Lung Cancer Risk Associated with PM2.5-Bound Polycyclic Aromatic Hydrocarbons in a University Cafeteria in Southern Nigeria

Polycyclic aromatic hydrocarbons (PAHs) emitted during biomass combustion are ubiquitous airborne contaminants with established carcinogenic potential. This study assessed concentrations of PM₂.₅-bound PAHs and the associated lung cancer risk within the main student cafeteria of the University of Benin, Nigeria. Active air sampling was conducted in cooking and eating areas using calibrated high-volume samplers. Mean ∑PAH concentrations of 12.8 ng/m³ and 16.1 ng/m³ were observed in the cooking and eating areas, respectively, compared to 1.0 ng/m³ at a control site. Elevated concentrations were attributed primarily to firewood combustion used for food preparation. The benzo[a]pyrene-equivalent (BaP-TEQ) concentration was estimated at 0.886 ng/m³, corresponding to a lifetime lung cancer risk of 7.7 × 10⁻⁵. These findings indicate impaired indoor air quality and suggest that prolonged exposure to PM₂.₅-bound PAHs in informal food preparation environments may pose significant health risks. Improved ventilation and the adoption of cleaner cooking fuels are recommended to reduce exposure.