United States
Environmental Protection
Agency
SPA 910/9-66 12°
Ap-j| 198s
R^i Assessment of Human
Health Risk from Ingesting
Fish and Crabs From
Commencement Bay

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FINAL REPORT
ASSESSMENT OF HUMAN HEALTH RISK FROM INGESTING
FISH AND CRABS
FROM COMMENCEMENT BAY
Prepared by:
Versar, Inc.
6850 Versar Center
P.O. Box 1549
Springfield, Virginia 22151
Prepared for:
Mr. James Krull
Washington State Department of Ecology
Mail Stop PV-11
Olympia, Washington 98504
Performed Under EPA Contract No. 68-03-3149
U.S. Environmental Protection Agency
Office of Solid Waste and Emergency Response
March 1985
US. EM
Rxoooooscna

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TABLE OF CONTENTS
Page
1.0 INTRODUCTION		1
L . 1 Background		1
1.2 Report Organization		3
2.0 RISK ASSESSMENT METHODOLOGY		5
2.1	Exposure Evaluation		5
2.1.1	Methods for Assessing Exposure to
Contaminants in Fish and Crab Muscle
Tissue		6
2.1.2	Exposure from Ingestion of Fish
Livers		9
2.2	Health Effects (Hazard Assessment) Methodology...	11
2.3	Risk Assessment Calculations		16
2.3.1	Calculation of Carcinogenic Risk		16
2.3.2	Noncarcinogenic Risk Calculation		18
2.4	Summary of Limitations in this Risk Assessment...	18
3.0 COMMENCEMENT BAY FISH AND SHELLFISH SURVEY RESULTS		20
4.0 RISK ASSESSMENT RESULTS		24
4.1	Risk for Chemicals Detected in Tissue Samples....	24
4.2.1	Risk via Fish Muscle Tissue Ingestion		24
4.2.2	Risk via Ingestion of Crab Muscle Tissue..	31
4.2.3	Risk via Ingestion of Fish Livers		36
4.2	Risk for Chemicals Not Detected in Tissue
Samples		37
5.0 SUMMARY AND INTERPRETATION OF RISK ANALYSIS		42
6.0 REFERENCES
52

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APPENDICES (bound separately)
APPENDIX A.
APPENDIX B.
APPENDIX C.
APPENDIX D.
APPENDIX E.
APPENDIX F.
APPENDIX G.
Derivation of Boat Fishing Population
Location of Sampling stations
Pollutants Undetected in All Samples from All Sites
Organics Data from Commencement Bay Bioaccumulation
Study
Metals Data from Commencement Bay Bioaccumulation
Study
Liver Data from Commencement Bay Bioaccumulation
Study
Calculations of Exposure to and Risk from Ingesting
Commencement Bay Fish and Shellfish
APPENDIX H.
Sources of Data for Values in Table 8

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LIST OF TABLES
Page
Table 1. populations Exposed by Consumption Rate		8
Table 2. Ingestion of Fish Liver		10
Table 3. Health Effects Data		12
Table 4. Chemicals Detected in Fish and Crabs		21
Table 5. Worst-Case Risk for Nondetected Noncarcinogenic
Chemicals			38
Table 6. Worst-Case Risk for Nondetected Carcinogenic
Chemicals						39
Table 7. Summary of Risk Assessment		43 •
Table 8. Comparative Exposure for Contaminants of
Concern		46
Table 9. Projected Lifetime Cancer Cases		51

