Publication Summary

Concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenylether flame retardants (PBDEs), and selected metals (zinc, lead, cadmium, and arsenic) were measured in several fish species collected from six locations in the Spokane River during 2005. The primary objectives were to (1) evaluate trends over time based on previous studies, and (2) provide data to the Spokane Regional Health District and the Washington State Department of Health for their use in determining if a review or revision to the current fish consumption advisory is warranted. The report includes an evaluation of spatial trends and puts the results in a statewide perspective.

The Department of Ecology conducted a study to obtain up-to-date information on concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenylether flame retardants (PBDEs), and selected metals (zinc, lead, cadmium, and arsenic) in several species of sport fish and bottom fish in the Spokane River. Fish samples were collected from six locations between the Washington/Idaho state line and lower Long Lake during August through November, 2005.

The primary objectives were to (1) evaluate trends over time based on previous studies and (2) provide data to the Spokane Regional Health District and the Washington State Department of Health for their use in determining if a review or revision to the current fish consumption advisory is warranted. The advisory is based on data collected in 1999 and 2001. The report includes an evaluation of spatial trends and puts the results in a statewide perspective.

Results of the fish tissue analyses indicate that peak concentrations occur in the following reaches: Mission Park (PCBs), Ninemile and upper Long Lake (PBDEs), Stateline (zinc, lead, and cadmium), and Long Lake (arsenic - fillet samples only). Compared to historical levels, PCB concentrations appear to have decreased in fish from all parts of the Spokane River except the Mission Park reach.

Relative to other parts of the state, Spokane River fish have substantially elevated concentrations of PBDEs, as well as zinc, lead, and cadmium (whole fish samples only). Arsenic concentrations do not appear unusually elevated.

Recommendations include conducting further investigations into the elevated PCB levels found in the Mission Park reach, identifying sources of PBDEs to the river, and continuing to monitor levels of PCBs, PBDEs, zinc, lead, cadmium, and arsenic in Spokane River fish.

Link to EIM data for User Study ID DSER0016