U.S. Department of the Interior USGS Fact She

U.S. Geological Survey 

NATIONAL WATER-QUALITY ASSESSMENT PROGRAM Prepared in cooperation with 

Washington State Department of Ecology

PCBs inTissue of Fish From the Spokane R

Washington, 1999

Electrofishing on the Spokane River, Washington

(Photograph by Ken Skinner, U.S. Geological Survey)

Several studies over the past 6 years have indicated that elevated concentrations of polychlorinated biphenyls (PCBs) in the Spokane River, 

Washington, are a potential hazard to human and 

aquatic health. To help address these concerns, 

fish were collected from the Spokane River in 1999 

and analyzed for PCBs for a cooperative study by 

the U.S. Geological Survey (as part of the National Water-Quality Assessment Program) and the 

Washington State Department of Ecology. This 

Fact Sheet summarizes comparisons of PCB concentrations in fish tissue recommended by national criteria with concentrations in fish tissue analyzed for this 1999 cooperative study and for 

previous studies.

Introduction

A cooperative study between the U.S. Geological 

Survey (USGS) and the Washington State Department of 

Ecology (WDOE), completed in July 1999, documented 

elevated concentrations of polychlorinated biphenyls 

(PCBs) in sportfish (rainbow trout and whitefish) and largescale suckers in the Spokane River, northeastern Washington. Concentrations of PCBs in fillets of sportfish collected from four sites on the Spokane River ranged from 0.07 

to 1.61 parts per million (ppm—1 part PCB to 1 million 

parts of tissue). These concentrations exceed the human 

consumption criterion of 0.0053 ppm for edible fish tissue. 

Concentrations of total PCBs in most of the rainbow trout 

(whole body and fillets) and largescale sucker (whole 

body) samples exceed the criterion of 0.11 ppm for fish-eating wildlife. When these data are added to data from previous studies during 1993–94 and 1998–99, it is evident that 

concentrations of PCBs in fish have remained 10 times 

higher than the criteria for more than 6 years. The 1999 

cooperative study, which focused on edible fish

information to help evaluate human health risk 

ed in a health advisory for Spokane River fish c

tion, issued on March 7, 2001. The advisory is 

at the Washington Department of Health Web p

http://www.spokanecounty.org/health/EHS/Adv

SR_Fish_PCBi.htm

What Are PCBs?

PCBs are a group of similar, manufactured

chlorine chemicals. Their primary use was to in

trical equipment such as high-voltage transform

also were used in a wide variety of other materi

ing heat-transfer fluids, hydraulic fluids, plastic

and dyes, oils, pesticide preparations, adhesives

servatives, and fluorescent light fixtures. They 

manufactured in 1929. Peak production in the U

States was 38,600 tons in 1970 (Smith and othe

PCBs are long-lived in the environment an

mulate (increase in concentration) in fish and ot

mals where they can be toxic. They are consider

carcinogens (cancer-causing agents) and have b

cated in other serious human health effects (U.S
2

Table 1. Summary of samples collected for thr

studies at four sites on the Spokane River, Wash

[WDOE, Washington State Department of Ecol

USGS, U.S. Geological Survey; NAWQA, Natio

Water-Quality Assessment Program]

Study

Sample 

description Fish sp

WDOE, 

1993–94

3–5 composites of 

5–8 fillets

Rainbow 

mountain 

fish

1–2 composites of 

5 whole fish

Largescal

sucker

USGS 

NAWQA, 

1998–99

1 composite of 8 

whole fish

Largescal

sucker

USGS/WDOE, 

1999

5–8 fillets analyzed 

individually

1 composite of 5 

whole fish

Rainbow 

mountain 

fish

1–2 composites of 

5 whole fish

Largescal

sucker

Spokane River near Post Falls, Idaho, 1999. (Photograph by

Terry R. Maret, U.S. Geological Survey)

mental Protection Agency, 1998, online). Human exposure to PCBs is predominantly dietary, especially through 

consumption of fish (U.S. Environmental Protection Agency, 1999a). Manufacture of PCBs in the United States ended in 1977, but because of their environmental persistence, 

significant amounts of PCBs remain in the environment 

today. 

