The Air Force ignored decades of warnings from its own researchers in continuing to use a chemical-laden firefighting foam that is a leading cause of contaminated drinking water for at least 6 million Americans, including thousands of people south of Colorado Springs.

Multiple studies dating back to the 1970s found health risks from the foam, and even an agreement 16 years ago between the Environmental Protection Agency and the foam's main manufacturer to stop making the substance did not curtail the Air Force's usage. Until drinking water tests announced by health officials this year revealed contaminated wells here, the Air Force did almost nothing to publicly acknowledge the danger of the firefighting chemical.

That contamination sent residents across southern El Paso County scrambling to buy bottled water and to test their blood for the toxic chemical, which, when ingested, can remain in the body for decades.

The Gazette's investigation into the military's research of perfluorinated compounds, the intensely powerful chemical in the foam, found:

- Studies by the Air Force as far back as 1979 demonstrated the chemical was harmful to laboratory animals, causing liver damage, cellular damage and low birth weight of offspring.

- The Army Corps of Engineers, considered the military's leading environmental agency, told Fort Carson to stop using the foam in 1991 and in 1997 told soldiers to treat it as a hazardous material, calling it "harmful to the environment."

- The EPA called for a phaseout of the chemical 16 years ago and 10 years ago found the chemical in the foam "likely to be carcinogenic to humans."

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