Dear EarthTalk: What is being done about arsenic contamination in drinking water?
—Erika Maxel, Cleveland, OH
Arsenic occurs naturally in our environment, and there are trace amounts of it in all living matter. In fact, arsenic is part of the Earth’s crust, and as a natural component of underground rock and soil it can work its way into our groundwater in amounts that pose little or no threat to human health.
However, arsenic is also a by-product of industrial activity, such as coal burning, waste burning, copper smelting, and mining for gold and other metals. It is also an agricultural byproduct as it is a component of some pesticides and feed additives. U.S. smokestack and agricultural industries release thousands of pounds of arsenic into the environment each year—and as a result arsenic can show up in public water supplies in amounts that do pose health threats.
According to a 1999 study by the National Academy of Sciences, excessive arsenic in drinking water can cause bladder, lung and skin cancer, and may cause kidney and liver cancer. The study also found that arsenic harms the central and peripheral nervous systems, as well as heart and blood vessels, and causes serious skin problems. It also may cause birth defects and reproductive problems.
The U.S. government regulates arsenic content in drinking water by setting a maximum contaminant level which, for many years, was 50 parts per billion. After further and more recent study, the U.S. Environmental Protection Agency (EPA) recommended in 2001 that the maximum level be lowered to just 10 parts per billion. Initially, the Bush administration rejected the recommendation, arguing that there was no scientific consensus to justify the $200 million it would cost to change the standard. But pressure from environmental and public health organizations convinced the White House to change course and adopt the stricter standard, which will take effect in 2006.
Although few if any municipal water systems in the U.S. exceed the present limit, it is estimated that many will have to install or upgrade treatment processes in order to meet the new stricter standard. Research by the Natural Resources Defense Council (NRDC) indicates that more than 34 million Americans drink tap water supplied by systems containing average levels of arsenic that pose unacceptable health risks.
Consumers can determine the arsenic levels, if any, in their drinking water by reading the Drinking Water Quality Report (also known as the Consumer Confidence Report) issued in July every year by each municipal water utility. Individuals can reduce their exposure to arsenic in drinking water by using a water filter certified by the National Sanitation Foundation (NSF). Consumers should also beware that bottled water is not necessarily any safer than tap water. According to NRDC, bottled water is often nothing more than tap water that may or may not have been filtered—so filtration is the only way to be sure that drinking water is arsenic-free.
CONTACTS: U.S. EPA Arsenic in Drinking Water page, http://www.epa.gov/safewater/arsenic.html; EPA Consumer Confidence Report page, http://www.epa.gov/safewater/ccr1.html; Natural Resources Defense Council, (212) 727-2700,
Dear EarthTalk: What is the modern meat industry’s impact on the environment?
—Jeremy Smith, Bellefonte, PA
In E – The Environmental Magazine‘s January/February 2002 cover story, "So You’re an Environmentalist
Why Are You Still Eating Meat?" author Jim Motavalli wrote, "Just about every aspect of meat production—from grazing-related loss of cropland and open space, to the inefficiencies of feeding vast quantities of water and grain to cattle in a hungry world, to pollution from "factory farms"—is an environmental disaster with wide and sometimes catastrophic consequences."
Indeed, according to the Sierra Club, producing one pound of grain-fed beef requires about 16 pounds of wheat and—as staggering as it sounds—2,500 gallons of water. Furthermore, millions of acres of forest have been cleared worldwide to make room for the large areas of land needed for cattle grazing. In the United States, more than 260 million acres of forest have been cleared to grow crops to feed animals raised for meat, and an acre of trees disappears every eight seconds.
Tropical rainforests are also being cut to create grazing land for cattle. Fifty-five square feet of rainforest may be destroyed to produce just one quarter-pound burger. Since trees absorb carbon dioxide, the leading "greenhouse gas," this significant loss of forest contributes to global warming as well.
Soil erosion is also mostly due to the meat industry which, according to the Worldwatch Institute, is directly responsible for 85 percent of all soil erosion in the U.S. because so much grain is needed to feed the animals. Livestock is fed more than 80 percent of the corn and 95 percent of the oats grown by American farmers. The world’s cattle alone consume a quantity of food equal to the caloric needs of 8.7 billion people—more than the entire human population on Earth.
A recent report prepared for the Senate Agricultural Committee concluded that animal waste is the largest contributor to pollution in 60 percent of the rivers and streams classified as "impaired" by the U.S. Environmental Protection Agency. The report states that food animals produce waste at a rate of roughly 68,000 pounds per second. Major waste pollutants that make their way into our waterways include nutrients like nitrogen and phosphorus that can cause massive fish kills, harmful bacteria and viruses, and toxic heavy metals, which are present in some commercial livestock feed.
Critics also point to the fact that meat-based diets exacerbate world hunger. Harvard nutritionist Jean Mayer estimates that a 10 percent reduction in U.S. meat consumption would free up enough grain to feed 60 million people. Some 40 percent of the world’s grain harvest is fed to livestock, while nearly a billion people go hungry each day.
While environmental groups recognize the benefits of vegetarianism as an alternative, few recommend it for everyone. Meat-loving environmentalists can look for small farms that feed livestock natural, organic diets, treat animals more humanely, and practice more sustainable land use.
CONTACTS: E Magazine, January/February 2002 issue, http://www.emagazine.com/view/?142; Sierra Club, (415) 977-5500, http://www.sierraclub.org/factoryfarms ; Worldwatch Institute, (202) 452-1999, http://www.worldwatch.org.