What is being done about arsenic contamination in drinking water?

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, <http://www.nrdc.org; National Sanitation Foundation, (800) NSF-MARK, http://www.nsf.org.