EPA-540/1-86-013
                       Agency
Office of Emergency and
Remedial Response
Washington DC 20460
Off'ce of Research and Development
Office of Health and Environmental
Assessment
Environmental Criteria and
Assessment Office
Cincinnati OH 45268
                       Superfund
vvEPA
                       'HEALTH EFFECTS ASSESSMENT
                        FOR POLYCYCLIC AROMATIC HYDROCARBONS  (PAHs)
                                     U.S. Environmental Protection Agerfcv
                                     Region V, Library
                                     230 South Dearborn  Street
                                     Chicago,  Illinois  60604

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                                              EPA/540/1-86-013
                                              September 1984
          HEALTH  EFFECTS  ASSESSMENT
FOR  POLYCYCLIC AROMAUC  HYDROCARBONS  (PAHS)
       U.S. Environmental  Protection Agency
        Office of Research and  Development
   Office of Health  and Environmental Assessment
   Environmental Criteria  and Assessment Office
               Cincinnati, OH  45268
       U.S. Environmental  Protection Agency
     Office of  Emergency and Remedial Response
   Office of Solid Waste  and  Emergency Response
               Washington, DC  20460
                Chicago, 1L   Ov':''J-i-

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                                  DISCLAIMER

    This  report  has  been funded  wholly  or  In  part  by  the United  States
Environmental  Protection  Agency under  Contract No.  68-03-3112  to  Syracuse
Research Corporation.  It has been subject  to  the  Agency's  peer  and adminis-
trative review, and  1t has been  approved  for  publication  as an EPA document.
Mention of  trade  names or commercial  products  does not  constitute  endorse-
ment or recommendation for use.
                                      11

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                                    PREFACE


    This report  summarizes  and evaluates Information relevant  to  a  prelimi-
nary Interim assessment of  adverse  health effects  associated  with  polycycllc
aromatic hydrocarbons.  All estimates  of acceptable  Intakes  and carcinogenic
potency presented  1n  this  document should  be  considered as  preliminary  and
reflect limited  resources  allocated to this project.   Pertinent  toxUologlc
and environmental  data  were  located  through  on-Hne literature searches  of
the Chemical  Abstracts, TOXLINE,  CANCERLINE  and  the CHEMFATE/DATALOG  data
bases.   The basic  literature  searched  supporting this document  1s  current  up
to September, 1984.   Secondary sources of  Information have also been  relied
upon 1n the  preparation  of  this  report  and  represent large-scale  health
assessment  efforts  that   entail  extensive  peer  and  Agency  review.   The
following Office  of  Health  and Environmental  Assessment  (OHEA)  sources  have
been extensively utilized:


    U.S. EPA.  1980a.   Ambient  Water  Quality  Criteria  for Acenaphthene.
    Environmental  Criteria  and Assessment  Office,  Cincinnati,  OH.   EPA
    440/5-80-015.  NTIS  PB  81-117269.

    U.S. EPA.  1980b.   Ambient  Water  Quality  Criteria  for Fluoranthene.
    Environmental  Criteria  and Assessment  Office,  Cincinnati,  OH.   EPA
    440/5-80-049.  NTIS  PB  81-117608.

    U.S. EPA.   1980c.  Ambient Water  Quality Criteria  for  Polynuclear
    Aromatic  Hydrocarbons.    Environmental   Criteria   and   Assessment
    Office,  Cincinnati,  OH.   EPA 440/5-80-069.   NTIS  PB  81-117806.

    U.S. EPA.  1983a.  Review  of  Tox1colog1c Data  1n  Support  of Evalua-
    tion for  Carcinogenic   Potential  of:  Anthracene.   Prepared by  the
    Carcinogen Assessment Group,  OHEA, Washington, DC for the Office of
    Solid Waste  and Emergency  Response, Washington, DC.

    U.S. EPA.  1983b.  Review  of  Tox1colog1c Data  1n  Support  of Evalua-
    tion for  Carcinogenic   Potential  of:  Benzo[a]anthracene.   Prepared
    by   the  Carcinogen Assessment Group, OHEA,  ORD,  Washington, DC  for
    the Office of Solid  Waste  and Emergency  Response,  Washington,  DC.

    U.S. EPA.  1983c.  Review  of  Tox1colog1c Data  1n  Support  of Evalua-
    tion for  Carcinogenic   Potential   of:  Benzo[a]pyrene.  Prepared  by
    the Carcinogen Assessment  Group,  OHEA,  ORD, Washington,  DC  for  the
    Office  of Solid Waste and  Emergency Response, Washington,  DC.

    U.S. EPA.  1983d.  Review  of  Tox1colog1c Data  1n  Support  of Evalua-
    tion for  Carcinogenic  Potential   of:  D1benz[a,h]anthracene.   Pre-
    pared by the  Carcinogen Assessment Group, OHEA,  ORD,  Washington, DC
    for the  Office of  Solid  Waste  and Emergency  Response,  Washington,
    DC.
                                   111

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    U.S. EPA.  1983e.  Review of Toxlcologlc Data  1n  Support  of  Evalua-
    tion  for  Carcinogenic  Potential  of:  Fluorene.   Prepared  by  the
    Carcinogen  Assessment   Group,  OHEA,  ORD,   Washington,  DC  for  the
    Office of Solid Waste and Emergency Response,  Washington,  DC.

    U.S. EPA.   1983f.   Reportable  Quantity for Acenaphthene.   Prepared
    by  the Environmental Criteria and  Assessment  Office,  Cincinnati,  OH
    for the  Office of Solid  Waste  and Emergency  Response, Washington,
    DC.

    U.S.  EPA.   1983g.   Reportable  Quantity  for   Benzo[a]pyrene.   Pre-
    pared by  the  Environmental  Criteria and Assessment Office,  Cincin-
    nati,  OH for  the Office  of Solid  Waste  and Emergency  Response,
    Washington, DC.


    The Intent In  these assessments 1s  to  suggest  acceptable  exposure levels
whenever sufficient data were  available.   Values  were not derived  or larger
uncertainty  factors  were employed  when  the  variable data were limited  1n
scope  tending  to  generate conservative {I.e.,  protective)  estimates.   Never-
theless, the  Interim  values presented  reflect  the relative degree  of hazard
associated with exposure or  risk to  the chemlcal(s) addressed.

    Whenever possible, two  categories  of  values have  been  estimated for  sys-
temic  toxicants (toxicants  for which cancer 1s  not the  endpolnt of concern).
The  first,  the AIS  or  acceptable  Intake  subchronlc, 1s  an  estimate of  an
exposure  level  that  would  not  be  expected  to cause  adverse effects  when
exposure occurs  during  a limited time Interval  (I.e.,  for an  Interval  that
does  not  constitute a  significant  portion of  the Hfespan).  This  type  of
exposure  estimate has not  been  extensively used  or  rigorously defined,  as
previous  risk  assessment  efforts   have  been  primarily  directed  towards
exposures from  toxicants  In ambient air or water  where lifetime exposure  1s
assumed.  Animal   data  used for  AIS  estimates  generally Include  exposures
with  durations  of 30-90 days.   Subchronlc  human  data are rarely  available.
Reported exposures are  usually  from chronic occupational  exposure situations
or from reports of acute accidental  exposure.

    The AIC, acceptable  Intake  chronic,  1s  similar  In  concept to  the  ADI
(acceptable  dally Intake).   It 1s  an  estimate  of  an  exposure  level  that
would  not  be expected  to  cause adverse  effects  when exposure occurs  for  a
significant  portion  of  the Hfespan [see  U.S. EPA (1980d) for  a discussion
of  this  concept].   The  AIC  1s route  specific  and  estimates  acceptable
exposure  for a  given route with  the  Implicit  assumption that  exposure  by
other  routes Is Insignificant.

    Composite  scores  (CSs)  for  noncardnogens  have  also   been  calculated
where  data  permitted.   These values are used  for  ranking  reportable quanti-
ties;  the methodology for their development 1s explained 1n U.S. EPA  (1983h).
                                      1v

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    For compounds for which there 1s sufficient evidence  of  cardnogenlcHy,
AIS and  AIC values  are  not derived.   For  a discussion  of  risk assessment
methodology for  carcinogens  refer to  U.S.  EPA (1980d).   Since  cancer 1s a
process that 1s  not  characterized by  a  threshold,  any exposure contributes
an Increment of  risk.  Consequently, derivation  of  AIS and  AIC  values would
be Inappropriate.  For  carcinogens,  q]*s  have  been computed  based  on oral
and Inhalation  data  1f available.

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                                   ABSTRACT


    In  order  to  place the  risk  assessment  evaluation  1n  proper  context,
refer  to  the preface  of   this  document.   The  preface outlines  limitations
applicable to all documents of  this  series as  well  as  the appropriate Inter-
pretation and use of the quantitative estimates presented.

    The major Issue  of  the PAH risk assessment 1s  the potential  cardnogen-
1dty  of  these  compounds.   There are  limited data available  which can  be
used  for  quantitative  risk  assessment,  however,  this does  not   Imply  that
there  are  not  adequate qualitative  data  to  consider  many of the  members  of
this class as animal  carcinogens.   In addition, PAH containing mixtures  are
documented to contribute to Increased Incidence of  cancer  1n  the  human  popu-
lation.  The contribution  of  Individual chemical species  to  the  carcinogenic
potency of  these mixtures  and  the  Interactions  of various componets  cannot
be adequately addressed at  present.

    The  one  PAH,  benzo(a)pyrene,   for  which  adequate  dose-response  data
following  exposure  by  appropriate  routes (Inhalation,  oral) are  available
has  been  used  to develop  a  cancer-based risk assessment for PAHs.   Since
data Indicate  that  benzo(a)pyrene 1s one  of  the most  potent  carcinogens  of
the  PAHs   tested,  1t  1s   suggested  that  cumulative   exposures  to  mixtures
containing PAH concentrations should result 1n a risk  that 1s less than that
predicted for benzo(a)pyrene alone.  However,  H should be kept  1n mind that
many  of the  PAHs are  still   Inadequately  characterized   1n  terms  of  their
carcinogenic potential;  that   Interactions  of constituents  of mixtures  are
poorly  defined;  and  that  potency  ranking has  been   done  using  mouse  skin
exposure data (data for other  routes  from  which potency comparisons could be
made are not available).

