Global Water Crisis and Future Food Security in an Era of Climate Change

By Munir A. Hanjra and M. Ejaz Quereshi

Abstract: "Food policy should serve humanity by advancing the humane goals of eradicating extreme poverty and hunger. However, these goals have recently been challenged by emerging forces including climate change, water scarcity, the energy crisis as well as the credit crisis. This paper analyses the overall role of these forces and population growth in redefining global food security. Specifically, global water supply and demand as well as the linkages between water supply and food security are examined. The analysis reveals that the water for food security situation is intricate and might get daunting if no action is taken. Investments are needed today for enhancing future food security; this requires action on several fronts, including tackling climate change, preserving land and conserving water, reducing the energy footprint in food systems, developing and adopting climate resilient varieties, modernising irrigation infrastructure, shoring up domestic food supplies, reforming international food trade, and responding to other global challenges."

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The Emerging Global Water Crisis: Managing Scarcity and Conflict Between Water Users

By William A. Jury and Henry J. Vaux Jr.

Excerpt: "In the absence of coordinated planning and international cooperation at an unprecedented scale, the next half century will be plagued by a host of severe water‐related problems, threatening the well being of many terrestrial ecosystems and drastically impairing human health, particularly in the poorest regions of the world. The latter portion of this chapter discusses ways in which this emerging crisis may be mitigated."

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Biology and Water Pollution Control

By Charles E. Warren

Summary: "Within this text, the reader is attuned to the role biology can and should play in combating the alarming increase in water pollution. Both the urgency of the problem and the biological techniques that are being developed to cope with the water pollution crisis are scrutinized; what is and is not known about the problem is explained; past, present, and proposed control methods are analyzed; and promising new approaches to the effective biological conservation of our diminishing clean water resources are suggested. Initial chapters deal with the historical, social, technological, and legal background of the pollution problem as well as biological approaches used in water pollution control. Physical and chemical properties of water are described and the various types of water pollution and their effects on the aquatic environment are categorized. The core of the book consists of four sections that examine in detail the morphology and physiology of aquatic organisms, ecology of the individual organism, ecology of the individual organism, population ecology, and community ecology. In concluding chapters, it is shown how the field of biology may be applied to the solution of existing water pollution problems."

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Blue Covenant: The Global Water Crisis and the Coming Battle for the Right to Water

By Maude Barlow

Excerpt: "Simply put: life requires access to clean water; to deny the right to water is to deny the right to life. The fight for the right to water is an idea whose time has come. It has become the rallying cry of the water justice movement. This story, by no means over, is also told in these pages."

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Cancer Risks From Arsenic in Drinking Water

By A H Smith, C Hopenhayn-Rich, M N Bates, H M Goeden, I Hertz-Picciotto, H M Duggan, R Wood, M J Kosnett, and M T Smith

Abstract: "Ingestion of arsenic, both from water supplies and medicinal preparations, is known to cause skin cancer. The evidence assessed here indicates that arsenic can also cause liver, lung, kidney, and bladder cancer and that the population cancer risks due to arsenic in U.S. water supplies may be comparable to those from environmental tobacco smoke and radon in homes. Large population studies in an area of Taiwan with high arsenic levels in well water (170-800 micrograms/L) were used to establish dose-response relationships between cancer risks and the concentration of inorganic arsenic naturally present in water supplies. It was estimated that at the current EPA standard of 50 micrograms/L, the lifetime risk of dying from cancer of the liver, lung, kidney, or bladder from drinking 1 L/day of water could be as high as 13 per 1000 persons. It has been estimated that more than 350,000 people in the United States may be supplied with water containing more than 50 micrograms/L arsenic, and more than 2.5 million people may be supplied with water with levels above 25 micrograms/L. For average arsenic levels and water consumption patterns in the United States, the risk estimate was around 1/1000. Although further research is needed to validate these findings, measures to reduce arsenic levels in water supplies should be considered."

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Methylation study of a population environmentally exposed to arsenic in drinking water

By C Hopenhayn-Rich, M L Biggs, A H Smith, D A Kalman, and L E Moore

Abstract: "Methylation is considered the detoxification pathway for inorganic arsenic (InAs), an established human carcinogen. Urinary speciation analysis is used to assess the distribution of metabolites [monomethylarsonate (MMA), dimethylarsinate (DMA), and unmethylated arsenic (InAs)], as indicators of methylation capacity. We conducted a large biomarker study in northern Chile of a population chronically exposed to high levels of arsenic in drinking water. We report the results of the methylation study, which focused on the effects of exposure and other variables on the percent InAs, MMA, DMA, and the ratio of MMA to DMA in urine. The study consisted of 122 people in a town with arsenic water levels around 600 micrograms/l and 98 participants in a neighboring town with arsenic levels in water of about 15 micrograms/l. The corresponding mean urinary arsenic levels were 580 micrograms/l and 60 micrograms/l, of which 18.4% and 14.9% were InAs, respectively. The main differences were found for MMA:DMA; exposure, smoking, and being male were associated with higher MMA:DMA, while longer residence, Atacameño ethnicity, and being female were associated with lower MMA:DMA. Together, these variables explained about 30% of the variability in MMA:DMA. Overall, there was no evidence of a threshold for methylation capacity, even at very high exposures, and the interindividual differences were within a much wider range than those attributed to the variables investigated. The differences in percent InAs were small and within the ranges of other studies of background exposure levels. The biological significance of MMA:DMA, which was more than 1.5 times greater in the exposed group, and its relationship to sex, length of exposure, and ethnicity need further investigation because its relevance to health risk is not clear."

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Public Drinking Water Contamination and Birth Outcomes

By Frank J. Bove, Mark C. Fulcomer, Judith B. Klotz, Jorge Esmart, Ellen M. Dufficy, Jonathan E. Savrin

Abstract: "The effects of public drinking water contamination on birth outcomes were evaluated in an area of northern New Jersey. After excluding plural births and chromosomal defects, 80,938 live births and 594 fetal deaths that occurred during the period 1985–1988 were studied. Information on birth outcome status and maternal risk factors was obtained from vital records and the New Jersey Birth Defects Registry. Monthly exposures during pregnancy were estimated for all births using tap water sample data. Odds ratios of ≥1.50 were found for the following: total trihalomethanes with small for gestational age, central nervous system defects, oral cleft defects, and major cardiac defects; carbon tetrachloride with term low birth weight, small for gestational age, very low birth weight, total surveillance birth defects, central nervous system defects, neural tube defects, and oral cleft defects; trichloroethylene with central nervous system defects, neural tube defects, and oral cleft defects; tetrachloroethylene with oral cleft defects; total dichloroethylenes with central nervous system defects and oral cleft defects; benzene with neural tube defects and major cardiac defects; and 1,2-dichloroethane with major cardiac defects. Total trihalomethane levels >100 ppb reduced birth weight among term births by 70.4 g. By itself, this study cannot resolve whether the drinking water contaminants caused the adverse birth outcomes; therefore, these findings should be followed up utilizing available drinking water contamination databases."

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