What do you mean?
> the amount of lead is harmless for DIY solderers.
To date, the FDA, CDC, and the WHO state that "no amount of lead is harmless". It's just that we can't get a sensitive enough handle on the neurological effects to determine a good metric for it.
On another note, does anyone know if the Respro masks are suitable for protection against lead (+ the stuff with lead) inhalation while soldering? The "techno" mask has a HEP-A filter and a charcoal mesh, which I would have thought would be enough for most of the lead particulate?
You have to breath it or ingest it for it be dangerous. In soldering it does not get anywhere near hot enough to vaporize, so really all you have to worry about is ingestion.
As long as you either don't touch the solder, or are careful after touching it to not touch anything that may find its way into you until you can thoroughly wash whatever parts of you touched the lead (or were touched by parts of you that touched the lead), you should be OK.
The biggest health risk during soldering is going to come from the flux. It's the flux burning that produces the smoke you see and smell during soldering.
Here's a document from LBNL on safe soldering practices that goes into the components of solder (leaded and lead-free) and their dangers: http://www2.lbl.gov/ehs/ih/pdf/safeSolderingFinal.pdf
Although that degree of caution is more or less warranted when dealing with lead solder in paste form, I have to admit. That crap gets everywhere.
Exactly.
Fumbling around with a soldering iron and some leaded solder a little bit, few times a decade, won't give you cancer or any poisoning. Safety considerations are aimed at people doing lots of soldering, because at this point the amount of flux fumes they might breathe in (or risk of ingesting lead) becomes a possible risk.
(And to be honest, I believe most of this safety advice is aimed not at DIY people, and not even at people who occasionally have to solder something at work, but to have a stick that will prevent employers in soldering shops from creating very unhealthy conditions for their workers.)