    Using data  for  stomach tumors  1n mice following oral  exposure to benzo-
(a)pyrene,  a  q-|*  of  11.53  (mg/kg/day)'1 was  computed  for  oral  exposure.
Similarly, using  data on Incidence of respiratory  tumors  1n  hamsters exposed
to  benzo{a)pyrene  by  Inhalation  exposure,   a  q-j*   of  6.11  (mg/kg/day)~a
was derived.
                                      v1

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                               ACKNOWLEDGEMENTS


    The  Initial  draft  of  this  report  was  prepared  by  Syracuse  Research
Corporation under  Contract No.  68-03-3112  for ERA'S  Environmental  Criteria
and  Assessment  Office,  Cincinnati,  OH.   Or.  Christopher  DeRosa and  Karen
Blackburn were the Technical Project Monitors  and  Helen Ball  was the Project
Officer.  The final documents  In  this  series  were  prepared for the Office of
Emergency and Remedial Response, Washington, DC.

    Scientists from  the  following U.S. EPA offices  provided  review  comments
for this document series:

         Environmental Criteria and Assessment Office, Cincinnati, OH
         Carcinogen Assessment Group
         Office of A1r Quality Planning and Standards
         Office of Solid Waste
         Office of Toxic Substances
         Office of Drinking Water

Editorial review for the document series was provided by:

    Judith Olsen and Erma Durden
    Environmental Criteria and Assessment Office
    Cincinnati,  OH

Technical support services for the document series  was provided by:

    Bette Zwayer, Pat Daunt, Karen Mann and Jacky Bohanon
    Environmental Criteria and Assessment Office
    Cincinnati,  OH

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TABLE OF CONTENTS

1.
2.


3.










4.










5.


ENVIRONMENTAL CHEMISTRY AND FATE 	
ABSORPTION FACTORS IN HUMANS AND EXPERIMENTAL ANIMALS . . . .
2.1.
2.2.
ORAL 	
INHALATION 	
TOXICITY IN HUMANS AND EXPERIMENTAL ANIMALS 	
3.1.


3.2.


3.3.


3.4.
SUBCHRONIC 	
3.1.1. Oral 	
3.1.2. Inhalation 	
CHRONIC 	
3.2.1. Oral 	
3.2.2. Inhalation 	
TERATOGENICITY AND OTHER REPRODUCTIVE EFFECTS 	
3.3.1. Oral 	
3.3.2. Inhalation 	
TOXICANT INTERACTIONS 	 	
CARCINOGENICITY 	 ,
4.1.


4.2.




4.3.
4.4.
REGULi
HUMAN DATA 	 	
4.1.1. Oral 	 ,
4.1.2. Inhalation 	 	
BIOASSAYS 	 ,
4.2.1. Oral 	
4.2.2. Inhalation 	 ,
4.2.3. Mouse Skin Assays 	
4.2.4. PAH Containing Mixtures 	
OTHER RELEVANT DATA 	 	
WEIGHT OF EVIDENCE 	
*TORY STANDARDS AND CRITERIA 	
Page
. . . 1
. . 5
. . 5
. . 5
, . 7
, , 7
. . 7
7
, . . 8
, . . 8
, . . 8
, , 8
, . . 8
. . . 9
. . . 9
, . . 10
. . . 10
. . . 10
. . . 10
. . . 11
. . . 11
. . . 20
. . . 24
26
. . . 26
26
. . . 30
       V111

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                           TABLE OF CONTENTS (cont.)

                                                                        Page

 6.  RISK ASSESSMENT	   32

     6.1.   ACCEPTABLE INTAKE SUBCHRONIC (AIS)  	   32
     6.2.   ACCEPTABLE INTAKE CHRONIC (AIC)	   32
     6.3.   CARCINOGENIC POTENCY (q-|*)	   32

            6.3.1.   Oral	   33
            6.3.2.   Inhalation	   33

 7.  REFERENCES	   35

APPENDIX A: Summary Table for PAH	   46

APPENDIX B: Cancer Data Sheet for Derivation of q-|*	   47

APPENDIX C: Cancer Data Sheet for Derivation of q^*	   48
                                      1x

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                               LIST  OF TABLES

No.                              Title                                Page

1-1     Selected Physical  and  Chemical Properties and CAS
        Numbers of a  Few PAHs	    2

4-1     CarclnogenlcHy  of Benzo[a]pyrene Administered 1n the Diet
        to Hale and Female CFW Mice  at Levels of 1-250 ppm	   12

4-2     Cardnogenldty  of Benzo[a]pyrene Administered 1n the Diet
        to Male and Female Swiss Mice at Levels of 250-1000 ppm ...   13

4-3     Cardnogenldty  of Benzo[a]pyrene Administered In the Diet
        to Male and Female Swiss CFW Mice at a Level of 250 ppm ...   14

4-4     Oral Cardnogenldty Testing of Benz[a]anthracene
        Administered  by  Gavage to Male B6AF-] Mice	   16

4-5     Oral Cardnogenldty Testing of D1benz[a,h]anthracene
        Administered  In  the Drinking Water to Male and Female
        DBA/2 Mice	   17

4-6     Cardnogenldty  Testing of Fluorene Administered 1n the
        Diet to Female Buffalo Rats	   18

4-7     Cardnogenldty  Testing of Fluorene Administered 1n the
        Diet to Albino Rats	   19

4-8     Cardnogenldty  of Benzo[a]pyrene to Male Syrian Golden
        Hamsters by Inhalation	   21

4-9     Cardnogenldty  of Benzo[a]pyrene 1n Syrian Hamsters
        Following Intratracheal Administration of 0.10-1.0 mg/week.  .   22

4-10    Cardnogenldty  of Benzo[a]pyrene 1n Syrian Golden
        Hamsters Following Intratracheal Administration of
        18.2-36.4 mg/anlmal 	   23

4-11    Cardnogenldty  Testing of Anthracene 1n Female
        Osborne-Mendel Rats by Lung  Implantation	   25

4-12    Genotoxldty  of  Selected PAH	   27

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                             LIST  OF  ABBREVIATIONS





ADI                     Acceptable dally Intake



AIC                     Acceptable Intake chronic



AIS                     Acceptable Intake subchronlc



BCF                     B1oconcentrat1on factor



bw                      Body weight



CAS                     Chemical Abstract Service



CS                      Composite score



GI                      Gastrointestinal



NOEL                    No-observed-effect level



ppm                     Parts per million



TLV                     Threshold limit value



TWA                     Time-weighted average
                                      x1

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                     1.  ENVIRONMENTAL CHEMISTRY AND FATE

    Polycycllc  aromatic  hydrocarbons  (PAHs)  are a  class  of  compounds  that
are  formed  during the  Incomplete  combustion or  pyrolysls  of  organic  mate-
rials  containing  carbon and  hydrogen.   Several  hundred different  PAHs  have
been  Identified  from combustion and  pyrolysls  sources  (Grimmer,  1983).   In
this  discussion,  only  a few  PAHs  compounds  (containing 2-6  aromatic  rings)
that  occur  most  frequently  1n the  environment  (Grimmer,   1983)  and  also
appear  on  the  U.S.  EPA's  list  of priority  pollutants will  be  considered.
The relevant  physical  and  chemical properties and CAS  Registry numbers  of a
few selected PAHs are given 1n Table 1-1.
    The  half-lives  of  PAHs   In  a  particular   medium  are   not  known  with
certainty.   Based on the available experimental  data,  some  speculation about
the  half-lives  can  be  made.    According to  the  theoretical  predictions  of
Cupltt  (1980) and  the  experimental  work  of  Yamasakl  et  al.  (1982),  the
majority of  naphthalene, phenanthrene,  anthracene,  fluoranthene  and  pyrene
should exist  1n the  vapor phase  1n the  atmosphere.   On the other hand, benz-
[a]anthracene, chrysene,  benzo[a]pyrene (BaP) and  benzo[gh1]perylene  should
exist predominantly  1n  the  partlculate  sorbed phase 1n  the  atmosphere.   The
removal of  PAHs from  the  atmosphere can  occur  through photochemical  reac-
tions,  chemical  reactions  (principally  with OH  radicals,  ozone and  NO }
and  physical  removal mechanisms  (wet  and  dry  deposition).   The  PAHs  that
exist predominantly  1n the  vapor phase  In  the atmosphere (e.g., naphthalene,
phenanthrene,  anthracene,  fluoranthene  and  pyrene)  are  likely  to be  removed
primarily through  direct or  Indirect  photochemical  reactions  (Atkinson  et
al.,  1984;  NAS, 1983;  Mabey  et al.,  1981).  The  half-life for  these  com-
pounds  1n  the atmosphere  should  be <1  day.   The primary  removal  mechanism
                                      -1-

