Cancer incidence among physicians occupationally exposed to ionizing radiation in Finland

Scand J Work Environ Health. 2006 Oct;32(5):368-73. doi: 10.5271/sjweh.1032.


Objectives: Occupational radiation exposure was estimated, and the cancer incidence among physicians working with radiation was compared to that of unexposed physicians.

Methods: A cohort of 1312 physicians was identified from the Finnish occupational radiation exposure registry. Radiation exposure data were obtained from 1970 to 2001 on the basis of individual dosimeters. Never-monitored Finnish physicians (N=15 821) were used as a reference group, identified from census data of Statistics Finland. Incident cancer cases were identified by record linkage with the Finnish Cancer Registry.

Results: The cumulative radiation dose exceeded the recording level (0.3-3.0 mSv during a 3-month period for 1029 radiation-exposed physicians (59.8%). Six percent of the radiologists had received a cumulative dose of 50 mSv or more. Altogether there were 41 cancers observed among the radiation-exposed physicians and 998 cases found in the never-monitored group. Standardized incidence ratios (SIR) for all cancers were comparable with those of the general population among physicians monitored for radiation [SIR 1.0, 95% confidence interval (95% CI) 0.7-1.4] and other physicians (SIR 1.0, 95% CI 1.0-1.1). For specific cancer sites, a slightly elevated risk of female breast cancer was found among monitored physicians when compared with other physicians (rate ratio 1.7, 95% CI 1.0-3.1). No obvious dose-response relationship was found for the overall cancer incidence.

Conclusions: According to the results from a nationwide cohort, occupational exposure to medical radiation is not a strong risk factor for cancer among physicians. Possible excess risk could not be reliably demonstrated even after the follow-up of a nationwide cohort for up to 30 years.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cohort Studies
  • Female
  • Finland / epidemiology
  • Humans
  • Male
  • Neoplasms / classification
  • Neoplasms / epidemiology*
  • Neoplasms / etiology
  • Occupational Exposure*
  • Physicians*
  • Radiation Injuries / epidemiology*
  • Radiation, Ionizing