28 - Pathophysiology of Nitrate Toxicity in Humans in View of the Changing Trends of the Global Nitrogen Cycle With Special Reference to India

Abstract

The sources of nitrates for human can be drinking water, food, and air. After ingestion, nitrates get converted to nitrite by gastrointestinal microflora leading to methemoglobinemia and increase in free oxide radicals that predispose cells to irreversible damage. It may cause other effects such as cancer, increased infant mortality, abortions, birth defects, recurrent diarrhea, recurrent stomatitis, histopathological changes in cardiac muscles, alveoli of lungs and adrenal glands, and deterioration of immune system of the body. NOx is also toxic for human, and when inhaled, it can cause unconsciousness; vomiting; mental confusion; congestion and inflammation of respiratory tract; pulmonary edema; and genetic mutations thereby adversely affecting the development of fetus and decreasing fertility. The associations between nitrate pollution and health issues are derived from epidemiological studies (episodic, time series, crossover, and cohort), toxicological studies, and controlled human studies. Indian studies on adverse health effects of nitrate pollution are limited to only a few cross-sectional studies. Appropriate interventions at human and environmental levels may prevent humans from these toxic manifestations.