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                                                                   TABLE 1-1
                                    Selected Physical and Chemical Properties and CAS Nunbers of a Few PAHs
Compound
Naphthalene
Phenanthrene
Anthracene
Fluoranthene
Pyrene
i
M Benz[a]anthracene
Chrysene
Benzol a Jpyrene
Benzo(g,h,l]pery1ene
Molecular
Weight
128.16
178.22
178.22
202.24
202.24
228.20
228.20
252.30
276.30
CAS No. Vapor Pressure
(nwHg)
91-20-3 0.082 at 25*C
85-01-8 6. 8x10' • at 20'C
120-12-7 1.95xlO~« at 20'C
206-44-0 5.0x10'* at 25«C
129-00-0 2.5xlO"» at 25»C
56-55-3 101xlO~» at 20*C
218-01-9 6.3xlO'» at 25'C
50-32-8 5,6x10"» at 25*C
191-24-2 1.03x10->« at 25*C
Water Solubility
31.7 mg/l at 25'C
1 mg/kg at 25'C
0.0446 mg/kg at 25*C
0.206 mg/kg at 25*C
0.132 mg/kg at 25'C
9.4 vg/kg at 25 'C
1 .8 vg/kg at 25*C
1.2 yg/kg at 25*C
0.7 vg/kg at 25*C
1*9 *ow3 Bcfb Reference
3.37 146 Mackay et al.. 1980. 1982
4.46 1.230 Wise et al.. 1981;
U.S. EPA, 1980c
4.45 1.210 Wise et al.. 1981;
Mackay ard Shlu. 1977;
U.S. EPA, 1980c
4.90 2.920 Wise et al.. 1981;
U.S. EPA. 1980c;
Mabey et al.. 1981
4.08 2.800 Mabey et al.. 1981;
Wise et al., 1981;
U.S. EPA, 1980c
5.61 11.700 Wise et al.. 1981;
U.S. EPA. 1980c;
Santodonato et al., 1981
5.61 11.700 Wise et al.. 1981;
U.S. EPA. 1980c;
Mabey et al.. 1981
6.06 28.200 Wise et al.. 1981;
U.S. EPA. 1980c;
Mabey et al., 1981
6.51 68.200 Wise et al.. 1981;
U.S. EPA, 1980c;
Mabey et al., 1981
aKow » octanol/water partition coefficient
bBCF - bloconcentratlon factor, values estimated from the equation of Vclth et  al.,  1979

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for benz[a]anthracene and BaP  from  the  atmosphere  1s  likely to be ozonolysls
reactions  (NAS,  1983).  The  expected  half-life  for  this  process 1s likely to
be <1 day.   It  should be  remembered that the reactivities of the participate
sorbed portions  of  the  PAHs  are  strongly dependent  on the materials on which
these  compounds are  sorbed  (Korfmacher  et  al.,  1980).   Depending  on  the
nature of  partlculate matter, the  half-life of partlculate-sorbed  PAHs  may
be  several  days to  a  few weeks.   This Increased stability  of partlculate-
sorbed  PAHs  may permit  these  compounds  to  participate  1n   long  distance
transport.   In   the  absence  of  any  chemical  reactions,  PAHs  may  stm  be
removed from  the atmosphere  by physical removal mechanisms.   In  the case of
BaP,  the  half-life  for  dry  deposition  of partlcle-sorbed  compound  has  been
estimated to be -5.5 days (Cupltt, 1980).
    Data sufficient for assessing the aquatic fate  of PAHs are not available
1n  the  existing literature.   Based  on  the Information  currently available
(Callahan  et al.,  1979;  Mabey   et  al.,  1981), the following  conclusions
regarding the aquatic fate of PAHs can be made.
    The three  likely  mechanisms  that may  be responsible  for  the  removal of
PAHs  from  aquatic  media  are  volatilization,   photochemical   reactions  and
mlcroblal  degradation.   With  the exception  of naphthalene  and  other  PAHs
that  have  relatively  high vapor  pressures,  volatilization Is  not  likely to
be  a   significant   removal  mechanism.   In  the case of  naphthalene,  both
volatilization  and  adsorption may  be quite  competitive,  with  the  dominant
process  being  dictated  by   the  aquatic  conditions.   High  stream and  wind
velocities  could enhance  volatilization,  while high  organic  carbon  content
could  facilitate sedimentation and  the  subsequent  mlcroblal  degradation of
partlcle-sorbed naphthalene.
                                      -3-

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    Photolytlc degradation  of  dissolved PAHs  1s  another mechanism by  which
PAHs can be  removed  from aquatic media.  However, the  sediment-water  parti-
tion coefficients (Mabey et a!., 1981)  for most PAHs  are such that the major
portion of the PAHs  are expected to remain  1n a  partlculate-sorbed  state  1n
water bodies.  In  view of  this,  If one considers the  light  attenuation  and
scattering In  water  bodies  occurring with  Increased depth  and  partlculate
content, photolysis  does not  appear  to be  a  significant  removal  mechanism
for PAHs.
    The  predominant  mechanism  that  1s  likely  to dictate  the fate of  most
PAHs  1n  aquatic  media  Is  sorptlon  onto partlculate  matter   and  subsequent
sedimentation and mlcroblal degradation.  Depending on  the  nature  of  the PAH
and the  characteristics of the  aquatic  medium,  the  half-life  for mlcroblal
degradation  could  range  from  <1 day  to several  years.  Compounds with  <4
cyclic rings are more amenable to mlcroblal degradation  than compounds with
>4 cyclic rings.
    The predominant  mechanism  for  the  removal  of PAHs  from  soils 1s  likely
to be mlcroblal degradation.   Based on  the  assumption that  the potential for
mlcroblal  degradation of PAHs  1s  greater 1n  soils  than 1n  aquatic  systems
(Callahan  et al.,  1979),  the half-life  of PAHs 1n  soils could range  from <1
day to  a few years.   Considering  the soil  sorptlon  coefficient  (Kenaga and
Goring,  1980}  and water  solubilities,   these compounds  are  not  expected  to
have  high mobility  1n  soils.   Therefore,  significant  leaching of  these
compounds  Into  groundwater  1s  not  expected, particularly  from  soils  with
higher organic carbon content.
                                      -4-

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           2.   ABSORPTION  FACTORS  IN  HUMANS AND EXPERIMENTAL ANIMALS
2.1.   ORAL
    Few  quantitative  data  are available  regarding the  oral  absorption  of
PAHs; however, oral absorption of PAHs may be  Inferred  from  the  demonstrated
toxldty  of  PAHs  following  oral  administration  (Smyth et  a!.,  1962;  U.S.
EPA,  1980c,  1981;  Santodonato et  a!.,  1981).   Polycycllc  aromatic  hydro-
carbons  as  a  class are highly I1p1d soluble and  1t  has  been proposed  that
they  readily  absorbed  from the  GI   tract,  primarily  by  passive  diffusion
(Rees  et al., 1971).   In particular, BaP,  chrysene,   and benz[a]anthracene
are reported  to  be readily  transported  across the GI  mucosa  (Rees et  al.,
1971).
    A  somewhat  different  assessment  of  the  oral absorption  of  PAHs  was
tendered by Grimmer (1983)  who generalized  that the mucous  layer  lining the
GI tract may Impede absorption.   Rats  given  BaP by gavage  1n starch solution
(100 mg) or In  the diet (250  mg) absorbed -50% of the  administered compound
(Chang,  1943).   Regardless  of the  type  of  solvent  used,  BaP readily  pene-
trates the  forestomach  epithelium of mice  (Chang, 1943).   In the  glandular
stomach, however,  the type  of  solvent used plays  a decisive role  1n absorp-
tion  of  BaP  (Ekwall  et  al.,  1951;  Setala,  1954).   HydrophlUc  solvents
enhance  the absorption  of BaP from  the  glandular stomach, while  llpophHU
solvents do not modify BaP absorption.  Mitchell and Tu (1979) reported that
an aqueous  suspension of pyrene  was  poorly  absorbed   from  the  gut of  male
Fischer 344 rats.
2.2.    INHALATION
    Limited experimental  data  are available regarding  the pulmonary absorp-
tion of  PAHs;  however, pulmonary  absorption of PAHs may be Inferred from the
demonstrated  toxldty  of  PAHs   following  Inhalation  exposure  (U.S.   EPA,
                                     -5-

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1980c, 1981;  Santodonato  et  al.. 1981).  As  a  class,  PAHs are highly  I1p1d
soluble  and  capable   of  passage  across  epithelial  membranes  (U.S.   EPA,
1980c).   Benzo[a]pyrene,  and  presumably other  PAHs,  are  readily  absorbed
through the  lungs  (Kotln  et  al., 1969;  Va1n1o  et al., 1976).  Mitchell  and
Tu  (1979)  reported  rapid  pulmonary  absorption  of  a pyrene aerosol  (300-500
yg/1  of   air)  by  male  Fischer   344  rats;  widespread  tissue distribution
was seen after 60 minutes  of  exposure.
                                      -6-

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                3.   TOXICITY  IN  HUMANS AND  EXPERIMENTAL ANIMALS
3.1.   SUBCHRONIC
3.1.1.   Oral.  As  reported  1n  the abstract of a  Polish study, Knobloch et
al.  (1969)  administered  acenaphthylene  or  acenaphthene  orally  to rats at  a
dose  level  of 0.6 g  acenaphthylene/kg  bw  1n  olive  oil   for  40 days  or  2  g
acenaphthene/kg bw 1n olive  oil  for  32  days.   Treatment  with  either  compound
resulted  1n  considerable body weight  loss,  unspecified  changes  1n  the
peripheral  blood  pattern, changes  1n  renal   function,  and Increased  serum
amlnotransferase activities.   In addition, rats exposed  to acenaphthene  had
mild morphological damage  to the liver  and kidneys, changes consistent with
mild bronchitis, and localized Inflammation of the perlbronchlal tissue.
    Genetic differences  appear  to  Influence the subchronlc oral  toxlclty of
BaP 1n mice.   Specifically,  the Ah locus, which determines the IndudblHty
of aryl hydrocarbon  hydroxylase, plays  a major role In  determining  the oral
toxlclty  of  BaP,  presumably by Influencing  the  pathways of  blotransforma-
tlon.  Robinson et al. (1975) administered  BaP 1n  the  diet  at  a level  of  120
mg/kg  bw   to   nonresponslve  (poorly  Induclble)  AKR/N   mice  (Ah /Ah   type)
and  to responsive   (markedly   Induclble)  mice (Ah /Ah   type).   Nonrespon-
slve mice developed aplastlc anemia  and  died  within 4  weeks,  whereas respon-
sive mice remained healthy for at least  6 months.
3.1.2.   Inhalation.   As  reported  1n  the  abstract   of a  Russian  study,
Reshetyuk  et  al.  (1970)  observed chronic nonspecific  pneumonia  1n male rats
following  exposure   to  acenaphthylene  at   a  concentration of   18  mg/m3   or
acenaphthene  at  12  mg/ma  for  4 hours/day, 6  days/week, for  5  months.   The
report did  not provide  details concerning control  animals or  experimental
protocol  (U.S. EPA,  1980c).
                                      -7-

