Levels and carcinogenic risk assessment of polycyclic aromatic hydrocarbons in the breast milk of selected lactating mothers in Abeokuta, Nigeria

Abstract

This study evaluated the levels and carcinogenic risks of polycyclic aromatic hydrocarbons (PAHs) in the breast milk of lactating mothers. Breast milk biomonitoring provides insights into human exposure levels of PAHs from increasing environmental sources, which is scantily reported in Nigeria. Twenty-eight breast milk samples were obtained from lactating mothers with written informed consent, and lifestyle data was elicited with a structured questionnaire. Eight PAH compounds were analyzed using Gas Chromatography with Flame Ionization Detector. Detected PAH levels significantly exceed the European Union maximum permissible limits for human exposure (0.001 mg/kg) in all samples. Benzo[a]pyrene (BaP) (1.07 mg/kg) was the highest, and lowest was benzo[b]naphtho[2,1-d]thiophene (BNT) (0.07 mg/kg), which was higher than the average concentrations reported in most studies globally. This may suggest substantial risks of acute and chronic health effects to vulnerable groups (lactating mothers and newborns). The carcinogenic risk assessment indicates that 60% of infants may develop carcinogenic health risks due to the ingestion of PAH-contaminated breast milk. Low birth weight, preterm birth, and fetal loss were experienced by the participating mothers. Findings highlight the potential health risk posed by the elevated levels of PAHs, thus necessitating timely interventions that would mitigate the risks of PAHs.