Defence researchers looking for a way to detect exposure to biological weapons have stumbled on a way to predict illness well before any other symptoms.
They have been using a device that measures the minute (typically 5 parts per billion) amount of nitric oxide in the breath. Nitric Oxide is known to be a key signaller in the immune system, and the researchers found that increased breath levels of the gas (up to 50 parts per billion) are found in those suffering from infections, or those who fell ill a few days later. NO is also higher in those suffering from asthma.
The researchers are now hoping to develop a commercially available breathalyser for use by doctors, but it could also be extremely useful for athletes treading the fine line between maximum training and illness.