Publication Summary

During 2008, the Washington State Toxics Monitoring Program analyzed 36 fish tissue samples representing 16 species of fish from 25 freshwater sites in Washington. Contaminants frequently detected were mercury, PCBs, PBDE flame retardants, 4,4-DDE, and dioxins and furans.

Contaminant levels in 24 samples from 14 sites did not meet Washington's water quality standards. Contaminants not meeting standards were PCBs, toxaphene, 4,4′-DDE, dioxins/furans, hexachlorobenzene, and dieldrin.

Recommendations include (1) add 14 sites to the federal Clean Water Act Section 303(d) list, and (2) evaluate results to assess risks to human health from the consumption of contaminated fish.

Between 2001 and 2008, the Washington State Toxics Monitoring Program (WSTMP) exploratory monitoring component characterized toxic contaminants in 268 fish tissue samples from 129 sites. Results from the 2008 sampling are reported for 25 sites across Washington State representing 13 freshwater species of fish. Contaminants assessed were persistent, bioaccumulative, and toxic chemicals (PBTs) such as mercury, PCBs, dioxins and furans, chlorinated pesticides, and PBDE flame retardants.

Sample results spanned the range of values found in other studies of fish tissue in Washington. Mercury was detected in 100%, PBDEs in 92%, PCBs in 94% (combined Aroclor and congener analyses), and DDT compounds in 92% of the 36 samples analyzed. Dioxin/furans were detected in 85% of 33 samples analyzed.

A total of 67% of all samples did not meet National Toxics Rule (NTR) criteria for contaminants in fish tissue. Total PCBs, toxaphene, and 4,4′-DDE accounted for most of these exceedances. Other contaminants exceeding NTR criteria were hexachlorobenzene, dieldrin, and 2,3,7,8-TCDD.

This study recommends that six lakes and eight river sites be listed as Category 5, Does Not Meet Criteria, during the 2010 assessment cycle for the federal Clean Water Act Section 303(d) List for Washington State. Samples collected from the other 11 sites met Washington State water quality standards.

The current list of target analytes was also reviewed. Recommendations include discontinuing analysis of PCB congeners and the majority of chlorinated pesticides because of the limited information these analyses provide.

Link to EIM data for User Study ID WSTMP08