Lets hope your bang on robv.
About the arsenic supply.......I worked at Teck/Cominco for 30 years and I know for sure that they have arsenic as a by product of smelting lead bullion. In fact everyone in my plant had to wear PPE to protect from it and have urine samples taken on a regular basis to test for it. I also think that they have gallium as a by product of electrowinning zinc. Let me check a few sources and get back about that....cheapie