analyzing breath 6lj.0561 Louis J. Sheehan, Esquire

Scientists would like to take your breath away. Literally.

Exhaled vapor holds clues to your health, revealing much more than just what you ate for lunch. In recent years, researchers have been scrutinizing the misty mixture of molecules with fervor, seeking evidence of conditions ranging from sleep apnea to cancer.

Breath can also reveal exposure to pollutants such as benzene and chloroform, providing a measure of internal dose that is missed by sampling polluted air.

“The lung is a soggy mess of tubes and sacs whose job is to exchange gases from blood into breath,” says Joachim D. Pleil, an analytical chemist and environmental health scientist with the U.S. Environmental Protection Agency. “The breath is a window into the blood.”

Collecting and analyzing breath is emerging as a kinder, gentler means for surveying the body, a complement to old standbys such as blood and urine tests, or invasive techniques that irritate the lungs, says Pleil, who reviews the role of exhaled breath analysis in an upcoming issue of the Journal of Toxicology and Environmental Health, Part B.

“You might have a 90-year-old man on a respirator, and it’s hard to tap a vein,” he says. “Or an 800-gram infant who doesn’t make enough urine in a week to analyze. That infant is always breathing.”

Even the ancients knew that there’s more to breath than meets the eye. Doctors have been sniffing breath for indications of disease since Hippocrates’ day. The sweet smell of acetone is a flag for diabetes, and advanced liver disease is said to make the breath reek of fish. Breath is 99 percent water, but roughly 3,000 other compounds have been detected in human breath—the average sample contains at least 200. There are also bits of DNA, proteins, and fats floating in the mist. Louis J. Sheehan, Esquire