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1.0 INTRODUCTION
1.1 Background
The Commencement Bay area of the Puget Sound is an active
port in the industrial city of Tacoma, Washington. As such, it
has historically received pollution from industrial waste
discharges, disposal of dredge spoils, and port-related
pollution. The Nearshore/Tideflats area has been designated an
EPA Superfund site as a result of concerns over elevated levels
of many organic and inorganic pollutants in the sediments,
evidence of biological effects in the area, and potential public
health impacts from fish and shellfish consumption. The
Washington State Department of Ecology has, by cooperative
agreement with the U.S. Environmental Protection Agency, been
designated lead agency for the Remedial Investigation of the
site. As part of the Investigation an assessment of potential
personal risk experienced by area residents consuming fish and
shellfish from the area is required.
The purpose of this document is to quantify the level of
individual risk that may be experienced by persons eating fish
and crabs from Commencement Bay. This risk assessment is based
on a large volume of monitoring data generated during the summer
and fall of 1984 by the Washington State Department of Ecology
and its consultants.
Unlike previous attempts at risk assessment for the
population eating fish from Commencement Bay, this effort is not
limited by a lack of data on levels of pollutants in fish tissue.
It is instead hampered by (1) an inability of today's scientific
instrumentation to detect very low levels of pollutants, and (2)
a basic lack of data on the predictable human health effects of
exposure to pollutants. Readers must bear these two limitations
in mind at all times, for they have two ramifications on this
risk assessment, which are discussed below.
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In exposure evaluation, it is often assumed that, although a
pollutant is not detected in a sample, it is potentially present
at a level approximately equal to the method detection limit.
For extremely harmful pollutants, the resulting risk assessment
may indicate that harmful effects can be expected, though that
may very well be untrue if the actual level of pollutant is
substantially below the detection limit. This approach has been
used in this document as a conservative approach to protection of
human health.
A similar conservative approach is related to the type of
health information used to predict human risk. Much of that
information is taken from studies of the effects of chemicals on
small laboratory animals, a common toxicological practice. Those
data must then be adjusted to account for the larger size of
humans, the longer lifespan and potential period of human
exposure, and the possibility that humans may be more sensitive
to a chemical than the animal on which the test was performed.
These practices are standard procedure, and most of the health
effects data used in this assessment are from t-he U.S.EPA, but
they are acknowledged to be very conservative. For example, the
unit risk scores for carcinogens are based on the upper 95
percent confidence interval of the dose-response slope. Many
feel that they overpredict human risk, and that possibility must
be considered here.
The conservative approach may be more justified if one takes
into account the fact that this risk assessment deals in detail
with only one source of exposure to the chemicals being reviewed:
ingestion of fish and crabs. Some other estimated environmental
exposures for some of the chemicals are presented in Section 5
for comparative purposes. It is almost certain that there is
exposure to many of these chemicals through other means— in
drinking water, though inhalation of ambient air, and so on.
Although risk from eating fish may not exceed some level of
acceptability, that exposure along with other environmental
exposures may sum to an excessive level of risk.
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This risk assessment is based on the best available data and
utilizes state-of-the-art monitoring data and risk analysis
techniques. It is not, however, a perfect representation of the
potential effects of eating Commencement Bay fish, because of the
limitations discussed above. It is designed to err on the
conservative side of protecting health in the Tacoma area.
1.2 Report Organ i zation
Following this introduction, there are four sections to this
report:
Section 2 discusses the methodology upon which the
assessment is based. The methods for calculating the rate of
fish and crab consumption and the exposed population
are discussed. Next is a brief discussion of the health
effects data that are used in the risk assessment, along
with a summary table of the values used in the assessment of
human risk. The calculations to quantify human health risk
are described. Finally, the liberal and conservative aspects
of this assessment are listed, along with more general
uncer ta i nt ies.
Section 3 summarizes the results of the survey of fish and
crab tissue contamination in Commencement Bay that was
undertaken in the summer and fall of 1984.
Section 4 presents the risk assessment results. Much of the
information is presented in appendices in tabular form so
that the derivation of results is obvious. Discussed in
this text are the results that suggest that a certain
pollutant may, under some circumstances, present a risk to
human health.
Section 5 is the summary and analysis of results, including
which chemicals appear to be of concern, whether any of the
waterways presents a higher risk from fishing than do the
others, and the significance of health risks relative to
contaminant levels in fish from other areas.
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Throughout the report, the level of contamination of seafoods
caught in the Commencement Bay project reference area, Carr
Inlet, will be referred to as a benchmark. Also discussed
throughout the report are the limitations previously discussed,
as well as others that pertain to a particular set of data or a
specific scenario.
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2.0 RISK ASSESSMENT METHODOLOGY
"Risk assessment" is a term loosely applied to an analysis
of hazard potential in an environment. All risk assessments have
two elements in common:
(1)	An assessment of exposure to one or more substances
(2)	An assessment of the hazard associated with exposure to
a substance or collection of substances
These two elements must then be integrated into an analysis of
the level of risk experienced by a group, or population. This
integration can be accomplished on different levels; the risk to
each exposed individual over his or her lifetime can be
calculated, or the cumulative risk to the entire exposed
population can be predicted as the total number of illnesses
expected over a 70-year period. This report will focus on the
individual risk experienced by each person eating fish and crabs
from Commencement Bay, which is probably the most meaningful
statistic to most persons. Projected lifetime cancer cases for
the total estimated exposed population for two chemicals, PCBs
and arsenic, will be presented. Also presented will be the
projected number of persons at each consumption level for a range
of consumptions from one pound per day to one pound per year.
Each major step in the risk assessment process— exposure
evaluation, hazard evaluation, and calculation of risk— is
discussed individually in the following sections.
2 . 1 Exposure Evaluation
This analysis addresses three types of exposure: ingestion
of fish muscle tissue, ingestion of crab muscle tissue, and
ingestion of fish livers. The first two (ingestion of fish and
crab muscle tissues) are dealt with in a manner different from
that for eating of fish livers.
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2.1.1 Methods for Assessing Exposure to Contaminants in Fish and
Crab Muscle Tissue
There are two elements to assessing exposure to the
population eating fish and crabs from Commencement Bay; these
interrelated elements are estimating the exposed population, and
estimating the rate of fish and crab ingestion. This assessment
relies on data from the Tacoma-Pierce County Health Department
(TPCHD) to provide these estimates.
The TPCHD conducted a survey of recreational fishermen in
1981, questioning survey participants on the amount and type of
fish they catch, the frequency of their fishing, and the
fishermen's plans for their fish and crabs (whether they planned
to eat the catch). This catch/consumption survey was conducted
during the late summer and fall of that year, and it focused on
shore fishing.
The catch/consumption survey is detailed in a report by
Pierce et al. (1981). They concluded that a total of 2900
fishermen fished the shores of Commencement Bay, with varying
frequency, in that year. That estimate did not include the
results of the abbreviated survey of boat fishermen. We have
taken that part of the survey and adjusted the results for
seasonal frequency as Pierce et al. did for shore fishermen (see
Appendix A for derivation). The frequency of boat fishing was
assumed to be equal to the frequency of shore fishing; they may,
in fact be quite dissimilar. The boat fishermen (an estimated
1170 persons) have been added to the shore fishermen to derive a
new total of 4070 fishermen. This procedure assumes that the
shore fishing and boat fishing populations do not overlap and
that no one is "double counted;" it is quite likely that the
addition of boat fishermen makes the resulting total exposed
population an overestimate. Pierce et al. report that the
average family size is 3.74 persons; assuming that all members
eat fish, the total exposed population is 4070 x 3.74, or
approximately 15,200 persons.
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The data from Pierce et al. also allow estimation of the
frequency of fishing, which (when combined with a value from the
survey on average catch per fishing trip) can be keyed to the
amount of fish and crabs eaten. Table 1 presents a frequency
distribution of fish muscle tissue ingestion rates from this
survey. The maximum ingestion rates reported by Pierce et al.
form the basis of the distribution in Table 1 used throughout
this report. The risk assessment is keyed to this table, because
the risk to persons eating Commencement Bay fish and crabs daily
is considerably different from the risk to persons fishing only
once or twice a year and eating those fish. No data on shellfish
(i.e., crab) consumption were specifically compiled by Pierce et
al. or the other sources evaluated; consumption of crab was
therefore assumed to follow a distribution equal to finfish
consumpt i on.
Rates of fish and crab ingestion, in grams per day, are
multiplied by the average level of contaminant, in micrograms per
gram of fish, to yield exposure in micrograms per day. Exposure
calculations in this assessment are based on a number of
scenarios, to aid decision-makers. The average level of
contaminant in fish has been calculated by Tetra Tech (in
preparation) for:
-	each station from which fish or crabs were collected
for analysis,
-	each waterway or other large area (all stations within
that area combined), and
-	all nearshore/tideflats stations together.
In all cases, the method detection limit was used in the
calculation of means if a substance was not detected. Exposure
calculations have been performed with each of these averages;
results will therefore be keyed to area of the Bay.
An assumption inherent in this analysis is that the fish and
crabs examined for contaminants are representative of what is
eaten by Commencement Bay fishermen. The assessment is again
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Table 1. Population Exposed by Consumption Rate
Frequency
Frequency
percent
Ingestion
Rate
Intake
9/day
Population
Exposed
Da i ly
Weekly
Mon thly
Bimonthly
Twice/year
Yearly
0.2
6.6
11.4
7.3
17 . 2
57.3
lb ./day
lb./week
lb./mo.
lb./2 mos,
lb./6 mos,
lb./year
453 .0
64.7
15. 1
7.4
30
1005
1735
1111
2618
8721
Total
100.0
15, 220
Source: Pierce et al. (1981)
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somewhat conservative at this point; all fish analyzed were
English sole, which are not commonly eaten and have been found to
be, as bottom-dwelling fish, among the most contaminated in
Commencement Bay (Tetra Tech, unpublished Task 3 report on
bioaccumulation). All shellfish analyzed were Dungeness crabs
and rock crabs. Data ace not sufficient to state that crabs are
either more or less contaminated than other types of shellfish
that may be caught in the Bay.
2.1.2 Exposure from Ingestion of Fish Livers
A subgroup of special interest in this assessment . is the
population that eats fish livers. Although this group is
believed to be small, their exposure to contaminants in
Commencement Bay fish may be higher than that of individuals
eating muscle tissue because many chemicals are known to
concentrate in organs such as the liver.
The assessment of exposure from eating livers Is based on
maximum observed values in composites of livers from fish caught
at the sampling stations in the bioaccumulation study. Means
were not used because several livers were pooled for each
chemical analysis, and the maximum observed values actually
represent the mean of several liver samples.
No data on the amount of fish liver eaten are available from
the TPCHD survey or other sources consulted. It was therefore
assumed that the amount of liver eaten is proportional to the
amount of fish muscle eaten; i.e., that persons who do eat livers
would consume the livers from all the fish they catch and
consume. The average proportion of liver weight to muscle weight
for 13 species of Commencement Bay fish is 0.12 (Gahler et al,
1982), the factor that is used in scaling exposures. Table 2
presents data on the frequency distribution of liver consumption
as a function of muscle tissue consumption. This is certainly an
upper bound estimate; it is unlikely that consumption of fish
livers would ever exceed the range of intakes in Table 2.
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Table 2. Ingestion of Fish Livers
Fish Intake	Liver Intake
Frequency	g/day	g/day
Daily	453.0	54.4
Weekly	64.7	7.8
Mon thly	15.1	1.8
Bimonthly	7.4	0.9
Twice/year	2.5	0.3
Yearly	1.2	0.1
Source: Derived from Pierce et al. (1981) and Gahler et al.
(1982)
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2.2 Health Effects (Hazard Assessment) Methodology
Table 3 summarizes the available data, from the U.S.
Environmental Protection Agency, on the human health effects of
chemicals monitored for in Commencement Bay fish tissues. The
chemicals listed in this table can be classified as having either
carcinogenic or noncarcinogenic effects. These effects are
associated with different types of data and are treated
differently in the risk assessment process. Although some
chemicals have multiple effects, only the most significant (in
severity or in terms of occurring at the lowest dose) are
d iscussed.
Chemicals that are called "carcinogens" in this assessment
are substances that the EPA considers possible cancer-causing
agents; they have not in all cases been implicated as causes of
cancer in humans. Most of the available data on these chemicals
are derived from animal studies, both for evidence and strength
of carcinogenicity. The presumption in the scientific community
today is that carcinogenicity is not a threshold effect; any
exposure, no matter how low, can be associated with a
quantifiable cancer risk. The potency of the carcinogen is
expressed as a risk score, which is the probability of effect per
unit dose of chemical, in units of (mg/kg/day)	The unit
cancer risk scores in this study are those published by the
U.S.EPA's Carcinogen Assessment Group (USEPA 1984).
Noncarcinogens are usually assumed to exhibit thresholds,
that is, to cause some ill effect only after a certain dose is
exceeded. That dose is given the term the No Observed Effect
Level, or NOEL, by toxicologists. Since NOELs have been derived
almost exclusively from studies of small mammals, the measured
NOEL is usually divided by some safety factor to estimate a level
that can be considered safe for humans. The safety factor takes
into account the variability in the toxicity of a chemical
between the experimental species and humans and within the human
population as well as other deficiencies in the experimental
data. This resulting value is the one used in this assessment,
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Table 3. Health Effects Data
CHEMICAL
RISK SCORE
CARCINOGENS	pec mgAg/day
acrylonitrile	0.552
aldrin	11.4
arsenic	14
benzene	0.052
benzidine	234
beryl1 inn	4.86
carbon tetrachloride	0.083
chlordane	1.61
chromium	41
hexachlorobenzene	1.67
dichloroethane (1,2)	0.037
trichloroethane (1,1,2)	0.0573
trichloroethane (1,1,1)	0.0016
tetrachloroethene	0.035
trichloroethene	0.019
tetrachloroethane (1,1,2,2)	0.201
hexachloroethane	0.0142
trichlorophenol (2,4,6)	0.0199
chloroform	0.183
DDT	8.42
dichloroethylene (1,1 and 1,2)	1.04
dieldrin	30.4
dinitrotoluene	0.311
tetrachlorodioxin	425000
diphenylhydrazine	0.768
halomethanes	0.183
heptachlor	3.37
heptachlor epoxide	3.76
hexachlorobutadiene	0.0775
hexachlorocyclohexane (HCH)	4.75
alpha	11.1
beta	1.84
ganma (Lindane)	1.33
dimethyl nitrosamine	25.9
diethyl nitrosamine	43.5
dibutyl nitrosamine	5.43
NN diphenyl amine nitrosamine	0.0049
N-nitrosodipropylamine	31
dibenzo(a,i)pyrene	476
bienzo(a) pyrene	11.5
DEHP	0.0141
Sources: USEPA (1983,1984)
HEALTH
EFFECT
brain tumors
liver timors
skin cancer
leukemia
bladder cancer
leukemia
liver timors
liver cancer
when inhaled; no value for ingested
liver timors
circulatory hemangiosarcomas
hepatocellular carcinomas
liver timors
liver tumors
liver timors
hepatocellular carcinomas
hepatocellular carcinomas
hepatocellular carcinomas, adenomas
hepatocellular carcinomas
liver adenocarcinoma
kidney adenocarcinoma
liver tumors
mammary timors, hepatocellular carcinoma
hepatocellular and other carcinomas
hepatocellular carcinomas and adenomas
liver tunors
hepatocellular carcinoma
hepatocellular carcinoma
renal tubular adenoma and carcinoma
liver timors
liver tumors
liver timors
liver tumors
liver cancer
liver cancer
bladder and esophogeal cancer
bladder tunors
mammary tumors and hepatocarcinoma in mice
lung cancer-inhalation
stomach papillomas, carcinomas
liver,kidney cancer

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Table 3. Health Effects Data

