Baseline occurrence of organochlorine pesticides and other xenobiotics in the marine environment: Caribbean and Pacific collections

This ongoing survey reports the levels of persistent organic pollutants (POPs) in sea surface slicks collected on a global circumnavigation. Hydrophobic xenobiotic compounds such as POPs are known to accumulate on the sea surface in slicks at concentrations many fold greater than the underlying water column, raising concerns about the ecological impacts due to the high biological activity associated with this zone. Six different categories of POPs were reported: chlorobenzenes, hexachlorocyclohexanes, chlordane related compounds, organochlorine pesticides and other cyclodiene pesticides, DDTs and metabolites, and polychlorinated biphenyls. Concentrations ranged from <1 ng L−1 to 18.45 μg L−1. Ranking analysis indicates an independence of detected concentrations for each class of compounds and their geographical locations. Although concentrations observed were normally low and below commonly accepted toxic levels to animals and humans, they fall within the effective range of concentrations of many hormones and neurotransmitters, thus could potentially act as endocrine disrupters.