National Contaminant Biomonitoring Program: Concentrations of seven elements in freshwater fish, 1978–1981

Abstract

As a continuing part of the National Contaminant Biomonitoring Program, the U.S. Fish and Wildlife Service collected freshwater fish at 112 monitoring stations in 1978–1979 and 1980–1981. Three composite samples of three to five fish were collected at each of about half of the stations in odd-numbered years and at the other half in even-numbered years, and analyzed for lead, mercury, cadmium, arsenic, selenium, cooper, and zinc. The geometric means, minimum, and maximum of elemental concentrations (μg/g wet weight) during 1978–1979 and (in parentheses) during 1980–1981 were as follows: Pb 0.19, 0.10–6.73 (0.17, 0.10–1.94); Hg 0.11, 0.01–1.10 (0.11, 0.01–0.77); Cd 0.04, 0.01–0.41 (0.03, 0.01–0.35); As 0.16, 0.04–2.08 (0.14, 0.05–1.69); Se 0.46, 0.09–3.65 (0.47, 0.09–2.47); Cu 0.86, 0.29–38.75 (0.68, 0.25–24.10); and Zn 25.63, 7.69–168.1 (23.82, 8.82–109.2). The 85th percentile, calculated for station mean concentrations (μg/g wet weight) for 1978–1979 and 1980–1981, respectively, were: Pb 0.32 and 0.25; Hg 0.18 and 0.18; Cd 0.09 and 0.06; As 0.23 and 0.22; Se 0.70 and 0.71; Cu 1.14 and 0.90; and Zn 46.26 and 40.09. There was no significant upward or downward trend between collection periods of the national geometric means of any of the elements except for cooper which decreased significantly. Species differences in elemental concentrations contributed more variability to the data set than did station differences. The proportion of the collections composed of each species changed little between collection periods. Thus, the magnitude of the species effect on the national geometric mean of each period was probably fairly consistent; however, it precludes our making sound comparisons among various regions of the United States. As a participant in the National Contaminant Biomonitoring Program (NCBP), the U.S. Fish and Wild-life Service is responsible for monitoring temporal and geographic trends of organochlorine chemical and elemental contaminants in the nation's fresh-water fish, European starlings (Sturnus vulgaris), and waterfowl. Primary emphasis has been placed on organochlorine chemical contaminants; however, certain elements have been measured intermittently and additional elements have been added periodically since 1969. We summarize the concentrations of the seven elements—lead, mercury, cadmium, arsenic, selenium, copper, and zinc—measured in freshwater fish collected during 1978–1981. Data for earlier collections have appeared in other reports (Hendersonet al. 1972; May and McKinney 1981; Walshet al. 1977).