by DaleH » 21 Nov 2013, 11:20 pm
Funnily enough, I am a metallurgist. Even at temperatures below boiling, lead does give off fumes (just like water evaporating on a hot day, molten lead is no different). Lead fumes are the best way of adsorbing lead as the fumes go straight into your lungs where there is a great supply of blood (to transfer oxygen from the air into your blood) that will suck up the lead very easily.
Just like when soldering, well ventilated area and ideally with a fan blowing the fumes away from you (and everyone else).
Occasional exposure is no problem but as the lead accumulates in your system it adds up over time and can cause issues.
The other thing to be certain of is that you wash your hands (and face) prior to eating, drinking or especially smoking. Injection in this way is the second most effective way of ingesting lead.
If the right precautions are taken (no food, drink, smoking unless hands and face are clean), only getting the lead and molds as hot a needed to get a good cast and fume extraction / air flow, then casting your own will cause no issues.
Hope this helps. Happy to dig up more info and post it if anyone is interested.