Nitrates and Nitrites in Food and Water (Woodhead Publishing Series in Food Science, Technology and Nutrition)

From the Introduction With regard to nitrate and nitrite, the perceived hazards are to the ecological balance in rivers and lakes, and to human health. Increased nitrate levels in river water lead to increased growth of algae and consequent decrease in the level of biologically available oxygen (BAO). In extreme forms, the algae form unsightly blooms on the water surface, and the BAO level falls below that necessary to support fish and other animal life. At this extreme, there is little dispute that efforts should be made to restore the ecological balance, and this is best achieved by reversing the increase in nitrate concentration that caused the problem. The health hazards are less clear, but include the risk of methaemoglobinaemia in young infants and the possible risk of gastric cancer, particularly in certain high-risk patient groups. These health risks have led to legislation to control the exposure of humans to nitrate from drinking water and as a food additive . . . What can be done about this and how can the problem be solved (if, indeed, there is a problem)? It is normal practice to add nitrate and nitrite to food as a cosmetic and as a preservative. Is this necessary? If so, how much do we need to add? Are there alternatives? What effect does added nitrate have on total nitrate exposure of humans? . . . In this book, we have attempted to answer, or at least to give the background to, some of the questions. . . . Annotation Nitrate and nitrite are potentially dangerous substances which can have a detrimental effect on the ecological balance of rivers and lakes, and can cause harm to human health. This book puts into context the magnitude and complexity of the problems caused by nitrate and nitrite, and provides advice and information on ways to combat it. Hydrobiologica Contents include: Analytical methods; Nitrate occurrence in water; Nitrate and nitrite in foods; Nitrate and nitrite as food additives; Human exposure, Pharmacology and metabolism; Nitrates, nitrites and human disease The widespread occurrence of nitrate in the majority of foodstuffs and water supplies is well established (Ministry of Agriculture, Fisheries and Food 1987, Department of the Environment 1986).