Was the linear-no-threshold model not basically disproven by a study on people who lived in buildings built with steel scavenged from the ruins of Hiroshima or

Was the linear-no-threshold model not basically disproven by a study on people who lived in buildings built with steel scavenged from the ruins of Hiroshima or Nagasaki and therefore in an environment with elevated radioactive background levels. They showed lower incidence of cancer if I remember correctly?