ASSESSMENT OF HEAVY METAL CONTAMINATION IN VEGETABLES FIELD OF BOGURA DISTRICT: OVERVIEW OF POLLUTION INDICES AND RISK ASSESSMENT

Abstract

The current study focused on quantifying hazardous heavy metals (Pb. Cu, and Cr) in soil-vegetables (potato, tomato, pepper, cauliflower, and cabbage) systems in different Upazilla of Bogura district in Bangladesh to assess their effect on human health and the environment. The instrumental detection method was validated according to linearity, determination co-efficient, limit of detection (LOD), limit of quantification (LOQ), accuracy, and precision. All the vegetables and their field soil had Cu concentrations lower than the maximum permissible limit set by BFSA, FAO/WHO. The concentration of Cr and Pb in vegetables exceeded the maximum allowable limit, but their field soil in different Upazilla of Bogura District did not exceed the maximum allowable limit as per FAO/WHO. For contamination factor (CF), only Pb severely contaminated the vegetables (CF>6). The contamination degree (CD) data also showed that all vegetables had severe contamination. The pollution load index (PLI) results indicated vegetable field soil of Kahaloo, and Bogura Sadar had the highest PLI, while the vegetables produced in Nandigram and Dupchanchia had the lowest PLI. The bioaccumulation factor (BF) values were found ˂1 in all vegetables for Cu, Cr, and Pb indicating trace metal transfer from field soil to consumable parts. Furthermore, the potential ecological risk factor (ERi) by single metal and risk index (PERI) results revealed lower ecological risks in vegetable fields. Health risk assessment showed that all vegetable samples were unsafe for human consumption as the carcinogenic health risk (CHR˃10 ) and noncarcinogenic

health risk (HI ˃1) quotients seem more than the safe level in all vegetable samples. Findings show that heavy metal concentrations were high in vegetable fields endangering the environment and consumer health. Actions should be taken to reduce heavy metal pollution in the vegetable fields of different Upazilla of Bogura district to protect the environment and the consumer's health.