JD. Where did you get that info?
I did exactly as you suggested and googled welding galvanized steel and added OSHA. This is what I found this at http://www.osha.gov/doc/outreachtraining/htmlfiles/weldhlth.html
Zinc is used in large quantities in the manufacture of brass, galvanized metals, and various other alloys. Inhalation of zinc oxide fumes can occur when welding or cutting on zinc-coated metals. Exposure to these fumes is known to cause metal fume fever. Symptoms of metal fume fever are very similar to those of common influenza. They include fever (rarely exceeding 102o F), chills, nausea, dryness of the throat, cough, fatigue, and general weakness and aching of the head and body. The victim may sweat profusely for a few hours, after which the body temperature begins to return to normal. The symptoms of metal fume fever have rarely, if ever, lasted beyond 24 hours. The subject can then appear to be more susceptible to the onset of this condition on Mondays or on weekdays following a holiday than they are on other days.
Also from Sperkoengineering.com:
Zinc Fumes -- A Safety Hazard?
When zinc vapor mixes with the oxygen in the air, it reacts instantly to become zinc oxide. This is the same white powder that you see on some noses at the beach and the slopes. Zinc oxide is non-toxic and non carcinogenic. Extensive research nto the effects of zinc oxide fumes has been done, and although breathing those fumes will cause welders to think that they have the flu in a bad way, there are no long-term health effects.
I have welded galvanized steel (conduit) with no short term ill effects and feel confident that my life will not be reduced by doing so. I have read that some welders are sensitive to this and others are not, so I won't make any absolute claims. I am not a welder and don't weld galvanized steel for 8hrs a day. I do open the garage doors for good ventilation.
I'm not trying to start a fight, but just trying to clear up a misconception.