Is our fear of radioactivity based on scientific reality? From Hiroshima to Chernobyl, scientists have been studying the impact of human exposure to radiation for over 60 years and have always believed that any level of radiation is bad for you. But astonishing new evidence contradicts many common assumptions about the risks of radiation exposure. Leading scientists are now questioning whether or not radiation causes cancer, and are even finding evidence to suggest that exposure to radiation can have beneficial health effects.