A survey on nitrite and nitrate levels in vegetables and cucurbits cultivated in northern and western plains of Kermanshah city in 2012

Given that the capacity of vegetables and cucurbits absorption and retention has large amounts of nitrite and nitrate. Therefore, the intake of these products can threaten human health. The aim of this study was to determine nitrite and nitrate in cucurbits and vegetables cultivated in plains of sothern and eastern parts of Kermanshah. For this purpose, a total number of 330 samples was examined for determination of nitrate and nitrite. The samples were analyzed according to the instructions provided by the Institute of Standards and Industrial Research of Iran (No. 4106). The results showed that there are significant differences in the mean value of nitrite in vegetables and cucurbits, in the sampling locations (P<0.01). However, this difference was not significant (P>0.05) in the case of nitrate. The highest level of nitrite was estimated at 6.05±2.1 and 6.12±0.845 mg/kg in radish tubers and the lowest level was estimated at 0.1±0.022 and 0.174±0.085 mg/kg in cucumber samples in Mahidasht and Drood and Framan plains, respectively. In addition, the highest amount of nitrate in the Mahidasht plain was determined in spinach (392.11 ± 21.17 mg/kg) and in the Drood and Framan plain was observed in radish tubers (316.94 ±158.02 mg/kg). The lowest levels of nitrate in the both sampling areas were determined in tomatoes (11.42 ± 3.56 and 9.1±5.2 mg/kg, respectively). Moreover, a significant difference (P<0.01) was observed in the mean quantity of nitrate and nitrite in the different vegetables or cucurbits. It was concluded that the level of nitrite in some vegetables and cucurbits was higher than acceptable limit. Therefore, it is essential to reduce the application of nitrogen fertilizers in these areas.