WASHINGTON — After massive underground plumes of an industrial solvent were discovered in the nation's water supplies, the Environmental Protection Agency mounted a major effort in the 1990s to assess how dangerous the chemical was to human health.
Following four years of study, senior EPA scientists came to an alarming conclusion: The solvent, trichloroethylene, or TCE, was as much as 40 times more likely to cause cancer than the EPA had previously believed.
The preliminary report in 2001 laid the groundwork for tough new standards to limit public exposure to TCE. Instead of triggering any action, however, the assessment set off a high-stakes battle between the EPA and Defense Department, which had more than 1,000 military properties nationwide polluted with TCE.
By 2003, after a prolonged challenge orchestrated by the Pentagon, the EPA lost control of the issue and its TCE assessment was cast aside. As a result, any conclusion about whether millions of Americans were being contaminated by TCE was delayed indefinitely.
For The Record
Los Angeles Times Friday March 31, 2006 Home Edition Main News Part A Page 2 National Desk 2 inches; 71 words Type of Material: Correction
Risks of solvent: Due to an editing error, an article in Wednesday's Section A about the regulation and dangers of the industrial solvent trichloroethylene, or TCE, quoted Alex A. Beehler, the Pentagon's top environmental official, as saying: "We are all forgetting the facts on the table. Meanwhile, we have done everything we can to curtail use of TCE." Beehler actually said, "We are all for getting the facts on the table."
What happened with TCE is a stark illustration of a power shift that has badly damaged the EPA's ability to carry out one of its essential missions: assessing the health risks of toxic chemicals.
The agency's authority and its scientific stature have been eroded under a withering attack on its technical staff by the military and its contractors. Indeed, the Bush administration leadership at the EPA ultimately sided with the military.
After years on the defensive, the Pentagon -- with help from NASA and the Energy Department -- is taking a far tougher stand in challenging calls for environmental cleanups. It is using its formidable political leverage to demand greater proof that industrial substances cause cancer before ratcheting up costly cleanups at polluted bases.
The military says it is only striving to make smart decisions based on sound science and accuses the EPA of being unduly influenced by left-leaning scientists.
But critics say the defense establishment has manufactured unwarranted scientific doubt, used its powerful role in the executive branch to cause delays and forced a reduction in the margins of protection that traditionally guard public health.
If the EPA's 2001 draft risk assessment was correct, then possibly thousands of the nation's birth defects and cancers every year are due in part to TCE exposure, according to several academic experts.
"It is a World Trade Center in slow motion," said Boston University epidemiologist David Ozonoff, a TCE expert. "You would never notice it."
Senior officials in the Defense Department say much remains unknown about TCE.
"We are all forgetting the facts on the table," said Alex A. Beehler, the Pentagon's top environmental official. "Meanwhile, we have done everything we can to curtail use of TCE."
But in the last four years, the Pentagon, with help from the Energy Department and NASA, derailed tough EPA action on such water contaminants as the rocket fuel ingredient perchlorate. In response, state regulators in California and elsewhere have moved to impose their own rules.
The stakes are even higher with TCE. Half a dozen state, federal and international agencies classify TCE as a probable carcinogen.
California EPA regulators consider TCE a known carcinogen and issued their own 1999 risk assessment that reached the same conclusion as federal EPA regulators: TCE was far more toxic than previous scientific studies indicated.
TCE is the most widespread water contaminant in the nation. Huge swaths of California, New York, Texas and Florida, among other states, lie over TCE plumes. The solvent has spread under much of the San Gabriel and San Fernando valleys, as well as the shuttered El Toro Marine Corps base in Orange County.
Developed by chemists in the late 19th century, TCE was widely used to degrease metal parts and then dumped into nearby disposal pits at industrial plants and military bases, where it seeped into aquifers.
The public is exposed to TCE in several ways, including drinking or showering in contaminated water and breathing air in homes where TCE vapors have intruded from the soil. Limiting such exposures, even at current federal regulatory levels, requires elaborate treatment facilities that cost billions of dollars annually. In addition, some cities, notably Los Angeles, have high ambient levels of TCE in the air.
An internal Air Force report issued in 2003 warned that the Pentagon alone has 1,400 sites contaminated with TCE.
Among those, at least 46 have involved large-scale contamination or significant exposure to humans at military bases, according to a list compiled by the Natural Resources New Service, an environmental group based in Washington.