The solvent, found in chemicals used to remove adhesives and paint, has been shown to cause cancer in lab animals, and the Environmental Protection Agency took steps to increase restrictions on TCE five years ago. Government agencies that run waste sites heavily polluted by TCE -- such as the Defense Department, the Energy Department and NASA -- blocked the EPA's efforts, accusing them of exaggerating the risks.
However, the NAS reports that more has become known about TCE exposure and its link to cancer and other health issues in the last five years, and recommends that the EPA revise its assessment of TCE's dangers.
"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."
EPA spokesperson Jennifer Wood said the agency would "aggressively move forward" in assessing the dangers of TCE, armed with the NAS report findings. "EPA will determine whether or not to address the drinking water standard once the risk assessment is complete," she said.
Current EPA requirements call for no more than 5 parts per billion of TCE in drinking water. If the assessment finds stricter regulations are needed, the government could be forced to clean up the contaminant at military bases and other sites.
The Bush Administration, in an effort to mediate the problem, has asked the NAS to investigate the issue.
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