Assessment of Human Health Risks Emanating from Underground Water Quality Based on Selected Physicochemical Parameters

Abstract

This study was designed to assess groundwater pollution from four borehole samples commonly used at Kibaha district informal settlements. This was achieved using grab sampling with three replications. The samples were tested for physicochemical groundwater quality. The maximum temperature was recorded at Msufini borehole sample, reaching 28.81ºC, while the minimum temperature was observed at Kikongo, registering 26.31ºC. There were variability pH levels, with mean values ranging from 6.55 at Msufini/Boko Kibaoni to 7.21 at Ruvu Darajani. The lowest mean total hardness was found at Boko Kibaoni borehole samples (24.14 ± 2.48 mg/L), whereas the highest was detected at Ruvu Darajani borehole samples (147.20 ± 1.01 mg/L). The highest nitrate concentration, reaching 3.85 mg/L, was observed at the Ruvu Darajani borehole sample, while phosphate concentrations ranged from 0.02 to 2.41 mg/L at the Kikongo and Ruvu Darajani boreholes, respectively.The Hazard Index (HI) via oral intake for adults ranged from 44.8 at Kikongo to 3,447.1 at Ruvu Darajani, while for children, it varied from 44.8 to 5,389.0 at Kikongo and Ruvu Darajani, respectively. A high Hazard Index for both adults and children via oral intake signals a notable risk to human health, warranting prompt action to mitigate exposure and address contamination sources. This may entail implementing water treatment measures to borehole water sources, enhancing wastewater management practices, and enforcing regulations to safeguard the safety of borehole drinking water supplies.