Appraisal of probabilistic human health risks of heavy metals in vegetables from industrial, non-industrial and arsenic contaminated areas of Bangladesh

Abstract

Monitoring of heavy metal content in commonly consumed vegetables is of high priority for food safety, and public health risk assessment. Vegetables were collected from industrial, non-industrial, arsenic contaminated region and one of popular vegetable markets of Bangladesh for analyzing heavy metals (As, Cd, Pb, Cu and Zn) using Atomic Absorption Spectroscopy (AAS) with standard digestion procedure. Results showed significant variations of heavy metal content among vegetables and most of cases the metals (except Cu and some of Zn) revealed several times higher concentrations than that of maximum permissible level (MPL) values, which indicated the vegetables were contaminated through either natural or anthropogenic activities. The dietary intake of metals are responsible for association of health risk that evaluated by target hazard quotient (THQ), hazard index (HI), and target carcinogenic risk (TR) calculations. Estimated daily intake (EDI) for all metals were below the maximum tolerable daily intake (MTDI) values of all vegetables. The THQs for single metals were less than 1 (except As and Pb for few vegetables), indicating the inhabitant would not possess health hazard for single metal through vegetables consumption. However, the total target hazard quotient (TTHQ) of all metals were >1 (except Cu and Zn for industrial and non-industrial sites), suggesting potential health risk. HI values were found more than 1 (36.24 for industrial site, 16.74 for non-industrial site, and 15.03 for local market) representing the selected vegetables intake might be affected quality of food safety of densely populated Bangladesh. The probabilistic risk, individual, and total cancer risk (TR) for As and Pb were exceeded the threshold level (10−4) and safe limit (10−6), respectively, indicating peoples who have been consuming these vegetables long time, they might be exposed by lifetime cancer risk. Sensitivity analysis revealed that the metal concentration has high influence on carcinogenic risks.