PNNL

Abstract

Pollution investigations by the Center for Coastal Assessment and Monitoring of the National Oceanic and Atmospheric Administration (NOAA) have been conducted since 1984 and have incorporated extensive biological and chemical analyses. Since 1993, one of the suites of biological tests utilized in these studies has been the biomarker P450HRGS, which is more recently referred to as EPA Method 4425. Extracts of sediments are applied to a human cell line with a reporter gene at the CYP1A1 site. Light produced by the extracts is a function of the concentrations and potencies of those compounds with an affinity for Ah-receptor (polycyclic aromatic hydrocarbons [PAHs], polychlorinated biphenyls [PCBs], dioxins/furans). These compounds are carcinogenic, can produce chronic toxicity, and those containing chlorine are persistent and bioaccumulated. Nineteen coastal regions and 1309 samples from the three U.S. coasts have been evaluated as part of the NOAA investigations. The stratified random sampling approach used by NOAA provides estimates of the areas (km2) of each region containing levels of the compounds above thresholds. From analysis of the data base, sediments with concentrations at or below 11 µg benzo[a]pyrene equivalents (B[a]PEq)/g would not be expected to produce effects on the benthos. At 32 µg B[a]PEq/g and above there is the potential for impacts on the biota, and above 60 µg/g, the degradation of the benthic community has been observed. Several of the regional surveys found no samples at or above 60 µg B[a]PEq/g, but 60% of the samples from New York Harbor (280 km2) were above this level. Analyses of data from Puget Sound and Chesapeake Bay demonstrate an increase in samples above 32 µg B[a]PEq/g in more populated and industrial regions. A targeted investigation of the distribution of the three important classes of compounds identified by Method 4425 would be more cost effective by first screening samples by this method before expending substantial funds in the detailed chemical analysis of all samples.