PCB and organochlorine pesticides in Canadian human milk--1992.

Human milk (497 samples) representing donors from across Canada were analyzed for 24 organochlorine pesticides and industrial chemicals and 40 PCB congeners. PCBs, p,p'-DDE, hexachlorobenzene (HCB), and trans nonachlor were present in all samples. Compared to earlier surveys in Canada, concentrations of most residues determined declined, and were lower than those reported recently in European countries. Although regional differences were minor, residues of PCBs, p,p'-DDE, and trans nonachlor were higher in the Ontario, Quebec, and Eastern regions, and all residues were slightly higher in the Great Lakes Basin compared to the rest of Canada. Concentrations of PCBs, DDTs, HCB, and trans nonachlor were higher in participants who consumed greater than 100 g of fish weekly.