(P19-034-23) Organochlorine Pesticides (OCPs) and Polychlorinated Biphenyls (PCBs) in Breast Milk Samples Collected in 2020/2021 in Norway

Objectives: The first months of life, the primary food source for most infants is maternal breast milk, leading to interests in the transfer of persistent organic pollutants (POPs) from mother to child. The aim of this study is to determine the concentrations of POPs in breast milk and compare the levels with their corresponding health-based guidance values.

Methods: From November 2020 to October 2021, mother-child pairs were recruited from randomly selected healthcare centers in 29 municipalities in Innlandet County, Norway. We analyzed 120 breast milk samples for organochlorine pesticides (HCB, HCH, chlordanes, Mirex, DDT) and polychlorinated biphenyls (PCBs). The analytes were quantified using GC-MS at an ISO 17025 accredited laboratory. The levels of the different POPs were compared with their corresponding health-based guidance values.

Results: PCBs, and from not detected (ND) to 2059.4 ng/g lw (median 16.6) for ∑DDTs. Chlordanes and HCH were detected in 98% and 64% of the samples, respectively, with concentrations ranging from ND to 33.86 ng/g lw (median 3.0) for ∑chlordanes, and ND to 11.96 ng/g lw (median 0.9) for ∑HCHs. We found that 50% of the breast milk samples had PCB concentrations that exceeded tolerable daily intake (TDI).

Conclusions: The estimated intake of ∑PCBs exceeded the TDI for 50% of the nursing children, implying that the PCBs levels in breast milk in Norway may pose a health risk. However, the estimated intake of the other POPs was below the health-based guidance values and we found that the concentrations of POPs in breast milk in Norway have declined significantly in the last 20 years.

Funding Sources: Innlandet Hospital Trust