Assessment of potential health impact of volatile organic compounds of underground water samples around fuel station in Okinni area Osogbo, Osun State, Nigeria

Abstract

Levels and potential toxicity of volatile organic compounds (VOCs) were analyzed in underground water from six locations near a fuel station in Okinni, Osun State, Nigeria. Samples were collected and analyzed using standard procedures. A total number of seven VOCs were detected with varying concentrations, they were: benzene, toluene, chlorobenzene, ethylbenzene, m, p-xylene, o-xylene, and dichloromethane. One-way ANOVA results showed a significant difference (p < 0.5) in VOC concentrations across locations. Most VOCs exceeded USEPA and WHO threshold values, indicating contamination likely from fuel station leachates, as suggested by the low toluene to benzene ratio (T/B < 2). Odour Hazard Index (OHI) values were below 1 in all but location 3, where m,p-xylene, and o-xylene levels were 0.921 and 1.105, respectively, implying that the water from location 3 was not safe given the odour risk assessment.. Carcinogenic risks were more significant through ingestion than dermal contact. Non-carcinogenic risk values were within safe limits except in location 3. Consequently, using the borehole water from location 3 for domestic activities could expose the people of these communities to serious health issues. Therefore, there is a need for urgent attention from the relevant authorities to safeguard the health of this populace.