We had leaded (Ethyl) gasoline in cars which was banned 25 years ago and that had noticeable statistical effects on IQ an emotional regulation (violence) for more than a generation.
https://www.quora.com/Can-I-get-lead-poisoning-from-inhaling...
The primary means of exposure in a lab setting is through ingestion of particulate matter by getting it on your food or clothes -> mouth
Here's an environmental safety article from MIT. It mentions lead oxide fumes from soldering. What do I know other than the required lab safety training.
Most of the fumes come from the flux boiling way, not the solder itself. (Mind you, I still wouldn't recommend breathing flux fumes. Those are bad in their own way. Adequate ventilation is important!)
Lead is unequivocally bad for you, but the amount that actually enters your system from soldering activities is miniscule.
It's good to minimize these substances in our daily life since they do add up over decades. The problem with leaded gas in cars is that there were just so many cars out there burning the stuff. Duration of exposure and amount of exposure both matter.
That said... do wash your hands after handling leaded solder, especially before eating.
(I used to have a summer job in high school assembling circuit boards for an electronics test company. I easily clocked a couple hundred hours soldering under a magnifying lamp with leaded solder. I'm sure the burns I gave myself from accidently touching the soldering iron itself did more damage than the lead. :P)
The difference is not the amount of cars, but that the temperature and pressure in car engines makes lead vaporise, so it can be breathed in.
A soldering iron doesn't reach those temperatures (vaporising the lead is the opposite of what you want when soldering).
In all seriousness, very little. I would personally want more than just a bathroom fan to do fume evacuation. Outside on a patio/balcony is my usual spot. I also have a 120mm computer fan that I hacked onto a gooseneck mount so I can blow the fumes away from my face.
The times I can't be outside, usually due to weather, I use a table right in front of an open window, and one of those dual fan window fans set to exhaust mode, and that sucks the fumes outside effectively.
I'd call that a reasonably good setup, and, as a bonus, the fumes don't hit me directly in the face, which soldering fumes have a tendency to do.
Also something to remember about ingestion is that, lead only forms salts in acidic environments, and, your stomach is quite acidic, which is why it's such a problem. Combine that with lead accumulating in your body and, well, it's best to avoid it, and it's simple enough to avoid it.
The fumes are flux fumes, not lead fumes. They're still bad to breathe but not specific to leaded solder.
