Distribution of Heavy Metal and Organic Contaminants in Plants and Soils of Windsor and Essex County, Ontario

Abstract

Concentrations of four contaminants were determined in the soils and plants of Essex County and the city of Windsor in southwestern Ontario. Concentrations of lead and cadmium in county soils were not significantly greater than accepted provincial background levels; average concentrations were 12 mg kg –1 and 0.38 mg kg –1 dry soil for lead and cadmium, respectively. Lead concentration in tissues of crop plants was less than 1/4 of that in adjacent soil; cadmium concentration was similar to that in adjacent soil. Concentrations of both metals were significantly higher within the city. Soil lead averaged 44.8 mg kg –1 and soil cadmium 0.62 mg kg –1 dry soil. These concentrations correlated significantly with traffic volume on nearby streets. In roots of Chenopodium averages were 18.1 mg kg –1 for lead and 0.60 mg kg –1 for cadmium. PCBs were generally undetectable or present only in trace amounts in both soils and goldenrod plants in Essex County. Octachlorostyrene (OCS), while undetectable in soil, was found in leaves at concentrations of about 1 μg kg –1 in the county. City soils contained higher concentrations of PCBs; average Arochlor 1260 concentration was 13.17 μg kg –1; OCS was not detectable. Concentrations of both OCS and Arochlors 1254 and 1260 were higher in goldenrod tissues in the city than in parallel county samples. These data suggest limited dispersal of pollutants from urban-industrial sources into the surrounding area.