Two hundred and nine different forms, or congeners, 

of PCBs exist. They differ in the number and location of 

chlorine atoms in the molecule. In the United States, PCBs 

were sold as mixtures of congeners under the trade name 

Aroclor1. Aroclor mixtures are identified by their number; 

for example, Aroclor 1254 contains PCB congeners with 

1 or 2 chlorine atoms and an average chlorine content of 

54 percent by weight. Total PCBs were estimated by adding Aroclor 1248, 1254, and 1260.

Study Background

PCBs have been identified in previous studies as contaminants of potential ecological concern in the Spokane 

River. The origin of PCBs in the Spokane River is probably 

past industrial activities or other direct discharges along the 

river (Washington State Department of Ecology, 1995; 

Golding, 1996). Organochlorine compounds, including 

PCBs, were analyzed in whole-body fish from 16 sites 

throughout the Northern Rockies Intermontane Basins 

study area in eastern Washington, northern Idaho, and 

western Montana as part of the National Water-Quality 

Assessment (NAWQA) Program in 1998 and 1999 (fig. 1). 

Total PCBs were detected in tissue of fish from 15 of the 

16 sites examined for contaminants. Concentrations of 

PCBs were highest in fish from the Spokane River and its 

tributaries downstream from Post Falls, Idaho. PCB concentrations detected in fish from the Spokane River during 

that study exceeded the 0.11 ppm criterion set f

tection of fish-eating wildlife (Newell and othe

and the 0.0053 ppm human consumption criteri

ble fish tissue (U.S. Environmental Protection A

1999b). Previous studies by WDOE in 1993 an

have documented elevated concentrations of PC

Spokane River. 

A study by Maret and Dutton (1999) docu

presence of PCBs in the Spokane River and sum

information on synthetic organic compounds in 

ern Rockies Intermontane Basins. These investi

reported PCB concentrations in Spokane River 

sediment that exceeded Washington's freshwate

screening guideline of 0.021 ppm for total PCB

(2000) also reported elevated concentrations of 

bottom sediment at sampling sites immediately 

from Upriver Dam, which suggests that sedime

sible source of PCBs available for ingestion by 

in sediment are not discussed in this Fact Sheet

tional information can be found in WDOE repo

ington State Department of Ecology, 1995; Gol

and at the USGS Web site http://idaho.usgs.gov

spokane/index.html

Other contaminants such as zinc and other 

elevated in the Spokane River sediment and tiss

(Maret and Skinner, 2000). An ecological risk a

of elevated metal concentrations in the Spokane 

pared for WDOE indicated that zinc in aquatic 

intensify the effects of PCBs in fish and other a

ganisms (Kadlec, 2000). 

1Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government.
3

Figure 1. Location of cooperative U.S. Geological Survey/Washington State Department of Ecology 1999 study a

and river mile sampling site locations, Spokane River, Washington, within the National Water-Quality Assessment

(NAWQA) Northern Rockies Intermontane Basins study area.

EXPLANATION

63

River mile marker—Sampling site location

 number, below, is mileage from mouth of 

 Spokane River at 7 Mile bridge, Washin

 Spokane River below Greene Street at

 Spokane, Washington

 Spokane River at Sullivan Road bridge 

 Trentwood, Washington (Plantes Fe

 Spokane River above Liberty bridge a

 Harvard Road near Otis Orchards,

 Washington (State line)

77

85

96

EXPLANATION

National Water-Quality Assessment (NAWQA)

 Northern Rockies Intermontane Basins

 sampling sites, 1998–99

IDAHO

WASHINGTON MONTANA

Northern Rockies

Intermontane Basin

NAWQA study area

0

0

20

20

40 MILES

40 KILOMETERS

49°

47°

46°

49°

48°

47°

46°

118°

118°

117°

116°

116°

114°

114°

117°

115°

115°

113°

113°

48°

Pend Oreille

River

Spokane Coeur

d' Alene

Coeur

Coeur

d' Alene

Lake

Pend

Oreille

Lake

Spokane

Missoula

Kalispell

Flathead

Flathead

Lake

Clark

Fork

Clark

Blackfoot

Butte

Bitterroot

River

Fork

River

River

d' Alene

River

River

South Fork

Base from U.S. Geological Survey digital data,

1:100,000, 1994; Urban areas, 1:2,000,000, 2001; 

