An analysis of a 1972 Agent Orange test area in the western Utah desert found no detectable quantities of the herbicide.
Air Force officials said 35 pounds of Agent Orange were applied to the test plot on the Utah Test and Training Range under various conditions to test if the chemical would biodegrade. A year later, only trace amounts were found in soil and groundwater analyses.Agent Orange has been blamed for a variety of illnesses among Vietnam veterans who were exposed to the chemical, which was used to defoliate jungle areas and deny cover to enemy troops.
Samples taken by environmental engineering contractors in 1984 as part of the base's Installation Restoration Program were found to be below detection limits, according to a report released this week.
The report concluded that the herbicide either decomposed or was blown away and recommended no further environmental action.
But Capt. Ed Heyse, Air Force environmental engineer, doubted that the herbicide could have been carried away by the wind. Heyse said the chemical either biodegraded or was diluted into the ground.
The test plot was located on a section of the Utah Test and Training Range in an arid area that experiences temperatures as hot as 106 in the summer and winds up to 100 mph, which result in high evaporation rates.
Bill Sinclair, state hazardous-waste bureau manager, said the decision document is still under review by the Utah environmental division. He suggested that an arid environment along with exposure to a lot of sunlight could cause the chemical to break down and change into other organic compounds.
But he said that change could be detected by a scan that would pick up a breakdown of compounds that probably would be less toxic in nature.
The report concluded that there was no danger to people since the nearest town is more than 50 miles away and the closest large population center is 75 miles away in Salt Lake City.
The Agent Orange test area was one of 13 potentially contaminated sites investigated in Phase II of the base's Installation Restoration Program by Radian Corp. and Science Applications International Corp.