Environmental Problems, Their Causes, and Sustainability 1

Officials are working to find ways to make itharder to access or damage water purification plantsand pipes. They are upgrading surveillance camerasand other security measures. They are also developingchemical tests and biological indicators that quicklyindicate the presence of chemical or biological agents,and they are working on emergency response plans incase of contamination. A major problem is that protectingthese systems will cost several billion dollars andso far Congress has not provided enough funds to getthe job done.How Can We Purify Rural Drinking Waterin Developing Countries? The Low-TechDecentralized ApproachResearchers have developed several simple andinexpensive ways for individuals and villagesin developing countries to purify drinking water.Ways to purify drinking water can be simple. In tropicalcountries without centralized water treatment systems,the WHO is urging people to purify drinkingwater by exposing a clear plastic bottle filled with contaminatedwater to intense sunlight. In the strong sunlightfound in most tropical countries, heat and thesun’s UV rays can kill infectious microbes in as little as3 hours. Painting one side of the bottle black can improveheat absorption in this simple solar disinfectionmethod. Where it has been used, incidences of dangerouschildhood diarrhea have decreased by 30–40%.In Bangladesh, households receive strips of clothfor filtering cholera-producing bacteria from drinkingwater. Villages where women use such strips to strainwater have cut cholera cases in half.Another simple method involves adding a smallamount of a chlorine-disinfectant solution to plastic orclay water-storage vessels with a narrow mouth andcap and a spigot—similar to what U.S. campers frequentlyuse. The storage vessel design helps protectthe disinfected water from additional bacterial contamination.Trials in Zambia, Kenya, and India showthat this approach can cut the rate of diarrheal diseasein half. This highly publicized method is now in use in15 developing countries.How Well Is Drinking Water QualityProtected by Law? The Legal ApproachMost developed countries have laws establishingdrinking water standards, but most developingcountries do not have such laws or do not enforcethem.About 54 countries, most of them in North Americaand Europe, have standards for safe drinking water.The U.S. Safe Drinking Water Act of 1974 requires theEPA to establish national drinking water standards,called maximum contaminant levels, for any pollutantsthat may have adverse effects on human health. However,such laws do not exist or are not enforced in mostdeveloping countries.Privately owned wells are not required to meetfederal drinking water standards for two reasons. Oneis that it costs at least $1,000 to test each well and ownerswould need to retest their water every few years.The other is that some homeowners oppose mandatorytesting and compliance.Health scientists call for strengthening the U.S.Safe Drinking Water Act in several ways. One is tocombine many of the drinking water treatment systemsthat serve fewer than 3,300 people with nearbylarger systems. Another is to strengthen and enforcepublic notification requirements about violations ofdrinking water standards. They also call for banningall toxic lead in new plumbing pipes, faucets, and fixtures(current law allows fixtures with up to 10% leadto be sold as lead free). According to the NaturalResources Defense Council (NRDC), such improvementswould cost about $30 a year per U.S. household.However, water-polluting industries are pressuringelected officials to weaken the Safe Drinking WaterAct. One proposal is to eliminate national tests ofdrinking water and public notification requirementsabout violations of drinking water standards.A second proposal is to allow states to give drinkingwater systems a permanent right to violate the standardfor a given contaminant if the provider claims itcannot afford to comply. Another suggestion is to eliminatethe requirement that water systems use affordable,feasible technology to remove cancer-causing contaminants.Finally, there are suggestions to greatly reducethe EPA budget for enforcing the Clean Water Act.xHOW WOULD YOU VOTE? Should the Safe Drinking WaterAct be strengthened? Cast your vote online at http://biology.brookscole.com/miller14.Is Bottled Water the Answer? Solutionor Expensive Rip-off?Some bottled water is not as pure as tap water andcosts much more.Despite some problems, experts say the United Stateshas some of the world’s cleanest drinking water. Yetabout half of all Americans worry about getting sickfrom tap water contaminants, and many drink bottledwater or install expensive water purification systems.Studies reveal that in the United States bottledwater is 240 to 10,000 times more expensive than tapwater. In addition, about one-fourth of it is tap water,bacteria contaminate about one-third of it, and variouspotentially harmful organic chemicals contaminateabout one-fifth of it. On the other hand, some countrieshttp://biology.brookscole.com/miller14515