LAYTON — Residents of the area surrounding Hill Air Force Base need not fear ill health from chemicals that have moved off the base in the past 40 or more years into neighboring air and water, according to a federal health agency's report.
Carole Hossom, environmental health scientist at the Agency for Toxic Substances and Disease Registry, conducted an hourlong public meeting attended by some 20 residents of the area at a local hotel to discuss the report. She said none of the toxic agents from HAFB are likely to cause cancer and the exposure to agents is diminishing as the base changes its way of disposing of solvents and other toxic agents.
The chemical, trichloroethylene, was used as a degreaser and cleaning solvent for planes in the maintenance area of the base in the 1960s and '70s. The TCE plume has spread out from the base into surrounding communities.
A 100-page document distributed by Hossom said her agency concluded that exposure to contaminated groundwater, soil, residential air, surface water, fruits and vegetables does not pose a health hazard to residents and workers at Hill or the surrounding communities.
The agency is seeking public comments on its report through April 28. It can be reached on the Web at www.atsdr.cdc.gov or by calling 1-888-42ATSDR.
In the public health assessment document, the agency said exposure to contaminated surface water and contaminated fruit are less of a health concern than indoor air exposure. Contaminated groundwater in the shallow aquifer is not used as a source of drinking water and there is no accessibility to contaminated soil at HAFB.
"Some of the contamination found in the indoor air in sampled homes was not found in the groundwater contamination plumes located near the homes. For a majority of the communities studied, background samples found the same level of contamination as in homes directly above the groundwater plumes," the document said.
"From this information, it appears that groundwater off-gassing in most of the communities is not a significant source of indoor air contamination."
Although exposure occurred in indoor air, surface water, crops, groundwater and soil, the levels are much lower than shown to cause adverse health effects, the report said.
At the Patriot Hills Housing Area, where volatile organic compounds have been detected in indoor air, the levels of those compounds are low, below those associated with adverse health effects. The report added that the only surface water on the base where exposure to contaminated water is possible has toxic levels far below those associated with adverse health effects.
Several hundred homes and a school in Roy, Sunset, Clinton, Layton, the Craigdale subdivision of Riverdale, and South Weber sit above groundwater plumes that have migrated from Hill AFB, the report noted. However, indoor monitoring of air in the buildings showed volatile organic compound contaminants present were below those known to be associated with adverse health effects.
The agency used indoor modeling techniques to determine how high indoor air concentrations could have been in the past from groundwater off-gassing. The results of the modeling indicate that past indoor air levels were several times higher than they are today, but at levels far below those shown to cause adverse health effects, the report said.
Future indoor air concentrations are not expected to be higher due to the efforts that have been initiated or soon will be initiated at Hill. In communities that have had indoor air sampled, both before and after remediation efforts were implemented, the indoor air concentrations are declining, indicating that remediation efforts are working, the report said.
"Additionally, the waste disposal practices on Hill AFB that led to this groundwater contamination have stopped and remedial actions have been put in place at most source area locations that have either cleaned up or controlled contamination from leaving the base," the report said.