Adjusting external doses from the ORNL and Y-12 facilities for the Oak Ridge Nuclear Facilities mortality study

Watkins, Janice P.; Cragle, Donna L.; West, Charles; Tankersley, William G.; Frome, E. L.; Crawford-Brown, Doug

doi:10.2172/87336

Cited by 3 publications

(4 citation statements)

References 6 publications

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“…(22) Additional details on obtaining this equation are avail- Tables 3 and 4 show numbers of adjusted and estimated doses for X-10 and Y-12, respectively, and methods by which they were obtained. Because 97 percent of X-10 doses after 1956 and Y-12 doses after 1960 for the X-lO/Y-12 even were identical in the unadjusted and adjusted analysis files, the impact of dose adjustment on cumulative external doses can be appraised by examining plots from earlier years.…”

Section: Annual External Dose By Facilitymentioning

confidence: 99%

Collection, Validation, and Treatment of Data for a Mortality Study of Nuclear Industry Workers

Watkins

Cragle

Frome

et al. 1997

Applied Occupational and Environmental Hygiene

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Section: Annual External Dose By Facilitymentioning

confidence: 99%

Collection, Validation, and Treatment of Data for a Mortality Study of Nuclear Industry Workers

Watkins

Cragle

Frome

et al. 1997

Applied Occupational and Environmental Hygiene

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“…Each person-year is on a single hard copy record. A sample of 211 person-years was computerized [27] (see http://www.orau.gov/ehsd/cerdoc1.htm). This includes 90 person-year records randomly sampled from all records and 121 person-year records from a stratified sample of higher exposures.…”

Section: Results and Conclusion Regarding The Ornl 194to 195cohortmentioning

confidence: 99%

“…The data set used in [27,20] consists of weekly information from the 211 person-years. In this report, we use a more detailed data set from the same 211 person-years that includes daily information.…”

Section: Results and Conclusion Regarding The Ornl 194to 195cohortmentioning

confidence: 99%

“…The sample of 211 person-years that were computerized from hard copy records (see Section 5) is described in more detail in [27]. During data entry, an estimate was obtained of the time required to enter one complete person-year: 52 weekly film-badge entries required 31 minutes, and 715 daily pocket-meter readings required 85 minutes.…”

Section: Feasibility and Benefits Of Computerizing Hard-copy Ornl Datamentioning

confidence: 99%

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Dose Estimation from Daily and Weekly Dosimetry Data

Ostrouchov¹

2001

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Statistical analyses of data from epidemiologic studies of workers exposed to radiation have been based on recorded annual radiation doses (yearly dose of record). It is usually assumed that the dose values are known exactly, although it is generally recognized that the data contain uncertainty due to measurement error and bias. In our previous work with weekly data, a probability distribution was used to describe an individual's dose during a specific period of time and statistical methods were developed for estimating it from weekly film dosimetry data. This study showed that the yearly dose of record systematically underestimates doses for Oak Ridge National Laboratory (ORNL) workers. This could result in biased estimates of doseresponse coefficients and their standard errors. The results of this evaluation raise serious questions about the suitability of the yearly dose of record for direct use in low-dose studies of nuclear industry workers. Here, we extend our previous work to use full information in Pocket meter data and develop the Data Synthesis for Individual Dose Estimation (DSIDE) methodology. Although the DSIDE methodology in this study is developed in the context of daily and weekly data to produce a cumulative yearly dose estimate, in principle it is completely general and can be extended to other time period and measurement combinations. The new methodology takes into account the "measurement error" that is produced by the film and pocketmeter dosimetry systems, the biases introduced by policies that lead to recording left-censored doses as zeros, and other measurement and recording practices. The DSIDE method is applied to a sample of dose histories obtained from hard copy dosimetry records at ORNL for the years 1945 to 1955. First, the rigorous addition of daily pocket-meter information shows that the negative bias is generally more severe than was reported in our work based on weekly film data only, however, the amount of bias also varies greatly between person-years. Second, the addition of pocket-meter information reduces uncertainty for some person-years, while increasing it for others. Together, these results suggest that detailed pocket-meter and film dosimetry information is required to obtain unbiased and reliable dosimetry data for use in epidemiologic studies of workers at ORNL.

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A Mortality Study of Employees of the Nuclear Industry in Oak Ridge, Tennessee

Frome¹,

Cragle²,

Watkins³

et al. 1997

Radiation Research

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An analysis was conducted of 27,982 deaths among 106,020 persons employed at four Federal nuclear plants in Oak Ridge, Tennessee, between 1943 and 1985. The main objectives were to extend the evaluation of the health effects of employment in the nuclear industry in Oak Ridge to include most workers who were omitted from earlier studies, to compare the mortality experience of workers among the facilities, to address methodological problems that occur when individuals employed at more than one facility are included in the analysis, and to conduct dose-response analyses for those individuals with potential exposure to external radiation. All-cause mortality and all-cancer mortality were in close agreement with national rates. The only notable excesses occurred for white males for lung cancer [standardized mortality ratio (SMR) = 1.18, 1,849 deaths] and non-malignant respiratory disease (SMR = 1.12, 1,568 deaths). A more detailed analysis revealed substantial differences in death rates among workers at the Oak Ridge plants. Evaluation of internally adjusted log SMRs using Poisson regression showed that workers employed only at Tennessee Eastman Corporation or K-25 and at multiple facilities had higher death rates than similar workers employed only at X-10 or Y-12, and that the differences were primarily due to non-cancer causes. Analysis of selected cancer causes for white males indicated large differences among the workers at the different facilities for lung cancer, leukemia and other lymphatic cancer. Dose-response analyses for external penetrating radiation were limited to a subcohort of 28,347 white males employed at X-10 or Y-12. Their collective recorded dose equivalent was 376 Sv. There was a strong "healthy worker effect" in this subcohort-all-cause SMR = 0.80 (4,786 deaths) and all-cancer SMR = 0.87 (1,134 deaths). Variables included in the analyses were age, birth cohort, a measure of socioeconomic status, length of employment, internal radiation exposure potential and facility. For external radiation dose with a 10-year lag, the excess relative risk was 0.31 per Sv (95% CI = -0.16, 1.01) for all causes and 1.45 per Sv (95% CI = 0.15, 3.48) for all cancer. The estimated excess relative risk for leukemia was negative but imprecisely determined. A preliminary dose adjustment procedure was developed to compensate for missing dose but not other dosimetry errors. Results of the analyses using the adjusted doses suggest that the effect of missing dose is an upward bias in dose-response coefficients and test statistics.

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Adjusting external doses from the ORNL and Y-12 facilities for the Oak Ridge Nuclear Facilities mortality study

Cited by 3 publications

References 6 publications

Collection, Validation, and Treatment of Data for a Mortality Study of Nuclear Industry Workers

Collection, Validation, and Treatment of Data for a Mortality Study of Nuclear Industry Workers

Dose Estimation from Daily and Weekly Dosimetry Data

A Mortality Study of Employees of the Nuclear Industry in Oak Ridge, Tennessee

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