Concentrations, Water Quality Indices and Associated Health Risk Assessment for Heavy Metals in Upper Genale-Dawa River Basin of Sidama Regional State and Gedio Zone of Southern Ethiopia

The objective of this paper was to investigate the concentration, water quality indices and associated health risk assessment for heavy metals in the Upper Genale Dawa River Basin of Sidama Regional State and Gedio Zone of Southern Ethiopia using appropriate standard analytical techniques and other relevant procedures. Data obtained reveals that the measured heavy metals concentrations, (mean, mg/L) followed the order of Hg (0.029) > Mn (0.028) > Cu (0.022 ) > Pb (0.022 ) > Ni (0.021) > As (0.021) > Co (0.019) > Cd (0.017) > Fe (0.017) > Zn (0.016) > Cr (0.016) > Se (0.014). Pollution indices with values Drinking Water: HPI (1958.404), HEI (35.103), MI (35.103); Irrigation water: HPI (7471.117), HEI (4.5142) indicated that water quality was compromised for both drinking and irrigation uses. Risk assessmentvalues HI-ingestion for child and adult are 7.83 and 5.76 and HI-dermal for child and adult are 1.91 and 1.01 respectively revealed non-carcinogenic hazards (HQ and HI) primarily linked to arsenic and cadmium, presenting intolerable risks, especially for children. The summation of Carcinogenic risk (ΣCR) show that CR-ingestion for child and adult are 6.44*10-2 and 4.74*10-2 and CR-dermal for child and adult are 5.01*10-4 and 2.65*10-4 respectively. Carcinogenic risk evaluations indicated a high risk for developing cancer based on oral intake, while dermal exposure remained within acceptable limits. This research highlights the urgent need for monitoring and intervention strategies to mitigate heavy metal pollution in the Genale Dawa River Basin, ensuring community health and environmental safety.