In clarifying the statement that the final assesment characterizes the chemical as "carcinogenic to humans and as a human non-cancer health hazard," the EPA issued the following statement:
Chemicals may cause more than one type of health effect. It is possible that a particular chemical could cause both cancer plus other health effects that are not cancer.In the case of TCE, the IRIS assessment concludes that TCE is carcinogenic to humans. This means there is convincing evidence in humans (from epidemiology studies) that TCE causes kidney cancer. This is supported by evidence in humans that TCE may cause human lymphomas and liver cancer, and there is consistent evidence from laboratory studies that TCE causes cancer in laboratory rats.
In addition to causing cancer, TCE can also cause other health effects (in other words, health effects that are not cancer). This includes effects on the central nervous system, the kidney and liver, the immune and male reproductive systems and the developing fetus.
"This assessment is an important first step, providing valuable information to the state, local and federal agencies responsible for protecting the health of the American people," said Paul Anastas, assistant administrator for the EPA's Office of Research and Development. "It underscores the importance of EPA's science and, in particular, the critical value of the IRIS database for ensuring that government officials and the American people have the information they need to protect their health and the health of their children."
TCE is one of the most common man-made chemicals found in the environment. It is a volatile chemical and a widely used chlorinated solvent. Frequently found at Superfund sites across the country, TCE’s movement from contaminated ground water and soil, into the indoor air of overlying buildings, is of serious concern. EPA already has drinking water standards for TCE and standards for cleaning up TCE at Superfund sites throughout the country.
TCE toxicity values as reported in the assessment will be considered in:
- Establishing cleanup methods at the 761 Superfund sites where TCE has been identified as a contaminant
- Understanding the risk from vapor intrusion as TCE vapors move from contaminated groundwater and soil into the indoor air of overlying buildings
- Revising EPA’s Maximum Contaminant Level for TCE as part of the carcinogenic volatile organic compounds group in drinking water, as described in the agency’s drinking water strategy
- Developing appropriate regulatory standards limiting the atmospheric emissions of TCE – a hazardous air pollutant under the Clean Air Act
This assessment has undergone several levels of peer review including, agency review, inter-agency review, public comment, external peer review by EPA’s Science Advisory Board in January 2011, and a scientific consultation review in 2006 by the National Academy of Sciences. Comments from all reviewers are addressed in the final assessment.
EPA continues to strengthen IRIS as part of an ongoing effort to ensure concrete research and science are used to protect human health and the environment. In May 2009, EPA restructured the IRIS program to reinforce independent review and ensure the timely publication of assessments. In July 2011, EPA announced further changes to strengthen the IRIS program in response to recommendations from the National Academy of Sciences. EPA’s peer review process is designed to elicit the strongest possible critique to ensure that each final IRIS assessment reflects sound, rigorous science.
For more information on IRIS go here.
Editorial comment: In the Spring of 1991 routine testing conducted by the Missouri Department of Health documented the presence of trichlorethylene (TCE) in the well water of several residences just south of Joplin in the Village of Silver Creek. (Silver Creek is located immediately south of FAG Bearings Corporation, an industrial facility that used substantial quantities of TCE in its manufacturing process from 1972 through 1981.) Because the residents of the Village of Silver Creek were not privy to water from the city of Joplin water system, they depended on their individual wells for their entire water supply.
According a report made by Shamberg, Johnson and Bergman, one of several law offices involved, initially, a class action was filed in the United States District Court for the Western District of Missouri, but it was not certified by the federal district court. They then filed a consolidated action for individual claimants represented by the three law firms in Missouri state court, in Neosho, Missouri. Litigation was actively conducted in both state and federal court for over two and one-half years, resulting in a settlement in the amount of $4,000,000 between FAG Bearings Corporation and the 68 plaintiffs. Settlement included payment for the diminished value of the plaintiffs property, as well as for nuisance (the loss of use of enjoyment of property as a result of the TCE contamination). The settlement also provided for repayment of the cost of the water system put in by the Village of Silver Creek, as well as payment to the Missouri Department of Natural Resources for the water system installed in Saginaw Village, located to the south.
Claims were brought under the Comprehensive Environmental Response, Compensation and Liability Act, CERCLA, the Resource Conservation and Recovery Act, RCRA, as well as state law claims for nuisance, trespass, strict liability, negligence, medical monitoring, fear of cancer, and increased risk of cancer.