Distribution and sources of polycyclic aromatic hydrocarbons in the sediments of Lake Erie, Part 1. Spatial distribution, transport, and deposition

We examined the spatial distribution of polycyclic aromatic hydrocarbons (PAH) in Lake Erie, lower Great Lakes. The molecular distribution of parental PAH is combined with their compound- specific carbon isotope signatures to statistically identify three distinctive zones within the lake. Portions of the lake that are immediately adjacent to the major cities of Detroit, Cleveland and Buffalo compose the City Zone, characterized by the highest PAH concentrations and 13C-enriched isotopic compositions. The two other clusters partitioned the lake into a southern sector and a northern sector, with the latter exhibiting the lowest PAH concentrations and the most 13C-depleted isotopic compositions. It appears that PAH are fluvially introduced at the three major cities, and are further transported and redistributed by surface and bottom circulation. This contamination superimposed on a natural background, seen in the northern part of the lake, is probably responsible for the observed distribution pattern.