Comprehensive assessment of water pollution and health risks in the Angereb Reservoirs, Gondar, Ethiopia

Angereb Reservoirs are experiencing significant levels of pollution due to various anthropogenic activities such as agricultural runoff, untreated sewage discharge and industrial waste, were degrading water quality and causing eutrophication. Communities used Angereb Reservoir water is at increased risk of waterborne diseases; particularly heavy metal causes chronic health problems. However there was lack of comprehensive data on the cause and extent of pollution in the Angereb Reservoir. This comprehensive assessment highlights urgent need for integrated water resource management and effective pollution control strategies. This study was conducted through a multi-faceted and systematic approach involving several key methodologies. Six water samples were collected along the strategic points of the reservoir between May 2023 and March 2024. Different standard analytical methodologies were applied for analysis of water quality parameters including pH, dissolved oxygen, nutrients and heavy metals. The finding indicates that the concentration (mg/L) of heavy metals were Fe (0.01–6.56), Zn (0.67–5.22), Cu (0.009–0.19), Mn (0.0–1.89), Cr (5.06 × 10–5–0.03), Cd (0.029–0.27) and Pb (0.001–2.216). Cd and Pb were exceeded WHO for safe drinking water, heavy metal evaluation index values was > 10. Hazard Quotient (HQ), hazard index (HI) and incremental lifetime cancer risk (ILCR) were calculated. Average HQ values for Cd and Pb were above the risk threshold (HQ>1), indicating significant long-term exposure risks. HI>1 suggested potential non-carcinogenic effects. Furthermore, ILCR values exceeding 10–4 threshold, shows that Cd and Pb were the major risk factor for cancer particularly in children. The findings underscore the urgent need for Cd and Pb removal from Angereb reservoir.