ORGANIC TRACE CONTAMINANTS IN ST-LAWRENCE-RIVER WATER AND SUSPENDED SEDIMENTS, 1985-1987

The concentrations of organic trace contaminants, including chlorobenzene congeners, hexachlorocyclohexane isomers, DDT group pesticides, polychlorobiphenyls (PCB) and several other biocides, such as mirex, dieldrin and endosulfan, have been determined in water and suspended sediments of the St. Lawrence River. The data cover important areas of the river between Kingston and Quebec City for four sampling periods, i.e. May 1985, October 1985, June/July 1986 and June 1987. The results indicate: (i) low levels of suspended sediments at the head of the river (∼ 1 mgl-1) which increase towards the river mouth to ∼10 mgl-1 (up to 25 mgl-1 in October 1985); (ii) significant inputs of PCB along certain river sections; (iii) low levels of mirex in suspended sediments throughout the river; (iv) the riverine lakes in the St. Lawrence (Lakes St. Francis, St. Louis and St. Pierre) appear to be short-term contaminant sinks only. © 1990.