Spatial analysis and GIS mapping of regional hotspots and potential health risk of fluoride concentrations in groundwater of northern Tanzania

• DOI: 10.1016/j.scitotenv.2020.139584
• Publication Date: 2020-05-21T01:19:06Z
• Authors: Julian Ijumulana; Fanuel Ligate; Prosun Bhattacharya; Felix Mtalo; Chaosheng Zhang
• Keywords: Skeletal fluorosis

Safe drinking water supply systems in naturally contaminated hydrogeological environments require precise geoinformation on contamination hotspots. Spatial statistical methods and GIS were used to study fluoride occurrence groundwater identify significant spatial patterns using concentrations. The global local Morans I indices used. While the positive index indicated structure occurrence, clusters identified mapped at p-value of 0.05. demonstrated sources with concentrations below or above WHO guideline Tanzania standard for considered as 'regional cool spots' hotspots', respectively. Two regional hotspots around Stratovolcano Mountains north-east south-west area; along Neogene Quaternary volcanic formations Palaeo-Neoproterozoic East African Orogen (Mozambique Belt). two largest spots dominated major minor rift escarpments west east area respectively while small ones emerged mountains north south. Furthermore, outliers boundary an indication processes controlling mobilization groundwater. all had 1.5 mg/L, some extremely low 0.5 mg/L which is not safe human consumption. For hotspots, 96% mg/L. probability having source varied from one geological unit another least probabilities.