Contamination of polychlorinated biphenyls and organochlorine pesticides in breast milk in Korea: Time-course variation, influencing factors, and exposure assessment

Breast milk is a noninvasive specimen to assess maternal and infant exposure to polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs). In this study, 206 breast milk samples were collected from 87 participants during lactation, at <7, 15, 30, or 90days postpartum in four cities in Korea. The total concentrations of PCBs (σPCB) and OCPs (σOCP) ranged from <LOQ to 84.0 (median: 12.1) ngg^-1 lipid weight and from <LOQ to 559 (median: 144) ngg^-1 lipid weight, respectively. The residue levels of these contaminants measured in our study were relatively lower than those reported for European, African and Asian populations. Within a month postpartum typically after day seven the levels of σPCB and σOCP significantly increased. Some OCP compounds were correlated with maternal age, BMI, parity, and delivery mode. Certain types of dietary habits such as seafood and noodle consumption were significantly associated with σPCB and σOCP. The estimated daily intakes (EDIs) of σPCB and σOCP were 45.2-127ngkg^-1bwday^-1 and 625-1259ngkg^-1bwday^-1 during lactation, respectively, which are lower than the threshold values proposed by the US EPA and Health Canada. The exposure of Korean infants to chlordanes via breast milk had a potential health risk which deserves further investigation.