But it doesn't appear to have caused a spike in cancer diagnoses, according to a Utah Department of Health study that looked at cancer cases from 1973 to 2001.
"We didn't really find any associations to elevated cancer rates and those communities associated to the plume," Wayne Ball, environmental epidemiology program manager for the Health Department, said Friday.
The latest study won't end efforts to examine the environmental or health consequences of the trichloroethylene (TCE) tainted water in the communities surrounding Hill Air Force Base. The chemical, used to clean airplane engines and military vehicles from the 1940s to the 1970s, has not been discovered in drinking water. It is no longer in use.
TCE has been known to cause cancer in some laboratory animals, which caused concern in the communities affected by the contamination. The communities with contaminated groundwater include Syracuse, Clearfield, Clinton, Roy, Riverdale, Sunset, South Weber and Layton. Using 2000 census estimates, Ball believes 53,500 Utahns live above the contaminated plumes.
Ball promises to conduct another health review in the next few years when the Utah Cancer Registry, which includes data on every diagnosed cancer case, is updated.
If Ball and his staff find any increase in cancer rates, a more thorough epidemiological study will follow.
But he is not surprised by the results of his most recent review.
"Mainly, because the exposures to these plumes are minimal, so you wouldn't expect to see anything," he said.
The U.S. Department of Health's Agency for Toxic Substances and Disease Registry found in 2003 that the levels of TCE were not high enough to create a public health hazard.
Still, Lewis Garrett, director of the Davis County Health Department, calls the contamination "a major environmental concern."
Hill Air Force Base has begun efforts to clean up the waste. During that extensive cleanup effort, the base will continue monitoring homes such as the Clearfield residence of Jennie Rene.
She expects Hill technicians to leave a monitoring unit in the crawl space of her home on Nov. 8. The equipment tests to see if the TCE has become airborne. She said a similar test was conducted last year and showed that her air was clean.
"It concerns me," Rene said. "If it is bad, I want to know, so I'm glad that they test."
In homes where TCE has been found in the air, Hill has installed ventilation equipment.
Still, Rene is not ready to leave her home of 50 years due to the environmental concern about living above contaminated plumes.
"I have just let it go," she said.