You might be looking at the wrong part of the equation: it's the rosin mostly that does damage. To quote a sort of reputable source
( the UK government) : 'Rosin-based solder flux fume is now regarded as one of the most important causes of occupational asthma in Britain. When the asthmatic effects are fully developed they are permanent and irreversible. "
That said... I once had a lead test to see if I was contaminated from soldering. That was at the point where I had used about ten rolls of solder. It was a fasting test (no food beforehand) and they took so much blood for the test, and I was so woozy form not having eaten that I staggered out of the clinic, passed out on the street, and ended up being taken by ambulance to the hospital emergency room. The lead tests came back negative, along with a $200 bill for the ambulance.
The moral of the story is this: solder fumes from any kind of rosin-based solder are well known to be damaging. However, you would have to inhale a LOT of it to get sick, and as you can see from the above story, sometimes worrying about it will get you in more trouble than not worrying about it.