Assessment of the Pollution Levels, Sources, and Exposure Risks of Polychlorinated Biphenyls (PCBs) in Urban Park Dusts within Lagos Metropolis

Abstract

Polychlorinated Biphenyls (PCBs) represent organic contaminants that are persistent hazardous, carcinogenic, and genotoxic, thereby endangering both human well‐being and the ecosystem. This research delved into concentration patterns, sources, and health hazards associated with PCBs in dust collected from vehicle parks in Lagos metropolis. PCBs in samples of Lagos park dust extended from 1.00 to 36.80 ng/g, with PCB 18 exhibiting the highest mean concentration of 17.02 ng/g. Among the 12 PCBs studied, 5 Cl atom PCBs contributed the highest percentage, constituting 30% of the total PCB content in Lagos park dust. Dioxin‐like PCBs (DLPCBs) made up 27% of the overall PCBs composition in the dust. Using the positive matrix factorization method, eight sources of PCBs were identified, with biomass combustion contributing the highest proportion at 42% of the total PCB emissions. Health risk estimates revealed that the magnitude of PCBs exposure in human followed the order: ingestion > dermal contact > inhalation. PCBs exposure through ingestion in children was 9.33 times higher than that of adults, potentially attributed to the inadvertent intake of dust particles by children via hand‐to‐mouth contact. Cancer risk assessments for all PCB congeners remained below 10−6, indicating acceptable risk levels. PCB 18 had the highest cancer risk values, reaching 8.69 × 10−9 for children and 1.19 × 10−9 for adults.