I agree completely with Sawfiler. I have torch cut and welded tons of heavily galvanized steel over the last 50 years. Just some adequate ventilation and care is all that is required to be perfectly safe. A little zinc oxide is NOT hydrogen cyanide and the effects are definitely overstated here. (Seems like everyone is afraid of everything these days and automatically takes things to the extreme.) As Sawfiler notes, over exposure to zinc oxide fumes results in a condition called the "zinc chills" (also called metal fume fever as the condition can be caused by other metals as well). While the symptoms do go away in a day or so by themselves, you can make them go away in a few minutes by drinking a glass of whole milk. I know this for a fact because I have had the zinc chills a few times over the years. And, by the way, the last time I had the chills, I didn't have a cold or flu for seven years afterward......(think "Zicam")
Just my $0.02