Human health risk from groundwater consumption: A case study in the Apaaso-Tafo Community in the Bono East Region of Ghana.

Abstract

Water is a nutrient for life and a resource for human development, and therefore towns and cities often build treatment systems to provide wholesome water for consumption, bathing, washing, etc. For rural communities where centralised water treatment plants are lacking, groundwater (GW) is often the resource of choice due to its relatively low pathogenic loading and turbidity. However, GW is highly susceptible to contamination from anthropogenic activities. In the Bono East region of Ghana, 94 % of solid waste and 89 % of wastewater are disposed of on the roadside without treatment, posing a contamination risk to water resources. Despite the potential for GW contamination in the region, few researchers have assessed GW quality, and none has evaluated the human infectious risk from GW consumption. In this case study, GW quality in the Apaaso-Tafo community in the region was assessed and the infectious health risks posed to consumers were evaluated. Twenty GW samples were collected from ten boreholes. The concentrations of metals (Ca²⁺, Mg²⁺ and Fe) were determined using atomic absorption spectroscopy, bacteria (total and faecal coliform) using Multiple Tube Fermentation and Membrane Filter Techniques, and physicochemical qualities using electrometric, titrimetric, argentometric and spectrophotometric methods. The water quality indices (WQI) and the infection probability from drinking the GW were computed. The WQI showed that most (80 %) GW samples are within acceptable limits. Except for the pH, temperature, turbidity and total coliform bacteria, all parameters met the WHO standards. 40 % of the boreholes contained 50 to 500 cfu/100 mL of coliform bacteria and posed daily infection risks between 1 and 7.63 %. It is recommended that standpipes on boreholes be fitted with membrane or nano filters capable of removing bacteria and viruses to reduce infection risk. The authorities should also monitor GW quality regularly and respond to changes in quality with the appropriate intervention such as issuing 'boil-before-drinking' notices to consumers or encouraging parents to provide bottled and sachet water for their young children. Future research with an increased number of communities, sample size and sampling frequency should also be conducted to enhance the generalisability of these findings.