Alexander de Seversky (1894-1974), in youth an ace pilot for Russia's Tsarist Navy, emigrated to the US and became involved in military aviation there. He visited Hiroshima and Nagasaki shortly after the 'nuke blasts', talking to witnesses, and in a Reader's Digest article in February 1946 - let on between the lines that the 'nuclear weapons' were fake. He avoided saying so directly, but pointed out that, "To my surprise, Hiroshima looked exactly like all the other burned-out cities in Japan." Directly under ground zero, Seversky saw "buildings structurally intact, topped by undamaged flag poles, lightning rods, railings, signs, and other comparatively fragile objects ... I could find no traces of unusual phenomena ... It simply is not true that matter was vapourised ... tree trunks and walls with growing vines disprove the claims of superheat ... it was fire, just fire, that took such high toll of life."

https://www.henrymakow.com/2020/07/nuclear-bombs-do-not-exist.html

Possibly, but I'd need to know what caused the leukemia epidemic (previously a very rare disease) in the 1960's, if not nuclear radiation.