Study area The samples were collected from Tarutia, Tangail Sadar Upzila of Tangail district, Bangladesh. Tangail district area is 334.26 km2and situated at the middle part in Bangladesh. Tangail Sadar Upazila is densely populated area in Bangladesh and population density is 1,100 /km2 (BBS2011). The study area is situated between Tangail Sadar is located at 24.2500N to 89.9167E. Tangail as an industrial vicinity of Bangladesh possesses highly vulnerable to environmental pollution. There are different kinds of industries in Tangail district such as garments, packaging industry, dyeing,brick kiln, metal workshops, battery manufacturing industries, tanneries, textile industries, pesticide and fertilizer industries, different food processing industries which pro-duce huge volumes of effluents that contain heavy metals. After production, these industries discharge untreated wastes randomly to river and canals (Proshadet al. 2017). Then, the disposed wastes are mixed with soils and the soil is continuously being polluted by toxic elements in Bangladesh. Rice and vegetable sampling Rice and vegetables were collected near industrial vicinity, and at each sampling station,same species of rice and vegetables were collected as sub-samples and were thoroughly mixed to form a composite sample. One hundred and thirty-five samples of eleven different agricultural crops i.e. rice (Oryza sativa), sponge guard (Luffa cylindrical), bittergourd (Momordica charantia), papaya (Carica papaya), okra (Abelmuschus esculentus), bean (Phaseolus vulgaris), brinjal (Solanum melongena), chili (Capcicum frutescens), Bottle gourd (Lagenaria siceraria), Cucumber (Cucumis sativus), and Indian spinach (Basella alba) were collected by hand from the selected agricultural fields during March–April 2017. Plant samples were collected for chemical analysis kept in polythenezip bags with definite marking and tagging and brought to the laboratory on the day of sampling. Rice and vegetable samples were washed with distilled water and cut into small pieces and was kept in oven at 70–80C to attain constant weight (Tiwariet al. 2011). The fresh and dry weights were recorded to calculate moisture contents. The processed samples were brought to Yokohama National University, Japan, for chemical analysis. Heavy metal analysis All chemicals were analytical grade reagents; Milli-Q water (Elix UV5 and Milli-Q, Millipore, Boston, MA, USA) was used for the preparation of solutions. The Teflon vessel and polypropylene containers were cleaned, soaked in 5% HNO3 for more than 24 h,then rinsed with Milli-Q water and dried. For metal analysis, 0.3–0.5 g of the food sample was treated with 6 mL 69% HNO3 (Kanto Chemical Co, Tokyo, Japan) and 2 mL 30% H2O2 (Wako Chemical Co, Tokyo, Japan) in a closed Teflon vessel and was digested in a Microwave Digestion System (Bergh of speedwave1, Eningen, Germany). The digested samples were then transferred into a Teflon beaker, and a total volume was made up to 50 mL with Milli-Q water. The digested solution was then filtered by using syringe filter (DISMIC1–25HP PTFE, pore size¼0.45 mm; Toyo Roshi Kaisha, Ltd., Tokyo, Japan) and stored in 50-mL polypropylene tubes (Nalgene, New York, NY,USA). After that, the digestion tubes were then cleaned using blank digestion procedure following same procedure of samples. For heavy metals, samples were analyzed using inductively coupled plasma mass spectrometer (ICP-MS, Agilent 7700 series, Santa Clara, CA, USA). Instrument operating conditions and parameters for metal analysis are done. The detection limits of ICP-MS for the studied metals were 0.7, 0.6, 0.8, 0.4,0.06, and 0.09 ng/L for Cr, Ni, Cu, As, Cd, and Pb, respectively. Multi-element StandardXSTC-13 (Spex CertiPrepVR, Metuchen, NJ, USA) solutions were used to prepare calibration curves. Internal calibration standard solutions containing 1.0 mg/L of indium (In),yttrium (Y), beryllium (Be), tellurium (Te), cobalt (Co), and thallium (TI) were purchased from Spex Certi PrepVR (Metuchen, NJ, USA). During the procedure, 10 mg/Linternal standard solution was prepared from the primary standard and added to the igested samples. Multi-element solution (purchased from Agilent Technologies, Japan) was used as tuning solution covering a wide range of masses of elements. All test batches were evaluated using an internal quality approach and validated if they satisfied the defined Internal Quality Controls (IQCs). Before starting the analysis sequence, relative standard deviation (RSD,<5%) was checked by using tuning solution purchased from Agilent Technologies. The certified reference materials INCT-CF-3 (corn flour) bought from the National Research Council (Canada) were analyzed to confirm analytical performance and good precision (relative standard deviation bellow 20%) of the applied method.