RISK SCORE

HEALTH
CARCINOGENS
per
mg/kg/day
EFFECT
PCBS

4.34

hepatocellular carcinoma
toxaphene

1.13

hepatocellular carcinoma and adenoma
tetrachloroethylene

0.04

hepatocellular carcinoma
tr ichloroethylene

0.0126

hepatocellular carcinoma
vinyl chloride

0.0175

liver angiosarcoma
BCEE

28

various carcinomas
CHEMICAL





ADI

SAFETY
HEALTH
HONCARCINOGENS
ug/day
FACTOR
EFFECT
acrolein

1100
1000
unknown via oral exposure
DDD

3010
1
hunched appearance, increades urination
DDE

350
1
hepatic necrosis in rats
a-endosulfan

280
100
brain and kidney damage
b-endosulfan

280
100
brain and kidney damage
endosulfan sulfate

280
100
brain and kidney damage
endrin

70
100
nervous system, leukocytosis, kidney degeneration
endrin aldehyde

70
100
nervous system, leukocytosis, kidney degeneration
antimony

292
100
altered blood chemistry
cadmium

700
?
renal tubular necrosis in hunans
chromium-VI

175
1
kidney tubular necrosis
chromium-III

357000
1
sterility
cyanide

330
100
hypoxia (oxygen blockage)
lead

100
?
brain dysfunction and anemia in humans
mercury

20
10
ataxia,cerebellar atrophy, impaired vision in humans
manganese

10000
?
neurological dysfunction in humans
nickel

1460
1000
fetal mortality or reduced body weight
seleniun

700
10
liver and endrocrine gland effects
silver

16
5
kidney hemorrhage, liver, stomach, and intestine damage
thalliun

37
1000
nerve, kidney, liver, and stomach damage
zinc

15000
100
copper deficiency and anemia in himans
fluorotr ichloromethane

201000
10
cardiac arrythmia
dichloroethane (1,1)

8100
?
liver function changes
dichloropropane (1,2)

980
1
liver function changes
dichloropropane (1,3)

180
1000
liver function changes
dichloropropylene (1,3)

180
1000
liver function changes
hexach1orocyc1opentadiene

36
100
no oral effects known
bis 2-chloroisopropyl ether

70
10
no oral effects known
chlorobenzene

1008
1000
nervous systan depression; liver, kidney necrosis
dichlorobenzene (1,2)

107000
100
cirrhosis of liver
dichlorobenzene (1,3)

140000
100
cirrhosis of liver
dichlorobenzene (1,4)

161000
100
cirrhosis of liver
trichlorobenzene (1,2,4)

464
10
liver metabolism changes in monkeys
Sources: USEPA (1983,1984)

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Table 3. Health Effects Data
CHEMICAL




ADI
SAFETY
HEALTH
NONCARCINOGENS
ug/day
FACTOR
EFFECT
ethylbenzene
1600
1
weight increase, kidney effects
nitrobenzene
4000
10
blood cyanosis in himans by inhalation or dermal exposure
toluene
134000
100
nervous system effects and cardiac arrythmia
total xylenes
160000
10
maternal toxicity
phenol
6800
500
kidney and liver damage
chlorophenol
6900
1000
increased nervous response in hurians
dichlorophenols
7000
1000
convulsions in cats
pentachlorophenol
2100
100
micro-level changes in hunan liver and kidney via inhalation
nitrophenols
140
1000
effects unknovwi
dinitrophenol
140
1
numerous for 2,4- eyes, skin, nerves, liver, spleen in humans
dimethylphenol
7000
190
liver, spleen pathology
dinitro-o-cresol
71
10
effects on human skin when inhaled
diethy1phtha1ate
875000
100
decreased growth
dimethylphthalate
1800
10
kidney effects on himans when inhaled
di-n-butylphthalate
1800
10
brain abnormalities in humans when inhaled
di-n-octylphthalate
1800
10
effects unknown
acenaphthene
18
7
enzyme blood changes in humans when inhaled
fluoranthene
420
1
mortality at high dose via dermal contact
naphthalene
18000
10
cataracts in humans (inhalation), rats (oral)
Sources: IJSEI'A (1983,1984)

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Table 3. Health Effects Data
NOTES:
All effects foe rats unless otherwise noted
Carcinogen data from 1984 docunent; some values may have changed
Noncarcinogenic ADIs from 1983- latest published data; many values under review
See text for explanation of safety factor
Sources: USKPA (1901,1984)

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and it is termed the Acceptable Daily Intake (ADI). Effects are
considered possible in a sensitive subpopulation when the
exposure or dose exceeds the ADI; or, as it is usually expressed
here, if the ratio of exposure to the ADI equals or exceeds 1.
ADIs are set with chronic (70 year) exposure as the time frame,
and that exposure duration is usually factored into the safety
factor. Safety factors can range from 1 if the data are of good
quality, based on long-term human (usually occupational) exposure
to 1000 if the original health data are from short-term studies
of small lab animals.
2.3 Risk Assessment Calculations
The exposure and effects data discussed above are combined
in this step of the assessment to calculate risk to the
individuals ingesting fish from Commencement Bay. Just as there
are two types of effects data, there are two types of risk
calculations. These are outlined below.
Risk is assessed on a chemical-by-chemical basis throughout
this report. There is evidence for many combinations of
chemicals that interaction occurs, either as synergistic effects
(magnifying the probability or severity of an effect), as
additive effects (combining similar effects of two chemicals), or
as antagonistic effects (preventing an effect entirely or
lessening its severity). The evidence of these interactions is
relatively weak. Furthermore, while the combined effect of two
chemicals may be known, the combined effect of the complex
mixture of Commencement Bay pollutants is definitely unknown.
2.3.1 Calculation of Carcinogenic Risk
As described previously, risk scores (the health effects
data used in risk assessment for carcinogens) are in units of
risk per mg chemical/kg human body weight/day (mg/kg/day)~1.
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Multiplying exposure in mg/kg/day by the risk score will yield a
unitless probability of cancer in an individual, or individual
risk. The entire train of logic is presented below:
conc. chemical,uc[ x ingestion rate,c[ = exposure, ii£
g	day	day
exposure, jjg x 10~^mg /70 kg person = exposure in
day	ug	mg/kg/day
exposure, mg/kg/day x unit risk, (mg/kg/day)-^ = individual
risk
Environmental risks are usually expressed in these terms.
Various levels of individual risk may be considered acceptable,
depending on a number of circumstances. An individual risk level
of 10"^ indicates that one in one million persons exposed to that
level of contaminant would be expected to develop cancer over an
'average1 lifetime of 70 years, assuming continuous exposure.
For comparative purposes, consider the following statistical
risks over a 70-year lifetime (NY State Department of Health
1981) :
death from a hurricane- 2.8 x 10~5
death by an aviation accident- 7.0 x 10"^
fatal automobile accident- 1.8 x 10"2
— ^
death from being struck by lightning- 3.5 x 10
Individual risk can be multiplied by the number of
persons exposed at that level to estimate the total number of
persons expected to develop cancer among the exposed population
over the 70-year lifetime. That calculation has not been
performed for all chemicals in this risk assessment. It has been
performed only for the chemicals with the highest absolute risks;
calculations indicate that, for the vast majority of chemicals,
both individual and cumulative risk (i.e. cases) are very low.
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2.3.2 Noncarcinogenic Risk Calculations
Because noncarcinogenic chemicals exert a threshold effect,
the assessment of risk at a calculated level of exposure entails
simply comparing the exposure to the ADI. If exposure exceeds
the ADI, all persons exposed at that level are assumed to be
affected; if exposure is equal to or less than the ADI, none of
the individuals are affected. There is no provision in this
method for degree of effect. However, the ratio of exposure to
the ADI indicates the weight of evidence of projected effects to
a limited degree.
2•4 Summary of Limitations in this Risk Assessment
It was stated earlier that this risk assessment is designed
to be a reasonable indicator of risk to the population eating
fish from Commencement Bay. Some methods used are by their
nature conservative (tending to overpredict risks) and some are
liberal (not considering factors that may make actual risk higher
than is indicated herein). Some methods simply entail
uncertainties that cannot be defined as either liberal or
conservat i ve.
Conservative Factors
The currently-accepted approach to risk assessment is
generally conservative.
The maximum potential ingestion rate used in this
assessment, one pound of fish per day, is acknowledged
to be high.
Exposure is assumed to occur continuously for 70 years.
Nondetected chemicals are assessed by assuming that the
level of contaminant is equal to the method detection limit
(rather than much less, or even zero).
18

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Contaminant levels in English sole, a bottom fish, are
used to represent levels in all fish eaten; sole are
thought to be more highly contaminated than most fish.
Potential antagonistic effects between chemicals that
occur together are not accounted for.
Liberal Factors
Not all contaminants present can be analyzed by the
laboratory equipment available at this time; risk from
those chemicals cannot be accounted for.
It is possible that fish other than English sole may be
contaminated at higher levels than the sole in this
survey.
Possible additive or synergistic effects of multiple
chemicals are not quantified.
General Uncertainties
Tissue levels can vary by season. All data were
collected in the summer and fall months.
Cooking fish may alter the chemical constituents, and
measurements of contaminant levels in raw fish may not
accurately represent exposure levels.
19

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3.0 COMMENCEMENT BAY FISH AND SHELLFISH SURVEY RESULTS
The monitoring data upon which this assessment is based came
from a comprehensive survey of Commencement Bay performed in mid-
1984. Among the media sampled were fish muscle tissue, fish
livers, and crab muscle tissue. The sampling was performed at
defined stations throughout Commencement Bay and at a reference
site, Carr Inlet. The reference site was chosen to represent an
area in Puget Sound where the sediments were relatively
uncontaminated. Appendix B shows the location of each sampling
site. Further details on the 1984 monitoring can be obtained
from a report currently under preparation (Tetra Tech).
Appendix C lists the numerous compounds that were never
detected in the fish sampled during this survey, as well as the
method detection limits of the analysis. The fish were all
English sole, chosen to aid in a conservative analysis because
these bottom fish generally reach contamination levels higher
than do other fish. The human health risk that would result if
fish with levels of these substances equal to the method
detection limit were routinely ingested is evaluated.
Appendices D, E, and F are the summaries of organics levels
in fish and crab muscle tissue, metals in fish and crab muscle
tissue, and all contaminant levels in fish liver samples,
respectively. The compounds that were detected in fish muscle
tissue are further summarized in Table 4. The mean for the
Commencement Bay data is compared to the corresponding mean for
the Carr Inlet reference area.
Table 4 indicates that detected chemical levels in
Commencement Bay fish often, but not always, exceed levels in the
Carr Inlet reference area. Many chemicals listed in this table
were never detected in Carr Inlet samples. The absolute
frequency of detection of each chemical at each site is part of
the summaries in the Appendices; relative frequency is indicated
in Table 4.
20

