Heavy Metal Contamination in Gopalganj Agriculture: Levels and Health Risks

Heavy metal contamination in agricultural systems poses a growing food safety concern in developing regions. This study assessed cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn) in soils, irrigation water and commonly consumed vegetables from rural, mixed and industrially influenced sites in Gopalganj, Bangladesh. Samples were analyzed using atomic absorption spectroscopy. Overall, metal concentrations in soils, vegetables and water were below the maximum permissible values recommended by WHO/FAO and national standards (eg, soil: Cd 3 mg kg^-1, Pb 50 mg kg^-1, Ni 50 mg kg^-1, Zn 300 mg kg^-1 vegetables: Cd 0.05-0.1 mg kg^-1, Pb 0.1-0.3 mg kg^-1; drinking water: Cd 0.003 mg L^-1 Pb 0.01 mg L^-1). Mean soil levels were low (mg kg^-1 : Ni ~0.4, Cu ~0.5, Pb ~0.3), while Zn was the most detectable metal in vegetables (~0.4 mg kg^-1). Irrigation water contained only trace metals near detection limits. However, soils near industrial areas showed significantly higher Ni and Cu (p < 0.05), with slight increases of Cd, Pb, and Cr in vegetables and water. Moderate metal correlations suggested common sources. Health risk indices (HQ, HI) were well below 1, indicating no significant non-carcinogenic risk. These findings provide baseline data and highlight the need for continued monitoring.