25 YEARS OF SURVEILLANCE FOR CONTAMINANTS IN HUMAN BREAST-MILK

To monitor the exposure of Canadian populations, Health Canada has car ried out six major surveys of breast milli contaminants, beginning in 1967. In these national surveys, breast milli was collected from nursi ng mothers at various times in their nursing period, and the concentra tions of chlorinated hydrocarbons were measured. There was a downward trend from 1967 to 1992, in the concentrations of organochlorine (OC) pesticides and polychorinated biphenyl hydrocarbons (PCBs). This regre ssion was observed for samples across Canada, except for a sharp isola ted increase in 1982 for the Quebec Province. As the disappearance cur ves of the chemicals surveyed follow the same pattern for both Ontario and Canada, a similar decline could be expected of OC concentrations in human breast milk in the Great Lakes Basin.