ABSTRACT
The contamination of water due to both intensive fertilization and waste effluents from industries has produced an increase of nitrate concentration in groundwater. Nitrates are reduced to nitrites in the digestive system, affecting hemoglobin and impairing its function as oxygen-carrier, thus causing the “blue baby syndrome”. They are also related to several forms of cancer, e.g. ovarian and prostate cancers. This contamination problem has led to the introduction of guidelines to establish upper limits for the concentration of nitrates and related species (nitrites and ammonia) in water for domestic use. The Drinking Water Directive-European Commission (98/83/EC) sets a maximum allowable concentration of nitrate of 50 ppm, 0.1 ppm for nitrite and 0.5 ppm for ammonia. The World Health Organization recommends a maximum nitrate concentration of 10 mg L−1 in drinking water. The U.S. Environmental Protection Agency (EPA) has established a maximum contaminant level (MCL) in drinking water of 10 mg L−1 as nitrate-N to protect infants from methemoglobinemia (Ward et al., 2005).
