More than 2,000 nuclear weapons have been detonated in the past 80 years. Their effects still linger around the world

Growing up in Salt Lake City, Utah, in the 1950s and 60s, Mary Dickson was among the millions of American schoolchildren taught to “duck and cover” in the event of a nuclear war.

“I just remember thinking, ‘That’s not going to save us from a bomb,’” she told CNN. At that time, Dickson didn’t know that nuclear weapons were…