Perspective: Nuclear weapons testing460,000 Premature Deaths: The Horror That Was Nuclear Weapons Testing

Published 29 July 2019

In March 1954, over the Bikini Atoll, the United States detonated a 15-megaton hydrogen bomb —one thousand times more powerful than the bomb that destroyed Hiroshima. It was the largest explosion ever set off by Americans, and also the dirtiest. Researchers have now found that, more than sixty years after the nuclear tests the United States conducted in the area, the levels of radiation in several Marshall Island atolls, exceed that found at Chernobyl or Fukushima. The United States also detonated hundreds of atomic bombs in Nevada, and a 2017 study suggested that fallout from the Nevada nuclear testing could have led to between 340,000 and 460,000 premature deaths, mostly Americans and mainly through cancer.

For a brief fraction of a second on an early March morning in 1954, the United States summoned a second sun into existence above Bikini Atoll. This was the Castle Bravo thermonuclear test, one of several dozen nuclear detonations the United States carried out in the Marshall Islands during the Cold War. At 15 million tons of TNT—one thousand times more powerful than the bomb that destroyed Hiroshima—it was the largest explosion ever set off by Americans. 

Zack Brown and Alex Spire write in the National Interest that it was also the dirtiest, as a new study published this month shows. Researchers from Columbia University, analyzing soil samples from , Researchers from Columbia University, analyzing soil samples from several Marshall Island atolls, discovered widespread radioactivity. Bikini Island itself was declared unsafe for human habitation, while the three other atolls had significant radionuclide concentrations—mainly americium, cesium, and plutonium. In some cases, the level of radioactivity—more than sixty years since the last mushroom cloud loomed over Bikini’s azure lagoon—exceeded that found at Chernobyl or Fukushima. 

Brown and Spire note that American nuclear testing didn’t just occur in the middle of the Pacific. Throughout the Cold War, the United States detonated hundreds of atomic bombs in Nevada at a test site just northwest of Las Vegas. Many of these tests were above-ground, exposing the continental United States to the same radioactive fallout that fell over those remote atolls. 

As with the Marshall Islands, the radiological effects of this testing were widespread—and immense. A 2017 study from the University of Arizona suggested that the fallout generated by the Nevada nuclear explosions exposed millions of Americans to its lethal radiation. The study suggested that fallout from the Nevada nuclear testing could have led to between 340,000 and 460,000 premature deaths, mostly Americans and mainly through cancer.