Q: What is trichloroethene , or TCE? Is it a threat to base workers and residents? What are some health effects?

A: Trichloroethene (TCE) is one of the major chemical contaminants found in groundwater — and to some extent, in soil — at Edwards Air Force Base, along with tetrachloroethene (PCE), jet fuel and diesel.

At the start of the cleanup process, TCE contamination at Edwards was much more prevalent than it currently is – a good sign that cleanup of this particular contaminant is heading in the right direction.

TCE is a nonflammable, colorless liquid with a somewhat sweet odor and burning taste. Primarily the chemical is used by industrial fabrication and repair facilities to remove grease from fabricated metal parts.

The general public is unlikely to be exposed to TCE or its degradation products because its use and accidental releases have occurred in the industrial areas of Edwards, which are concentrated in the vicinity of the flight line and the Air Force Research Laboratory Propulsion Directorate. The only potential exposure may be to military or civilian personnel who may use it as a solvent at maintenance and repair facilities. Base bioenvironmental engineers constantly monitor the chemical’s use and determine what protection is needed before anyone comes in contact with TCE contamination.

For those living in base housing facilities, there is no threat to health as far as drinking water is concerned. Most of Edwards’ drinking water, including all water supplied to housing, comes from the Antelope Valley-East Kern pipeline . Additionally, bioenvironmental engineers monitor and take samples of the drinking water on a weekly basis. The contaminant level of TCE in drinking water cannot exceed 5.0 parts per billion.

TCE may become a health hazard to people if exposed for a long period of time, or, if exposed to the chemical in large amounts. Some examples of the health effects of TCE if exposed in small amounts over a period of time include, but are not limited to, headaches, dizziness, poor coordination, lung irritation, liver and kidney damage, and impaired pregnancy. However, the extent of some of the effects mentioned is not yet clear. Exposure to TCE in large amounts may cause nausea, impaired heart function, unconsciousness and possibly death.

Some studies done with mice and rats have suggested that high levels of TCE may cause liver or lung cancer. Some studies of people exposed over long periods to high levels of TCE in drinking water or in workplace air have found evidence of increased cancer. However, results from the study are questionable because other chemicals could have caused the cancer.

For more information on TCE, visit the Agency for Toxic Substances and Diseases Registry’s Web site at http://www.atsdr.cdc.gov . The ATSDR can also be contacted by telephone at (888) 422-8737, or by mail at: Agency for Toxic Substances and Diseases Registry, Division of Toxicology, 1600 Clifton Road NE, Mailstop E-29, Atlanta, GA 30333.

Below is a list of trade names that may help you find out whether you are using this chemical at home or at work.

Edwards AFB: The Mission
The Air Force Flight Test Center is tasked to support the Air Force Materiel Command mission by conducting and supporting research, development, test and evaluation of both manned and unmanned aerospace systems.

This mission involves not only all aspects of testing aerospace systems, but includes the flight evaluation and recovery of research vehicles, development testing of aerodynamic decelerators, and the operation of the U.S. Air Force Test Pilot School.

Edwards Flight Test Range
To support this testing, the Flight Test Center operates and manages the Edwards Flight Test Range. The Center also operates a fleet of test bed aircraft for early development and checkout of new avionics and Advanced Range Instrumentation Aircraft (ARIA) worldwide, in support of space and missile tests.

Mobile Range
The Advanced Range Instrumentation Aircraft (ARIA) travel the globe and serve as airborne tracking and telemetry data-recording and relay stations. They fly over land where ground tracking stations are limited by geographical constraints and over broad ocean areas where tracking stations do not exist.

The unit supports a variety of national and international customers, both military and commercial, including NASA and Department of Defense missions supporting unmanned space launches, cruise missile tests, Army, Navy and Air Force ballistic missile tests and space shuttle launches.

Weapons systems testing
However, the majority of the workload consists of testing total weapon systems, including all major subsystems...This includes both complete new weapons system testing, as with the B-2, C-17 and F-22. In addition, this extends to major modifications to existing systems, such as the F-16 Block 50 upgrade, and subsystem upgrades, for example, improving the B-1 battery system.