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. . . .

Nitrate and nitrite are potentially dangerous substances which can have a detrimental effect on the ecological balance of rivers and lakes, and cause harm to human health. EC legislation to determine acceptable levels of nitrate and nitrite in food and water means that all water and food companies will need to be fully aware of the ramifications. These two factors have prompted this book, which 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.

Nitrite and Nitrate in Human Health and Disease delivers a comprehensive review of nitrite and nitrate biology, from basic biochemistry to the complex physiology and metabolism of these two naturally occurring molecules in the human body. Well-organized and well referenced chapters cover the rich history of nitrite and nitrate, sources of exposure, and the physiological effects when consumed through foods containing nitrite and nitrate. The chapters are written by leading experts, all of whom share their research and perspectives in order to help define the context for benefits vs. any potential risks associated with nitrite and nitrate use, either through dietary ingestion or therapeutic dosing. This diverse collection of authors includes vascular biologists, physiologists, physicians, epidemiologists, cancer biologists, registered dieticians, chemists, and public health experts from five countries in both academia and government. Nitrite and Nitrate in Human Health and Disease provides a balanced view of nitric oxide biochemistry, and nitrite and nitrate biochemistry in physiology and in the food sciences.

On cover: Health protection of consumers

Inherent toxicants and processing contaminants are bothnon-essential, bioactive substances whose levels in foods can bedifficult to control. This volume covers both types of compound forthe first time, examining their beneficial as well as theirundesirable effects in the human diet. Chapters have been writtenas individually comprehensive reviews, and topics have beenselected to illustrate recent scientific advances in understandingof the occurrence and mechanism of formation, exposure/riskassessment and developments in the underpinning analyticalmethodology. A wide range of contaminants are examined in detail,including pyrrolizidine alkaloids, glucosinolates, phycotoxins, andmycotoxins. Several process contaminants (eg acrylamide and furan),which are relatively new but which have a rapidly growingliterature, are also covered. The book provides a practical reference for a wide range ofexperts: specialist toxicologists (chemists and food chemists),hygienists, government officials and anyone who needs to be awareof the main issues concerning toxicants and process contaminants infood. It will also be a valuable introduction to the subject forpost-graduate students.

The Safe Drinking Water Act directs the U.S. Environmental Protection Agency (EPA) to establish national drinking-water standards for chemical and biological contaminants in public water supplies. The standards are to be set at concentrations at which no adverse effects on human health occur or are expected to occur from lifetime consumption, allowing a margin of safety; enforceable standards are standards that are feasible to achieve with the use of the best technology available. The standards are to be reviewed periodically to ensure continued protection of public health. Consistent with the requirement for periodic review, EPA asked the National Research Council to evaluate the current drinking-water maximum-contaminant-level goals (MCLGs) and maximum contaminant levels (MCLs) for nitrate and nitrite in public water supplies. The Subcommittee on Nitrate and Nitrite in Drinking Water, convened under National Research Council procedures, reviewed information on the occurrence and toxicity of nitrate and nitrite. The subcommittee evaluated this information in the context of the drinking-water standards for those substances and drew conclusions about the adequacy of the current standards to protect human health.