Growing scientific evidence suggests the most widespread industrial contaminant in drinking water — a solvent used in adhesives, paint and spot removers — can cause cancer in people.
The National Academy of Sciences reported Thursday that a lot more is known about the cancer risks and other health hazards from exposure to trichloroethylene than there was five years ago when the Environmental Protection Agency took steps to regulate it more strictly.
"Armed with the results from the NAS review, EPA will aggressively move forward" on a new risk assessment of TCE, spokeswoman Jennifer Wood said Thursday. "EPA will determine whether or not to address the drinking water standard once the risk assessment is complete."
TCE, which is also widely used to remove grease from metal parts in airplanes and to clean fuel lines at missile sites, is known to cause cancer in some laboratory animals. EPA was blocked from elevating its assessment of the chemical's risks in people by the Defense Department, Energy Department and NASA, all of which have sites polluted with it.
TCE is a colorless liquid that evaporates at room temperatures and has a somewhat sweet odor and taste. It is one of the most common pollutants found in the air, soil and water at U.S. military bases. Until the mid-1970s, it also was used as a surgical anesthetic.
TCE also has been found at about 60 percent of the nation's worst contaminated sites in the Superfund cleanup program, the academy said.
Its 379-page report recommends that EPA revise its assessment of TCE's risks using "currently available data" — so no more time is wasted.
That's a step that could lead to stricter regulations. EPA currently requires limiting TCE to no more than 5 parts per billion parts of drinking water. A stricter regulation could, in turn, force the government to require more thorough cleanups at military and other sites.
A committee of academy experts said "a large body of epidemiologic data is available" on TCE showing the chemical is a possible cause of kidney cancer, reproductive and developmental damage, impaired neurological function and autoimmune disease.
"The committee found that the evidence on carcinogenic risk and other health hazards from exposure to trichloroethylene has strengthened since 2001," the report said. "Hundreds of waste sites are contaminated with trichloroethylene, and it is well documented that individuals in many communities are exposed to the chemical, with associated health risks."
In 2001, EPA issued a draft document saying the risks of TCE causing cancer in humans were higher than previously thought. But that pronouncement was dropped after other federal agencies accused EPA of inflating the risks.
To mediate the issue, the Bush administration asked the academy to study the issue.