PCB and DDE residues in milk supplies of Ontario, Canada 1985-1986

PCB and DDE levels in milk producing regions in Ontario, Canada, were monitored to assess the incidence, levels, and trends in contamination. A total of 1184 samples were evaluated for PCBs and 920 samples were analyzed for DDE. PCB levels ranged from 13-19 mu g/kg and were similar for all regions. DDE levels displayed greater variability, ranging from 1.4-16.5 mu g/kg. The highest DDE contamination was found in south and central Ontario, with the lowest contamination in the northern region. Both PCB and DDE concentrations in milk have declined significantly since 1970.