Status of the Contamination in Sediments and Biota from the Western Beaufort Sea (Alaska)

摘要

Surficial sediments in the western Beaufort Sea containedgenerally high concentrations of arsenic (up to 58 ppm as correctedfor grain size), very low amounts of organo- chlorine compounds andconcentrations of total polycyclic aromatic hydrocarbons (PAHs)ranging from ~l60 to ll00 ng/dry weight. Invertebrates containedhigher con- centrations of total PAHs than fish, with naphthalenebeing thc largest contributor. Diagnostic ratios of various PAHcompounds in our samples do not suggest crude oil as the main sourceof PAHs. Other sources of PAHs to the region include rivers outflow,coastline erosion, oil seeps, diagenesis, and long-range atmospherictransport. Organochlorine contaminants were consistently found in oursamples at concentrations generally lower than those found in otherparts of the United States. l37 Cesium (Cs) was found in measurableamounts in all sediments and biota samples. Isotopic ratios showedthat radionuclides originated most likely from global fallout.Compared to other coastal areas off Alaska, the Arctic, and thcconterminous United States, Beaufort Sea contamination appearsgenerally low.