On the Marshall Islands , the detonation of Castle Bravo was the cause of most of the radiation exposure to the surrounding populations . The fallout levels attributed to the Castle Bravo test are the highest in history . The exposure to fallout has been linked to increase the likelihood of several types of cancer such as leukemia and thyroid cancer . The relationship between I-131 levels and thyroid cancer is continuing to be researched . There are also correlations between fallout exposure levels and diseases such as thyroid disease like hypothyroidism . Populations of the Marshall Islands that received significant exposure to radionuclides have a much greater risk of developing cancer . The Castle Bravo test detonation produced an explosion of approximately 15 megatons , which is about three times its predicted value . Populations neighboring the test site were exposed to high levels of radiation resulting in mild radiation sickness of many ( nausea , vomiting , diarrhea ) . Several weeks later , many people began suffering from alopecia ( hair loss ) and skin lesions as well . The female population of the Marshall Islands have a sixty times greater cervical cancer mortality than a comparable mainland United States population . The Islands populations also have a five time greater likelihood of breast or gastrointestinal mortality , and lung cancer mortality is three times higher than the mainland population . The male population on the Marshall Islands lung cancer mortality is four times greater than the overall United States rates , and the oral cancer rates are ten times greater
Castle Bravo
Castle Bravo
Nuclear testing at Bikini Atoll