Lead is toxic to work with so it wouldn't be something I would want to start doing. Especially when I can buy coated bullets and someone else deal with it. I had lead poisoning about 20 years ago. It's a long and expensive process to remove it from your body. I'm not saying that casting is unsafe, just that personally I don't want the exposure.
I've been casting for about 12 years.
Before that I had reloaded tens, if not, hundreds of thousands of rounds using uncoated cast lead bullets from commercial manufacturers since 1987.
I take usual precautions: good ventilation, no eating while casting etc but nothing extraordinary.
While getting some routine blood work done about 2 months ago, I asked my doctor if I should have my lead level tested.
He said "Absolutely!" (Also said the same as you, the removal process is slow and expensive)
Results came back; "no elevated levels of lead whatsoever"
My doctor said in all the tests he ordered for lead over 30 years, only one came back elevated: a police officer who shot in a league for many years
indoors.
I'm curious if you know what caused your lead poisoning.
Did you work with lead in some capacity in industry?
It's my understanding elemental lead cannot be absorbed through the skin, has to be ingested.
Molten lead gives off no "fumes" as long as it doesn't exceed it's boiling point which, IIRC is over 3000°F.