Environmental Challenges (Apr 2025)
Pollution profiling and quality assessment of Bonsa River, Tarkwa Nsuaem, Ghana; toxic element, ecotoxicology, health risk assessment, and multivariate analysis
Abstract
Anthropogenic activities have contributed significantly to the erratic supply of potable drinking water to various parts of Ghana posing significant health risks, water scarcity, and security issues for consumers and the environment. This study aimed to assess the physicochemical, microbiological, and toxic element concentrations, determine the Water Quality Index (WQI), estimate potential human health risks, characterize the pollution potential and ecological risks, and identify pollution sources in the Bonsa River using multivariate statistical analyses. The findings indicated that the river water was acidic and the turbidity, Ca2+, Mg2+, DO, Fe, Pb, Hg, Cr, As, aerobic plate count, Escherichia, total, and fecal coliforms were higher than their respective maximum recommended limits. The multivariate analysis indicated illegal mining, geological influences, open defecation and sewerage runoff from waste dumps strongly influenced contaminant sources, transport, and enrichment. The WQI status ranged from 3484 % to 10,525 %, indicating an unsuitable water source for domestic, irrigation, and industrial applications. Children have higher chronic daily exposure to potentially toxic elements compared to adults, and oral exposure to toxic elements was significantly higher than dermal exposure. The cumulative carcinogenic risk exceeded 10−4 and the total non-carcinogenic risk exceeded 1, indicating a high potential for cancer, adverse health risks, and water-related diseases. The pollution and ecological indices indicate a severe contamination water status associated with high ecological sensitivity. This study provides benchmark data for monitoring Bonsa River's water quality and identifying areas for interventions to enhance water quality and safeguard the river's ecosystem.
