unless your stripping radiators without an exhaust fan like i was for
a couple of years you will not have a problem. seriously. you can get
a mask if you want but get plenty of filters/masks because if you use one more
than once your doing more damage than not wearing one. some people get
effected in different ways by different chemicals but really i think some people
need to harden up. obviously breathing in anything isnt good. and yes
lead gets airborne when its burnt, brushed, sanded you would be surprised.
if your really worried you might want to consider gloves as handling the lead
can be dangerous too. we used to have to leave our clothes at work because of
lead contamination. all it takes is for you to not wash your hands and touch
things and it builds up. i have been around it for years.

there is no need to take risks if you dont want to, especially ones that can be
avoided. if you choose to wear a mask than thats your choice, personally i have
better things to worry about. i wouldnt go breathing it in though.

just for the record every three months we were tested for lead exposure. normal people
with relative exposure (mesured in ug's per litre or something) was 5 and under.
i was getting 6's 9's and 11's for ages then moved workshops and it got up to 36.5 ug/ltr.
it said anything over 40 requires urgent medical attention. it was higher than nearly
anyone i knew.

i dont think any casual soldering will give you lead poisening.