Coleman lantern mantles, the kind you use for camping, were made using thorium nitrate into the 1990's and plenty are still out in the wild. I have a package of them stored safely away that send my geiger counter absolutely nuts. I'd be far more concerned about those things than some glass-bound thorium waste buried in a supposedly properly built landfill. With all the environment scrutiny Kodak has had to endure, I'd feel pretty confident that the landfill was built correctly.