Atmospheric testing of nuclear bombs between 1955 and 1963 released a pulse of C14 atoms that are now incorporated into everything alive on the planet today, making them ideal biological markers. The radioactive markers have proven a treasure-trove for researchers studying everything from neuronal regeneration in the brain (previously thought not to happen) to forensic sciences.
The fallout is actually having the effect of advancing our knowledge of biological processes and, in the case of forensics sciences, identification of individuals and even their dates of death. The latter helps both police and other authorities, while families of the deceased may gain a sense of closure. Atomic miracles.