EPA finalizes long-delayed TCE assessment - big step to protecting public health

Today EPA took an important step towards protecting the public and wildlife from trichloroethylene (TCE), a very hazardous mutagenic cancer-causing chemical that pollutes the nation’s water and air. TCE is also the culprit involved in the Woburn, MA cancer cluster of childhood leukemia cases (and the subject of the movie, “A Civil Action” starring John Travolta). EPA's press release is here.

This much-delayed action is a triumph of science over special interest politics. The public won today. Here I tell the history of science-manipulation for this chemical, but for the political shenanigans see today's blog of my colleague Daniel Rosenberg.

TCE is a chlorinated solvent used primarily for metal degreasing—most notably for jet parts—and is a widespread drinking water contaminant that is leaching from military bases and industrial sites throughout the country. In addition to cancer, TCE causes harmful effects to the central nervous system, kidney, liver, immune system, male reproductive system, and the developing fetus. The EPA has been trying to finalize its assessment of TCE for 22 years, making today’s announcement a long-overdue victory for health.

The last EPA assessment of TCE was 24 years ago, in 1987, classifying TCE as a "probable" human carcinogen (Group 2B). In 1989, the EPA started to update its TCE cancer assessment, but didn’t issue a draft for public and peer review for a dozen years, until 2001. The 2001 EPA draft for TCE calculated that the chemical was 5 to 65 times more toxic than previously estimated, and classified it as "highly likely" to cause human cancer. It identified children as a susceptible population, and noted that co-exposure to some other chemicals may augment the toxicity of TCE.

The 2001 draft also triggered a decade-long firestorm of criticism from the chemical industry, the Department of Defense (DOD) and the Department of Energy (DOE), which together are responsible for about 750 TCE-contaminated dump sites in the nation.

EPA sent its TCE draft assessment to its Scientific Advisory Board (SAB) in 2002 for peer review by independent scientific experts. The SAB issued a very favorable report. Nonetheless, Bush Administration political appointees forced the EPA to put the draft assessment on hold.

The Pentagon forced the draft into a further delay by insisting on a consultation from the National Academies, delaying the report by two more years and costing more than $1 million of taxpayer money. However, the review, completed in 2006, was very favorable of the EPA draft, urging EPA to finalize it as soon as possible.

In the spring of 2007 the Bush Administration side-stepped the science by issuing a rule exempting the military and certain industries from laws that would put a limit on air emissions of TCE and other halogenated solvents.  The exemption was challenged in court by NRDC and other environmental groups. In 2009 the Obama Administration agreed to reconsider the Bush-era air emission exemptions. The outcome of that process is still pending.

In 2009, the EPA staff again updated its still-draft TCE assessment, classifying TCE as carcinogenic to humans by all routes of exposure, based mainly on its high risk of causing kidney cancers, but also on Non-Hodgkin’s lymphoma and liver cancer. It is the 2009 draft with minor changes that was finalized today and issued to the public as the new 2011 health assessment, to be used to set more protective clean-up standards and exposure limits across the country.

Details on the history of industry obfuscation for TCE and other chemicals will be forthcoming in my soon-to-be-released report. Learn the tricks of the trade, how to recognize when public health is getting snookered, and much more. Watch for it!

About the Authors

Jennifer Sass

Senior Scientist, Health program

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