it is  reported as the equivalent

    concentration of calcium carbonate (CaC'O ).
                                            :i

llyperplasia:  Abnormal multiplication or'increase in the number

     of normal cells in normal arrangement in a tissue.


Hypolimnion: The region of a body of water that extends from the

     bottom of the thermocline to the bottom of the water body and

     is essentially independent of most surface phenomena.

-------
LC25: The concentration ol' a toxicant that is lethal  (fatal) to twenty-




    five percent of the organisms tested under the test conditions in




    a specified time.






l/lfiO: The concentration of a toxicant which is lethal (I'alaP to




    fifty percent of the organisms tested under tin; lest conditions




    in a specified  time.   |l is virtually identical with Thru and Tl,f>0.






LUfiO: The dose of a toxicant that is lethal (fatal) to fifty percent

                                                        * '


    of the organisms tested under the test  conditions in a specified




    time.   A dose is the quantity actually administered to the




    organism and  is not identical with a concentration, which is the




    amount of toxicant in a unit of test medium rather than the




    amount ingested by or administered to the organism.
Liter (I).- The volume occupied by OIK; kilogram of water at a pressure


                                                 0            i
    ol 7f>0 mm of mercury and a temperature ol 4  ('.  A liter is



    1. 057 quart.
Methylmercury;  Mercury which has been methylated, usually through.



    some biological agent,  such as bacteria.






Microgram per liter (ug/1): The concentration at which one millionth



    of a gram (one microgram) is  contained in a volume of one liter.



    Where  the density of solvent is equal  to one, one ug/1 is equiva-



    lent to  one part per billion (ppb) or one microgram per kilogram



    (ug/kg).

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lUicrogram per kilogram (ug/kg):  The concentration at which one



    millionth of a gram (one micrograrn) is contained in a mass of




    one kilogram.  A kilogram is 2. 2046 pounds.






Milligram per kilogram {mg/kg):  The concentration at which one




    thousandth of a gram (one milligram) is contained in a mass «>f




    one kilogram.  A gram contains 1000 milligrams.






Milligram per liter (nig/1):  The concentration at which one milligram




    is contained in  a volume of one liter.  Where the density of the




    solvent is equal to one, one mg/1  is equivalent to one part per




    million (ppm) or one milligram per kilogram (mg/kg).






Milliliter (ml): A volume equal to one thousandth of a liter.






Nanogram per liter (ng/1): The concentration at which one billionth




    •of a gram (one  nanogram) is contained in a volume of one liter.




    'Where the  density of the solvent is equal  to one, one ng/1 is




    equivalent  to one part  per trillion or one  nanogram per kilogram




    (ng/kg).






Neoplastic:  Describing any new and  abnormal growth, such as a tumor.






Part per million (ppm): A concentration in which one unit is contained




    in a total of a million units.  Any  units may be used (e.g.,  weight,




    volume) but in any given application identical units must be used



    (e.g. ,  grams per million grams or liters per million liters).




    Where the  density of the solvent is one, one part per million is




    equivalent  to one milligram per liter.

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1'arts per thousand (o/oo):  A concentration at which one unit is
    contained in a total of a thousand units.  The rules for using
    this term are the same as those for parts per million.  Normally.
    this term is used to specify the salinity of estuarine or sen waters.

Piscicide;  A substance used for killing fish.

Static bioassay:  A bioassay in which the toxicant is not renewed during
    the test.

Thermocline; That layer in a body of water where the temperature.
    difference is greatest per unit of depth.  It  is the layer in which
    the drop  in temperature is 1  {.'.. or greater per meter of. depth.

TLrn - Median Tolerance Limit;  The concentration of a test material
    at which  fifty percent of the test animals are able to survive-
    under test conditions for a specified period of exposure.  It is     >
    virtually  synonymous with LC50 and TL50.

TJ,T)0:  Synonymous with TLm and virtually synonymous with LC50.

Turnorigenic:  Causing or producing tumors.

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