Groundwater fluoride contamination and probabilistic health risk assessment in fluoride endemic areas of the Upper East Region, Ghana

Abstract

Groundwater fluoride contamination has long been recognized as a water-related health issue in some parts of Ghana. However, the extent of fluoride contamination and the related human health risk to the communities in the fluoride endemic areas are not adequately studied. In this paper, fluoride concentrations in existing and newly drilled wells were assessed. Probabilistic non carcinogenic human health risk assessment, uncertainty and sensitivity analysis for three age groups (Group A: 0e10 years; Group B: 11e20 years; Group C: 21e72 years) was also carried out using Monte Carlo simulation technique. The results showed that, 27.27% and 15.38% of the existing wells in the Bongo and Kassena Nankana West districts have fluoride values above the guideline value 1.5 mg L 1 respectively. The non-carcinogenic risk of fluoride associated with oral ingestion recorded a mean Hazard Quotient (HQ) > 1 for younger age group (0e10 years) in all the study areas signifying potential health risk to this age group. Additionally, when the upper 95th percentile is used for the HQ, the oral ingestion for all the age categories recorded an HQ > 1. Sensitivity analyses indicated that fluoride concentration in the drinking water and ingestion rate were the most relevant variables in the model to reduce the potential health effect. The study established the basis for a strong advocacy and public awareness on the effect of water quality on human health and proposed some management strategies to guide future groundwater resources management to reduce the potential health risk to the population.