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Epidemiology and Genomics Research Program

U.S. Radiologic Technologists (USRT) Cohort

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Lead Contacts and/or Principal Investigators (PIs):

Funded Since: 1980
Funding Source: NCI Intramural Program (DCEG)
Year(s) of Enrollment: 1982
Study Website:

The U.S. Radiologic Technologists (USRT) Study is a collaborative effort between the University of Minnesota, the NCI, and the American Registry of Radiologic Technologists (ARRT). One of the key goals of the study is to understand how repeated occupational low-dose ionizing radiation exposures, such as those potentially experienced by radiologic technologists, are related to cancer and other health conditions.

This study began in 1982 by identifying current and former radiologic technologists who were certified by the ARRT for at least two years from 1926 to 1982. Ultimately 146,022 eligible technologists were identified, including 106,958 women and 39,064 men. Since 1983, the study has conducted three surveys: in the mid-1980s, mid-1990s, and the mid-2000s. Beginning in 1998, the study also began collecting blood samples from selected groups of participants. Cause of death information is obtained from death records for technologists who have died. Long-term follow-up with study participants is important to fully assess potential health effects, such as cancer, which can take many years to develop.

This study is unique, not only because it represents the most comprehensive study of people who are exposed to radiation in medical jobs, but also because it is a nationwide study representing all fifty states in the United States. It is the largest study of people working in the medical field who are exposed to ionizing radiation. It is also unique in that the population is mostly women.