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3.2.   CHRONIC
3.2.1.   Oral.   The only  available  chronic  oral  bloassays  for  PAHs  are
Investigations of the carclnogenldty of  BaP  and  d1benz[a,h]anthracene  (U.S.
EPA,  1980c).   The  lack  of  appropriate  protocols  (I.e., nontumor  pathology)
and  detailed  reporting  of  symptoms render  these carclnogenldty  bloassays
Inadequate for use 1n evaluating other endpolnts.
3.2.2.   Inhalation.  Pertinent  data  regarding  the nontumor-related  chronic
toxldty  of  PAHs  administered  by  Inhalation could  not  be  located  In  the
available literature.
3.3.   TERATOGENICITY AND OTHER REPRODUCTIVE EFFECTS
3.3.1.   Oral.  Rlgdon and  Rennels  (1964)  fed female rats a  diet  containing
BaP  at  a  level  of  1000  mg/kg  (equivalent to  50 mg/kg/day)  for  up  to  3.5
months.    Of  seven  pregnant treated  animals, only  one dam carried  viable
fetuses  to term,  delivering four pups on the 23rd day  of pregnancy.  Two  of
the  four   pups  were  stillborn,  one  of  which  was   grossly  malformed  (not
necessarily treatment-related).   A third  pup was killed  for  observational
purposes  and  the  fourth  pup  apparently  died  of  starvation  3  days  after
birth, as the dam did not  show any  signs  of lactation.  The  authors were  not
certain   1f  this  absence of  lactation  was  treatment-related.   At autopsy,
four  dead  fetuses  were  found   1n  the right  uterine horn of  a second  dam.
Signs of  toxldty  (body  weight changes  or hlstopathologlcal  changes)  were
not observed 1n the treated dams.
    In a  teratogenldty  and reproduction study,  Rlgdon and  Neal  (1965)  fed
male and  female mice diets containing BaP at a  level of 0,  250,  500  or  1000
mg/kg over various  time  spans  during  mating,  gestation and  post-partum.   No
apparent  reproductive,  teratogenlc,  embryotoxlc  or  fetotoxlc effects  were
observed 1n the experimental animals.
                                      -8-

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    Mackenzie and  Angevlne (1981) administered  BaP  orally at a  level  of  10
mg/kg  bw  to CD-I mice  during  pregnancy.   There was no effect on  fetal  body
weights  but a  marked  and  specific  reduction  of  gonadal weight  occurred.
Also,  reduced  fertility  and  reproductive capacity  were   reported  among  the
offspring.   At   a   level  of  40  mg/kg/day,   almost  complete  sterility  was
observed 1n both sexes of offspring (Mackenzie and Angevlne, 1981).
3.3.2.   Inhalation.   Pertinent  data  regarding   the  teratogenlc   effects
resulting  from   Inhalation  exposure  to  PAHs  could not   be  located  In  the
available literature.
3.4.   TOXICANT INTERACTIONS
    U.S. EPA  (1980c) has  extensively  described the synerglstk  and  antago-
nistic  Interactions  among  different  PAHs  and  between   PAHs  and  non-PAHs
chemicals.    Briefly,  metabolism  of PAHs  by the  mlcrosomal  mixed  function
oxldase  enzyme   system  yields  several  types  of   reactive and  potentially
carcinogenic Intermediates.   Chemicals that  Induce or  Inhibit   this  enzyme
system alter the  patterns of  PAHs  metabolism and,  hence,  alter  their  toxic
and carcinogenic properties.
                                      -9-

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                             4.  CARCINOGENICITY
    The cardnogenldty  of  PAHs  has been  extensively  tested  by application
to the  skin  of  mice,  and been the  subject  of  only limited Investigation by
other routes of administration.  The studies discussed below were previously
summarized  by   U.S.  EPA  (1983a,b,c,d,e).   More  complete reviews  of  the
cardnogenldty  bloassays of PAHs  are  presented by  IARC  {1973,  1983), U.S.
EPA (1980a,b,c,  1981) and Santodonato et  al.  (1981).
4.1.   HUMAN DATA
    Few case  reports  are available on  the  direct  carcinogenic  effects of
PAHs on humans.  Cottlnl  and Mazzone  (1939)  applied a 1% solution of BaP 1n
benzene to small areas  of exposed  and  unexposed skin of 26 patients.  Up to
120  dally applications  were  applied  over  a  4-month  period.   Regressive
verrucae  developed  1n  all  of  the  26  patients within  this  time.  Although
reversible and  apparently benign,  these changes were  thought  to represent
early  stages  of  neoplastlc   proliferation.    Similar   cases  of  epidermal
changes were reported  by Rhoads  et al.  (1954)  and  Klar  (1938)  1n men acci-
dentally  exposed  to BaP.   Numerous epldemlologlc  studies  of  human popula-
tions  (primarily worker  groups)  have  shown   a  clear  association  between
exposure  to PAHs-conta1n1ng mixtures (soots, tars,  oils, etc.) and Increased
cancer risk (Santodonato et  al.,  1981;  IARC,  1973,  1983;  U.S. EPA, 1981).
4.1.1.   Oral.    Pertinent  data regarding  the  carc1nogen1c1ty  of  pure  PAHs
to  humans following oral exposure  could not  be  located  1n  the available
literature.
4.1.2.    Inhalation.  Pertinent  data  regarding the cardnogenldty  of  pure
PAHs  to  humans  following Inhalation exposure  could not  be  located 1n  the
available literature.
                                     -10-

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4.2.   BIOASSAYS
    The carcinogenic  properties  of  certain PAHs compounds have  been  studied
1n  animals  for more  than 50  years.   The predominance  of  testing has  been
done with  oral,  Inhalation exposures,  mouse  skin assays, Implantations  and
subcutaneous Injections.
A.2.1.    Oral.   Benzo[a]pyrene was  administered  to  mice  1n  the diet  at
various concentrations  to test  Us  cardnogenlclty  (Neal and Rlgdon,  1967;
Rlgdon and  Neal,  1966,  1969).   These  studies  are summarized  1n  Tables  4-1,
4-2 and  4-3.   A dose-response relationship was  noted  for  the  Incidence  of
stomach tumors (paplllomas and carcinomas)  In male and  female  CFW-Sw1ss  mice
treated with  1-250  ppm  BaP  for up  to  197  days (Neal  and   Rlgdon,  1967).
Stomach tumors were reported  1n  animals  treated  with  20,  40,  45, 50,  100 and
250 ppm BaP  (5/23,  1/40,  4/40, 24/34, 19/23 and 66/73,  respectively),  while
control animals  (0/289)  and  those treated with  1,  10 and 30  ppm BaP  (0/25,
0/24 and  0/37,  respectively)  did  not  have  similar  tumors.   An  Increased
Incidence of  lung  adenoma and leukemia was noted  In mice  treated with  250
and 1000 ppm  BaP,  1n  addition to the  Increase  In  stomach tumors  (Rlgdon  and
Neal,  1966,  1969).
    There 1s  no  evidence  that anthracene 1s an  animal  carcinogen 1n  studies
where administration  has  been by the  oral  route.  In  two studies,  Druckrey
and Schmahl (1955)  and  Schmahl and  Relter (unpublished  data), there  were  no
reports of  any  tumor  formation  caused  by the administration  of  anthracene.
No  tumors  were  reported   1n  31   rats  treated with  4.4 g anthracene  (total
dose)  during  a  33-month  study (Schmahl  and Relter,  unpublished).   Druckrey
and Schmahl   (1955)  reported   no  tumors  1n  28  rats  receiving 4.5 g  (total
dose)  anthracene.
                                     -11-

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                                                                            TABLE 4-1
                          Carcinogentelly of Benio[a]pyrene Administered In the Diet to Hale and Female CFW Nice at Levels of 1-250 ppm*
rsj
i

(0.
14.
(B.
(13
(17
(19
(21
(39
(70

Dose
1 ppm
48 mg total dose)
10 p|M
48 mg total dose)
20 ppm
88 mg total dose)
30 ppm
.32 mg total dose)
40 ppm
.76 mg total dose)
45 ppm
.8 mg total dose)
50 ppm
.4-29.4 mg total dose)
100 ppm
.2-48.8 mg total dose)
250 ppm
-165 mg total dose)
0.0 ppm
Duration
of Treatment
110 days
110 days
110 days
110 days
110 days
110 days
107-197 days
98-122 days
70-165 days
NA
Duration
of Study
140 days
140 days
226 days
143-177 days
143-211 days
141-183 days
124-219 days
118-146 days
88-185 days
70-300 days
Purity
of
Compound
NR
NR
NR
NR
NR
NR
NR
NR
NR
NA
Vehicle or
Physical
State
diet
diet
diet
diet
diet
diet
diet
diet
diet
basal diet
only
Target
Organ
stomach
stomach
stomach
stomach
stomach
stomach
stomach
stomach
stomach
stomach
	 : 	 1 	
Tumor Type
paplllomas/carctnomas
paplllomas/carclnomas
papl 1 lomas/carc Inomas
paplllomas/carclnomas
papl 1 lomas/carc Inomas
paplllomas/carctnomas
paplllomas/carclnomas
papt 1 lomas/carc Inomas
paplllomas/carclnomas
paplllomas/carclnomas
Tumor
Incidence
0/25
0/24
5/23
0/37
1/40
4/40
24/34
19/23
66/73
0/289
         •Source:  Adapted from Neal and Rlgdon.  1967
         NA > Not  applicable
         NR « Not  reported

