Facts about Trichloroethylene (TCE) at the Chicago Heights Boulevard Site, St. Louis County, Missouri
At some time before 1988, an unknown quantity of the industrial chemical trichloroethylene (TCE) was released at an industrial site just northwest of the Elmwood Park neighborhood in north St. Louis County, Mo. The chemical traveled down through the soil and into the groundwater, where it flowed generally southeast of the industrial site. Groundwater contaminated with TCE presently exists beneath several Elmwood Park homes located adjacent to the industrial site.
The area where TCE is mixed with groundwater is called the groundwater contamination plume. Because TCE evaporates easily, its vapors tend to leave the groundwater and travel upward through the soil. If a home happens to be located over or near those vapors, the vapors can enter the home, primarily through the sump system and cracks in the foundation. This is called “vapor intrusion” because the vapors intrude or enter into the home. TCE vapors that become trapped in a home, at certain levels, may pose health risks.
In 1988, PerkinElmer, Inc., purchased the industrial property where the TCE release previously occurred. Since purchasing the property, PerkinElmer has worked with the Missouri Department of Natural Resources (MDNR) to identify the extent of the groundwater contamination plume. Most recently, in September 2012, MDNR transferred regulatory oversight for the site to EPA Region 7.
WHAT IS TCE?
Trichloroethylene (TCE) is a colorless liquid solvent. It is odorless at the low concentrations being found in some of the homes in Elmwood Park. TCE is used primarily for cleaning and degreasing metal parts. It has also been used in adhesives, paint thinners, spot removers, and typewriter correction fluid. In the past, it was even used as a surgical anesthetic. Because TCE is used in many industrial, household and hobbyist products, it is not unusual for very low concentrations to be found in indoor air. TCE is one of the most common contaminants found by EPA at groundwater contamination sites around the country.
WHAT ARE THE HEALTH EFFECTS ASSOCIATED WITH EXPOSURE TO TCE?
Exposure to TCE can cause adverse health effects, especially at high levels. Impacts to the central nervous system, male reproductive system, immune system, kidney and liver function, and the developing fetus have all been reported, as have some fatalities, as a result of exposure to very high concentrations of TCE. High concentration exposures to TCE have typically occurred in the cases of industrial workers who experienced regular or prolonged exposure to TCE in association with their jobs, and not to persons exposed to TCE because of vapor intrusion in their homes.
Concentrations of TCE found in samples of groundwater below homes in Elmwood Park, and in air samples collected inside and beneath homes in the neighborhood, have been much lower than concentrations typically found in occupational settings.
Although TCE concentrations in occupational settings may be tens, or even hundreds of thousands of times higher than those a person might be exposed to in a home setting, lower level exposures may still pose health risks.
DOES TCE EXPOSURE CAUSE CANCER?
EPA classifies TCE as potentially “carcinogenic (cancer causing) in humans by all routes of exposure.” The primary cancers associated with TCE exposure are kidney cancer and non-Hodgkin’s lymphoma, although cancers of the liver, gall bladder and bile ducts have also been reported. The risk of developing cancer from TCE exposure is a function of several factors, including length of exposure, the level of TCE in indoor air, and individual susceptibility.
WHAT ABOUT NON-CANCER HEALTH RISKS FROM TCE EXPOSURE?
TCE can cause adverse effects to a developing fetus during pregnancy. Primary developmental effects are heart problems in the fetus, most likely as a result of a mother’s exposure to TCE during the first trimester of pregnancy. For adults and children, exposure to lower concentrations of TCE may also result in kidney and immune system problems.
TCE EXPOSURE IN ELMWOOD PARK
At this site, the primary risk of residents being exposed to TCE would come from breathing vapors that may have entered their homes.
IS LOCAL WATER SAFE TO DRINK?
Because the Elmwood Park neighborhood gets its water from a public water supply system that undergoes regular testing for safety, residents should have no concerns about TCE exposure from their drinking water, or from showering, bathing or other skin contact. The public water supply is separate from the groundwater beneath the Elmwood Park neighborhood.
HOW IS TCE CONTAMINATION BEING ADDRESSED AT THIS SITE?
Under its agreement with MDNR, PerkinElmer has installed vapor intrusion systems at five residences where elevated levels of TCE have been detected in indoor air. These systems are installed through the basement floor or foundation slab. A small fan pulls vapors from beneath the home’s foundation and sends them outside, where they dissipate quickly. Further air sampling is planned to ensure that the systems are working properly.
Under a proposed agreement, EPA Region 7 will work with PerkinElmer to further characterize the groundwater plume, sample additional homes to determine if vapor intrusion is occurring, and take mitigation measures, where appropriate.For more information about TCE at this site, contact:
Environmental Protection Agency Region 7
11201 Renner Boulevard
Lenexa, Kansas 66219
Toll free: 800-223-0425