Nitrate Intake from Drinking Water in Isfahan in 2004.

Drinking water is the fastest and most direct form of nitrate consumption by the population. High concentrations of nitrate in drinking water can be hazardous to health, especially for infants and pregnant women. Nitrate contamination of drinking water is endogenously reduced to nitrite and subsequent nitrosation reactions give rise to carcinogenic N-nitroso compounds. The objective of this study was to determine the quantities of NO3- in the consuming drinking water in Isfahan. In this study, 513 water samples were collected from different houses from municipalities of three different zones of Isfahan. Each house was sampled five times during July, August and September of 2004. The average Nitrate concentration for the total samples was 22.8 ± 10.4 mg/L. Nitrate concentrations ranged from 6.6 to 63.5 mg/L. Nitrate concentrations exceeded the maximum contaminant level of 45 mg/L in 19 water samples (3.7%), whereas 332 samples (64.7%) had nitrate concentrations of less than 25 mg/L. There was a significant difference between three zones for monitoring nitrate with averages 16.4 ± 4.9, 18.7 ± 8.9 and 31.2 ± 8.7 mg/L for zone 1, 2 and 3 respectively. Based on results of this study, with one unremarkable exception, the nitrate levels found in the water analyzed were optimum for human consumption and complied with WHO and current European Legislation.