Albers Equal-Area Conic projection

Standard parallels 46° 00', 48° 30',

central meridian -115° 00',

No false easting or false northing

North

Fork

117° 30' 117° 22' 30" 117° 15' 117° 00'

47° 37' 30"

47° 45'

117° 07' 30"

Little

Spokane

River

River

Spokane

River

Spokane

Creek

Hangman

63

77

85

96

Upriver

Dam

Nine Mile

Dam

Spokane

Post

Falls

WASHINGTON

IDAHO

Long Lake

0

0

2

2

4 6 8 KILOMETERS

4 6 8 M
4

Figure 3. PCBs in tissue of whole-body largescale 

from four sites on the Spokane River, Washington, 1

and 1998–99. [River mile markers shown on figure 

from Washington State Department of Ecology (WDO

1993–94 (Washington State Department of Ecology

U.S. Geological Survey (USGS) National Water-Qua

Assessment (NAWQA) study, 1998–99; and coopera

USGS/WDOE study, 1999 (U.S. Geological Survey, 

TO

TAL PCBs, IN PARTS PER MILLION

(ppm), WET WEIGHT 

0.001

0.01

0.1

1.0

0.004

0.04

0.4

4.0

Flow direction

Fish-eating wildlife

criterion 0.11 ppm

(Newell and others, 1987)

WDOE study, 1993–94

USGS NAWQA study, 1998–99

USGS/WDOE study, 1999

EXPLANATION

63 77 85

Sampling Methods and Analysis RIVER MILE

In July 1999, the USGS collected fish from four sites 

on the Spokane River (indicated by river mile marker in 

fig. 1). Fish were collected using EPA methods (U.S. Environmental Protection Agency, 2000), and tissue samples 

were analyzed by WDOE for PCB Aroclors and some 

PCB congeners.

Whole-body composites (five fish combined for one 

analysis) and individual fillet samples were collected. 

Three species of fish—rainbow trout, mountain whitefish, 

and largescale sucker—were collected to obtain information on individual species bioaccumulation of PCBs for 

ecological risk assessment and human health evaluations 

(Johnson, 1999). Specific protocol for fish tissue analysis 

can be found in the WDOE Quality Assurance Project Plan 

(Johnson, 1999). A summary of samples collected for the 

1993–94 WDOE study, the 1998–99 USGS NAWQA Program study, and the 1999 USGS/WDOE cooperative study 

is given in table 1. These three studies had different objectives, and the samples were analyzed and the da

rized differently. Therefore, only a general com

among the three studies is made in this Fact She

Summary of Findings

Total PCB concentrations in tissue sample

fish collected from four sites on the Spokane R

the 1993–94 and 1999 studies are summarized i

Concentrations in all fish fillets and whole-bod

exceeded the edible fish tissue criterion of 0.00

fact, the concentrations of PCBs in fish tissue we

higher than the criterion and have been at this l

past 6 years. Concentrations were highest in rai

fillets collected in 1999 behind Upriver Dam at 

mile 85. The PCB concentrations in Spokane R

were about 100 times higher than those in more 

streams in Washington (Serdar, 1999).

Total PCB concentrations in whole-body s

largescale suckers are summarized in figure 3. A

Figure 2. PCBs in tissue of sportfish from four sites on the

Spokane River, Washington, 1993–94 and 1999. [River mile

markers shown on figure 1; data from Washington State Department of Ecology (WDOE) study, 1993–94 (Washington

State Department of Ecology, 1995); and cooperative U.S.

