Health Risk Assessment of Heavy Metals in Groundwater Around Some E-Waste Dumpsites from Three States in Southwestern Nigeria

Background and Objective: The e-waste dumpsites, among others, are eye sore in many developing countries, with damaging effects on public health and the environment. Although e-waste dumpsites are sparse, the few ones that exist may contain high levels of heavy metals released into the environment. Therefore, carcinogenic and non-carcinogenic health risks posed by heavy metals are used to determine the quality of groundwater in the study area. Materials and Methods: Thirty samples of groundwater from the hand-dug wells were collected, with five samples from each of the six stations. The elemental analysis of some toxic heavy metals was performed using an atomic absorption spectrophotometer. The data preparation and arrangement were carried out using Microsoft Excel. Results: None of the heavy metals were detected in samples of groundwater from Karakata Market, Akure. The results of the carcinogenic and non-carcinogenic tests for adults and children showed that hazard quotient and hazard index values were below one in all the pathways like inhalation, ingestion and dermal. This implies that the heavy metals posed no carcinogenic or non-carcinogenic threat to the inhabitants of the study area. The total cancer risks due to ingestion and inhalation revealed that ingestion was the principal exposure pathway. The total cancer risk for children and adults was within the acceptable limits of the United States Environmental Protection Agency and the World Health Organization. Conclusion: The study indicated that all the results were below the limit recommended. Therefore, no environmental or health risk is expected in the study areas. However, no matter how small the environmental and health risks may be, long-term exposure to heavy metals may be detrimental to human health.