BACKGROUND AND OBJECTIVE: Nitrate and Nitrite are entered to environment and ground water resources through using the chemical fertilizers, discharging the effluent of municipal and industrial sewage treatment plants and discharging the human wastewater. Nitrate is the cause of Methemoglobinemia disorder in babies. The aim of this study was to determine the concentration of Nitrate and Nitrite in drinking water of transmission line and of consumption points in rural and urban places of Babol.

METHODS: This cross-sectional descriptive study was performed in Babol in 2013. A total of 376 water samples were randomly collected from water transmission line and consumption points in rural and urban places of Babol in summer and winter. Spectrophotometer of HACH Company, DR5000 model with 520 and 570 nm wavelengths was used for measurement of Nitrate and Nitrite concentration in water. The results were compared with national standards and WHO guideline of Nitrate and Nitrite concentrations in drinking water.

FINDINGS: The concentrations of Nitrate and Nitrite in drinking water of transmission line and consumption points of rural places were 4.4±2.7 and 0.04±0.02 mg/l and 8.3± 5.3and 0.035±0.03 mg/l, respectively. In urban localities these amounts were 8±1.5 and 0.045±0.3 mg/l and 8.8±3.7 and 0.038±0.035 mg/l. There was significant difference between the Nitrate of water in transmission line and consumption points (P= 0.03). The concentrations of Nitrate and Nitrite in drinking water in summer and winter were 6.7±1.9 and 0.03±0.001 mg/l and 9.4±3.9 and 0.04±0.001 mg/l respectively. There was significant difference for the concentration of Nitrate in terms of analysis (P=0.014).

CONCLUSION: Result of this study showed that the maximum Nitrate and Nitrite concentrations in all rural and urban water supplies in summer and winter were fewer than the standard of drinking water of Iran and WHO guidelines. However, it is necessary to monitor continuously the contents of the nitrogenous compounds into the drinking water resources due to undesirable effects on the human.