Geological Survey (USGS)/WDOE study, 1999 (U.S. Geological Survey, 1999)] TO

TAL PCBs, IN PARTS PER MILLION

(ppm), WET WEIGHT

0.001

0.01

0.1

1.0

0.004

0.04

0.4

4.0

Flow direction

63 96 77 85

Edible fish tissue criterion

0.0053 ppm (U.S. Environmental

Protection Agency, 1999)

Composite of five to eight fillets from WDOE study, 1993–94

Composite of five whole bodies from USGS/WDOE study, 1999

Individual fillet from USGS/WDOE study, 1999

Hatchery fillet from USGS/WDOE study, 1999

EXPLANATION

Rainbow troutRainbow troutRainbow troutRainbow trout

Mountain whitefishMountain whitefish

Mountain whitefish

Mountain whitefish

Rainbow trout

Rainbow troutRainbow trout

RIVER MILE
5

Rainbow trout, Oncorhynchus mykiss, South Fork Coeur

d'Alene River, Idaho, 2000. (Photograph by Dorene MacCoy,

U.S. Geological Survey)

trations of PCBs in whole-body suckers exceeded the fisheating wildlife criterion. As previously stated, PCBs can 

accumulate in tissue and biomagnify (increase incrementally) at each level of the food chain, which causes high 

risk to predatory wildlife such as eagles and river otters.

With the additional data collected for the 1999 USGS/

WDOE study, a more thorough analysis of the risk to human health could be done. As a result, a health advisory 

has been issued by the Washington State Department of 

Health and the Washington State Department of Ecology. 

A summary of the advisory is given on the back of this 

Fact Sheet. Further investigation of the biological community structure and habitat is needed to fully understand the 

environmental risks of PCBs in the Spokane River.

References Cited

Golding, S., 1996, Spokane River PCB source monitoring follow-up study November and December 1995: Olympia, 

Wash., Washington State Department of Ecology, Environmental Investigations and Laboratory Services Program, 

Publication no. 96–331, 15 p.

Johnson, A., 1999, Metals and PCB analysis of Spokane River 

fish and crayfish samples collected in 1999, quality assurance project plan: Olympia, Wash., Washington State 

Department of Ecology, Environmental Assessment Program, 8 p.

———2000, Reconnaissance survey on metals, semivolatiles, 

and PCBs in sediment deposits behind Upriver Dam, Spokane River: Olympia, Wash., Washington State Department 

of Ecology, Publication no. 00–03–021, 19 p.

Kadlec, M., 2000, Ecological risk analysis of elevated metal concentrations in the Spokane River, Washington: Olympia, 

Wash., Prepared for the State of Washington Department of 

Ecology, Toxics Cleanup Program, Contract no. C0000233, 

78 p.

Maret, T.R., and Dutton, D.M., 1999, Summary of information 

on synthetic organic compounds and trace elements in tissue 

of aquatic biota, Clark Fork-Pend Oreille and Spokane River 

Basins, Montana, Idaho, and Washington, 1974–96: U.S. 

Geological Survey Water-Resources Investigatio

98–4254, 55 p.

Maret, T.R., and Skinner, K.D., 2000, Concentration

trace elements in fish tissue and streambed sedi

Clark Fork-Pend Oreille and Spokane River Ba

ington, Idaho, and Montana, 1998: U.S. Geolog

Water-Resources Investigations Report 00–415

Newell, A.J., Johnson, D.W., and Allen, L.K., 1987, 

River biota contamination project—fish flesh cr

civorous wildlife: New York State Department o

Environmental Conservation, Division of Fish a

Bureau of Environmental Protection, Technical 

87–3, 182 p.

Serdar, D., 1999, PCB concentrations in fish from W

(Thurston County) and the Lower Elwha River: 

Wash., Washington State Department of Ecolog

mental Assessment Program, Publication no. 98

Smith, J.A., Witkowski, P.J., and Fusillo, T.V., 1988

organic compounds in surface waters of the Uni

a review of current understanding: U.S. Geolog

Circular 1007, 92 p.

