Integrated evaluation of slum living conditions and health risk assessment of groundwater quality in selected communities of Abeokuta, Southwestern Nigeria

Abstract

This study evaluated slum conditions and assessed human health risks associated with drinking water in three communities of Abeokuta, Ogun State, Nigeria. Twenty-one groundwater samples were collected and analyzed for physicochemical and microbiological parameters using standard procedures. Physicochemical analyses were performed using the standard procedure. All digested samples were analysed for selected heavy metals (Cd, Cu, Fe, Mn, Ni, Pb, and Zn) using an Atomic Absorption Spectrophotometer (AAS, Model 210/211VGP, Buck Scientific, E. Norwalk, CT, USA). Microbiological parameters were determined through serial dilution, isolation, and identification of isolates. The Water Quality Index (WQI) and health risk indices average daily intake, hazard quotient (HQ), hazard index (HI), and cancer risk (CR) were computed. One hundred and five structured questionnaires were administered to residents to obtain data on housing, infrastructure, and sanitation. Data were analyzed using SPSS (version 23). Results showed that most water parameters met WHO standards, except for electrical conductivity, which gave mean values ranging from 793.70 to 1153.00 µS/cm, and other parameters (mg/L) which gave (380.00–481.10) for hardness, 0.55–0.80 for Fe and 0.07–2.33 for Cu. The total bacterial count (1990 cfu/mL) exceeded the WHO limit (50 cfu/mL), indicating contamination. The WQI values (> 300) revealed the water was unsuitable for consumption, while HI values > 1.0 indicated potential health risks. Questionnaire results showed that 61%, 83%, 77%, 60%, and 40% of respondents were male, married, educated, employed, and earned above ₦100,000, respectively. Moreover, 57% and 97% lacked access to clean water and sanitation. This study showed that slum residents face poor water quality and significant health risks due to contaminated groundwater and inadequate sanitation.