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                                                                   TABIE 4-2
               CarcinogenicIty of Benzo[a]pyrene Administered In the Diet to Male and female Swiss Nice at Levels of 200-1000 ppm*
Dose
1000 ppn
(1 mg/g food)
1000 ppm
(1 mg/g food)
250 ppn
(0.25 rog/g food)
250 ppn
(0.25 mg/g food)
0.0 ppra
Duration
of Treatment
73-83 days
127-187 days
72-99 days
147-196 days
NA
Duration
of Study
73-83 days
127-187 days
72-99 days
147-196 days
111-120 days
Purity
of
Compound
NR
NR
NR
NR
NA
Vehicle or
Physical
State
diet
diet
diet
diet
diet only
Target
Organ
stomach
lung
stomach
lung
stomach
lung
stomach
lung
stomach
lung
Tumor Type
paptlloma/carclnoma
adenoma
papll loma/carc Inoma
adenoma
papll loma/carc Inoma
adenoma
papll loma/carc Inoma
adenoma
papll loma/carc Inoma
adenoma
Tumor
Incidence
5/9
7/9
13/13
3/13
12/5?
26/52
9/13
10/13
2/108
25/108
•Source: Adapted from Rldgon and Neal,  1966
NA ~ Not applicable
NR = Not reported

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                                                 TABLE 4-3

        Carctnogentctty of Benzo[a]pyrene  Administered  In  the  Diet  to Hale and  Female  Swiss  CPU Mice
                                           at  a  Level of 250 ppma


Dose

250 ppm
(0.25 mg/g
food)

0.0 ppm



Duration
of
Treatment
(days)
80-140



NA




Duration
of Study
(days)
80-140



62-300




Purity
of
Compound
NR



NA




Vehicle or
Physical
State
diet



diet only





Target Organ

stomach
lung
hematopoletlc
system
stomach
lung
hematopoletlc
system


Tumor Type

papllloma/carclnoma
adenoma
leukemia

papllloma/carclnoma
adenoma
leukemia


Tumor
Incidence

69/108
52/108
40/108

2/175°
33/151
0/175°

aSource: Adapted from Rldgon and Neal,  1969

DInc1dence of tumors In a control group reported  previously  by  Rlgdon  and  Neal  (1966)

NA = Not applicable

NR = Not reported

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    The  cardnogenldty  of  BaP  has  been  Investigated   1n  mice  following
administration by gavage  (Klein,  1963).   The compound, administered as a  3%
solution  1n  Methocel-Aerosol  O.T.,  was given  1n  0.5 ma doses,  3  times/week
for  5  weeks.    The  Incidence  of  lung  adenomas  and  liver  hepatomas was
elevated  1n animals  terminated  at  either  444  or  547   days;  these  tumor
Incidences are summarized 1n Table 4-4.
    D1benz[a,h]anthracene was  the  first  pure chemical ever shown  to  produce
tumors  1n  animals.   Many  early  studies  showed  a   carcinogenic  effect  In
animals  when d1benz[a,h]anthracene was  administered orally,  subcutaneously
or  applied   to the  skin  (IARC, 1973;  U.S. EPA,  1980c).   Snell and  Stewart
(1962,  1963) reported  on  the  tumorlgenlc activity  of  d1benz[a,h]anthracene
after  Its oral  administration 1n  groups of  male  and  female DBA/2  strain
mice.   An  olive oil  emulsion  containing 0.2  mg/mi  d1benz[a,h]anthracene
was used  as  a replacement  for  drinking water.   An  average  dally dose  of 0.76
mg  d1benz[a,h]anthracene  for  females  and  0.85 mg d1benz[a,h]anthracene  for
males  was  determined  from  fluid   consumption  volumes.   Among the  animals
surviving  at  200  days,   27/27  developed  pulmonary   adenomatosU,   24/27
developed carcinoma of the lung and 16 had hemang1oendothel1omas.   Among  the
surviving females,  12/13  developed  mammary  carcinomas. Among 29  controls,
one  case of pulmonary  adenomatosls   was  reported.    No   other  tumors  were
reported  1n  the  control  group.   These  tumor  Incidences  are  summarized  1n
Table 4-5.
    Chronic  administration  of  fluorene 1n the diet  at  levels of  0.05-0.5%
did not  result  1n  a significantly  Increased  Incidence of  tumors  1n  rats  at
any site  (Wilson et al.,  1947;  Morris et a!., 1960),  but  the data  1n  one
study  (Wlson  et al.,  1947)  was  Inadequately  reported.   These studies are
summarized 1n Tables  4-6 and 4-7.
                                     -15-

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                                                  TABLE  4-4
        Oral Carclnogenlclty Testing of Benz[a]anthracene Administered by Gavage to Hale B6AF-) Mice*
Dose or
Exposure
0.5 ml
3X solution
0.5 ml
O.OX solution
0.5 mi
3X solution
0.5 mi
O.OX solution
Duration
of Treatment
5 weeks,
3 doses/week
5 weeks,
3 doses/week
5 weeks,
3 doses/week
5 weeks,
3 doses/week
Duration
of Study
444 days
441 days
547 days
547 days
Purity
of
Compound
NR
NA
NR
NA
Vehicle or
Physical
State
Hethocel-
Aerosol
O.T.
Methocel-
Aerosol
O.T.
Methocel-
Aerosol
O.T.
Methocel-
Aerosol
O.T.
Target
Organ
lung
liver
lung
liver
lung
liver
lung
liver
Tumor
Type
adenoma
hepatoma
adenoma
hepatoma
adenoma
hepatoma
adenoma
hepatoma
Tumor
Incidence
37/39
18/39
10/38
0/38
19/20
20/20
6/20
2/20
*Source: Adapted from Klein, 1963
NA = Not applicable
NR = Not reported

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                                                 TABLE 4-5

                     Oral Carclnogenldty  Testing  of  D1benz[a,h]anthracene Administered
                            In  the  Drinking Water  to  Hale  and  Female DBA/2 M1cea
Dose or Duration
Exposure of
Treatment
0.2 mg/mt 258 days
(0.76-0.85
mg/day)


0.0 mg 259 days




0.48-0.56 167 days
mg/day



Duration Purity Vehicle or
of Study of Physical
Compound State
258 days NR olive oil
emulsion



289 days NA olive oil
emulsion
only


167 days NR olive oil
emulsion
only


Target Organ
lung

mammary gland
mesentery/
pancreas/lymph
lung

mammary gland
mesentery/
pancreas/lymph
lung

mammary gland
mesentery/
pancreas/lymph
Tumor Type
adenoma
carcinoma
mixed
hemangloendothel loma

adenoma
carcinoma
mixed
hemangloendothel loma

adenoma
carcinoma
mixed
hemangloendothel loma

Tumor
Incidence
27/27
24/27
12/13b
16/27

1/35
0/35
0/35
0/35

7/19
15/19
3/9b
6/19

aSource: Adapted from Snell and Stewart.  1962,  1963

blnc1dence of mammary tumors stated for  female  mice;  none occurred  In  males.

NA = Not applicable

NR = Not reported

-------
                                                                   TABU 4-6
                              Carcinogenic Ity  Testing of Fluorcne Administered  In the Diet to Female Buffalo Rats'
Dose or Duration of
Exposure Treatment
4.6 mg/dayb 18.1 months
(range. 4.1-19.2)



0 ing/day NA



i
00
4.3 mg/dayb 6.1 months
(range. 5.0-6.2)


0 mg/day NA


Duration of Study
19.0
(range.



15.5
(range,




10.2
(range.


13.9
(range.

month
-------
                                                 TABLE  4-7

                CardnogenlcUy Testing of Fluorene Administered In the Diet to Albino Rats*
Sex
NR
NR
Dose or
Exposure
0.062-1. OX
0.125, 0.25
or 0.5X
Duration
of
Treatment
104 days
453 days
Duration
of Study
104 days
453 days
Purity
of
Compound
NR
NR
Vehicle or
Physical
State
diet
diet
Effects
Organs appeared grossly
hlstologlcally normal
Squamous metaplasia of
bronchial epithelium

and
the
In
                                                                             three rats.   One rat on  the
                                                                             0.125X  diet  showed  a  small
                                                                             kidney  tubular  adenoma  of  a
                                                                             type  not  seen before In  the
                                                                             rat colony.
'Source: Adapted from Wilson et  al.,  1947

NR = Not reported

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4.2.2.   Inhalation.   Thyssen  et al.  (1981)  exposed groups  of 24  hamsters
by  Inhalation  to BaP at  levels  of  2.2,  9.5 or 46.5 mg/m3  for  4.5  hours/day
for  10 weeks,  and  3  hours/day thereafter, 7  days/week  for up to  675  days.
This  study Is  summarized 1n  Table  4-8.   No  treatment-related tumors  were
observed  1n animals  exposed  to  2.2  mg/m3.   Animals exposed  to 9.5  mg/m3,
however, developed  tumors of  the nasal  cavity (12%),  larynx  (31%),  trachea
(4%)  and  pharynx (2354).  Hamsters  exposed to BaP at a  level  of 46.5  mg/m3
also  developed  tumors of the  respiratory  tract  (13/25)  and upper  digestive
tract  (14/25).    No  tumors  of  these types  were  seen  1n control  animals
(Thyssen et al., 1981).
    Intratracheal administration  of  BaP resulted  1n an Increased  Incidence
of  respiratory  tract  neoplasms 1n both  sexes  of Syrian hamsters  (Ketkar  et
al., 1978;  Feron and  Kruysse,  1978).   These studies  are  summarized  1n Tables
4-9  and  4-10.    A  dose-related  response  was  reported  for  hamsters  treated
with  18.2   and  36.4  mg/anlmal  (total  dose)  for  52  weeks,   followed  by  a
29-week latency period.   The Incidence of  trachea! paplllomas  and  carcinomas
collectively with  lung  adenomas  was   4/29  and 3/27 for  low-dose males  and
females, respectively,  and  19/30 and  7/24  for high-dose males and  females,
respectively (Feron  and  Kruysse,  1978).   Ketkar  et al.  (1978)  reported  a
high dose-related mortality  1n hamsters  treated at  dose levels higher  than
those  used  by Feron  and Kruysse (1978).   Mean survival  times  ranged  from  40
weeks  for  male  hamsters  treated with  0.1  mg  BaP/week  to 10 weeks  for  males
treated with 1.0  mg BaP/week.   An  Increase 1n the  Incidence  of  respiratory
tract  carcinoma, adenoma  and papHloma was reported  1n  treatment groups  for
both males  and females,  but a  definite dose-related  response was  not  evident
(Ketkar et al.,  1978).
                                     -20-

