Abstract

In developing countries like Nigeria, waste management is a significant subject of the environment and public health concern due to the enormous volume of waste generated as a result of rapidly increasing human population. This study assessed the groundwater quality and the associated human health risk around dumpsites along an urban gradient in Benin City, a notable urbanised area in southern Nigeria. In accordance with the standard guidelines, groundwater samples were collected from three (3) locations close to solid waste disposal sites for physicochemical and heavy metals study. The results revealed that all measured parameters were within the permissible limits set by global regulatory standards for drinking water. Notably, metal levels like iron and zinc were elevated but still within acceptable limits. Human health risk assessment revealed that oral ingestion was the primary exposure pathway for heavy metals, and children were more vulnerable to the negative health impacts than adults. Among the metals analysed, chromium posed the highest cancer risk for both adults and children. However, there were no substantial non-carcinogenic health hazards indicated by the calculated Hazard Quotient (HQ) and Hazard Index (HI) values being below the permissible level (HQ, HI < 1). There is an urgent need for public health awareness to address the dangers of exposure to heavy metals from open dumping sites, particularly for the most vulnerable parts of the community, such as children.

Keywords: Waste dumpsite, Heavy metals, Borehole, Cancer risk, Children