>Ok, I'll bite. It's been a long day, so that may be why I can't see >why the radioisotopes in lead that was dug up 100 years ago would be >any more depleted than the lead that sat in the ground for the >intervening 100 years. Half-life is half-life, no?
>Now if it were something about the modern extraction process that >added contaminants, then I can see it. In nature, lead is found in deposits with trace elements of other heavy radio nucleotides. (U235/238/Th232). These are removed in processing, but one of their decay products is Pb-210. Pb-210 cannot be chemically removed from lead. (lead contains mostly stable Pb 207/208/209) New lead may also contain trace amounts of Polonium-210. So lead, when mined has trace amounts of radioactive Pb-210; as the half-life of Pb210 is only 22 years, it's fairly radioactive but also decays rapidly (1/32 of radiation left after 100 years, 1/1000th after 200) Casper _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
