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Abstract
| Status report on estimating historical radiation doses to a cohort of U.S. radiologic technologists
(2004
) | | Simon SL, Weinstock RM, Doody MM, Neton J, Wenzl T, Stewart P, Mohan AK, Yoder C, Hauptmann M, Freedman DM, Bouville A, Cardarelli J, Feng HA, Linet MS
| | Proceedings of a symposium
| | | | Data have been collected and physical and statistical models constructed to estimate unknown occupational radiation doses to 90,000 members of the U.S. Radiological Technologists cohort who responded to a questionnaire during the mid-1980s on occupational practices. Since the availability of radiation dose data differed by calendar time period, different models were developed for purposes of dose reconstruction during the years before 1960, 1960-1976, and 1977-1984. The dosimetry estimation used available film-badge measurements (approximately 350,000) for individual cohort members, information provided by the technologists on their work history and protection practices, and measurement and other data derived from the literature. The complete dosimetry model estimates annual and cumulative occupational badge doses (personal dose equivalent) for each technologist for each year worked from 1916 through 1984, as well as absorbed doses to organs and tissues including bone-marrow, female breast, thyroid, ovary, testes, lung and skin. Assumptions have been made about critical variables including average energy of x rays, use of protective aprons, position of film badges, and minimum detectable doses. Uncertainty of badge and organ doses was characterized for each year of each technologist’s working career. Monte Carlo methods were used to generate realizations of cumulative organ doses for preliminary cancer risk analyses. Estimates of organ dose (mGy) averaged over the cohort are presented here for purposes of summarizing the present (June 2004) findings: 24 mGy to female breast (n=67,736), 6.6 mGy to ovary (n=67,736), 40 mGy to testes (n=20,008), 11 mGy to lung (n=87,742), 62 mGy to thyroid (n=87,744), 3 mGy to bone marrow (n=87,652), 33 mGy to skin on the trunk of the body (n=87,744), and 79 mGy to skin on the head, neck, and arms (n=87,744). Maximum estimated doses where about 60 times the mean value for most organ/tissue sites. The models and predictions presented here, while continuing to be modified and improved, represent one of the most comprehensive dose reconstructions undertaken to date for a large cohort of medical radiation workers.
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