Relation of Lake Ontario fish consumption, lifetime lactation, and parity to breast milk polychlorobiphenyl and pesticide concentrations.

Lactating female members and spouses of male members of the New York State Angler Cohort who agreed to provide breast milk samples were the subjects of this study. Questionnaires were provided to participants focusing on Lake Ontario fish consumption, reproductive history, and lactation history. Milk samples were analyzed for 77 polychlorinated biphenyls (PCB) congeners, 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (DDE), a metabolite of dichlorodiphenyltrichloroethane (DDT), hexachlorobenzene (HCB), and 1,1a,2,2,3,3a, 4,5,5,5a,5b,6-dodecachlorooctahydro-1,3, 4-methano-1H-cyclobuta[cd]pentalene (Mirex). The percentage of samples with quantifiable levels, above the limit of detection (LOD), varied among the individual congeners from 10 to 100%. Nine PCB congeners (designated by their IUPAC No.) and DDE were found in all of the 100 samples analyzed. These include the following, in decreasing order of concentration: DDE>153>138>180>118>187>188>177>200. Total PCB concentrations were estimated by taking the sum of the concentrations of all PCB congeners (up to 77 congeners) above their respective LOD in a given sample. PCB concentrations increased with increasing concentration of milk lipid. Lipid adjusted PCB concentrations increased as a function of maternal age. PCB congener profiles in milk favored the higher chlorinated congeners, with the four highest congeners having 5 to 7 chlorine atoms. Fish eaters had a significantly higher level of several major PCB congeners with congeners 153 and 138 being 1.36 and 1.34 times higher, respectively. PCB and DDE concentrations, expressed on a lipid basis, varied inversely with parity. The total number of months of lifetime lactation varied inversely with the total PCB concentration in breast milk. A similar relationship was evident for DDE. These data are of use for risk assessment in estimating the relative exposure to these environmental contaminants in breast fed infants whose mothers consumed contaminated Lake Ontario fish. Copyright 1999 Academic Press.