That study is entirely based off simulation with the ultimate data being derived from survivors from Hiroshima and Nagasaki bonbings. We do not categorically know if there is a linear, no threshhold relationship between diagnostic radiation dose and cancer induction or if there is a threshhold dose below which radiation dose is “safe”. We also don’t know if low-level radiation is potentially beneficial (radiation Hormesis hypothesis).
That’s a lot of words to say, take that paper with a huge grain of salt.
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?
That’s a lot of words to say, take that paper with a huge grain of salt.