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                                                                             TABLE  4-8
                                        Carcinogen Icily of Benzol a]pyrene to Hale Syrian Golden Hamsters Via Inhalation*.b
i
rsj
Dose
2.2 mg/m»
(29 mg total dose)
9.5 »g/m»
(127 mg total dose)
46.5 mg/m«
(383 mg total dose)
0.0 mg/m*
Duration Duration
of of Study
Treatment
95.2 weeks 95.2 weeks
96.4 weeks 96.4 weeks
59.5 weeks 59.5 weeks
NA 96.4 weeks
Purity
of
Compound
NR
NR
NR
NA
Vehicle or
Physical
State
NaCl vapor
In air
Had vapor
In air
Nad vapor
In air
NaCl vapor
only
Target Organ
respiratory tract
upper digestive
tract
respiratory tract
upper digestive
tract
respiratory tract
upper digestive
tract
respiratory tract
upper digestive
tract
Tumor
Typec
tumors
tumors
tumors
tumors
tumors
tumors
tumors
tumors
Tumor
Incidence
0/27
0/27
9/26*1
7/26d
13/25«
14/?5e
0/27
0/27
          'Source:  Adapted  from Thyssen et al., 1981
          ^Exposure was  for  4.5 hours/day for the first 10 weeks. 3 hours/day thereafter for 7 days/week.
          cTumors were paplllomas, papillary polyps, and squamous cell carcinomas.
          ^3  nasal  cavity.  B laryngeal. 1 tracheal, 6 pharyngeal and 1 forestomach tumors
          el  nasal  cavity,  13 laryngeal, 3 tracheal, 14 pharyngeal, 2 esophageal and 1 forestomach tumor
          NA  - Not  applicable
          NR  - Not  reported

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                                                                            TABLE 4-9
                         Carclnogenlclty of Benzo[a]pyrene In Syrian Hamsters  Following Intratrachea! Administration of 0.10-1.0 mg/weeka
OJ
Sex
N
r
N
r
N
F
H
F
Duration Duration Purity
Dose of of of
Treatment" Study0 Compound
0.10 mg/week 40 weeks 40 weeks 97X
0.10 mg/week 34 weeks 34 weeks 97X
0.33 mg/week 24 weeks 24 weeks 97X
0.33 mg/week 28 weeks 28 weeks 97X
1.0 mg/week 10 weeks 10 weeks 97X
1.0 mg/week IS weeks IS weeks 97X
0.0 mg/week 41 weeks 41 weeks NA
0.0 mg/week 35 weeks 3S weeks NA
Vehicle or
Physical
State
bovine
albumin
bovine
albumin
bovine
albumin
bovine
albumin
bovine
albumin
bovine
albumin
bovine
albumin
only
bovine
albumin
only
Target Organ
respiratory tract
respiratory tract
respiratory tract
respiratory tract
respiratory tract
respiratory tract
respiratory tract
respiratory tract
Tumor Typec
various neoplasms
various neoplasms
various neoplasms
various neoplasms
various neoplasms
various neoplasms
various neoplasms
various neoplasms
Tumor
Incidence
5/26
12/30
7/29
10/28
6/27
6/30
0/29
0/30
         aSource: Adapted  from Ketkar et al.. 1978
         t>Hean Survival Time
         cCarc1nomas. adenomas, adenocarctnomas and paplllomas were reported.
         NA * Not applicable

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                                                                  TABLE 4-10                                            '
           Carclnogenlclty of Benzo[a]pyrene In Syrian Golden Hamsters Following Intratracheal  Administration of  18.2-36.4 mg/anlmal*
Sex
N

H

H


F

F

F


Dose
18.2 mg/hamster
total dose
36.4 mg/hamster
total dose
0.0 mg/hamster
total dose

IB. 2 mg/hamster
total dose
36.4 mg/hamsler
total dose
0.0 mg/hamster
total dose

Duration of Duration
Treatment of Study
52 weeks 81 weeks
(1 dose/week)
52 weeks 81 weeks
(1 dose/week)
52 weeks 81 weeks
(1 dose/week)

52 weeks 81 weeks
(1 dose/week)
52 weeks 81 weeks
(1 dose/week)
52 weeks 81 weeks
(1 dose/week)

Purity Vehicle or
of Physical
Compound State
>99X 0.9X NaCl

>99X 0.9X NaCl

>99X saline
vehicle
only
>99X 0.9X NaCl

>99X 0.9X NaCl

>99X saline
vehicle
only
Tumor
Target Organ Typeb
respiratory tract various

respiratory tract various

respiratory tract various


respiratory tract various

respiratory tract various

respiratory tract various


Tumor
Incidence
4/29

19/30

0/30C


3/27

7/24

0/28C


'Source: Adapted from Feron and Kruysse,  1978
bpapniomas and carcinomas of the trachea and pulmonary ademonas were most prevalent.
eCombined tumor Incidence of untreated and  vehicle controls.

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    In a  study  by Stanton et al.  (1972),  0.5  mg anthracene In 0.05 ml  warm
soft  1:1  wax-tr1capry!1n  was  Implanted   1n  the lung  by  a  thoracotomy  In
Osborne-Mendel  female  rats  (3-6 months old).   No epidermal carcinomas  were
reported  In  the 55-week study; however,  there  was  a granulomatous  reaction
1n  all  of  the  37  examined  animals.   No  tumors were  seen   In  10  control
animals.  This study 1s summarized 1n Table 4-11.
4.2.3.   Mouse  Skin  Assays.    Many  of  the  polycycllc   aromatlcs   produce
tumors In mouse skin when applied  topically alone  or 1n  combination with  a
promoter.   As  a result  of  the route  of  administration,   these studies  have
limited utility for  quantitative  risk  assessment.  However,  they  provide
useful  qualitative  data  which can  be used  to  estimate relative  potency.
U.S.  EPA  (1982)  has used  skin painting  data  on  five  PAHs  [dlbenzo(a.h)-
anthracene;  benzo(a)anthracene,  1ndeno(l,2,3-c,d)pyrene;  chrysene;  benzo(b)-
fluoranthene] tested  using  similar protocols to  qualitatively  compare  their
potency to BaP.  The  overall  ranking was  as  follows:  BaP  > DBA >  BbF >  BaA >
IP > chrysene.  This  type of  analysis  becomes  especially  Important  when risk
assessment estimates  for  PAHs as  a  class  are  attempted.   In addition  to
these compounds which  were  tested  using  similar protocols  (anthanthrene),
benzo(1)fluranthene,   7,l2-d1methylbenze(a)anthracene,    d1benzo(a,b)pyrene,
d1benzo(a,e)pyrene,   d1benzo(a,h)pyrene,  d1benzo(a,1)pyrene  have  all   been
shown to  have some  degree of  carcinogenic  activity  when tested 1n mouse skin
(CRC, 1983)  using various protocols (IARC, 1973).
    In addition,  PAHs containing mixtures have  been  found to  show  carcino-
genic acltlvHy  In  mouse skin Including:   crude  coal  tar,  blast furnace tar,
soot  extracts,  oil   shale  extracts, cigarette  smoke condensates,  petroleum
pitch, automobile exhaust (CRC, 1983; IARC, 1973).
                                     -24-

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                                                     TABLE 4-11


              Carclnogenlclty Testing of  Anthracene  In Female Osborne-Hendel  Rats  by Lung  Implantation*
en
l
Dose or
Exposure
0.5 mg
0.10 mi
vehicle
Duration of
Treatment
single Implant
single Implant
Duration
of Study
55 weeks
81 weeks
Purity of
Compound
refined
recrystalllzed
NA
Vehicle or
Physical
State
1:1 wax-
trlcaprylln
1:1 wax-
trlcaprylln
Target
Organ
trachea
trachea
Tymor Type
eptdermold
carcinoma
epldermold
carcinoma
Tumor
Incidence
0/37
0/10
    *Source: Adapted  from Stanton et al., 1972


    NA = Not applicable

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4.2.4.   PAH Containing Mixtures.   A  number  of occupational  exposure  situa-
tions  Involving  PAH  containing  mixtures  have been linked  to  Increased Inci-
dence  of  cancer  1n exposed  humars.   Exposure of chimney  sweeps  to  soot  and
coal tar has been  associated with  Increased  scrotal  cancer.   Increased Inci-
dence  of bronchial carcinoma has been  noted  1n  gasworkers  and coking workers
(CRC,  1983);  Increased skin  cancer  1n  workers  1n  the coal  tar and pitch
Industry  (IARC,  1973).   Soots,  coal-tars,   creosote  oils,  shale oils  and
cutting oils  have  been shown  to  be  carcinogenic 1n animals  following  skin
painting or  subcutaneous  Injection (IARC, 1973).  Diesel  exhaust condensate
and gasoline engine  exhaust  condensate have been shown  to cause  skin tumors
when topically applied to  mice (CRC, 1983).
4.3.   OTHER RELEVANT DATA
    A  large number of  short-term genotoxlclty  tests  have been performed  with
PAHs.  Qualitative  Indications  of  selected PAHs  genotoxlclty are summarized
1n Table 4-12.   Many  of  the PAHs  that have shown positive results 1n one or
more J[n  vitro  genotoxlclty  screening  tests have given negative  results  In
animal bloassays  (Santodonato  et  al.,  1981;  IARC,  1973,  1983; U.S.  EPA,
1981).
4.4.   WEIGHT OF EVIDENCE
    Certain  PAHs  have  demonstrated  a   carcinogenic  response  by  various
routes, while  others  are  considered  to  be noncarclnogenlc or  have  not  been
tested extensively.
                                     -26-

