Organochlorine pesticides and PCBs (including dl-PCBs) in human milk samples collected from multiparae from Croatia and comparison with primiparae

This study investigated the levels of 20 congeners of polychlorinated biphenyls (PCBs), including toxic dioxin-like PCBs and 7 organochlorine pesticides (OCPs) in 33 human milk samples collected in 2011 from multiparae living in Zadar, Croatia. Concentrations of ∑PCBs, ∑DDTs, ∑HCHs and HCB in samples ranged from 11.7 to 146.3, 8.7 to 89.2, 0.9 to 28.4, and  ng g⁻¹ milk fat, respectively. PCB congeners −153, −138, −180 and −170 dominated in the PCB profiles, while p,ṕ-DDE was the most abundant OCP. PCB-126 was the most abundant non-ortho PCB, while among mono-ortho PCBs, the congeners −118, −105 and −156 equally contributed to the mono-ortho PCB fraction. TEQs for dl-PCBs ranged between 0 and 13.3 pg g⁻¹ milk fat. The calculated estimated daily intakes for all compound groups were below the tolerable daily intake indicating no risk for breastfed infants. A comparison of our results with our previous study on primiparae revealed that the concentrations of the main contaminant groups are lower in the milk of multiparae, with the exception of toxic mono-ortho PCBs whose concentrations and TEQ remained similar among the groups, and HCB whose concentrations were found to be higher in multiparae. Concentrations of PCBs and OCPs found in the samples from this study did not exceed those from other parts of the world. This study revealed that there are differences in contaminant concentrations depending on the mothers’ parity and that this fact should be taken into account when risk assessment studies are conducted.