Polychlorinated biphenyl (PCB) and dichlorodiphenyl dichloroethylene (DDE) concentrations in the breast milk of women in Quebec

Objectives. This study documented the concentration of polychlorinated biphenyls (PCBs) and dichlorodiphenyl dichloroethylene (DDE) in the breast milk of women from Quebec, Canada, and assessed the impact of various sociodemographic and lifestyle factors on these levels. Methods. From 1988 to 1990, milk samples were obtained from 536 Quebec women and analyzed for seven PCB congeners and p,p'-DDE. Information was obtained on subjects' physical, sociodemographic, acid lifestyle characteristics. Results. Mean concentrations were 0.52 mg/kg lipids (95% confidence interval [CI] = 0.50, 0.54) and 0.34 mg/kg lipids (95% CI = 0.32, 0.35) for PCBs (Aroclor 1260) and DDE, respectively. Age and history of breast-feeding showed statistically significant correlations with PCB and DDE concentrations; Conclusions. Concentrations of PCBs and DDE measured in this study are at the lower end of the concentration range recently reported for women living in industrialized countries. The modulating factors identified here should be considered when conducting studies on organochlorine exposure and disease.