Trace metals in soil and vegetables and associated health risk assessment
The objective of this study was to assess the contamination level of trace metals in soil and vegetables and health risk to the urban population in Bangladesh. The range of Cr, Ni, Cu, As, Cd, and Pb in agricultural soils was 158–1160, 104–443, 157–519, 41–93, 3.9–13, and 84–574 mg/kg, respectively. Sequential extraction tests revealed that the studied metals were predominantly associated with the residual fraction, followed by the organically bound phase. Concerning Cu, Ni, Cd, and Pb in vegetables, more than 50 % samples exceeded the FAO/WHO recommended permissible limits. Considering the transfer of metals from soil to vegetables, Cu and Cd exhibited higher transfer factor (TF) values than the other metals. Target hazard quotient (THQ) for individual metal was below 1, suggesting that people would not experience significant health hazards if they ingest a single metal from vegetables. However, total metal THQ signifies the potential non-carcinogenic health hazard to the highly exposed consumers. The carcinogenic risk (TR) of As (1.9 × 10−4) and Pb (2.3 × 10−5) through consumption of vegetables were higher than the USEPA threshold level (10−6), indicating potential cancer risks.
KeywordsMetal pollution Agricultural land Vegetable Geochemical fractionation Risk assessment
The authors are grateful for financial support for conducting this research from the Leadership Program in Sustainable Living with Environmental Risk (SLER) at Yokohama National University under the aid of Strategic Funds for the Promotion of Science and Technology from the Ministry of Education, Culture, Sports, Science and Technology and also for Research Collaboration Promotion Fund provided by Graduate School of Environment and Information Sciences, Yokohama National University, Japan. Furthermore, we are thankful for the kind help from the members of Dhaka University, Bangladesh during the field sampling.
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