A Review of Adverse Effects and Benefits of Nitrate and Nitrite in Drinking Water and Food on Human Health

Introduction: The problem related to water pollution of nitrates and nitrites is both an issue in Iran and also most parts of the world. Studies to evaluate the acute and chronic effects of nitrate and nitrite have demonstrated that different concentrations of these compounds in water and food have been causing multiple diseases. Methods: In this paper, researchers reviewed published articles and research from 1950 to 2016 in English and Farsi, according to key words nitrate, nitrite, water, food and health effects, retrieved from databases, such as Medline, Scopus, Pub Med, and scientific information database (SID). Results: Consumption of drinking water and food containing high concentrations of nitrate and nitrite could cause diseases, such as cancer, methemoglobinemia, and enlargement of the thyroid gland and diabetes mellitus. The positive effects of low concentrations of nitrates and nitrites include a protective effect on the cardiovascular system, regulatory role in blood pressure, and homeostasis (also static) of the vessels Conclusions: As different concentrations of nitrates and nitrites have beneficial and undesirable effects on human health and regarding the high cost of treating water contaminated with nitrite and nitrate, more investigations should be done in setting the standards and levels of parameters used in drinking water.