Risk assessment and quantification of elemental concentrations in river and stream in Nigeria

Abstract

The rising prevalence of elements in surface water is becoming a major global environmental problem due to their resistance to change and capacity to accumulate in organisms. Humans are causing significant heavy metal contamination in the aquatic environment, which is killing aquatic creatures. The purpose of this study is to determine the elemental composition of surface water in Ogun State. Water samples were collected from a river that flows alongside Liberty Estate in Ewupe, Ado-Odo Ota Local Government Area, and a stream that runs alongside Pacific Estate in Iganmode. The element composition of water samples was determined using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). Several components were found to exceed the limitations imposed by the World Health Organisation (WHO) and the Environmental Protection Agency (EPA). In River I, sodium (Na) had the highest apparent concentration, whereas titanium (Ti) had the lowest average concentration. In River II, silicon (Si) had the highest apparent concentration, whereas chromium (Cr) had the lowest average concentration. Titanium (Ti) had the lowest mean concentration value, whereas sodium (Na) appeared to have the highest concentration in stream I. Stream II has the highest concentration of sodium (Na), while Uranium (U) has the lowest average concentration value. Nonetheless, the incremental lifetime cancer risk (ILCR) values for adults and children who drink river and stream water are similar, ranging from 10–9 to 10–8. This implies a high carcinogenic risk (CR) linked with drinking water from both sources. Children who had access to both stream and river water demonstrated higher risk levels than adults. Routine studies of the state's streams and rivers should be conducted to avoid the subtle impact that may emanate from the water bodies.