Persistent and Non-persistent Organic Pollutants in Human Breast Milk Samples, Association with Lifestyle and Socio-demographic Factors, and Their Genotoxic Effects on Mammary Epithelial Cells

Abstract Organic pollutants (OPs) have been associated with increasing rates of cancer, metabolic disorders, and obesity, and may accumulate in human breast milk, creating potential risks for breastfeeding infants. This study assessed the presence and concentrations of OPs in breast milk, including polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and selected non-POPs, and examined associations between pollutant levels and socio-demographic/lifestyle factors, as well as DNA damage in exfoliated mammary epithelial cells among lactating mothers living in Istanbul, Türkiye. In this hospital-based cross-sectional study, breast milk samples were collected and participants completed face-to-face questionnaires on sociodemographic and lifestyle determinants. Genotoxicity in exfoliated mammary epithelial cells was evaluated using the Comet assay. OPs in milk were quantified by gas chromatography and liquid chromatography-tandem mass spectrometry. PCBs were the predominant contaminants and PCB 153, PCB 101, and PCB 180 showed the highest concentrations. Among DDT (Dichlorodiphenyltrichloroethane) metabolites, p,p′-DDT was highest, while γ-HCH was the dominant HCH congener. Several non-POPs (propiconazole, pyriproxyfen, acetochlor, and propargite) were detected. Regular poultry consumption was associated with higher PCB 153 levels. Passive smoking correlated positively with total HCHs and γ-HCH, while active smoking was positively associated with PCB 153. Living in Istanbul for > 5 years was linked to higher propiconazole but lower PCB 28, o, p′-DDE, and p, p′-DDE. Comet tail intensity and tail moment were moderately positively associated with PCB 202, o, p′-DDE, and propiconazole. Detectable OP residues were present in breast milk, underscoring potential exposure risks for mothers and infants and supporting ongoing monitoring in urban populations to inform public health strategies.