Trace metals in soil and vegetables and associated health risk assessment Md Saiful Islam & Md Kawser Ahmed & Md Habibullah-Al-Mamun & Shigeki Masunaga Received: 1 April 2014 /Accepted: 1 September 2014 /Published online: 11 September 2014 # Springer International Publishing Switzerland 2014 Abstract 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. Consider- ing 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 con- sumption of vegetables were higher than the USEPA threshold level (10 -6 ), indicating potential cancer risks. Keywords Metal pollution . Agricultural land . Vegetable . Geochemical fractionation . Risk assessment Introduction Soil pollution changes the physical, chemical, and/or biological characteristics, which reduces the amount of cultivable land and habitation (Khan et al. 2010). Soil acts as a sink and also as a source of pollution with the capacity to transfer pollutants to the ground water and food chain, and then to the human and/or animals (Khan et al. 2010). Once trace metals are accumulated in soil, they pose potential risks to the ecosystem and also to human health due to their non-biodegradable and per- sistent nature (Muchuweti et al. 2006). Contamination Environ Monit Assess (2014) 186:8727–8739 DOI 10.1007/s10661-014-4040-y Electronic supplementary material The online version of this article (doi:10.1007/s10661-014-4040-y) contains supplementary material, which is available to authorized users. M. S. Islam : M. Habibullah-Al-Mamun : S. Masunaga Faculty and Graduate School of Environment and Information Sciences, Yokohama National University, 79-7 Tokiwadai, Hodogaya-ku, Yokohama, Kanagawa 240-8501, Japan M. Habibullah-Al-Mamun e-mail: almamunhabib@gmail.com S. Masunaga e-mail: masunaga@ynu.ac.jp M. S. Islam (*) Department of Soil Science, Patuakhali Science and Technology University, Dumki, Patuakhali 8602, Bangladesh e-mail: msaifulpstu@yahoo.com M. K. Ahmed Department of Oceanography, Earth & Environmental Sciences Faculty, University of Dhaka, Dhaka 1000, Bangladesh e-mail: kawser@univdhaka.edu M. Habibullah-Al-Mamun Department of Fisheries, University of Dhaka, Dhaka1000, Bangladesh