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Table 4. Chemicals Detected in Fish and Crabs
Detected in Only One Fish Sample




Chemical
S i te
Mean
Mean-Carr
Fluoranthene
MD-70
29.0
ND
1,3-Dichlorobenzene
CI-70
54.0
ND
Detected in Fish in Only
One Waterway

Chemical
S i te
Mean
Mean-Carr
Dimethylphthalate
Blair
37.0
ND
HCB
HY-7 2
26.0
ND
HCBD
HY-72
43.0
ND
Detected in Fish from More than
One Waterway

Chemical
Mean
Mean-Carr
Inlet
DEHP
194.0
35.0

Butyl benzyl phthalate
13.0
ND

Di-n-octyl phthalate
49.0
18.0

Di-n-butyl phthalate
425.0
21.0

Diethyl phthalate
11.0
ND

fluorotrichloroethane
11.0
92. 0

tetrachloroethene
66.0
7.0

Ethylbenzene
15.0
5.0

Toluene
11.0
11.0

Naphthalene
134. 0
54. 0

Xylenes
55.0
ND

PCBs
210. 0
36.0

Ant imony
1010.0
1070.0

Arsenic
4070.0
7940.0

Cadmi um
26.9
203.0

Chromium
197. 2
190. 0

Lead
218.0
218.0

Nickel
100. 3
115. 0

Selen i um
331.0
171.0

Si 1ver
11.9
8.0

Z i nc
3650.0
3720.0

Mercury
59.5
55. 0

21

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Table 4. (continued)
Chemicals Detected	in Only One Crab Sample
Chemical	Site Mean Mean-Carr Inlet
Phenanthrene	MD-70 20.0 ND
Fluoranthene	MD-70 12.0 ND
Chemicals Detec ted	in Crabs from More than One Wa terway
Chemical	Mean Mean-Carr Inlet
DEHP
28.0
1331.0
Di-n-butyl phthalate
172. 0
540. 0
Naphthalene
75.0
ND
PCBs
104. 0
22.0
Ant imony
1063.2
1000.0
Arsenic
1980.0
2370.0
Cadmium
150.0
92.0
Chromium
214. 7
237.0
Lead
478.0
195.7
Nickel
88.0
107.0
Selenium
194.0
138.6
S i1ver
138.4
197.0
Z i nc
39890.0
47420.0
Mercury
10. 3
44.6
Note: ND denotes not detected
All values in ppb (ng/g) wet weight
22

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Tetra Tech (a project consultant) has determined that some
of the liver data are questionable; those data (all metals) are
noted "Q" on the summaries in the Appendix. Laboratory analysis
of the complex liver tissue was difficult, resulting in qualified
values for arsenic, chromium, selenium, and lead. The listed
values are thought to be overestimates of the true level by as
much as a factor of 2 (for lead) to 11 (for chromium) (personal
communication with Robert Barrick, Tetra Tech, January, 1985).
As discussed previously, exposure and risk calculations
presented in the next section will be based on calculated means
for a waterway or the overall project area, depending on what
areal assessment is being accomplished. Those means are listed
in the appendices and are therefore not presented here.
23

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4.0	RISK ASSESSMENT RESULTS
4.1	Risks for Chemicals Detected in Tissue Samples
The bulk of this risk analysis is focused on the compounds
that were detected in one or more samples of Commencement Bay
fish and crabs. Appendix G contains all the exposure and risk
calculations performed for this report; this section discusses
those contaminants previously identified in Table 4 as being
present in fish muscle or liver tissue or crab muscle tissue
samples. The significance of these results is discussed further
in Section 5 of this report.
4.1.1 Risk via Fish Muscle Tissue Ingestion
The following paragraphs will present a chemical-by-chemical
discussion of the human health risks associated with chemicals
present in Commencement Bay fish muscle tissue. The data from
which this summary was derived are presented in Tables G-l and G-
2 in Appendix G. No risks were calculated for barium, iron, or
copper, essentially nontoxic metals (for which no ADIs have been
set) found in numerous fish and crabs. Chemicals are discussed
individually below, and presented in rough order of decreasing
concern (i.e., risk).
Recall from Table 1 that results are keyed to ingestion rate
as a function of fishing frequency. The maximum ingestion rate
of 453 g/day equates with fishing daily and eating a pound of
fish each day. Thirty persons in the Tacoraa area are believed to
be exposed at that rate. The 1005 persons eating a pound a fish
per week average 64.7 g/day consumption. Persons fishing monthly
(around 1735 people) are assumed to eat a pound of fish per
month, or 15.1 g/day. The average daily ingestion rate for
persons eating a pound of fish every two months (approximately
1111 persons) is 7.4 g/day. The majority of persons responding
24

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to the catch/consumption survey said they fish only twice a year
or once a year in the Bay (2618 and 8721 persons, respectively).
Persons fishing twice yearly have an average ingestion rate of
2.5 g/day, while persons fishing yearly average 1.2 g fish/day.
These ingestion rates and populations were used in the assessment
of both fish and crab consumption.
CARCINOGENS
Polychlorinated biphenyls were found in fish throughout
Commencement Bay and in Carr Inlet fish. Calculated average
individual lifetime risks (i.e., based on the calculated bay-wide
average fish muscle tissue levels) for eating fish from
Commencement Bay fish, by ingestion rate, are:
The risk associated with eating fish from Commencement Bay (using
average bay-wide PCB levels in the muscle tissue) is five times
higher than the risk associated with eating Carr Inlet fish.
There is some variability among fish taken from different
waterways. At the highest ingestion rate, the lifetime individual
risks from eating fish from different areas vary as shown below:
PCBs
1 lb./2 months
1 lb./6 months
1 lb./year
1 lb./day
1 lb./week
1 lb./month
6	x	10-3
8	x	10~4
2	x 10~4
9	x	10~5
3	x 10"5
2	x	10-5
City WW
Hylebos WW
Blair WW
Middle and
1	x	10"2
9	x	10~3
7	x	10~3
5	x	10"3
Sitcum WWs
Milwaukee WW
Ruston Shore
St. Paul WW
Carr Inlet
3	x	10~3
2	x 10"3
1	x	10*3
1	x	10"3
25

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The highest risks are associated with eating fish from the
Hylebos and City Waterways. Risks from eating fish taken from
along the Ruston shore decrease by more than a factor of two with
distance from the waterways. The adverse health effect
associated with PCB exposure is cancer of the liver; it is not,
however, a proven human carcinogen.
Recent studies (Crecelius and Apts 1984) of arsenic in fish
tissue indicates that only an average of 0.12 percent of the
measured arsenic is present in the toxic inorganic form. That
factor has therefore been applied to the calculated exposures and
risks in this analysis. The resulting predictions indicate that
the average lifetime individual risk associated with eating fish
from Commencement Bay, based on bay-wide average levels, is:
These risks are approximately equal to the risks associated with
eating fish from other areas, i.e. Carr Inlet. The average
individual lifetime risk associated with eating one pound of fish
daily from each of the waterways is presented below:
Arsenic
1 lb./2 months
1 lb./6 months
1 lb./year
1 lb./day
1 lb./week
1 lb./month
4	x	10"4
6	x	10~5
1	x	10~5
7	x 10~6
2	x 10~6
1	x 10*6
City WW
Hylebos WW
Blair WW
Middle WW
Sitcum WW
Milwaukee WW
Ruston Shore
St. Paul WW
Carr Inlet
3	x 10~4
3	x 10"4
7	x 10~4
2	x 10~4
2	x 10"4
2	x 10"4
7	x 10~4
2	x 10~4
7	x 10~4
26

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There is less than an order of magnitude difference among all the
areas. The carcinogenic effect suspected for persons ingesting
arsenic in its inorganic form is skin cancer.
Hexachlorobenzene
Hexachlorobenzene was found in two fish caught in the
Hylebos Waterway at levels very near the method detection limit.
The level at which it was present indicates that the lifetime
individual carcinogenic risk of ingesting fish contaminated at
this level for 70 years would vary as follows:
1
lb ./day
1
x
10-4
1
lb./week
2
X
10~5
1
lb./month
4
x
10~6
1
lb./2 months
2
x
10~6
1
lb./6 months
7
X
10-7
1
lb./year
3
X
10-7
Risk from consuming fish from Carr Inlet at the maximum 1 lb. per
day ingestion rate and assuming the compound is present at the
method detection limit is 0.7 x 10"^, a very slight difference
from the Hylebos Waterway risk at this ingestion rate. The
adverse human health effect associated with exposure to
hexachlorobenzene is liver tumors.
Hexachlorobutadiene
Hexachlorobutadiene was found in two fish taken from the
Hylebos Waterway, it was also found at just above the detection
limit. The average individual carcinogenic risk associated with
eating fish with this level of HCBD ranges as foliows:
1
lb./day
2
X
10-5
1
lb./week
3
X
10~6
1
lb ./month
7
X
10~7
1
lb./2 months
3
X
10~7
1
lb./6 months
1
X
10"7
1
lb./year
5
X
10~8
27

