Unraveling the Nexus: Exploring the Influence of Heavy Metals in Irrigation Water on Vegetable Quality and Human Health
Roland Songotu Kabange
Kumasi Technical University
Keywords: heavy metals, irrigation water, vegetable quality and human health
Abstract
The rising global population necessitates increased agricultural productivity to meet the growing demand for edible vegetables. Water scarcity has driven many farmers to irrigate crops with alternative water sources, including heavy metal-contaminated rivers. The environmental pollution and toxicological risks posed by heavy metals, particularly their tendency to bioaccumulate in human tissues, are well documented. Consequently, contamination of edible vegetables and agricultural soils has become a critical global environmental concern. This study assessed the impact of heavy metals on vegetable quality and human health risks in River Nyam, a mining-affected area in Obuasi Municipality, Ghana. Water samples from the river and selected edible vegetables were collected and analyzed during both the wet season (June – July) and dry season (November – December). Statistical analyses were performed and standardized indices such as total hazard quotient (THQ), and hazard index (HI) were computed based on the concentrations of heavy metals in the vegetables. Results revealed spatial variations in heavy metals concentration in River Nyam’s water across different sampling points. Concentrations of Zn, Mn, Cr and Pb in the vegetables were within permissible limits, while levels of Fe, Co, As, Cd, Cu, and Hg exceeded the acceptable limits. Most vegetables exhibited significant heavy metal contamination, and the calculated hazard index values (HI > 1) indicated potential risks for consumers. Overall, the study underscored the unsuitability of River Nyam’s water for agricultural irrigation due to its detrimental effects on vegetable quality and consumer health. The study also advocates strengthened water resources protection measures and comprehensive consumer risk assessments to support evidence-based policy formulation and decision making
