Ah, finally!
Yes we have all been bothered by this. I've never done much experiment myself to understand it, but the little I did also showed this was not due to breathing, which I had assumed first. (But holding your breath quickly shows it almost makes no difference!) But I had indeed noticed fumes tended to go towards my face when my arms would get closer to the iron. Never really analyzed the cause.
Of course the solution for me was to use a fume extractor. Now if you used only one arm for holding the iron, and hold the part you're soldering/or solder wire with a tool and put your other arm away, I guess this should also do. A fan or fume extractor is less trouble, though.
