Anecdotal 'evidence' will not get anybody anywhere. That's what the militant anti-smoking hawks are waiting for - if it's not themselves spreading those rumours.P.S I HAVE HEARD THAT THE HEATED VAPOUR OF VG IS CARCIOGENIC?
I suppose we all remember those cases where a product is carcinogenic for a number of years and then suddenly is declared to be harmless. Lord, a miracle?
Anyway, as for the fog machines and more anecdotes; as a session musician I've been touring myself quite a bit in the 80s. Some of the bands I played with also used those glycol based machines and there was in fact one isolated case where a roadie had massive health issues as described. However, after a series of checkups it turned out that it was a case of an extreme allergic reaction. I remember that bloke was allergic to a lot of things, not only the fog.
Secondly, there were always some "hobby chemists" in the band who had fun modding the hell out of those machines for "maximum effect". This could go from using anti-freeze to some really obscure chemicals I wouldn't even hold my nose over.
Under normal circumstances, touring bands and their staff are exposed to more health hazards from the Diesel fumes of their lorries.
<End of my anecdote. Any more takers?>