Strategies for combating nitrate pollution

Abstract

1. About 260 million tonnes of atmospheric nitrogen is being fixe d every year globally 2 . The global mean N use efficiency is estimated to be about 50% (ref. 3). The remaining quantity of nitrogen is lost into the environment. A large proportion of this nitr ogen gets converted into nitrate which, being soluble in water and not retained by soils, gets leached into water bodies. Leaching of nitrate from agricultural land and from other sources to groundwater is a global phenom enon. Groundwater is the major source for drinking purposes. Nitrates in drinking water is associat ed with a number of health problems such as methemoglobinemia, oral cancer, cancer of the colon, rectum and other gastr ointestinal cancers, Alzheimer’s disease, vascular dementia, absor ptive, secretive functional disorders of the intestinal m ucosa, changes in the maturation, differenti ation and apoptosis in intestinal crypts, multiple sclerosis, reduced casein d igestion, neural tube defects, cytogenetic effects in chi ldren, Non-Hodgkin’s lymphoma, hypertrophy of thyroid, development of tolerance (lowering of response) to n itrate drugs and recurrent stomatitis in human beings and methaemoglobinemia in ruminants and severe gastritis in monogastric animals, intestinal disorders in pigs, pregnancy-related disorders in rats, depression, muscle tre mors and incoordination in goats, loss of body weight and reduced water consumption in chickens, sexual disorders in sheep and hyperthyroid in foals 4 . Methaemoglobinemia was found prevalent in all age groups in areas of Raja sthan, with high nitrate concentr ations in drinking water 5