Arsenic and cadmium in food-chain gions/countries, including Europe and the United States (18). The cooking process C is commonly practised in rural areas in which water is not discarded while cooking vegetables to avoid loss of micronutrients. This cooking process increases the concentration of arsenic in cooked vegetables and, thus, water sourc- es being used for cooking vegetables have a great impact on the concentration of arsenic in food. We found that raw rice contained higher concen- tration of arsenic compared to raw vegetables. This might be due to two reasons. First, the vegetables that were collected from households in Matlab were grown in the vicinity of the homes (home-garden- ing), and pond- or river-water containing low levels of arsenic was used for irrigating vegetables, unlike rice grown in large fields where arsenic-contaminat- ed underground water is used for irrigation. Second, paddy has the enhanced capacity to accumulate ar- senic compared to other cereal crops that contain lower arsenic concentration (19). Plants are known to have differential absorption and translocation of arsenicals to its various parts, e.g. roots, stems, and leaves (20,21), which may explain the higher levels of arsenic in leafy vegetables than in non-leafy vege- tables. Metal transporter genes that translocate ar- senic into and out of the plants may also play a role in the accumulation of arsenic in different parts of vegetables (22). Moreover, the intake of arsenic and other toxic elements by plants from soil varies from region to region. Some types of soil have a capacity for very strong bonding while others do not (23). The use of water from both shallow and deep tube- wells for irrigation of agricultural lands, particularly during the dry period (November-March) for pro- duction of high-yielding varieties of rice augment the accumulation of excessive level of arsenic (8). Flooding changes the chemistry of soil dramatical- ly and makes arsenic more soluble; thus, recurrent flooding in Bangladesh redistributes and mobilizes arsenic in the surface-layer of soil from highly-ex- posed zones to low-exposure zones, especially via drainage from contaminated sources (24,25). Rice grown in flooded fields picks up more arsenic than rice grown in unflooded fields (24). Ponds may also be contaminated with arsenic where arsenic-con- taminated tubewells are installed near the ponds. The inflow of drainage from tubewells was found to be the major cause of arsenic contamination in pond-water (25). Cadmium is a pollutant which has strong negative effects on human and animal health. Chronic ex- posure to cadmium is associated with kidney dam- age, bone damage, cancer, low birthweight, sponta- 582 Khan SI et al. neous abortion, and many other ailments (26,27). We found that both rice and vegetables contained, on average, 30 µg/kg of cadmium. The maximum level of cadmium permitted by the Japanese Gov- ernment and by the Codex Alimentarius in rice is 400 µg/kg (28,29), and for leafy vegetables, the limit recommended by Codex Alimentarius is 200 µg/kg (29), which indicates that the concentration of cad- mium in Bangladeshi foods is still within the safe limit. However, since rice is a staple food in Bangla- desh and is consumed twice a day in large quanti- ties (average consumption of adults is 1,500 g of cooked rice per day) (30), it could result in accumu- lation of cadmium in the body within a short pe- riod. Iron-deficient individuals have higher uptake of cadmium than those with balanced iron reserve (31). Thus, menstruating women and children with low iron stores have higher resorption of cadmium because of increased expression of DCT-1, a metal ion transporter (32). Half-life of cadmium is 10 years which accumulates in the body and is not metabo- lized and detoxified as arsenic (27). Thus, chronic exposure to cadmium in staple food, especially among rice-eating population, would have serious public-health consequences. In our study, both rice and vegetables contained cadmium. The presence of cadmium in rice and vegetables in Matlab could be due to the use of chemical fertilizers, e.g. triple superphosphate, and pesticides (composed of cad- mium or its derivatives) for the cultivation of pad- dy and vegetables. Toxic metal deposition in urban and rural areas is a problem because of industrial wastage, sewage sludge, chemical fertilizers, and pesticides. As a consequence, grazing animals are exposed to pollutants deposited on pastures. Thus, humans are additionally exposed to cadmium-con- taminated animal products, especially from meat and milk (33-35). The mitigation of arsenic from the food-chain can be comprehended using different types of cooking methods and by changing the social behaviours of the communities through raising public awareness. Since the cooking practices do not affect concentra- tion of cadmium in food, efforts should be focused on changing the types of fertilizers and pesticides used that may lower the concentration of cadmium in food, e.g. using rice variety that requires lower use of pesticides and fertilizers. Limitations The limitations of the study are: (a) food samples (rice and vegetables) collected were not well-rep- resentative of all types of food consumed in other areas of Bangladesh and (b) fish or pulses were not included in the study that are also consumed in the daily diet. JHPN