Predicting bioaccumulation potential: A test of a fugacity-based model

Abstract

Clams (Macoma nasuta) from an unpolluted site in Yaquina Bay, Oregon were exposed in the laboratory for 28 days to 6 field-contaminated sediments (treatments) which varied widely in concentration of 10 organic pollutants. Mean accumulation factors (AF = (concentration in tissue/lipid, %/100)/(concentration in sediment/total organic carbon, %/100)) of 8 neutral organic compounds (DDE [p,p′], 2,2′,3,5′6-pentachlorobiphenyl, 2,3′,4,4′,5-pentachlorobiphenyl, Aroclor^® 1254, pyrene, chrysene, benzo[a]pyrene, benzo[b,(k)]fluoranthene) were homogeneous across treatments. Statistically significant differences were detected between some treatment AFs for ODD [p,p′] and benz[a]anthracene, and between some chemicals within treatments (experimentwise a=0.05). Accumulation factors were less than 2 and less variable in highly polluted, organically enriched sediments (total organic carbon > 3.69 ± 0.044%), but sometimes exceeded 2 in clams exposed to surficial (0–2 cm deep) sediments with low pollutant concentration and low organic carbon content (⩽ 0.86 ±0.037%). These results suggest that the AF model may provide reasonable estimates of bioaccumulation potential of hydrophobic neutral organic compounds in organically enriched, polluted sediments.