What is a nuclear test? Nuclear physicists find it necessary to make many kinds of tests, most of them quietly in laboratories. But the phrase "nuclear test" has come to mean an experiment that involves a nuclear explosion. Since all such tests are dangerous, the U.S. fires its small ones on the Nevada desert, its big ones on remote Pacific islands. Most of the 169 U.S. tests were exploded on tall towers so that their expanding fireballs would not hit the ground. A few nuclear devices were dropped from airplanes or suspended from captive balloons.
What are the dangers? All near surface...