Multi-criteria approach to water quality and health risk assessments in a rural agricultural province, southeast Nigeria

This paper assessed the quality and suitability of groundwater from hand-dug wells in Ikem agricultural province, Nigeria for human consumption and irrigation purposes. pH measurements revealed that the groundwater is slightly acidic. The trend of the cations concentrations is Ca2+ > Mg2+ > K+ > Na+ whereas that for anions is Cl− > PO42− > NO3− > HCO3– > SO42−. It was observed that the concentrations of all the ions were below their respective standard maximum allowable limits for drinking water. Similarly, all the analyzed heavy metals were also found within their respective acceptable limits. Heavy metal pollution index, heavy metal evaluation index, and contamination index confirmed that all the samples are excellent and safe drinking waters. However, water quality index placed the groundwater quality in good category, and therefore relatively suitable for drinking and domestic uses. Health hazard index revealed that, for adults, 64% of the samples pose low chronic risk while 36% predispose their consumers to medium chronic risk. However, for children, 94% of the samples pose medium chronic risk while only 4% predispose them to high chronic risk due to trace elements ingestion. Carcinogenic risk assessment due to Pb enrichment showed that all the samples pose negligible cancer risks to the consumers. All the irrigation water quality indices, except permeability index and potential salinity, classified the samples as suitable water for irrigation purposes. Keywords: Drinking water quality, Health risk assessment, Irrigation water quality, Pollution indices, Water chemistry, Water quality index