Water scarcity could overwhelm the next generation. (Environmental Intelligence).

Up to 7 billion people in 60 countries--more than the whole present population of the world--will face water scarcity within the next half-century, according to the United Nations' World Water Development Report released in March. The UN report is the most complete appraisal of water resources to date. Other reports released the same month offer dire projections of the impacts of water scarcity on human health, the environment, and global political stability(1)

Demand for fresh water has tripled in the past 50 years, and is continuing to rise as a result of population growth and economic development. About 70 percent of the demand is for agriculture. But increasing water use is not just a function of the greater number of people needing to eat and drink; it also results from pollution and misuse of available water supplies, both directly via dumping or runoff of effluents into water, and indirectly via pollution of air and soil. The damage is accelerated by wetlands destruction and other abuses-including human-caused global warming. According to the UN report, "recent estimates suggest that climate change will account for about 20 percent of the increase in global water scarcity" in coming decades.

Water mismanagement has become a crisis of governance that will impact heavily on public health and the environment, while heightening tensions and conflicts over declining resources. Worldwide, the greatest impacts will be on the poor, who are most vulnerable to water-borne illness--which further perpetuates their poverty. At present, 1.1 billion people lack access to clean water and 2.4 billion lack adequate sanitation. In 2000, an estimated 2.2 million people, most of them infants or children under five, died from waterrelated diseases.

It is not only the poor who are at risk, however. Around the same time the UN report was issued, two reports published in New Jersey revealed that the state's drinking water supply contains hundreds of chemicals, including steroids, detergents, pesticides, preservatives, and prescription medications. While all were found only in low concentrations, researchers cannot rule out possible health risks of ingesting low levels of multiple chemicals over long time periods. The water bodies studied contained antibiotics that could breed drug-resistant bacteria, and endocrine disruptors believed to cause neurological and reproductive birth defects. Other studies in the U.S. and Europe have yielded comparable results, with hundreds of lakes, streams, and rivers testing positive for traces of similar chemicals.

The UN report concludes that a more positive outcome is possible, if the global community improves infrastructure, takes full advantage of conservation and efficiency technologies, and enacts appropriate water pricing plans and water treaties. In the global North, upgrading water treatment facilities to deal with contaminants will be costly, but necessary to safeguard human health. One implication of the report is that attempting to rely only on water treatment is a losing battle and that it is becoming increasingly urgent, in all countries, to reduce or eliminate toxins at their source.

(1.) The report estimates that humans need 20 to 50 liters of water free from harmful contaminants daily to meet basic needs. For monitoring purposes, the World Health Organixation/UN Children's Fund defines reasonable access to water as at least 20 liters per day, from an improved source within one kilometer of the user's dwelling.