In article , litle ole me
writes

except that there is NO LEAD CONTENT IN THE FLUX FUMES.
Lead does not vaporize until much higher temperature than soldering
temperatures...

There will be lead in the fumes; molecules regularly detach themselves
and float off into the air from liquids (and can also do so for some
solids under certain conditions) at well below the vaporization
temperature, perhaps you have not noticed that water at room temperature
will evaporate, remember: molten is a liquid. This is why mercury spills
are such a problem, and why several years ago laboratories (schools
etc.) had to incur expense having floors lifted and mercury removed by
special vacuum cleaners, and using mercury vapour detectors to variety
'safe' levels. A few weeks ago I had to clean a spill caused by a broken
thermometer from a cupboard.
--
Ian G8ILZ