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This level of risk differs only slightly from that predicted for
eating fish from Carr Inlet with levels of HCBD equal to the
method detection limit. The maximum individual risk above is 2 x
10""-5, while the maximum individual risk at the method detection
limit also rounds to 2 x 10"^. Cancer of the kidneys is the
adverse health effect associated with exposure to HCBD.
Bis 2-ethylhexyl Phthalate (DEHP)
This chemical was found in numerous fish throughout
Commencement Bay as well as in the reference area. It is a
ubiquitous pollutant, and currently considered a relatively weak
carcinogen. Unpublished data indicate, however, that EPA may
reconsider the carcinogenicity of the phthalate and instead set
an ADI for noncarcinogenic effects. Assuming that the compound
is a carcinogen, the average individual lifetime risk throughout
Commencement Bay from ingesting this fish contaminant for 70
years is presented by ingestion rate below:
lb./day
2
X
10"5
lb ./week
3
X
10~6
lb ./month
6
X
10~7
lb./2 months
3
X
10~7
lb ./6 months
1
X
10~7
lb./year
5
X
10-8
There is some incremental increase in risk from Commencement Bay
fish over Carr Inlet fish. Below is the average individual
lifetime risk associated with eating a pound of fish daily from
each area in which DEHP was detected in fish:
City WW
2
X
10~5
Hylebos WW
3
X
10~6
Blair WW
4
X
10~5
Milwaukee WW
2
X
10~5
Ruston Shore
2
X
10"5
Carr Inlet
3
X
10"6
28

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DEHP exposure is associated with possible cancer of the liver and
kidneys.
Tetrachloroethene
This common environmental pollutant was found in many of the
fish samples from the City, St. Paul, and Hylebos Waterways (the
only areas studied for volatile organics). The average
individual lifetime risk from eating fish from Commencement Bay,
by ingestion rate, is:
1
lb./day
1
X
10~5
1
lb./week
2
X
10~6
1
lb./month
5
X
10"7
1
lb./2 months
2
X
10~7
1
lb./6 months
8
X
10"8
1
lb./year
4
X
10~8
By waterway, the maximum individual risk attributable to
tetrachloroethene from eating a pound of fish per day is:
City WW	8	x	10~6
St. Paul	2	x	10~5
Hylebos WW	2	x	10~5
Carr Inlet	3	x	10-6
Tetrachloroethene is a suspected human liver carcinogen when
i ngested.
NONCARCINOGEN S
Ratio of Exposure to API _1
Antimony
Average antimony exposure is predicted to exceed the ADI for
persons eating a pound of fish daily for 70 years from both
Commencement Bay and Carr Inlet (with ratios of exposure to ADI
29

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of 1.6 for both areas). Ratios are less than 1 for all other
ingestion rates studied. The predicted effect is listed as
altered blood chemistry.
Lead
Individual exposures to lead from fish from Commencement Bay
and Carr Inlet are about equal to the ADI for persons eating one
pound of fish daily. This indicates that there is no incremental
increase in risk over the reference area and that lead in fish
muscle tissue may pose a health problem for persons consuming
fish from both areas of Puget Sound. This is especially true if
the ADI, which is currently under review at EPA, is lowered
further. Brain dysfunction is the effect associated with chronic
exposure to dietary lead. Again, there is little difference
between levels in fish caught at different sites.
Mercury
Persons eating a pound of fish daily, from either
Commencement Bay or Carr Inlet, would be expected to exhibit some
toxicity as a result of the presence of mercury. The ratio of
exposure to the ADI is 1.35 for the Commencement Bay average and
1.2 for fish from Carr Inlet. For the other ingestion rates, no
effect (i.e., atrophy of the brain) would be expected.
Ratio of Exposure to ADI £ 1
The calculated ratio of exposure to ADI is, in all cases,
less than one for the following chemicals detected in
Commencement Bay fish:
Fluoranthene
1,3 Dichlorobenzene
Dimethylphthaiate
Butyl benzyl phthalate
30

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Di-n-butyl phthalate
Di-n-octyl phthalate
Diethyl phthalate
Fluorotr ichloromethane
Ethylbenzene
Toluene
Naphthalene
Xylenes
Cadmium
Chromium
Manganese
Nickel
Selenium
S i 1 ver
Zinc
DDE
No adverse human health effects would be expected from any of
these contaminants in Commencement Bay or Carr Inlet fish.
4.1.2 Risks via Ingestion of Crab Muscle Tissue
Complete calculations of exposure and risk from ingestion of
Commencement Bay crabs are presented in Tables G-3 and G-4 of
Appendix G to this report.
CARCINOGENS
PCBS
Polychlorinated biphenyls were found in crabs throughout
Commencement Bay and in Carr Inlet crabs. Calculated average
individual lifetime risks (based on the bay-wide mean level) for
eating crabs from Commencement Bay are:
1 lb./day	3 x 10~3
1 lb./week	4 x 10~4
1 lb./month	1 x 10~4
1 lb./2 months	5 x 10"^
1 lb./6 months	2 x 10~5
1 lb./year	8 x 10~6
31

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The maximum individual average risk from eating a pound of crab
each day for 70 years from each area in which it was detected is
summarized below:
Milwaukee WW
Carr Inlet
City WW
Middle WW
Sitcum WW
2	x	10"3
1	x	10-3
7	x	10"3
2	x	10"3
1	x	10"3
PCBs were not detected in crabs taken from the other study areas.
The method detection limits attained for some of the crab muscle
tissue analyses were higher than the measured levels in the
waterways listed above. Predicted risks from eating crabs from
the Hylebos and Blair Waterways, based on the method detection
limit, would therefore exceed the risks listed above, while risks
attributable to Carr Inlet crabs would be about 1 x 10~3. The
adverse effect associated with PCB ingestion is cancer of the
liver.
Recent studies (Crecelius and Apts 1984) of arsenic in
seafood indicates that only an average of 0.12 percent of the
measured arsenic is present in the toxic inorganic form. That
factor has therefore been applied to the calculated exposures and
risks in this analysis. The resulting predictions of average
individual lifetime risk, by ingestion rate, are:
Risks differ little among the various waterways and sampling
areas, as shown by the maximum individual lifetime risks that
Arsenic
1 lb./day
1 lb./week
1 lb./month
1 lb./2 months
1 lb./6 months
1 lb./year
2	x 10"4
3	x 10*5
7	x 10~6
4	x 10"6
1	x 10~6
6	x 10~7
32

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would result from eating a pound of crab daily from each area:
St. Paul WW
Carr Inlet
City WW
Hylebos WW
Blair WW
Middle WW
Sitcum WW
Milwaukee WW
3	x	10~4
2	x	10~4
1	x	10"4
2	x	10~4
2	x	10"4
1	x	10~4
2	x	10"4
2	x	10"4
No crabs were collected from the Ruston shoreline stations. Skin
cancer is the effect predicted for ingestion of inorganic
arsenic.
Bis 2-ethylhexyl Phthalate (DEHP)
This chemical was found in crabs in the City and Milwaukee
Waterways as well as in the reference area. It is a ubiquitous
pollutant, and a relatively weak carcinogen. The average
individual lifetime risk throughout Commencement Bay from
ingesting this crab contaminant for 70 years is presented by
ingestion rate below:
The differences between risks from eating crabs from the
different areas are more pronounced than for most other
contaminants. The list below is the individual lifetime risk
associated with eating a pound of crab muscle each day for 70
years from the areas in which DEHP was detected:
1 lb./2 months
1 lb./6 months
1 lb./year
1 lb./day
1 lb./week
1 lb. /month
3	x 10~6
4	x 10~7
9	x 10*8
4	x 10"8
1	x 10"8
7	x 10~9
City WW
Milwaukee WW
Carr Inlet
5 x 10~6
3 x 10~6
1 x 10~4
33

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As seen above, risks from Carr Inlet crabs are substantially
higher than risks from Commencement Bay crabs. As stated
previously, liver and kidney cancer is believed to be associated
with ingestion of DEHP.
NONCARCINOGENS
Ratio of Exposure to API >1
Antimony
Average antimony exposure is predicted to exceed the AD I
(with a ratio of 1.65) for persons eating a pound of crab caught
in Commencement Bay each day for 70 years. Carr Inlet crabs, if
eaten at the rate of a pound per day for 70 years, would also
lead to exposure exceeding the ADI (ratio of 1.5). No exceedance
of the ADI is predicted for the lower rates of ingestion. The
predicted effect is listed as altered blood chemistry. similar
ratios were calculated for ingestion of antimony in fish.
Lead
Individual exposures to lead from crabs from Commencement
Bay and Carr Inlet are equal to or exceed the ADI (by as much as
a factor of 4) for persons eating a pound of crab daily. Crabs
from the Sitcum Waterway appear to be associated with
significantly higher ratios of exposure to ADI than the other
sites. This indicates that, although there is no incremental
increase in risk over the reference area (except in the Sitcum),
lead may pose a significant health threat to persons eating crabs
from both areas of Puget sound. This is especially true if the
ADI, which is currently under review at EPA, is lowered further.
The adverse health effect for which the ADI is set for lead is
brain dysfunction, especially in children.
Silver
Exposure could exceed the ADI for silver (by a factor of 5
in some cases) for persons eating a pound of crab daily for 70
34