U.S. Environmental Protection Agency, 1998, Health 

PCBs: U.S. Environmental Protection Agency, O

lution Prevention and Toxics, accessed May 16, 

URL: http://www.epa.gov/pcb/effects.htm

———1999a, Polychlorinated biphenyls (PCBs) up

impact on fish advisories: Washington, D.C., U

mental Protection Agency, EPA 823–F–99–01

———1999b, Water quality standards; Establishmen

criteria for priority toxic pollutants; States’ com

revision of polychlorinated biphenyls (PCBs) cr

rule: Federal Register, 40 CFR, Part 131, p. 611

———2000, Guidance for assessing chemical conta

for use in fish advisories, vol. 1, fish sampling a

3d ed.: Washington, D.C., U.S. Environmental P

Agency, EPA 823–B–00–007 [variously paged

U.S. Geological Survey, 1999, Spokane River studie

May 16, 2001, at URL: http//idaho.usgs.gov/pro

spokane/index.html

Washington State Department of Ecology, 1995, De

Ecology 1993–94 investigation of PCBs in the 

River: Olympia, Wash., Toxic Investigations Se

Environmental Investigations and Laboratory S

Program, Publication no. 95–310, 54 p., 5 apps

—Dorene E. MacCoy

For additional information about this study, contact:

Dorene E. MacCoy

U.S. Geological Survey

230 Collins Road

Boise, ID 83702-4520

demaccoy@usgs.gov

Additional information about the Northern Rockies In

Basins NAWQA study is available at URL: 

http://montana.usgs.gov/nrok/nrokpage.htm

This Fact Sheet can be viewed in PDF format at UR

http://idaho.usgs.gov/public/reports.html
Background

The Spokane River has been impacted by many years 

of mining in the region and industrial discharge. Pollutants from these sources have been found in both 

sediment and fish. The Washington State Department 

of Health and the Spokane Regional Health District 

have found that some of these pollutants in fish are 

high enough to recommend consumption limits for the 

area indicated in the map below.

What are the contaminants and species of concern?

Lead and polychlorinated biphenyls (PCBs) were 

found at elevated levels in three fish species tested: 

rainbow trout, mountain whitefish, and largescale 

suckers.

What are the harmful effects of PCBs and lead? Who 

should be concerned?

Pregnant women and women considering pregnancy should carefully follow the meal limits given 

in table 1. The fetus is particularly susceptible to the 

harmful effects of lead and PCBs when the mother 

eats contaminated fish. Such effects can include learning problems that appear during childhood years. 

Negative effects on a child s behavior and ability to learn 

can also occur in children exposed to lead from birth 

through six years of age. Because lead was found at 

higher levels in whole fish samples, it is especially 

important for children under age six to eat only fillets according to the meal limits in table 1.

Animal studies have shown that PCBs affect th

reproductive and immune systems, liver and th

PCBs may cause cancer in humans. All adults 

children should observe the meal limits give

table 1. 

How much fish from the Spokane River should 

eat?

No one should eat rainbow trout or mountain w

fish caught between Upriver Dam and the WA

state line. The advised fillet meal limits given 

1 below are considered protective of all adults 

(including pregnant women) and children. All 

should be prepared as fillets because whole 

have higher levels of lead and PCBs. 

Table 1. Suggested fillet meal limits 

For additional information

For additional information, please contact the 

ington State Department of Health toll-free at 

485-7316 or the Spokane Regional Health Dis

(509) 324-1560 ext 3. The complete advisory 

able at: http://www.spokanecounty.org/health/

Advisories/SR_Fish_PCBi.htm.

Fish Species Recommendat

Above Upriver Dam to WA / ID state lin

Rainbow trout None

Mountain whitefish None

Largescale suckers One meal per mon

Below Upriver Dam to Nine Mile Dam

Rainbow trout One meal per mon

Mountain whitefish One meal every ot

month

Largescale suckers One meal per mon

Health Advisory for Spokane River Fish Consumpti

Update, March 2001

Note: One meal equals 8 ounces of fish for the av

adult. Meal sizes are assumed to be less for childr

Upriver Dam

Nine

Mile

Dam State Line

Spokane River

Washington Idaho

North

Advisory Area

(between these points)

Nine Mile Dam and WA/ID state line

Spokane

Printed on recycled paper Printed on recycled paper 6