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                                  TABLE 4-12

                         Genotoxldty  of  Selected  PAHa
          PAH
Positive Result 1n at Least One Genotoxldty Assay
Anthanthrene
Anthracene
Benz[c]acr1d1ne
Benz[a]anthracene
Benzo[b]fluoranthene
Benzofbjfluorene
Benzo[g,h,1]perylene
Benzo[a]pyrene
Benzo[e]pyrene
Carbazole
Chrysene
Coronene
Cyclopenta[c,d]pyrene
D1benz[a,h]acr1d1ne
D1benz[a,j]acr1d1ne
D1benz[a,c]anthracene
D1benz[a,h]anthracene
7H-D1benzo[c,g]carbazole
D1benz[a,h]pyrene
D1benzo[a,1]pyrene
1,4~D1methylphenanthrene
Fluoranthene
Fluorene
1-Methylphenanthrene
Perylene
Phenanthrene
Pyrene
Trlphenylene
aSource: Adapted from IARC,  1983

^Positive for cardnogenlclty 1n at least one animal  bloassay

cNegat1ve for cardnogenlclty 1n rats fed fluorene In the diet
                                     -27-

-------
    IARC (1983)  has  evaluated  selected PAHs based  on  the overall weight of

evidence of  cardnogenlcHy . to humans.   These classifications  range  from

Group 2A (BaP)  and  2B  meaning  that the compound 1s probably carcinogenic 1n

humans to Group 3 which  Indicates  that  there 1s  only limited animal  evidence

or a paucity of evidence such that  the  data base 1s  Inadequate  to  assess the

human carcinogenic  potential.   Some  of these  classifications  are based on

routes of exposure other than oral  and  Inhalation.  As a  class,  PAH-conta1n-

1ng soots,  tars and oils are most  appropriately  classified as Group  1  {IARC,

1983).  Applying the criteria proposed  by  the Carcinogen  Assessment  Group of

the U.S. EPA  (Federal  Register, 1984)  for evaluating  the overall weight of

evidence for  human  cardnogenlclty,  these chemicals  are most  appropriately

classified  In Group A.

    IARC has Judged  the  following  specific PAHs to be probably  carcinogenic

In  humans,  there  being  sufficient  animal  evidence  and or  limited  human

evidence.   The  corresponding   U.S.  EPA  grouping   (Federal  Register,  1984)

would be Group 81 or B2,  depending on the quality of the  evidence.


    1.  benz[a]anthracene
    2.  benzo[b]fluoranthene
    3.  benzo[JJfluoranthene
    4.  benzo[k]fluoranthene
    5.  benzo[a]pyrene
    6.  d1benz[a,h]acr1d1ne
    7.  d1benz[a,j]acr1d1ne
    8.  d1benz[a,h]anthracene
    9.  7H-d1benzo[c,g]carbazole
    10. d1benzo[a,e]pyrene
    11. d1benzo[a,h]pyrene
    12. d1benzo[a,1]pyrene
    13. d1benzo[a,l]pyrene
    14. 1ndeno[l,2,3-cd]pyrene
                                     -28-

-------
Further,  the  following  compounds have  limited  animal  evidence for cardno-

genldty,  however,  the evidence according to IARC 1s Inadequate for making a

definitive   statement  about  the  human  carcinogenic  potential.   The  appro-

priate U.S. EPA  classification  (Federal  Register,  1984) for these chemicals

1s Group  C-Poss1ble Human Carcinogen.


    1.  anthanthrene
    2.  benz[c]acr1d1ne
    3.  carbazole
    4.  chrysene
    5.  cyclopenta[c,d]pyrene
    6.  d1benz[a,c]anthracene
    7.  d1benz[a,j]anthracene
    8.  d1benzo[a,e]fluoranthene
    9.  2 and  3-methylfluoranthenes
                                     -29-

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                     5.   REGULATORY  STANDARDS AND CRITERIA

    Exposure criteria and  TLVs have been  developed  for PAHs as a  class,  as
well  as  for  several  Individual  PAHs.   The  U.S.   Occupational  Safety  and
Health  Administration  (OSHA)  has set  an 8-hour TWA concentration  limit  of
0.2  mg/m3  for  the  benzene-soluble fraction  of  coal   tar  pitch  volatlles
(anthracene, BaP, phenanthrene, acrldlne,  chrysene,  pyrene)  (Code  of Federal
Regulations, 1981).  NIOSH  (1977)  recommends  a concentration  I1ra1t  for  coal
tar,  coal  tar  pitch,  creosote  and mixtures  of  these  substances  at  0.1
mg/m3 of  the cyclohexane-extractable fraction  of  the  sample,  determined  as
a  10-hour  TWA.   NIOSH  (1977)  concluded  that  these  specific   coal   tar
products, as well as coke  oven emissions, are  carcinogenic  and can Increase
the risk  of  lung and skin cancer  In workers.   NIOSH  (1977) also recommends a
celling  limit   for  exposure  to  asphalt  fumes  of  5  mg  airborne  partlcu-
lates/m3 of air.
    Environmental  quality  criteria  for  PAHs  have  been  recommended   for
ambient water, which specify  concentration  limits  Intended to protect humans
against  adverse  health  effects.    The  U.S. EPA  (1980c)  has  recommended  a
concentration  limit  of  28  mg/a.  for  the  sum  of  all  carcinogenic  PAHs  1n
ambient water.   This  value  Is  based on a mathematical  extrapolation of the
results from studies with mice  treated  orally  with  BaP, and acknowledges the
conservative assumption  that  all  carcinogenic  PAHs  are equal  1n  potency  to
BaP.   Dally consumption of  water  containing  28 mg/8.  of  carcinogenic  PAHs
over  an entire lifetime  1s  estimated,  on  the  basis of the  animal  bloassay
data,  to  keep the  lifetime  risk of cancer  development below  one  chance  In
100,000.
                                     -30-

-------
    The U.S. EPA  has  not  recommended an ambient water  quality  criterion  for
noncardnogenlc PAHs as a class.  U.S.  EPA  (1980b)  has  recommended,  however,
an  ambient  water quality  criterion for  fluoranthene of  42  vg/8., which  1s
based  on  the extrapolation  of  results from  chronic  toxlclty tests  1n  mice
that received fluoranthene by repeated  application  to  the  skin.   In  deriving
this criterion for fluoranthene, the U.S. EPA  (1980b)  acknowledged that  data
suitable for quantitative risk  assessment of  noncardnogenlc  PAHs  are essen-
tially  nonexistent.   An ambient  water quality  criterion  of  0.02 mg/a  for
acenaphthene has  been recommended  by  the  U.S. EPA  (1980a)  on the basis  of
organoleptlc properties.
                                     -31-

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                              6.   RISK  ASSESSMENT
6.1.   ACCEPTABLE INTAKE SUBCHRONIC (AIS)
    Some  Individual  PAHs have  been  shown to  be  carcinogenic 1n  humans  and
others to be carcinogenic to  animals.   Data  are available  regarding BaP from
which  carcinogenic  potency can  be estimated.  It  1s  Inappropriate,  there-
fore, to calculate an AIS for  these chemicals.
6.2.   ACCEPTABLE INTAKE CHRONIC (AIC)
    Some  Individual  PAHs have  been  shown to  be  carcinogenic 1n  humans  and
others to be carcinogenic to  animals.   Data  are available  regarding BaP from
which  carcinogenic  potency can  be estimated.  It  1s  Inappropriate,  there-
fore, to calculate an AIC for  these chemicals.
6.3.   CARCINOGENIC POTENCY (q^)
    A  unit   risk for  carc1nogen1c1ty  1s presented  on  the basis  that  an
assumption  (risk  management decision)  Is made to consider  PAHs  carcinogenic
to humans as a  class of compounds or  that  Individual  compounds  are carcino-
gens  for  humans.   This assumption  (decision)  must  be made prior  to  the  use
of the  unit risk value.  Because  of  the relative paucity of PAHs  data that
1s useful for  potency estimation, the estimation of the unit risk  Is  based
upon the data from a single PAH compound, BaP.
    As U.S.  EPA  (1982)  states,  on the  basis of currently  available data, If
the cumulative PAHs  exposure  1s less  than or  equal  to  the  criterion  for  BaP
the  resultant  risk  should  be  <10~5.   If the  cumulative  exposure to  other
PAHs exceeds the  criterion level  recommended for  BaP,  the  resultant risk  may
exceed  10~5.   It  should be  stated that this approach  to  risk  assessment
Ignores  the possibility  of  carcinogenic synerglsm  of PAHs.   Practically,
however,  1t  seems  likely that the potential for  synerglsm  Is far  outweighed
by the difference In carcinogenic potency between  BaP and other  PAHs.
                                     -32-