-------
years. The ratio of the average, one pound per day Commencement
Bay exposure level to the ADI, 3.92, is slightly less than the
corresponding ratio for crabs from Carr Inlet (around 5.6). The
adverse effect predicted when exposure exceeds the ADI is damage
to the digestive system.
Zinc
The maximum ratio of exposure to ADI for zinc (from eating a
pound of crab each day for 70 years) is consistently around 1.3,
regardless of the location from which crabs were taken. Adverse
effects from zinc might therefore be expected in persons eating
one pound of crab on a daily basis; no effect is expected for
persons eating less than a pound per day. The health effect of
concern with zinc exposure is a change in blood chemistry
resulting in anemia and copper deficiency. No increase over the
reference area is noted.
Mercury
Persons eating a pound of crab daily, from either
Commencement Bay or Carr Inlet, would be expected to exhibit some
toxicity (brain atrophy and related effects) as a result of the
presence of mercury. The bay-wide average ratio of exposure to
ADI for Commencement Bay crabs is 2.33 at the pound/day ingestion
rate; the corresponding Carr Inlet ratio is 1.01. For the lower
ingestion rates, no effect would be expected, when the data are
evaluated by waterway, it is clear that the highest risk (with a
ratio of exposure to ADI of 5) is presented by crabs from the
Hylebos. Ratios of exposure to ADI are about 4 in the Sitcum,
around 2.5 in Milwaukee WW crabs, and near 1 for all other
locations.
Ratio of Exposure to ADI < 1
The following chemicals are not expected to lead to adverse
human health effects due to their presence in crabs from
Commencement Bay. The ratio of exposure to ADI is, in all cases,
less than 1 for:
35

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Phenanthrene
Di-n-butyl phthalate
Naphthalene
Fluoranthene
Cadmium
Chromium
Manganese
Nickel
Selenium
DDE
4.1.3 Risks From Ingestion of Fish Livers
A total of 21 chemicals were detected in at least one fish
liver composite sample from Commencement Bay. Table G-5 presents
exposure and risk calculations for these 21 substances; the
findings are summarized below.
Four of the chemicals present are considered carcinogens:
hexachlorobenzene, hexachlorobutadiene, PCBs, and arsenic.
Maximum individual lifetime risks (based on daily consumption of
0.12 pounds of fish liver) was the highest for PCBs, with a risk
of 2 x 10 , slightly higher than the predicted risk for fish
muscle tissue contaminated with PCBs. The individual risk from
hexachlorobenzene in fish liver was, for the 0.12 pound per day
ingestion rate, around 10~4. Maximum lifetime individual risk
- s
for hexachlorobutadiene was 10 for persons eating 0,12 pounds
of fish liver daily. All other carcinogenic risks were predicted
to be much lower. As this is a worst-case scenario, and risks
from less frequent ingestion of liver are very low, it is
unlikely that this route of exposure is of great concern. A
possible exception is PCBs. Better estimates of liver ingestion
rates would improve this analysis.
All ratios of exposure to ADI for the noncarcinogens present
in fish livers from Commencement Bay are less than 0.1. No
effects attributable to these chemicals would be expected from
liver ingestion.
36

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One compound detected frequently in livers, and for which
analysis is thought to be conclusive, is benzyl alcohol. No
health effects information could be found regarding this
chemical. It is not known whether this chemical is present due
to biological degradation of another contaminant or is itself a
direct contaminant. The highest levels of contamination
(and, therefore, potential risk) were found in livers of fish
caught in the waterways. Only benzyl alcohol, phenol, di-n-butyl
phthalate, PCBs, and naphthalene were detected in Ruston shore
fish livers.
Risks associated with eating livers from fish caught in Carr
Inlet are somewhat lower than risks associated with Commencement
Bay fish livers. The only organic compounds detected in livers
from Carr Inlet fish were naphthalene, phenanthrene, PCBs, and
di-n-butyl phthalate; all but the PCBs were found at levels
associated with insignificant risk from noncarcinogenic effects.
There was little difference between levels of organics in Carr
Inlet and Commencement Bay fish livers, with the exception of
PCBs, which were present in Commencement Bay fish livers at
levels approximately fifteen times the levels at which they were
present in Carr Inlet fish liver composites. Maximum individual
carcinogenic risks from PCBs in Carr Inlet crabs are around 1 x
4•2 Risks for Chemicals Not Detected in Tissue Samples
Tables 5 and 6 present the results of assessing human health
risk on a worst-case basis for substances that were never
detected in either fish muscle or liver tissue. This assessment
is conservative in three senses:
•	Exposure was assumed to occur at the chemical's method
detection limit; the actual level could be anything between
zero and the method detection limit.
•	Exposures and risk were calculated for the highest intake
rates of fish and liver (453 g/day for fish, 54.4 g/day for
liver) .
37

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Table 5. Worst-Case Risk for Nondetected Noncarcinogenic Chemicals

Fish
and Crab
Fish Liver


Detection
i Ratio of
Detection
Ratio of

Limit
Exposure to ADI
Limit
Exposure to

ug/g

ug/g

Chlorobenzene
0.005
0.002
NA

Isophorone
0.01
0.0004
0.025
0.0022
Chloroethane
0.01
0.0000647143
NA

Dichloropropane-1,2
0.01
0.005
NA

Chloromethane
0.01
0.0001
NA

Bromomethane
0.01
0.003
NA

Dichloropropylene-1,3
0.01
0.03
NA

Chlorophenol-2,
0.02
0.001
0.05
0.0004
Dichlorophenol-2,4
0.02
0.001
0.05
0.0004
Nitrophenol-2,
0.02
0.06
0.05
0.0194
Trichlorobenzene-1,2,4
0.02
0.02
0.05
0.0059
Dichlorobenzene-1,2
0.02
0.00008
0.05
0.00003
Dichlorobenzene-1,4
0.02
0.00006
0.05
0.00002
Nitrobenzene
0.02
0.002
0.1
0.0014
Phenol
0.02
0.001
detected

D ime thylphenol-2,4
0.04
0.001
0.05
0.0004
DDD
0.05
0.008
0.2
0.004
a-Endosulfan
0.05
0.08
0.2
0.04
b-Endosulfan
0.05
0.08
0.2
0.04
Endosulfan sulfate
0.05
0.08
0.2
0.04
Endrin
0.05
0.3
0.2
0.2
Endrin aldehyde
0.05
0.3
0.2
0.2
Nitrophenol-4,
0.1
0.3
0.2
0.1
Dini trophenol-2,4
0.1
0.3
0.2
0.1
Acrolein
0.1
0.0001
NA

D imethy1phtha1ate
detected

0.025
0.001
Diethylphthalate
detected

0.025
0.00000002
Di-n-octyl phthalate
detected

0.025
0.00001
Dibenzofuran
detected

0.025
0.0022
Dichlorobenzene-1,3
detected

0.05
0.00002
Tr ichlorophenol-2,4,5
detected

0.1
0.001
DDE
detected

0.2
0.03
Dinitro-o-cresol-4,6
detected

0.2
0.2
MA = not analyzed for




38

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Table 6. Worst-Case Risk for Nondetected Carcinogenic Chemicals
Beryllium
Ganma-HCH
Aldrin
Carbon tetrachloride
Tr ichloroethane-1,1,1
Dichloroethane-1,1
Trichloroethane-1,1,2
Chloroform
Chlorod ibromomethane
Dichloroethylene-1,2
Tr ichloroethylene
Benzene
Dieldrin
High molecular weight
Dichloroethane-1,2
Bromoform
Bromodichloromethane
Dichloroethylene-1,1
Vinyl chloride
Nitrosodipropylamine
Trichlorophenol-2,4,6
BCEE
Dinitrotoluene
Chlordane
DDT
Heptachlor
Heptachlor epoxide
a-HCH
b-HCH
d-HCH
Acrylonitrile
DEHP
NDPhA
Hexachloroethane
NA = not analyzed for
Fish and Crabs	Fish Liver
Detection Risk at 1 lb.	Detection Risk at .12 lb
Limit per day Limit	per day
ug/g Ingestion Rate ug/g Ingestion Rate
detected

0.002
2.00E-06
0.004
3.44E-05
0.2
2.07E-04
0.004
2.95E-04
0.2
1.77E-03
0.005
2.69E-06
NA

0.005
5.18E-08
NA

0.005
2.80E-04
NA

0.005
1.85E-06
NA

0.005
5.92E-06
NA

0.005
5.92E-06
NA

0.005
6.73E-05
NA

0.005
6.15E-07
NA

0.005
1.68E-06
NA

0.008
1.57E-03
0.2
4.72E-03
PAH 0.01
7.44E-04
0.275
2.46E-03
0.01
2.39E-06
NA

0.01
1.18E-05
NA

0.01
1.18E-05
NA

0.01
6.73E-05
NA

0.01
1.13E-06
NA

0.02
4.01E-03
0.05
1.16E-03
0.02
2.58E-06
0.1
1.55E-06
0.02
3.62E-03
0.05
1.09E-03
0.02
4.03E-05
0.1
2.42E-05
0.05
5.21E-04
0.2
2.50E-04
0.05
2.72E-03
0.2
1.31E-03
0.05
1.09E-03
0.2
5.23E-04
0.05
1.22E-03
0.2
5.84E-04
0.05
3.59E-03
0.2
1.72E-03
0.05
5.95E-04
0.2
2.86E-04
0.05
5.95E-04
0.2
2.86E-04
0.1
3.57E-04
NA

detected

0.025
2.74E-06
detected

0.05
1.90E-07
detected

0.1
1.10E-06
39

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• The health data are, by their nature, generally conservative
(as discussed in Section 2).
Table 5 indicates that, even with this highly conservative
assessment method, exposure to noncarcinogenic chemicals never
exceeds the Acceptable Daily Intake (ADI) (see Table 5).
Maximum potential individual risks to the carcinogenic
chemicals range from 10~2 to 10~8, with the majority in the 10~5
and 10~6 range, as seen in Table 6 and summarized below.
Ingestion of a pound per day of fish muscle tissue could result
in the following maximum individual lifetime cancer risks greater
than 10"^:
For PAHs, it is assumed that the maximum risk, as calculated
above, would result from the presence of benzo (a)pyrene, a
carcinogen, at its detection limit; quantitative risk data for
other potentially carcinogenic PAHs are not available. It is
important to note that the risks calculated above and in Table 6
apply only to a small group of persons eating fish daily and that
they are overstated even for that group (for the reasons listed
at the beginning of this subsection). The more common ingestion
rates of one pound per week to one pound per year result in
correspondingly lower risk levels.
Of the eleven carcinogenic substances or chemical classes
listed above, only two (PAHs and n-nitrosodipropylamine) were
aldrin
1.1	dichloroethane
1.2	dichloroethylene
PAHs
bromo form
bromodichloromethane
1,1 dichloroethylene
bis (chloroethyl) ether
dinitrotoluene
n-nitrosodipropylamine
acryloni tr ile
4	x 10-3
3	x 10~4
7	x 10"5
2	x 10-3
1	x 10~5
1	x 10-5
7	x 10~5
4	x 10"3
4 x 10"5
4 x 10~3
4 x 10"4
40

