Bioaccumulation of elements in the edible part of vegetables from the agricultural soil: Source apportionment and potential risks

Heavy metal (HM) pollution analysis is critical for understanding environmental contamination pathways, safeguarding food safety, and protecting human health. This study evaluates HM contamination in soils and vegetables from Raozan and Rangunia upazilas, Chattogram, Bangladesh, to identify contamination sources, assess ecological risks, and evaluate potential human health impacts. Seventeen elements (Na, Al, K, Sc, Cr, Mn, Fe, Co, Zn, As, Rb, Sb, Cs, La, Sm, Th, U) were analyzed using neutron activation analysis. Geo-environmental indices revealed significant enrichment of Sb and As, indicating a mixed geogenic and anthropogenic origin. Positive Matrix Factorization (PMF) modelling attributed 55 % of contamination to industrial and agricultural activities, while vehicular emissions and waste incineration contributed 20.2 % and 24.8 %, respectively. Bioaccumulation analysis revealed higher metal uptake in non-leafy vegetables, particularly for Zn (BCF = 1.148) and K (BCF = 2.69). Health risk assessments indicated excessive target hazard quotients (THQs) for Co (10.96), Cr (3.85), and Mn (3.15), with carcinogenic risks from Cr exceeding the acceptable limits suggested by the US EPA. These findings highlight the critical need for soil remediation, controlled agrochemical use, and stringent food safety regulations to mitigate HMs exposure and ensure environmental sustainability and public health.