Every once in a great while I ask the doctor to add a lead test to my annual physical. I hadn't done it in a while, and it came back at 8 this year. He said that it's not a level to be terribly worried about, but it is indicative of exposure and I need to figure out what's causing it.
The thing is, I hadn't cast anything at all for months, at least half a year or more I think. I've given it a lot of thought and have come up with a couple ideas that seem like possibilities routes of exposure.
The first is regarding brass. When I get home from the range I put my brass (and any extra I pick up abandoned at the range) in a bucket and wash it with a little soap and Lemishine (citric acid). I've often handled it with bare hands. I wonder if the citric acid and tiny amount of residual lead could be absorbed into bare skin? I have and use d-lead soap, and have been much more careful about hygiene when handling lead in recent years, but hadn't thought about citric acid allowing skin absorption?
The second is my garage. In the past I've casted in the garage a fair amount. I don't cast a lot like some others here, just off and on occasionally. I would cast with the garage door open and a small fan running. I had also tumbled brass in vibratory tumblers in the past, before I went to wet tumbling. My thought is that there could have been a bit of dust in the garage that could have contained a trace of residual lead. In the couple weeks before my physical I did a major cleaning and rearranging in the garage, and installed a vent hood for casting. Perhaps I stirred up and breathed this dust?