Low-dose radiation.
D000328:Adult; D000367:Age Factors; D000368:Aged; D006801:Humans; D007564:Japan; D008875:Middle Aged; D009381:Neoplasms, Radiation-Induced / Q000401:mortality; D009784:Occupational Diseases / Q000401:mortality; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000401:mortality*; D013997:Time Factors