Assessment of plutonium exposures for an epidemiological study of US nuclear workers.
An ongoing case-control study evaluating the association between workplace external radiation exposures and leukaemia mortality required an assessment of internal plutonium exposures as a potential confounder. Of the study participants, 1,092 were employed at four Department of Energy sites where plutonium-bearing materials were processed or stored. Exposures were assessed by first categorising exposure potentials based on available bioassay data, then estimating doses for workers in the highest categories using recent recommendations of the International Commission on Radiological Protection. Given the aetiology of leukaemia, equivalent dose to active bone marrow was chosen as the exposure variable. There were 556 workers each with at least one plutonium bioassay result, assigned to one of three evaluation categories. Dose estimates were made for 115 workers resulting in a collective equivalent dose of 2.1 person-Sv for 2,822 exposure-years, compared with 29.8 person-Sv estimated from photon exposures. Modelling uncertainties were examined by comparison of results from independent analyses and by Monte Carlo simulation.
Daniels
R D
RD
Division of Surveillance, Hazard Evaluations, and Field Studies, National Institute for Occupational Safety and Health, 5555 Ridge Avenue, R-44 Cincinnati, OH 45213, USA. RTD2@CDC.gov
Lodwick
C J
CJ
Schubauer-Berigan
M K
MK
Spitz
H B
HB
D016022:Case-Control Studies; D015986:Confounding Factors, Epidemiologic; D016021:Epidemiologic Studies; D006801:Humans; D007953:Leukemia, Radiation-Induced / Q000401:mortality*; D009010:Monte Carlo Method; D009688:Nuclear Reactors; D016273:Occupational Exposure; D011005:Plutonium / Q000009:adverse effects*; D011834:Radiation Monitoring / Q000379:methods*; D011835:Radiation Protection; D018570:Risk Assessment; D014481:United States / Q000453:epidemiology
D011005:Plutonium