If you had to pick a place in the world to release radioactive contamination, you couldn't do much worse than the upper atmosphere. Which is exactly why nuclear

If you had to pick a place in the world to release radioactive contamination, you couldn't do much worse than the upper atmosphere. Which is exactly why nuclear weapons testing was done in places like high altitude atmosphere (launched from the pacific ocean). Safety may have played a role but AFAIK these nukes were exploded in this part of the world mostly because it was remote enough from the countries doing the testing. After a few decades of dumping radioactive waste in oceans, we came back from the belief that dumping radioactive waste in the ocean is mostly harmless and a ban on this practice was put up in 1993.