i had a read what it looks likes to me is people being paranoid LOL like when we argued with dennis about asthma and Smoke machines i think the shortness of breath is just people reaction to seeing smoke, ill admit it does make the air seem thicker but then again thats what its meant to do and it says can give headaches, LOL that would have nothing to do with the Smoke but your eye's reaction to dense air your eye's have to strain to see threw smoke obviously hence getting a headache after spending 5 hours in a smoke filled room just my thoughts anyway