A SNIFF of your breath can reveal that you’re in for a bout of flu, up to a
week before the symptoms appear. Defence researchers discovered the technique by
accident when they were looking for a way to tell whether someone has been
exposed to a biological weapons agent.
Our breath contains about 16 per cent oxygen, 78 per cent nitrogen and 4 per
cent carbon dioxide. It also contains traces of other gases, including 5 parts
per billion of nitric oxide. NO is an important signalling molecule in the
immune system, so Robert Lad at the University of Maine…
