Bioaccessibility-based risk assessment of PAHs in soils from sites of different anthropogenic activities in Lagos, Nigeria using the fed organic estimation human simulation test method

The aim of this study was to carry out a bioaccessibility-based risk assessment of polycyclic aromatic hydrocarbons (PAHs) in soils from sites of different anthropogenic activities in Lagos, Nigeria. Using an in vitro gastrointestinal model—Fed Organic Estimation Human Simulation Test method (FOREShT), the concentration of bioaccessible 16 priority US Environmental Protection Agency (USEPA) PAHs in soils were determined. Total concentration of 16 priority USEPA PAHs was also determined. The concentration range was 702–253,922 ng g⁻1 and 92–760 ng g⁻¹ for total and bioaccessible PAHs, respectively. For persons involved with activities at these sites no health risks were observed, based on bioaccessibility values of PAHs. Mean daily intake of PAHs from these soils were below the oral mean daily intake threshold for PAHs in food. Also, overall estimated theoretical cancer risk (2.5 × 10⁻⁰⁹, 6.5 × 10⁻⁰⁷, 5.5 × 10⁻¹⁰, 2.7 × 10⁻⁰⁹, 6.5 × 10⁻¹⁰, 9.5 × 10⁻¹⁰, 2.0 × 10⁻⁰⁹, and 4.1 × 10⁻⁰⁷ for the eight sites based on their bioaccessible concentration) for exposure to PAHs in surface soils were below the health guidelines for extreme (1 × 10⁻⁰⁴) and normal (1 × 10⁻⁰⁶) exposures.