Trace metals concentration in vegetables of a sub-urban industrial area of Bangladesh and associated health risk assessment

Trace metals contamination of vegetables in the sub-urban industrial area of Bangladsh are increasing day by day. The mostly consumed vegetables like tomato (Lycopersicon lycopersicum), spinach (Spinacea oleracea), bean (Lablab purpureus), brinjal (Solanum melongena), potato (Solanum tuberosum), cauliflower (Brassica oleracea var botrytis), cabbage (Brassica oleracea var cupitata), and radish (Raphanus sativus) were collected from industrial area. Trace metals arsenic (As), manganese (Mn), zinc (Zn), cadmium (Cd) and lead (Pb) were measured using atomic absorption spectrophotometer (AAS). The descending order of trace metals followed the order of Zn>Mn>Pb>Cd>As. The results revealed that every vegetable contained the highest concentration of Zn range from 15 +/- 1.4 to 50 +/- 4.0 mg/kg fresh weight. Trace metals in vegetables exceeded the permissible level of FAO and WHO standard. The non-carcinogenic and carcinogenic risks were estimated on the basis of estimated daily intake (EDI), target hazard quotient (THQ), hazard index (HI) and target carcinogenic risks (TRs). The EDI values of all trace metals were below the maximum tolerable daily intake (MTDI). Total target hazard quotient (TTHQ) were greater than 1, indicated that if people consume these types of vegetables in their diet, they might pose risk to these metals. Finally, the total cancer risks (TRs) values were 6.4 x 10(-3) for As and 8.7 x 10(-5) for Pb which were greater than threshold value of USEPA (10(-6)), indicating that the consuming inhabitants of these vegetables are exposed to As and Pb with a lifetime cancer risk.