MONDAY, Sept. 17, 2001 (HealthDayNews) -- Arsenic is a lot greater risk in your drinking water than previously thought, particularly if you use well water, says a new government report.
The National Academy of Sciences committee that issued the report found people who drink water containing as little as 3 micrograms of arsenic per liter have about a 1-in-1,000 increased risk of developing bladder or lung cancer during their lifetime. At 5 micrograms, the risk from the naturally occurring element rises to about 1½ in 1,000. At 10 micrograms, the risk jumps to more than 3 in 1,000. And at 20 micrograms, your risk from bladder or lung cancer is close to 7 in 1,000.
The current Environmental Protection Agency (EPA) standard, set back in 1942, is 50 micrograms of arsenic per liter of tap water.
To picture how much arsenic 3 micrograms is, think of dumping 3 pounds of sugar into 125,000 gallons of water.
"The concern is largely with well water in small communities where it's not treated and where there is substantial geologic deposits of arsenic that enters the well water," says study author Dr. Robert Goyer, professor emeritus at the University of Western Ontario. Goyer chaired the committee that reviewed the research. The study was published recently by the National Academy of Sciences.
This report is considered another salvo in the continuing struggle that pits economics against the desire for totally safe drinking water.
One of the last acts of the Clinton Administration was to adopt a stricter standard of 10 micrograms of arsenic per liter of tap water -- a radical tightening from the existing standard. But the Bush Administration almost immediately suspended the proposed standard, saying the $200 million price tag for putting it in place would be too expensive for local communities.
"The bottom line is that we were to review the Environmental Protection Agency's (EPA) recommendations of January 2001 that stated the arsenic level in drinking water was to be set at 10 micrograms per liter -- a recommendation to be implemented over a six-year period of time," Goyer says.
Arsenic occurs naturally and is also a byproduct of industrial mining processes such as smelting. It is found in high concentrations in Western mining states as well as other parts of the country that rely on coal burning and copper smelting.
According to a 1999 National Academy of Sciences study used to set the stricter EPA proposed standard, arsenic in drinking water can cause bladder, lung and skin cancer, and may cause kidney and liver cancer. It can also damage the nervous system, the heart and blood vessels, and cause serious skin problems. In addition, it is associated with birth defects and reproductive problems.
The NAS committee reviewed studies from southwestern Taiwan originally used to establish the proposed, stricter EPA standard, Goyer reports. People from southwestern Taiwan have been exposed to large amounts of arsenic in drinking water and are considered the best source of data on estimating arsenic's impact on cancer risk.
"What happened is that we found higher risks than the original 1999 study because we used different assumptions and different mathematical models that looked at estimates of exposure in both food and water," Goyer says.
The NAS committee also looked at four new studies from Bangladesh, Chile, China and Finland "that were of significance," Goyer says. "Three were supportive of the previous studies that showed even very low levels of arsenic were associated with bladder cancer and lung cancer." The committee found the fourth study "problematic," Goyer says.
The new report will be used by the EPA to establish the arsenic drinking water standard within six months to a year, says a spokesman for the agency in Washington, D.C. He cited other reports that also addressed the problems surrounding a new standard.
"The whole issue is still in an active, public comment period," says the spokesman. "We need to review these reports, respond and draft a final report, and that takes anywhere from six months to a year."
What To Do
For more on the arsenic drinking water standard, see the Environmental Protection Agency, or the National Resource Defense Council. The Agency for Toxic Substances and Disease Registry also has more on arsenic and its effects.
To visualize how much arsenic they're talking about, take a look at this.
