Dioxins, polychlorinated biphenyls and other organohalogen compounds in human milk. Levels, correlations, trends and exposure through breastfeeding

Abstract

Polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF), together simplified termed "dioxins", polychlorinated biphenyls (PCB), polybrominated diphenylethers (PBDE) and organochlorine pesticides constitute lipophilic, persistent organic pollutants that bioaccumulate in the food chain and consequently can be found in humans at considerable concentrations. During the past 30 years our institute analyzed far more than 2,000 individual human milk samples for organochlorine pesticides and PCB and over 1,000 specimens for PCDD/PCDF. The results of these analyses provide an overview and reliable basis as to contamination of human milk with these compounds, their correlations among each other, the temporal trend of exposure through breastfeeding and the predominant parameters that influence the maternal body burden. It was found that the levels of most persistent organohalogen compounds in human milk decreased significantly over the past three decades and equally did their exposure through breastfeeding. Exceptions are PBDE, which are still extensively used as flame-retardants. PBDE levels in milk samples collected in the early 2,000s are approximately 60% higher compared to specimens sampled 10 years before. Moreover, in contrast to PCB, PBDE show no significant correlation with PCDD/PCDF in human milk, which might be interpreted as an indication for another mode of human exposure.