Nitrate Contamination

The nitrate content of drinking water is rising at an alarming rate in several regions of NATO countries and elsewhere in the world. The increase is due to lack of proper sewage treatment, and primarily to excess fertilizer application. Also, eutrophication in several coastal areas is triggered by high nitrate concentrations. The main purpose of this book is to integrate scientific knowledge related to exposure assessment, health consequences and control of nitrate contamination in water. The motivation is related to the magnitude, the possible adverse health effects, and the high cost of control ling nitrate contamination. Future research tasks are defined by an interaction among hydro logists, toxicologists and environmental engineers in an integrated framework for nitrate risk management. The target readership of this book is a mix of university colleagues, practitioners from both the private and public sectors and advanced graduate students working with the hydrological, health science or environmental engineering aspects of nitrate contamination. The main conclusions include: 1. For risk assessment purposes, knowledge and sufficiently accurate models are available to predict nitrate load and its fate in water under changes in land use. 2. Once agricultural exposure controls are implemented, the response times in ground water may be so long as to make controls unrealistic. 3. It is still unknown whether agricultural best management practice is a compromise between nitrate risk reduction and agricultural revenue. 4. The current drinking water guidelines of 10 mg/L NOrN need not be changed.

Texte du rabat

The nitrate content of drinking water is rising at an alarm-ing rate in several parts of the world. The increase is dueto the lack of proper sewagetreatment and primarily to ex-cess fertilizer application. Also, eutrophication inseveral coastal areas is triggered by high nitrate con-centrations. The main purpose of this book is to integratescientific knowledge related to exposure assessment, healthconsequences and control of nitrate contamination in water.The motivation is related to the magnitude, the possible ad-verse health effects, and the high cost of controlling ni-trate contamination. Future research tasks are defined byan interaction among hydrologists, toxicologists and envi-ronmental engineeres in an integrated framework for nitraterisk management.

Contenu
I. Overview of Problem.- Nitrates and their Control in the EEC Aquatic Environment.- Nitrate Contamination in the Contiguous United States.- The Nitrate Content of Drinking Water in Portugal.- Nitrate Contamination of Surface and Ground Water in Greece.- II. Exposure Assessment.- Risk Analysis for Water Supply from a River Polluted by Nitrate Runoff.- Nitrogen Modeling on a Regional Scale.- Nitrate Ground-water Modeling for Agricultural and Other Nonpoint Sources.- Principles of Monitoring and Analysis.- Nitrate Balances in Aquifers.- Fertilizer and Water Application, and Control of Nitrate Pollution: Management Issues.- Integrated Water and Nitrogen Management.- Biochemistry of a Plume of Nitrate-contaminated Ground Water.- Nitrate Contamination of Ground Water in Southern Ontario and the Evidence for Denitrification.- Nutrient Transport in Two Major Catchments of Turkey.- Potential Nitrate Pollution of Ground Water in Limestone Terrain by Poultry Litter, Ozark Region, U.S.A..- Nitrogen Management Research in the President's Water Quality Initiative.- Panel Discussion: Nitrate Exposure in Agriculture.- III. Health Consequences.- Evidence that N-Nitroso Compounds Contribute to the Causation of Certain Human Cancers.- The Significance for Human Health of Nitrate, Nitrite and N-Nitroso Compounds.- Epidemiological Studies of the Endogenous Formation of N-Nitroso Compounds.- Nitrate Exposure and Human Cancer.- Development of a Reliable Measure for Determining Nitrate Exposure for Use in Epidemiological Studies.- Quantifying Gastric Nitrate and Nitrate Reductase Activity in the Normal and Achlorhydric Stomach.- Potential Health Consequences of Ground-water Contamination by Nitrates in Nebraska.- Some Factors Affecting N-Nitroso Compound Formation from Ingested Nitrate inthe Stomach: Achlorhydria, Bacterial N-Nitrosation and its Modulation.- Panel Discussion: Health Consequences.- IV. Contamination Control.- Control of Ground-water Nitrate Pollution in Britain by Land-use Change.- Nitrate Treatment Methods: An Overview.- Experience with Nitrate-Removal Methods from Drinking Water.- A Newly Developed Process for Nitrate Removal from Drinking Water.- Nitrate Pollution in Ground Water.- Mitigating Nonpoint-Source Nitrate Pollution by Riparian-Zone Denitrification.- Elimination of Ground-water Contamination by Septic-Tank Effluent.- Control of Nitrogen Sources and Principles of Treatment.- U.S. Environmental Protection Agency Programs Related to the Agricultural Use of Nitrates.- Panel Discussion: Nitrate Treatment and Control.- V. Integration: The Systems Approach.- A Mathematical Systems Model of Nitrate Contamination.- Impact of Risk-related Concerns on the U.S. Environmental Protection Agency Programs.- Nitrate Risk Management.- Panel Discussion: Integration, the Systems Approach.