Polychlorinated biphenyls and organochlorine pesticides in human milk samples from two regions in Croatia

• We analyzed 27 organochlorine compounds in human milk samples from Croatia.
• p,p′-DDE, PCB-153, PCB-138 and PCB-180 were found in the highest concentrations.
• TEQ values were higher in samples from Zadar in comparison to Zagreb.
• Organochlorine compounds levels decreased significantly in 10 years period.

We analyzed 20 polychlorinated biphenyls (PCBs) and seven organochlorine pesticides (OCPs) in milk samples collected during 2009–2011 from primiparae living in two different regions in Croatia. p,p′-DDE is the dominant organochlorine pesticide. α-HCH/γ-HCH and p,p′-DDE/p,p′-DDT ratios indicate that there is fresh input of γ-HCH in investigated population on both locations, while this is not applicable to p,p′-DDT. The PCB profile was dominated by higher chlorinated congeners. Non-ortho PCB congeners which have the highest TEF values were not detected in any of individual samples. Toxic equivalents for mono-ortho substituted PCB congeners indicated higher exposure to toxic PCBs in Zadar, but estimated daily intakes for both locations indicate that infants consuming mother's milk are not at risk of adverse effects caused by PCBs and OCPs. Our study builds on the previous research of human milk samples collected in Zagreb and reveals that over 10-year period, levels of investigated organochlorine compounds decreased significantly.