Assessment of Polycyclic Aromatic Hydrocarbons and Polychlorinated Biphenyls from Selected Sites in Rivers State, Nigeria: Environmental and Health Implications

This study investigated the levels of Polycyclic Aromatic Hydrocarbons (PAHs) and Polychlorinated Biphenyls (PCBs) in soil from selected industrial sites in Rivers State, Nigeria. Samples obtained from a non-industrial site (control) and four industrial sites were analysed using Gas Chromatography-Mass Spectrometry (GC-MS). Results showed that the levels of PAHs and PCBs in the control sample were below detection limit (<0.01mg/kg). Additionally, PAH and PCB concentrations in industrial sites investigated ranged from 0.41mg/kg to 32.27mg/kg and 1.09mg/kg to 5.55mg/kg respectively. Indorama Petrochemical industrial site ranked the highest while PHED transformer oil storage site ranked lowest with respect to PAH and PCB contaminations. Human Health Risk evaluation showed HQ and TCR for PAH ranged from 0.00007 to 0.668 and 2.4x10-6 to 8.1x10-4 respectively. TCR for PAH exposure in Indorama Petrochemicals 8.1x10-4 (children) and 1.9x10-4 (adult)) exceeded the USEPA upper limit of 1x10-4. Similarly, HQ and TCR for PCB ranged from 0.00026 to 0.912 and 1.8x10-6 to 3.8x10-5 respectively. All HQ values obtained were below the USEPA limit of 1, thus, indicating negligible non-cancer risks. It was observed that dermal contact presented the highest risk for exposure routes from PAH and PCB contaminations in all investigated sites. Findings showed varying soil contamination from PAH and PCB across sites with different industrial activities. The Indorama Petrochemical industrial site showed the highest level of contamination and potential cancer risks from PAH exposure to both children and adults. Continuous monitoring and remediation actions are advocated to mitigate long-term PAH and PCB contaminations and protect public health.