Take My Breath Away…And Analyze It in a Lab

For years, police have been using breath to tell when people have had a little too much to drink, by taking Breathalyzer readings to determine their blood alcohol levels. Now, some scientists are hoping that your breath could say a lot more about you than how much you've had to drink or what you ate for lunch. Science Newsreported recently on Joachim D. Pleil, a scientist with the Environmental Protection Agency who is developing technology to learn more about a person's health by analyzing their breath. An average breath, Pleil says, contains 200 different chemicals. In total, scientists have identified more than 3,000 different compounds coming out of our mouths. If researchers figure out what the makeup of a person's breath says about their health, Pleil says, the benefits to medicine could be great. The main problem for breath researchers is knowing what to look for. A patient may have 200 different compounds in their breath, but that's just a jumble of data. However, patterns are beginning to emerge. Normal breath registers a pH of about 7.5, according to John Hunt of the University of Virginia Children's Hospital, but a person with respiratory disease might be exhaling a much more acidic mixture, as low as a pH of 3. And scientists have even had some success identifying the chemicals in a lung cancer patient's breath that aren't present in a healthy person's—a skill that could perhaps aid in diagnosis down the road. Even if researchers know what to look for, reliable breath-testing won't be easy to achieve. While a person's breath could contain a mix of hundreds of different molecules, they come only in minuscule amounts—99 percent of each breath is just water, so scientists are hunting for tiny clues. A patient must breathe into the collector for five minutes just to accumulate one milliliter of a sample, which then must be capped and analyzed. So it might be a while before your doctor tests your breath rather than your blood or urine. But on behalf of all of us who don't care for needles, it couldn't come fast enough. Image: flickr/Gagilas