TRANSPORT OF DETROIT RIVER POLLUTANTS FROM LAKE ERIE BY EPISODIC RESUSPENSION EVENTS

The transport of contaminated sediment out of Lake Erie is an important process controlling the fate of potentially toxic organic compounds in the lower Great Lakes. This transport was investigated by electron capture gas chromatographic mass spectrometry analysis of 2,4-di-tertpentylphenol (24DP) and 2-chloro-4,6-di-tert-pentylphenol (24DP6Cl) derivatized with pentafluorobenzyl bromide (PFBBr) to give PFB ether derivatives. 24DP and 24DP6Cl are unusual sediment-bound pollutants originating from a single point source on the Trenton Channel of the Detroit River. The concentrations of these compounds were determined in suspended solids collected between 1980 and 1993 in the Niagara River. Loads were found to be proportional to the third power of 24-h averaged wind velocities. We suggest that the phenol loads may be controlled by episodic resuspension of near-shore sediments in Lake Erie's eastern basin. The model suggests that about 2% of Detroit River sediment-bound pollutants is transported to Lake Ontario annually.