Assessment of human health risks associated with trace metal exposure through the consumption of Amaranthus viridis and Manihot esculenta grown in the Kimwenza gare area of Mont-Ngafula (Kinshasa, DRC)

Abstract

Introduction Human populations are exposed to trace metal contamination through foodstuffs, particularly leafy vegetables. Purpose This study assessed the human health risks associated with consumption of vegetables grown in the Kimwenza gare agroecosystem. It focused on the vegetables most commonly consumed by populations relying on this production area. Methods Surveys were conducted among residents living near the agroecosystem to identify the vegetables most frequently prepared and to collect data on consumption habits. Two vegetable species were selected for chemical analysis using an energy-dispersive X-ray fluorescence spectrometer (ED- XRF). The daily exposure dose and hazard quotient were calculated for cadmium (Cd) and lead (Pb). Pearson correlation analysis was performed using RStudio (version 4.5.1). Results Trace metal concentrations were determined with a 95% confidence interval. Lead concentrations were low, whereas cadmium concentrations exceeded the WHO/FAO permissible limit in five samples (0.129 ± 0.012, 0.164 ± 0.123, 0.133 ± 0.012, 0.291 ± 0.026, and 0.420 ± 0.028 mg/kg, compared with the limit of 0.10 mg/kg). Statistical analysis indicated that both vegetables accumulated trace metals proportionally (r = 0.967 to r = 0.995). Hazard quotient values calculated from the daily exposure dose were > 1 for cadmium, indicating a potential risk of non-carcinogenic health effects among consumers, with children being the most vulnerable group. Conclusion Consumption of vegetables grown in the Kimwenza gare agroecosystem may expose consumers to health risks, as indicated by hazard quotient values. Raising awareness among market gardeners and implementing periodic monitoring of trace metal concentrations could help reduce this risk.