Comparative analysis of sediment extracts from NOAA's bioeffects studies by the biomarker, P450 Reporter Gene System

Sediment samples collected from nine coastal and estuarine areas have been analyzed to determine response of a biomarker, P450 Reporter Gene System (R GS). This biomarker, using a transgenic cell line, detects the presence and potency of organic compounds that typically induce the CYP1A gene. Previou s investigations have shown that sediments containing chemicals which produ ce a response of 60 or more mu g/g of benzo[a]pyrene equivalents (B[a]PEq) also exhibited a degraded community structure. RGS data from all study area s combined (527 samples) show that the mean response is 22.7 mu g/g B[a]PEq , and the mean upper 99% confidence interval is 32. We believe that sedimen ts exhibiting B[a]PEq values of 32-50 are possibly contaminated to the exte nt that effects on benthic organisms may be observed, and those producing a n RGS response of 60 and greater are likely to contain levels of chemicals that will produce chronic toxicity. The majority of the stations investigat ed produced responses below 32 mu g/g B[a]PEq. No samples from coastal sout hern California produced responses greater than 39. However, samples produc ing induction over 60 mu g/g B[a]PEq were: 50%, San Diego Bay; 16%, Delawar e Bay; 8%, Sabine Lake; 4%, Northern Puget Sound; and 3%, Charleston Harbor . A strong statistical correlation was observed between the RGS responses a nd high molecular weight polycyclic aromatic hydrocarbon concentrations in the sediments from several of the study areas. Of the 2694 km(2) encompasse d in the surveys, only 0.42% of the area exhibited responses above 32 mu g/ g B[a]PEq, which represented 11.4 km(2). This assay is useful in identifyin g high levels of toxic and carcinogenic compounds in the sediments and pred icting the potential impact of these chemicals on the biological community. (C) 1999 Elsevier Science Ltd. All rights reserved.