I give what Edward has stated some merrit, due to the fact that some one casting bullets is more than likely a reloader. One could absorb heavy metals more so than say a plumber soldering pipe due to the fact that reloaders are constantly handling spent brass. Decapping, tumbling, sorting, and all of the other general fooling around that the prep. work requires. Where you would be exposed to those metals in left over priming compounds. I worry more about exposure to a batch of dusty tumbling media than I ever would worry about lead poisoning from casting. Your melt would have to be to vaporizing temperatures to absorb lead threw casting. And as others have said, don't lick the pot or the spoon.