Nitrates in drinking water indicates: September 2005

Ans. A: Remote fecal pollution Nitrates and nitrites are indicators of remote and recent fecal pollution respectively. An increase of nitrates in water is often associated with farming feilizer, pesticide or poor sanitary activities. The WHO guideline for nitrates in drinking water is established to prevent methaemoglobinaemia (blue babies), which is lethal in babies. It can be potentially hazardous with health risks for considerable groups of people and depends on the conversion of nitrates to nitrites and wells which were shallow, dug of located on large farms, or springs were more likely to have elevated concentrations of nitrates. Contamination of drinking water by nitrates is an evolving public health concern since nitrates can undergo endogenous reduction to nitrites (nitrate (III)), and nitrosation of nitrites can form N-nitrose compounds, which are potent carcinogens.