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Vegetables are an important part of a healthy and balanced diet. High concentrations of heavy metals and nitrates in vegetables may pose a risk to human health. In the present study, concentrations of nitrates and three heavy metals lead, cadmium, and chromium in some vegetables cultivated in the suburbs of Ahvaz city were determined. Also, the daily intake of these metals through consumption of vegetables was calculated. 100 samples of five kinds of vegetables (leek, sweet basil, radish, potato, and tomato) were collected randomly during the cultivation season between December 2013 and April 2014
. The samples were taken twice a day, in the morning and afternoon, for observation of the nitrate concentration. After preparation of the samples, atomic absorption spectrometry (AAS) was used to determine the heavy metals and spectrophotometer for determining the nitrate levels. The mean ± SD concentrations of Pb, Cd, and Cr in these vegetables were 6.13 ± 0.47, 2.53 ± 0.43, and 41.73 ± 2.19 mg/kg, respectively. High nitrate concentration was detected in radish (409.83 ± 5.97), while tomato had the lowest nitrate concentration (7.38 ± 0.16) mg/kg. Nitrate concentration in the afternoon samples was less than the morning samples. The daily intake of Pb, Cd, and Cr through consumption of these vegetables was 0.14, 0.06, and 0.99 mg/day, respectively. The mean concentrations of Pb, Cd and Cr in these vegetables were above the permissible levels recommended by food and agriculture organization/world health organization (FAO/WHO). The daily intake of Pb, Cd, and Cr through consumption of these was 65%, 100% and 165% of provisional tolerable daily intake (PTDI), respectively. The average of nitrate content in all samples was less than the standard limits.