Abstract:

The accumulation of polychlorinated biphenyls (PCBs), ∑DDTs, ∑chlordanes, ∑BHCs, dieldrin, heptachlor epoxide and other organochlorinated pesticides (OCPs) was measured in the tissues of different edible fishes collected along the Virginia Coast by employing the methods: MSPD (Matrix Solid Phase Dispersion) and GC-ECD (Gas Chromatography with Electron Capture Detector). BHC4s were the most predominant contaminants, followed by PCBs, chlordanes, dieldrin and the other OCPs. This study revealed that over the last decade, the concentrations of OCPs have declined in these regions. Even with this decline, the measured concentrations of PCBs and OCPs in edible fish are still worth reporting. It was observed, that concentrations of organochlorines were significantly in same range (low-high) with one another and were in the range of a few to several ngg^-1 on a wet weight basis.

In the tissue samples, ∑OCPs ranged from 4.30-196 ngg^-1 w.w with ∑BHC (266.101 ngg^-1 w.w) and Heptachlor epoxide (196 ngg^-1 w.w) collectively in all fish. Similarly ∑PCBs had an overall range 7.17-276.16 ngg^-1 w.w where Aroclor 1221 and Aroclor 1242 were the dominant components.

The redox conditions and the decay processes which affect the organic matter, control the concentrations of PCBs and OCPs in edible fish. These preliminary results suggest that the variations in PCBs and OCPs content in edible fish result largely from digenetic processes rather than changes in pesticide input resulting from local human activities.