Health-Risk Assessment of Heavy Metals in Drinking Water Obtained from Public Primary Schools in Akwa Ibom State, Nigeria

The presence of heavy metals in drinking water sources poses significant public health and environmental concerns, especially in children which affect their development when they exceed their permissible limits. This study assessed the levels of arsenic, cadmium, iron, lead, and vanadium in water obtained from drinking water bottles among children from three locations; St. Joseph Primary School (L1), Government School Ediene II (L2), and Government School Ibiaku Itam II (L3) of Uyo, Abak and Itu Local Government Areas respectively, in Akwa Ibom State, Nigeria. Seventy-five water samples (five water samples from each class from primary 1 – 5, which amounted to 25 water samples from each school) were collected from these schools, and levels of the specified heavy metals were quantified with an Atomic Absorption Spectrophotometer. The health risk analysis was assessed using Estimated Daily Intake, Hazard Index, and Cancer Risk. The concentration of lead, iron, and cadmium in the three schools was above the permissible standards. Lead had the highest EDI, followed by iron and cadmium; arsenic and vanadium were within the permissible limit. The Total HI of arsenic, cadmium, iron, lead, and vanadium was <1, indicating low non-carcinogenic risk. The total Cancer Risk was all within the permissible limit, indicating low cancer risk, although, the contribution of lead, iron, and cadmium was significant. The outcomes showed that the concentration of some heavy metals in the water being consumed by people in the study locations is more than the required limits. The result demonstrated both low non-carcinogenic risk and cancer risk.