As reported by the Washington Post.
The video that accompanies the article shows President Donald J. Trump speaking at a political rally in Alabama. He references the North Korean regime's threat to launch a nuclear tipped missile into the Pacific Ocean, and warns about the cancer that the plume (of radioactivity) could cause downwind and downstream.
Of course, Trump failed to acknowledge the radioactivity plumes the U.S. created with its many scores of atmospheric nuclear weapons tests, from 1946 to the early 1960s, including in the Pacific Ocean, as in the Marshall Islands. Even after U.S. (and U.K.) nuclear weapons testing at the Nevada Test Site went underground, after the Atmospheric Test Ban Treaty, up to one-third of all tests leaked radioactivity into the environment. An infamous example was the "Mighty Oak" test blast in 1986, which cracked the earth open, and a mushroom cloud, including radioactive contamination, erupted out, blowing and falling out downwind.