Comments about casting and hygeine
By far, the worst source of lead contamination is indoor ranges with poor ventilation. Burning powder reacts with the bases of bullets and the common primers contain lead styphanate which gets into the air on ignition. This is not as much of a concern on an outside range, but too much exposure is still possible on a windless day.
The tempertures involved in casting are not high enough to cause any vaporization of lead. For casters, breathing it is not the issue, and a respirator, while it may indeed do some good keeping the other particulates from the burning flux out of our lungs, that is generally only a problem when smelting and mixing alloys, and there is no lead vapor involved. (If there were, a particulate filter wouldn't stop it anyway.) The main problem comes with not washing your hands after handling lead and lead alloys when casting or loading. Elemental lead is not absorbed through the skin. If it enters your digestive system, however, then you can have problems. It is oxidized by the acid in your stomach, and lead oxide is nasty stuff. (The latex gloves are a really good idea, BTW.) Eating, drinking, and/or smoking while casting or loading is potentially the biggest problem after range lead. Lead on the outside of a cigarette is burned with the tobacco as you inhale, and that is hot enough to vaporize it. Any lead on your hands contaminates any food you pick up and put in your mouth, even tossing a few ice cubes in your glass is not a safe practice.
It may surprise you that very few casters when tested have elevated lead levels. Ours is a fairly technical hobby, and the sort of people who are drawn to it tend to be the intelligent, curious sort, and are usually well aware of the health concerns surrounding it. This is not to say that regular reminders aren't a good idea, they are. We all need to be aware, and to keep
washing our hands immediately whenever we take a break!