Researcher looks through the noise to discover potential risks from jet fuel

O'neil Guthrie, a research scientist and clinical audiologist who joined Northern Arizona University earlier this year, studied the risk of auditory problems among test subjects exposed to sustained noise and jet fuel. The research was designed to inform Air Force officials who were interested in hearing loss among airmen.

"What we found is that at low levels, it is not toxic to the ears but toxic to the brain," Guthrie said. "Over time, these small exposures could accumulate and affect the brain's function."

Clinical conditions such as anxiety, depression, sleep disorders and post-traumatic stress could be attributed, in part, to hydrocarbon-related disruptions in brain function, a factor previously overlooked during diagnoses.

Guthrie and his team conducted month-long experiments including exposure to jet fuel only, noise only and a combination. Different exposure levels also were tested. Additional experiments will build on the initial findings.

Hydrocarbons are found in fuels and many other commercial products including makeup and cleaning products. Guthrie said most people don't realize heightened exposure to these organic solvents can be toxic to the brain.

The National Institutes of Health, the Department of Defense and the Veterans Administration funded Guthrie's basic science research. His findings can be important for establishing guidelines for individuals working around fuel and noise, including those employed at airports and in the military.

Guthrie's other areas of research include improving the capacity of the body's cells to repair damaged genes and stimulating gut bacteria to supplement repair of DNA. Guthrie came to NAU to work as an audiologist, do research and teach.