Fluoride contamination and water quality fluctuations in Mianwali District Pakistan and its implications for human health and sustainable agriculture

This study offers a thorough evaluation of groundwater quality in the Mianwali region of Pakistan. A total 510 groundwater samples were collected from 176 government water supply facilities spread over three tehsils of the district. After that, the samples were examined for several Physio-chemical, and microbiological characteristics. The WHO standard level was surpassed by 35% of the samples collected for concentration of fluoride. According to the Fluoride Pollution Index (FPI) data, 68% of samples were classified as having moderate contamination, indicating a moderate presence of fluoride, while around 22% of samples fell into the low contamination group, signifying the fluoride concentration is within safe levels. It is noteworthy that 9% of the samples that were gathered had significant levels of fluoride contamination that were above the allowable limits for fluoride. The Gibbs plot analysis indicated that the overall control on groundwater chemistry in the study area is of rock types and evaporation. About 58% of the samples are affected by rock types and included significant contributions from minerals breakdown, chemical weathering of fluoride-rich rocks, showing high levels of fluoride. On the other hand, the remaining 41% of samples show the influence of evaporation: increased salinity and sodium levels are evident. The elevated fluoride concentrations in the groundwater sources pose health risks through dental and skeletal fluorosis to consumers consuming raw water. Moderate contamination, obtained for most samples, can also affect agricultural productivity by slowing down soil quality and crop uptake, hence entering the food chain. These results show clearly the importance of introducing effective and rational management of groundwater from the Mianwali region to protect human well-being and ensure sustainable water use.