The Concentrations of Ten Heavy Metals in Some Selected Lake Powell Game Fishes,

摘要

Ten tissue samples from each of four species of fishes--large-mouth bass,black crappie,walleye,and rainbow trout--from Lake Powell were analyzed and compared for the presence of concentrations of ten heavy metals:iron,calcium,magnesium,copper,chromium,cadmium,zinc,arsenic,selenium,and lead. Samples were digested with nitric and perchloric acids,and analyses were performed by atomic absorption spectrophotometry. Concentrations were expressed on a dry-weight basis for all tissues and were not corrected for percent recovery. Since cadmium,lead,arsenic,and selenium are toxic to humans,the concentrations of these heavy metals in the edible portions of Lake Powell fishes were compared to the maximum safety threshold levels established in several independent studies. At this time,none of the metals,aside from selenium,appears in concentrations high enough to pose a health hazard and should not be cause for concern. However,the high selenium levels in fish flesh may constitute a possible health hazard,although little is known of the factors influencing selenium assimilation in humans.