-------
detected at quantifiable levels in the 1984 survey of
Commencement Bay sediments (Tetra Tech, in preparation). PAHs
are, by their chemical nature, common in sediments but are not
persistent in fish muscle tissue; they are rapidly metabolized. A
recent study of English sole exposed to sediments contaminated
with labeled benzo(a) pyrene (Stein et al. 1984) indicated that
the compound was present after a short time only as metabolites
in the liver and bile. N-nitrosodipropylamine was found in only
two of the 151 samples of sediment from the bay analyzed for that
compound.
41

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5.0 SUMMARY AND INTERPRETATION OF RISK ANALYSIS
The following conclusions are derived from the discussion
above. Many of the compounds detected in fish or crab muscle
tissue or in fish liver tissue were present at levels that
correspond to carcinogenic risks less than 10"^ or, for
noncarcinogens, ratios of exposure to the ADI of less than 1.0.
Those substances are not discussed below; only chemicals for
which exposure exceeds the ADI or for which predicted
carcinogenic risk exceeds 10"^ are addressed in this section.
Risks are discussed in terms of both relative risk, comparing
risk associated with eating Commencement Bay fish to
corresponding risks from Carr Inlet fish and other environmental
exposures, and as absolute risk experienced by the sportfishing
population and their families.
Means were calculated setting nondetected values equal to
the method detection limit, which (along with other assumptions)
may result in an overstatement of risk. Recall also that 70
years of continuous exposure is assumed to occur and all
statements of risk are predicated upon that assumption.
The results presented in the previous section lead to the
conclusions summarized below and in Table 7.
Maximum individual 1ifetime risks for persons eating fish
from Commencement Bay are 10— or greater because of the levels
of six contaminants: PCBs, arsenic, hexachlorobenzene,
hexachlorobutadiene, tetrachloroethene, and bis(2-ethylhexyl
phthalate (DEHP). Average risks at the highest rate of
ingestion, based on bay-wide mean levels, are as follows:
PCBs
6
X
10~3
arsenic
4
X
10~4
hexachlorobenzene
1
X
10~4
hexachlorobutadiene
2
X
10-5
DEHP
2
X
10~5
tetrachloroethene
1
X
10~5
42

-------
Table 7. Summary of Risk Assessment
Carcinogens Ingestion Carr Inlet Commencement Bay Ratio*
Rate	Risk	Risk
PCBS
1
lb./day
1E-03
6E-03

1
lb./week
1E-04
8E-04

1
lb./month
3E-05
2E-04

1
lb./2 mos
2E-05
9E-05

1
lb./6 mos
6E-06
3E-05

1
lb./year
3E-06
2E-05
Arsenic
1
lb./day
9E-04
4E-04

1
lb./week
1E-04
6E-05

1
lb./month
3E-05
1E-05

1
lb./2 mos
1E-05
7E-06

1
lb./6 mos
5E-06
2E-06

1
lb./year
2E-06
1E-06
HCB
1
lb./day
7E-05
1E-04

1
lb./week
1E-05
2E-05

1
lb./month
1E-06
4E-06

1
lb./2 mos
7E-07
2E-06

1
lb./6 mos
2E-07
7E-0

1
lb./year
1E-07
3E-07
HCBD
1
lb./day
2E-05
2E-05

1
lb./week
3E-06
3E-06

1
lb./month
4E-07
7E-07

1
lb./2 mos
2E-07
3E-07

1
lb./6 mos
7E-08
1E-07

1
lb./year
3E-08
5E-08
Tetrachloro-
1
lb./day
2E-06
1E-05
ethene
1
lb./week
2E-07
2E-06

1
lb./month
5E-08
5E-07

1
lb./2 mos
3E-08
2E-07

1
lb./6 mos
9E-09
8E-08

1
lb./year
4E-09
4E-08
DEHP
1
lb./day
3E-06
2E-05

¦ 1
lb./week
5E-07
3E-06

1
lb./month
1E-07
6E-07

1
lb./2 mos
5E-08
3E-07

1
lb./6 mos
2E-08
1E-07

1
lb./year
8E-09
5E-08
43

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Table 7. (continued)


Noncarcinogens





Ingestion
Carr Inlet Ratio
C. Bay Ratio


Rate
Exposure/ADI
Exposure/ADI
Ratio
Antimony
lb./day
1.66
1.57
0.9

. lb./week
0.24
0.22


lb./month
0.03
0.05


lb./2 mos
0.02
0.03


lb./6 mos
0.01
0.01


lb./year
0.005
0.005

Lead
lb./day
0.99
0.99
1.0

lb./week
0.14
0.14


lb./month
0.03
0.03


lb./2 mos
0.02
0.02


lb./6 mos
0.01
0.01


lb./year
0.005
0.005

Mercury
lb./day
1.20
1.35
1.1

lb./week
0.18
0.19


. lb./month
0.04
0.04


lb./2 mos
0.02
0.02


. lb./6 mos
0.01
0.01


lb./year
0.005
0.005

Zinc
. lb./day
1.43
1.20
0.8
(crabs)
. lb./week
0.20
0.17


lb./month
0.05
0.04


lb./2 mos
0.02
0.02


lb./6 mos
0.01
0.01


lb./year
0.005
0.005

Silver
lb./day
5.58
3.92
0.7
(crabs)
. lb./week
0.80
0.56


lb./month
0.19
0.13


lb./2 mos
0.09
0.06


lb./6 mos
0.03
0.02


lb./year
0.01
0.01

Risk via fish muscle tissue ingestion unless noted otherwise
* Ratio of risk from Commencement Bay seafood to risk from Carr Inlet
seafood
44

-------
Individual risks at lower ingestion rates are proportionately
lower.
Three carcinogenic compounds are present in fish and crab
muscle tissues at levels di fferent from the levels in Carr Inlet
fish and crab muscle tissues— PCBs, tetrachloroethene, and
DEHP. In the following discussion, all risks are individual
risks at the highest level of consumption (one pound per day).
The exposure that could result from eating Commencement Bay fish
and crabs can also be put in perspective by comparing the levels
at which they are present in Commencement Bay fish to levels in
fish from other areas. Table 8 summarizes some readily available
information on these three chemicals as well as the other
pollutants discussed in this summary.
The risk due to consumption of fish containing PCB is higher
for fish from Commencement Bay (6 x 10""^) than for fish from Carr
Inlet (1 x 10""*). The calculated risk due to consumption of fish
decreases as one moves away from the City Waterway (1 x 10"^)
toward the Ruston shoreline (2 x 10""*). It should be noted that
the major dietary source of PCBs is fish. PCBs are common
pollutants of fish and other aquatic organisms. It is apparent
from Table 8 that the PCB levels in fish from Commencement Bay
are well within the reported ranges for fish taken from other
industrialized areas.
The risk due to consumption of tetrachloroethene in
Commencement Bay fish (1 x 10"5) exceeds the risk due to that
pollutant from ingestion of Carr Inlet fish (3 x 10""^).
Volatiles were not assayed for in the Ruston samples. In the
waterways, risks ranged from 2 x 10~5 in the Hylebos and St. Paul
Waterways to 8 x 10 in the City Waterway. The levels of this
common industrial solvent in fish caught throughout the U.S. are
listed in Table 8; levels in Commencement Bay fish are at the
high end of the range. Exposure to DEHP is commonly experienced
in the U.S. because this chemical is a component of all plastic
vinyl products, as shown in Table 8. The calculated risks due to
the presence of DEHP in fish averaged 2 x 10"^ in Commencement
Bay and 3 x 10~® in Carr Inlet. The mean values of DEHP in this
45

-------
Table 8. Comparative Exposure for Contaninants of Concern


AVERAGE LEVEL




CHEMICAL

IN FISH FROM

DESCRIPTION

OTHER

COMMENCEMENT


OF

EMVIROfWENTAL

BAY
CARR INLET
OTHER AREAS
DATA
SOURCK
EXPOSURES

pp*> (ng/g)
Pffc (ng/g)
PPb (ng/g)


ug/day
PCBS
210
36
320
pelaware Bay, 7 fish, 1982
Belton et al. 1962
8.7 (dietary)



14 to 410
Los Angelas, 1980, 65 samples of croaker
Gossett et al. 1983
USEPA 1980



300 to 3280
Hudson River, 8 species, 1981 survey
Belton et al. 1982




100 to 13100
New Bedford Harbor, 1978-1980
Weaver 1983




1100
polluted areas of U.S., Dover sole
see Appendix H




16
refeter»ce areas of U.S., Dover sole
see Appendix H




555
polluted areas of U.S., starry flounder
see Appendix l(




25.5
reference areas of U.S., starry flounder
see Appendix H

IICB
11
<10
0.9
polluted areas of U.S., winter flounder
see Appendix H
0.074



0.92
reference areas of U.S., winter flounder
see Appendix H
USEPA 1980
HCBO
40
<40
unknown


unknown
DEHP
194
35
290
332 Japanese shellfish samples
Versar 1982
55 to 14,230



30
FDA (1974), Mobile Bay, AL
Versar 1992
Versar 19B2



1200
FLA (1974), San Francisco, CA
Versar 1982




14600
Survey of hatchery salmon
Vetsar 1982

Tetra-
66
7
<1 to 41
marine fish in north Atlantic
Pearson and McConnell
0.0018 to 17.
chloroethene




from consumer
antimony
1009.3
1070
unknown


Versar 1981
mercury
59.5
55.4
96.0
NOAA survey of 1179 flatfish
NOAA 1978
3.4 (dietary)



