Assessing regional groundwater quality and its health implications in the Lokpaukwu, Lekwesi and Ishiagu mining areas of southeastern Nigeria using factor analysis

Unusual occurrence of mental-related illnesses has been reported in the Ishiagu mining area of South Eastern Nigeria and this may be related to the long-term consumption of heavy metal-contaminated groundwater. Groundwater from 27 domestic water sources (mainly open hand dug wells and springs) was therefore sampled within two seasons and analyzed for both physical and chemical parameters. Results were compared with international standards for drinking water and also subjected to factor analysis. The analysis showed that iron has the highest concentration of heavy metals exceeding the WHO-permitted desirable limit of 0.3 mg/l in about 73% of cases. Manganese was ubiquitous in groundwater samples exceeding the EU-permitted limits in about 41% of cases. Zinc, although within acceptable international limits was also common in samples from the Ishiagu central area, the Ayaragu, and the Amaubiri-Lokpauku axis. Lead and cadmium occurred in 3 and 13% of cases, respectively, and was outside international regulatory standards for drinking water. Long-term exposure to manganese and cadmium may therefore be a significant cause of the prevalence of mental related illness in the study area. There is also the possibility of impacts from other elements previously undetected in the groundwater system of the study area (but revealed through factor analysis) including arsenic, vanadium, bromine and fluorite (ide) and this needs urgent investigation. Major factors affecting groundwater quality included mineral dissolution and polluted discharge/recharge from mining operations.