INSECTICIDE RESIDUES IN BOTTOM SEDIMENTS OF TWO NEW BRUNSWICK STREAMS DRAINING AGRICULTURAL LAND

Bottom sediments from two streams draining agricultural land in New Brunswick were analyzed for organochlorine and organophosphorus insecticide residues. Most samples contained appreciable quantities of DDT plus metabolites (up to a total of 2.07 ppm), about one-third contained smaller quantities of endrin (up to 0.45 ppm) and approximately one-fifth contained dieldrin (up to 0.01 ppm). No other organochlorine and organophosphorus insecticides were detected. The highest residue levels were found in the watershed with the more intensive agricultural production and in proximity to fields producing intertilled crops.