Radionuclide concentrations in white sturgeon from the Columbia River

Abstract

Although radioactive releases from the U.S. DepaItment of Energy's Hanford Site have been monitored ha the environment since the reactors began operating in 1945, recent information regarding historical releases of radionuclides has led to renewed in.terest in estimating human exposure ure to radionuclides at Hanford. Knowledge of the fate of radionuclides in some fish species may be important because of the potential for food-chain transfer to humans. White sturgeon. (Acipenser _ansmonranu_ were selected for study because they are long-lived, reside year-round in the Hanford Reach, are benthic, and are an important commercial and sport species _nthe Columbia River. They also have a greater potential for accumulating persistent radionuclides than shorter-lived species with pelagic and/or anadromous life histories. The purpose of our study was to summarize data on historical concentrations of indusu'ial radionuclides in white su,age.on and to collect addi'tional data on current body burdens in the Columbia River. Historic data on concentrations in white sturgeon were gleaned from a number of reports. Studies conducted from 1953 to 1955 indicated that high concentrations of radionuclides (as total beta) were present in some internal organs and on the external surface of white sturgeon from the Hanford Reach, Average concentrations were about 40 pCi/g for liver and kidney and exceeded 60 pCi/g fbr fins and scutes. The principal radionuclides present ip tire tissues of white sturgeon collected from the Hanford Reach duaing 1963 to 1967 were 32p, 5lCr ' and 65Zn. Average concentrations of 32p in muscle were typically two to seven times greater than 65Zn and ranged from 25 to 57 pCi/g. When separate tissues were taken from sturgeon, ave;_ageconc_'ntrations of radionuclides were usually in the order gut contents > carcass> muscle. Limited data from locations in the Columbia River downstream of the Hartford Reach in 1953, 1965, and 1966 indicated that low amotmts of radionuclides were available for uptake by white sturgeon. Esti.. mated dose contribution from consumption of sturgeon in the mid-1960s was less than the dose. estimated from consumption of more commonly harvested fish species (e.g., mountain whitefish). A field stuciy conducted in 1989 and 1990, as an activity of the Hanford Site Surface Environmental Surveillance Project, showed that radionuclide concentrations in white sturgeon tissue from the Hanford R.each had decreased dramatically since the time of major reactor operation. Maximum concentt_ations for any measured industrial radionuclide in muscle madcartilage of white sturgeon collected from several locations in the Columbia River were less than 0.01 pCi/g. Principal radionuclides of historical significance (32p, 5 lCr , and 65Zn) were not detected in these samples, Tl'_epotential annual dose from Hanford-orgin radionuclides to individuals consuming "¢'t 'I sturgeon muscle in 1991 would be,less than 0.01 mrern. Thus, present levels of radionuclides found in edible tissue of white sturgeon pose no risk ...

Trends in radionuclide concentrations in Hanford Reach fish, 1982 through 1992

“…Concentrations of the radionuclide burden of white sturgeon (Acipenser rransmonranus) have decreased significantly since the 1960s. There were no significant differences in concentrations of 90Sr or 137Cs in sturgeon cartilage or muscle collected from the Hanford Reach and locations upstream and downstream of the Site (Dauble et al 1993). Trends from 1972 through 1988 in other species of wildlife and fish monitored at the Hanford Site have been reported (Eberhardt et al 1989).…”

Factors affecting the quality of fish caught by Native Americans in the Zone 6 fishery 1991 through 1993

“…Tissues (muscle, cartilage, and viscera) were tested for radionuclide contamination. Results showed that radionuclide concentrations in white sturgeon collected in the W o r d Reach had decreased dramatically since the time of m j o r reactor operations in the mid-1950s (Dauble et al 1992). Additionally, there was no significant difference in radionuclide concentration for fish caught in the Hanford Reach when compared to fish caught upstream or downstream of Hanford.…”

Survey of radiological contaminants in the near-shore environment at the Hanford Site 100-N Area reactor

“…The maximum concentration of wSr in a whitefish offal sample (0.49 pCi/g) was collected fiom between the 100-N to 100-D Areas in 1995 pisping 1996). A study of white sturgeon from the Hanford Reach conducted from 1989 to 1990 found that the maximum concentration of radionuclides were less than 0.0 1 pCi/g and that there was little to no human dose from consumption of these sturgeon (Dauble et al 1993).…”