He enriched the oxygen or the carbon dioxide in the air breathed by experimental subjects and found not a hint of suppression or exacerbation of yawning compared with control subjects breathingnormal air.
The normal way of catching the infection, caused by a bacterium called Coxiella burnetii, is breathing in barnyard dust which contains dried placental material, birth fluids, and faeces.
Breathing particulate-laden (aka smoggy) air may be hardening your arteries faster than normal, according to research published today in PLOS Medicine.