Health risk assessment of the levels of Persistent Organic Pollutants in ambient air around urban dumpsites in Nigeria

Abstract

Open dump disposal is the commonly used means of disposing Municipal Solid Waste (MSW) in Nigeria, just like in various other developing and underdeveloped countries. The environment (land, air, and water) has become contaminated due to this unwholesome practice of uncontrolled dumping of MSW. Notable among the contaminants are persistent organic pollutants (POPs). This study measured polycyclic aromatic hydrocarbon (PAH) and polychlorinated biphenyls (PCB) concentrations of the Igbatoro and Federal University of Technology, Akure (FUTA) dumpsites' ambient air within 30 days (October 2021). The air samples were collected following the standard operating procedures prescribed by the UNEP (2017) and evaluated using gas chromatography-mass spectrometry (GC–MS). The results obtained revealed that considerable levels of PAH and PCB are found at the dumpsites. The summation of the concentration levels of PAH \(\left(\sum \text{PAH}\right)\) for FUTA and Igbatoro dumpsites were 3.55 × 10^-5 and 5.51 × 10^-5 µ/m³ while \(\sum \text{PCBs}\) are 1.00 and 0.99 \(\text{ng}/{\text{m}}^{3}\). Cancer risk values of 1.10 × 10^–5 and 1.23 × 10^–5 obtained for FUTA and Igbatoro dumpsites respectively are within the acceptable limits of 1 × 10 ⁻⁶ to 1 × 10 ⁻⁴. The inhalation rate analysis values of 1.53 × 10^–6 ng TEQ kg⁻¹ day⁻¹(1.53 fg TEQ/kg per day) and 3.38 × 10^–6 ng TEQ kg⁻¹ day⁻¹ (3.38 fg TEQ/kg per day) obtained for adults and children respectively at these dumpsites are below the permissible threshold. Despite, being a short-term risk level assessment for the dumpsites, this study highlights the need for effective waste management strategies and the enforcement of environmental regulations to reduce the release of harmful pollutants into the atmosphere, ultimately safeguarding public health and the environment. However, a long-term assessment (annual) of the PAH compounds and PCB congeners within and around the selected dumpsites is recommended for an effective and reliable evaluation of the dumpsite risk, especially concerning ambient air.