title: Insecticide residues in soils on fifteen farms in southwestern Ontario, 1964-1974.
mesh_terms: D003634:DDT / Q000032:analysis; D007306:Insecticides / Q000032:analysis*; D008722:Methods; D009864:Ontario; D009943:Organophosphorus Compounds / Q000032:analysis; D009946:Organothiophosphorus Compounds; D012987:Soil / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis*
chemical_list: D007306:Insecticides; D009943:Organophosphorus Compounds; D009946:Organothiophosphorus Compounds; D012987:Soil; D012989:Soil Pollutants; D003634:DDT