55
polluted areas of U.S., Dover sole
see Appendix H
USEPA 1983



157
reference areas of U.S., Dover sole
see Appendix H




60
polluted areas of U.S., winter flounder
see Appendix K




40
reference areas of U.S., winter flounder
see Appendix H

lead
218
218
73
polluted areas of U.S., Dover sole
see Appendix H
113 (total)

(fish)

78
reference areas of U.S., Dover sole
see Appendix H
USEPA 1980

479
196
900
polluted areas of U.S., Eastern rock crab
see Appendix 11


(crab)

589
reference areas of U.S., Eastern rock crabsee Appendix H

silver	138	197	390	polluted areas of U.S., American lobster see Appendix H	30 (dietary)
(crab)	555	reference areas of U.S., American lobster see Appendix M	USEPA 1990
270	polluted areas of U.S., Eastern rock crab see Appendix H
250	reference areas of U.S., Eastern rock crabsee Appendix 0
39895	47410	4(7080 polluted areas of U.S./ Eastern rook crab see Appendix JJ
(crab)	37245 reference areas of U.S., Eastern rock crabsee Appendix H
15000
Recommended Daily
Allowance
4070
7940 1400 to 17000 Discovery Bay, Piyjet Sound, 1982 Gahler et al. 1982 3.4 to 34000
1703 polluted areas of U.S., California mussel see Appendix li	in Tacoma
2300 reference areas of U.S., Cal ifornia musselsee >ippeix]ix II	Scliaum 1982

-------
survey of fish and crab muscle tissue are well within the range
of values reported elsewhere for similar studies, as seen in
Table 8.
Predicted maximum individual 1 ifetime risks from consumption
of fish exceeds 10— for both Commencement Bay and Carr Inlet due
to the presence of arsenic. The risk due to consuming fish
containing arsenic was calculated by assuming that 0.12% is in
the inorganic form. Risks from Commencement Bay fish are around
4 x 10-^, while risks from eating Carr Inlet fish are around 7 x
10"^. Although absolute estimated risks are on the order of 10"^
for persons eating a pound of fish muscle tissue daily, available
data (see Table 8) indicate that seafood in general contains
arsenic at levels approximately equal to those found in this
study.
Two carcinogens were detected only in fish from the Hylebos
Waterway. Hexachlorobenzene and hexachlorobutadiene were
detected in only two of the fifteen fish taken from the Hylebos
Waterway. The levels at which they were detected were only
slightly higher than the method detection limits, corresponding
to risks of 1 x 10~4 and 2 x 10~5 for hexachlorobenzene and
hexachlorobutadiene, respectively; risks from Carr inlet fish, as
calculated from the method detection limit, were 7 x 10~5 and 2 x
10"^ respectively. Risks from these pollutants in Carr Inlet
fish, in which they were not detected, could be anywhere between
zero and the maximum risks calculated above.
Limiting consumption of fish to one half pound a day would
result in exposure less than the Acceptable Daily intake for all
noncarcinogenic substances detected. Three chemicals are present
i n fish a t levels that would cause exposure to exceed the AD I at
a one pound per day consumption rate. Those three chemicals are
metals: antimony, lead, and mercury. Only for the pound per day
rate of ingestion could exposure exceed the ADI. There is
essentially no difference in the levels of these metals,
regardless of where the tissue samples were collected, and
therefore no difference in risk between Commencement Bay and the
Carr Inlet reference area. For comparison, reported levels of
47

-------
these chemicals in fish tissues from other areas are summarized
in Table 8.
Most chemicals that were analyzed for but not detected in
fish muscle tissue were also not detected in sediments. For two
chem icals that were not detected in f ish muscle, but were
detected in sediments, calculated risks at the method detection
limit were greater than 10—. As discussed previously in
Section 4, the majority of.the chemicals not detected in fish or
crab muscle tissue (35 of 48) were also not detected in sediment
analyses. The two chemicals were detected in sediments and, if
present in fish at the method detection limit, would result in
maximum risks greater than 10"^: PAHs (3 x 10"^) and n-
ni trosodipropylamine (4 x 10 ~* ^). Neither of these is, however,
expected to persist in fish muscle at levels near the detection
limit. PAHs have been shown to be fairly rapidly cleared from
muscle of English sole (Stein et al. 1984), appearing as liver
and bile metabolites. N-nitroso-dipropylamine was detected in
only 2 of 151 sediment samples, both from the Blair Waterway.
These findings constitute evidence that the chemicals analyzed
for but not detected in this study are not a significant threat
to human health.
In general, fish from the waterways are more contam inated
with the chemicals of concern 1 isted above than are fish from the
Ruston shoreline area. The Ruston shoreline and the City
Waterway have been found by Pierce et al. (1981) to be the areas
most frequently fished. Risks from eating fish caught in the
Ruston area are elevated above the bay-wide average for arsenic
only. Recall that for arsenic the highest risks were predicted
for eating fish from the Carr Inlet reference area. The
assessment of PCB risk, if addressed on a station-by-station
basis, indicates that PCB levels decline, as one moves toward Pt.
Defiance, with distance from the waterways. The City Waterway
was found to have the highest predicted individual lifetime risks
from PCBs and DEHP; risks attributable to the other carcinogens
assessed were average or below average as compared to the other
areas of the Bay and Carr Inlet. The PCB and DEHP risks at the
City Waterway, though elevated, were within a factor of 10 of the
calculated risks for the other areas.
48

-------
Carcinogenic risks from PCBs were also higher in the Hylebos
Waterway fish than in other areas. In addition, the Hylebos
Waterway was the only waterway in which hexachlorobenzene and
hexachlorobutadiene were detected in fish muscle tissues. Risk
from the presence of tetrachloroethene was also highest from
ingestion of this waterway's fish. Recall, however, that
volatiles were monitored for only in the Hylebos, St. Paul, and
City Waterways and Carr Inlet.
Finally, for no pollutant found in Commencement Bay fish
tissue were measured levels above the range reported elsewhere,
as seen from the data in Table 8.
Risk from ingestion of fish 1iver is difficult to estimate;
available data indicate that maximum individual 1ifetime r isks
due to the presence of three carcinogens detected in liver
composites could exceed 10—. At an ingestion rate of 0.12
pounds per day, the risk from PCBs in liver is 10~2; the risk
from hexachlorobenzene, 10""*; and the risk from
hexachlorobutadiene, 10"^. For no noncarcinogen did predicted
exposure from ingestion of livers exceed the ADI.
Risks from ingesting crab muscle tissue are approximately
the same as risks from eating fish muscle tissue. Bay-wide
average risks, based on consuming a pound per day, were as
fo1 lows:
PCBs	3 x 10~3
— 4
Arsenic	2 x 10
DEHP	3 x 10~6
Risks for all other carcinogens were less than 10"^. Average
risks from eating Commencement Bay crabs were greater than risks
from Carr Inlet crabs only for PCBs (with average Carr Inlet
risks of 1 x 10""3). Risks were equal in both areas for arsenic,
and DEHP risks were higher in Carr inlet crabs than in
Commencement Bay crabs. Exposure exceeded the ADI for the
following contaminants for persons consuming one pound of crab
muscle daily: antimony, lead, silver, zinc, and mercury. The
differences between Commencement Bay and Carr Inlet levels of the
49

-------
noncarcinogens were slight; only for mercury did Commencement Bay
levels (ratio of exposure to ADI of 2.33) exceed Carr Inlet
levels (ratio of exposure to ADI of 1.01). Consumption of less
than one pound of crab muscle per week would bring exposure
consistently below the ADI for all noncarcinogens.
The highest estimated incidence of cancer in the exposed
population of 15,220 persons is one to two cases of cancer in 70
years, attributable to PCBs causing cancer of the liver. For all
other carcinogens, the predicted incidence is less than _1 case.
All available data indicate that the chemical associated with the
highest individual lifetime cancer risk is PCBs; the next highest
risk is attributable to arsenic. Table 9 presents a calculation
of the maximum predicted cancer cases attributable to the two
chemicals over a 70-year exposure period. Only for PCBs does the
predicted number of cases exceed 1, even with the conservative
approach taken in this assessment (continuous exposure for 70
years, etc.). As arsenic exposure is predicted to result in
fewer than 1 case over 70 years, and it is the second highest in
individual risk, the presence of no other chemical is likely to
produce cancer among the exposed population under the types of
circumstances presented in this assessment.
"7 m
-2.1.
50

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Table 9. Projected Lifetime Cancer Cases
PCBs

Fish




Frequency
Intake
Exposure
Individual



g/day
mg/kg/day
Risk
Population
Cases
Daily
453.0
1.36E-03
5.90E-03
30
0.18
Weekly
64.7
1.94E-04
8.42E-04
1005
0.85
Monthly
15.1
4.53E-05
1.97E-04
1735
0.34
Bimonthly
7.4
2.22E-05
9.63E-05
1111
0.11
Twice/year
2.5
7.50E-06
3.26E-05
2618
0.09
Yearly
1.2
3.60E-06
1.56E-05
8721
0.14



Total
15220
1.69
Arsenic






Fish




Frequency
Intake
Exposure
Individual



g/day
mg/kg/day
Risk
Population
Cases
Daily
453.0
3.16E-05
4.42E-04
30
0.01
Weekly
64.7
4.51E-06
6.31E-05
1005
0.06
Monthly
15.1
1.05E-06
1.47E-05
1735
0.03
Bimonthly
7.4
5.16E-07
7.22E-06
1111
0.01
Twice/year
2.5
1.74E-07
2.44E-06
2618
0.01
Yearly
1.2
8.37E-08
1.L7E-06
8721
0.01



TOTAL
15220
0.13
51

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53

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