When we breathe, we take in air which is rich in oxygen (02) and expel air which is richer in carbon dioxide (CO2). The oxygen in the inhaled air is removed by the bloodstream and carried to the body so that the cells will have the oxygen they need to perform all their functions and indeed stay alive. A byproduct of cellular metabolism is CO2, which is picked up by the bloodstream and carried back to the lungs for exhalation. Good air in, bad air out. Simple and clean.
But the exhaled air contains more than just CO2. Hundreds of other molecules and compounds, also byproducts of our metabolic processes, are excreted by the lungs. These can be sampled and analyzed.
It seems that researchers at ETH Zürich and the University Hospital Zürich have begun analyzing exhaled air in the hopes of finding a “fingerprint” that could serve to individualize people. Much as true fingerprints and DNA do.
So far they have discovered that the chemicals exhaled by a given individual is highly specific and does not change dramatically over time. There are minor variations on a day-to-day basis but in general it seems that a person’s “breath print” is indeed unique. If so this could prove to be another useful method of identification.
Not to mention its medical possibilities. For many years doctors have used the odor of a patient’s breath to help make diagnoses. The odor associated with diabetic ketoacidosis, renal failure, and liver failure are each quite distinct. Though further testing is necessary to prove the diagnosis, it is often suspected from the odor surrounding the patient.