Bioaccumulation of potentially toxic elements in selected vegetables of Noakhali district, Bangladesh and their associated health risks

The accumulation of potentially toxic elements (PTEs) in vegetables through contaminated soil, fertilizer, and irrigation water poses serious food safety and public health concerns. This study quantified nine PTEs (As, Pb, Cd, Cr, Zn, Mn, Fe, Cu, and Hg) in vegetables, their cultivation soils, fertilizers, and irrigation water collected from 27 sites in Noakhali district, Bangladesh, using Atomic Absorption Spectrophotometry. The bioaccumulation factor (BF) of these elements from soil and water to the studied vegetables and the human health risks associated with their consumption were also determined. Most PTEs in studied vegetables, soil, fertilizer, and water were within the maximum allowable concentrations, except for Cd and Cr in certain vegetables and water samples. Soil quality indices indicated low to moderate contamination, with Cd under radish cultivation showing the highest ecological risk (PERI = 49.0). The BF was below the threshold (< 1) for soil-to-plant transfer but exceeded 1 for water-to-plant transfer for most of the vegetables. The estimated daily intake (EDI) values were below the maximum tolerable limits; however, the total target hazard quotient (TTHQ > 1) indicated potential non-carcinogenic risk, primarily driven by Cd (74% contribution). Carcinogenic risks (TCR) for As, Pb, Cd, and Cr were within acceptable limits (< 10–4), except for Cd in radish (8.39E-03) and cauliflower (3.40E-03). Overall, the findings reveal moderate PTE accumulation in the agricultural systems of Noakhali, emphasizing the need for regular monitoring and better fertilizer and irrigation management to ensure food safety and public health protection.