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    Exposure  to any  single  PAH compound  1n  occupational  or  envronmental
situations  Is  unlikely  to  occur.   Exposures are  expected to be  to  complex
mixtures with varying PAH constituents.   LHtle  1s  known  at  present  concern-
Ing potential Interaction of components 1n these complex mixtures.
6.3.1.   Oral.  To protect  for  carcinogenic  effects of all  PAHs,  a  carcino-
genic  potency  factor  for   humans,  q *,  can  be  derived   from  the study  of
Neal and Rlgdon (1967), 1n  which  BaP  at dose levels of 1-250 ppm 1n  the diet
was fed  to  strain  CFW mice for -110  days.   This  approach to criterion deri-
vations  adopts  the conservative  assumption that  all  carcinogenic PAHs  are
equal In potency to BaP.  The  Incidences  of  stomach tumors (mostly squamous-
cell paplllomas but some  carcinomas)  were 0/289  for controls, 0/25 at the 1
ppm (0.13 mg/kg/day)  level, 0/24 at  10 ppm (1.3 mg/kg/day), 1/23 at  20  ppm
(2,6 mg/kg/day), 0/37 at  30 ppm (3.9 mg/kg/day),  1/40  at 40 ppm (5.2 mg/kg/
day), 4/40  at  45  ppm  (5.85  mg/kg/day), 24/34  at 50  ppm  (6.5  mg/kg/day),
19/23 at  100 ppm  (13.0 mg/kg/day) and 66/73 at  250  ppm (32.5  mg/kg/day).
U.S.  EPA  (1980c)  used  these  Incidences  of  stomach tumors  to  derive  a  q *
of  11.53  (mg/kg/day)"1,  using the multistage  model of Crump adopted  by  the
U.S.  EPA  (Federal  Register,  1980)  for  computation of  carcinogenic  potency.
The data base from which this  q,* was  derived 1s presented 1n Appendix B.
6.3.2.   Inhalation.    Adopting  the  same  conservative  approach  as  taken
above for oral  exposure  to  carcinogenic PAHs, a  carcinogenic potency factor
for humans,  q,*,  can be  derived from  the  study  of  Thyssen et al.  (1981),
1n  which  Syrian golden hamsters  were  exposed  to BaP  by  Inhalation.   These
animals were  exposed  at levels  of  0,  2.2,   9.5  or 46.5  mg/m3 for  59.5-96.4
weeks.  The  Incidences  of  respiratory  tumors were  0/27  for controls,  0/27
for the low-dose group, 9/26  for  the  mid-dose  group,  and  13/25  for the high-
dose  group.   Because  of  early mortality  1n the  highest dose  group,  these
                                     -33-

-------
data  were  excluded  from  the  q,*  derivation.   Based  on  the  respiratory
tumor response  of  male hamsters, and  using  the linearized multistage  model
adopted  by  the U.S.  EPA  (Federal  Register,  1980),  a carcinogenic  potency
factor   (q,*)  of  6.11  (mg/kg/day)"1  can  be  derived   for   humans.    The
corresponding  dose associated  with  an  Increased  lifetime cancer  risk  of
10~s  1s  2.339xlO~s  mg/kg/day   or   1.64xlO~«  mg/day  for  a  70  kg  human.
Complete data for  derivation of  the q * are presented 1n  Appendix C.
                                     -34-

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                                7.   REFERENCES

Atkinson,  R.,  S.M.  Aschmann  and  J.N.  PHts,  Jr.   1984.   Kinetics  of  the
reactions  of  naphthalene  and blphenyl  with OH  radicals  and 0- at 294ileK.
Environ. Scl. Technol.   18:  110-113.

Callahan,  M.A.,   M.W.   SUmak,  N.W.  Gabel,  et  al.   1979.   Water-Related
Environmental  Fate  of   129  Priority  Pollutants.  Vol.  II.   Office  of  Water
Planning  and Standards,  Office of  Water  and  Waste  Management,  U.S.  EPA,
Washington, DC.  EPA 440/4-79-0295.

Chang, L.H.  1943.  The fecal excretion of  polycycllc  hydrocarbons  following
their  administration   to  the  rat.    J.   B1ol.  Chem.   151:  93.   (Cited  1n
Grimmer, 1983)

Code of  Federal  Regulations.   1981.   OSHA Safety and  Health Standards.   CFR
Vol. 29, Para. 1910.1000.

Cottlnl,  G.B.  and  G.B.  Mazzone.   1939.   The effects  of 3,4-benzpyrene  on
human skin.  Am.  J. Cancer.   37: 186.  (Cited 1n  U.S. EPA, 1983c)

CRC   Press.    1983.     Environmental    Carcinogens:   Polycycllc   Aromatic
Hydrocarbons.  G. Grimmer, Ed,  CRC  Press Inc.  Boca  Raton, FL.   p.  261.

CupUt, L.  1980.   Fate of Toxic and Hazardous Materials  1n  the A1r Environ-
ment.   Environmental  Sciences   Research  Laboratory,  Office  of  Research  and
Development, U.S.  EPA,  Research Triangle  Park, NC.   EPA  600/3-80-084.   NTIS
PB 80-221948.
                                     -35-

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Druckrey,  H.  and  D.  Schmahl.    1955.   Cancerogenlc  effect  of  anthracene.
Naturwissenschaften.  42: 159-160.  (Cited 1n U.S. EPA, 1983a)

Ekwall,  P.,  P.  Ermala,  K.  Setala and L.  Sjoblom.   1951.   Gastric absorption
of  3,4-benzpyrene.   II.  The  significance of the  solvent  for  the  penetration
of  3,4-benzpyrene  Into  the stomach wall.   Cancer Res.   11:  758.   (Cited  In
Grimmer, 1983)

Federal  Register.   1980.   Appendix C '—  Guidelines  and  Methodology  Used  In
the Preparation  of  Health  Effects Assessment Chapters of  the Consent Decree
Water Criteria Documents.  Federal Register.  45(231): 79347.

Federal  Register.    1984.   Environmental   Protection   Agency.    Proposed
guidelines    for  carcinogenic   risk  assessment.   Federal   Register.    49:
46294-46299.

Feron, V.J.  and  A.  Kruysse.   1978.   Effects of exposure  to  furfural vapour
1n  hamsters  simultaneously  treated  with  benzo[a]pyrene or dlethylnltros-
amlne.  Toxlcol.   11: 127-144.   (Cited 1n U.S.  EPA,  1983c)

Grimmer, G.   1983.   Environmental  Carcinogens:  Polycycllc   Aromatic  Hydro-
carbons.  Chemistry,  Occurrence,  Biochemistry, Cardnogenldty.   CRC Press,
Inc., Boca  Raton, FL.  p. 27-60.

IARC  (International  Agency for  Research on Cancer).   1973.   Certain  poly-
cycllc  aromatic  hydrocarbons  and  heterocycllc  compounds.   In:   IARC  Mono-
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                                     -36-

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IARC  (International  Agency  for  Research  on  Cancer).   1983.   Polynuclear
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                                     -37-

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Korfmacher, W.A., E.L. Wehry, G. Mamantov and D.F.S. Natusch.   1980.   Resis-
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                                     -38-

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                                     -39-

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Reshetyuk,  A.L.,  E.I.  Talaklna  and  P.A.  En'yakova.   1970.   Toxlcologlcal
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                                     -41-

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U.S. EPA.   1983e.   Review of Tox1colog1c  Data  1n Support of Evaluation  for
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                                                 APPENDIX  A

                                           Summary Table  for PAH
Carcinogenic
Potency
Inhalation
Oral
Species Experimental
Dose/Exposure
hamsters 2.2-9.5 mg/m»
mice 1-250 ppm
Effect
respiratory
tract tumors
stomach
tumors
Unit Risk or q-|*
6.11
(mg/kg/day)-»a.b
11.53
(mg/kg/day)~ia.b
Reference
Thyssen et al. ,
1981
Neal and
Rlgdon, 1967'
U.S. EPA, 1980c
aUses carcinogenic potency of benzo(a)pyrene

bThese values  require  that  an explicit decision be made  which  assumes that the compound  or  compounds  are
 likely to be  human carcinogens  Irrespective of the scientific uncertainty 1f any,  regarding this  assump-
 tion.

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                                  APPENDIX B
                    Cancer  Data  Sheet  for  Derivation of q-j*
Compound:  Benzo[a]pyrene
Reference:  Neal and Rlgdon, 1967
Species, strain, sex:  mice, CFW, male and female
Body weight:  0.034 kg (assumed)
Length of exposure (le) * 110 days
Length of experiment (Le) = 183 days
Llfespan of animal (L) = 630 days
Tumor site and type:  stomach, squamous cell carcinomas and paplllomas
Route, vehicle:  oral, diet
Experimental Doses
or Exposures
(ppm)
0
1
10
20
30
40
45
50
100
250

Transformed Dose
(mg/kg/day)
0
0.13
1.3
2.6
3.9
5.2
5.85
6.5
13.0
32.5
Input
Incidence
No. Responding/No. Tested
(or Examined)
0/289
0/25
0/24
1/23
0/37
1/40
4/40
24/34*
19/23*
66/73*
*These data not used because of lack of fit to multistage model.
                                     -47-

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                                  APPENDIX C
                    Cancer  Data  Sheet  for  Derivation of q-j*

Compound:  Benzo[a]pyrene                                 "'
Reference:  Thyssen et a!., 1981
Species, strain, sex:  hamsters/Syrian golden/male
Body weight:  0.12 kg (assumed)
Length of exposure (le) =  666.4  days for  lower  dose  and  674.8  days  for
                           higher dose and controls
Length of experiment (Le) = 666.4  days  for  lower dose  and 674.8  days  for
                            higher dose and controls
Llfespan of animal (L) = 666.4 days for lower dose and 674.8 days  for  higher
                         dose and controls
Tumor site and type:  respiratory  tract/paplllomas,   papillary  polyps  and
                      squamous-cell carcinomas
Route, vehicle:  Inhalation/Nad vapor In air
Experimental Doses
or Exposures
0 mg/m3
2.2 mg/m3
9.5 mg/m3

Transformed Dose
(mg/kg/day)
0
0.0892
0.385
Input
Incidence
No. Responding/No. Tested
(or Examined)
0/27
0/27
9/26
See conversions on following page
                                     -48-

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                                  CONVERSIONS
0 mg/m3 = 0 mg/kg/day
2.2 mg/m3 x [( "yeefcs  x 4.5 hours  ^  85.2 weeks   ^_hours

              95.2 weeks   24 hours      95.2 weeks   24 hours     7 days
0.037 mVday * 0.12 kg x 666t4 days x <666'4 days) 3 = 0.0892 rag/kg/day
                         666.4 days    666.4 days
9.5 mg/m3 x [ 10 weeks  x 4.5 h0urs} f  86.4 weeks x _3_hpjurs)]   7_dajti

             96.4 weeks   24 hours      96.4 weeks   24 hours     7 days
0.037 m'/day * 0.12 kg x 674'8 days x <674'8 days) 3 = 0.385 rog/kg/day
                         674.8 days    674.8 days
                                                          Protectlon
                                        230 South  Dearborn Street
                                        Chicago, Illinois  60604
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