Risk and significance of chest radiograph and pulmonary function abnormalities in an elderly cohort of former nuclear weapons workers

Our plain-English summary of Risk and significance of chest radiograph and pulmonary function abnormalities in an elderly cohort of former nuclear weapons workers, by M.A. Mikulski, P.G. Hartley, N.L. Sprince, et al (Journal of Occupational and Environmental Medicine, 2011).

The study

• Authors: M.A. Mikulski, P.G. Hartley, N.L. Sprince, W.T. Sanderson, S. Lourens, N.E. Worden, K. Wang, L.J. Fuortes
• Journal: Journal of Occupational and Environmental Medicine
• Published: 2011;53(9):1046-53
• Cited by: 4 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Objective: To estimate prevalence and risk factors for International Labour Organization radiographic abnormalities, and assess relationship of these abnormalities with spirometry results in former Department of Energy nuclear weapons workers.

Methods: Participants were offered chest x-ray (CXR) and lung function testing. Three occupational medicine physicians read CXRs.

Results: Forty-five (5.9%) of 757 screened workers were found to have isolated parenchymal abnormalities on CXR and this rate is higher than that in many Department of Energy studies. Parenchymal and pleural and isolated pleural abnormalities were found in 19 (2.5%) and 37 (4.9%) workers, respectively, and these rates are lower than those in other Department of Energy studies to date. Lung function impairment was associated with radiographic abnormalities.

Conclusions: This study found an elevated rate of parenchymal abnormalities compared to other DoE populations but the effect of age or other causes could not be ruled out.

(C)2011The American College of Occupational and Environmental Medicine

In plain English

This study examined X-rays and breathing tests of former workers at a Midwest nuclear weapons assembly plant run under contract to the Atomic Energy Commission (later the Department of Energy), 1949 to mid-1975. Of 1005 screened workers, 757 with X-rays read by all three readers were analysed. Asbestos, beryllium, high explosives and barium exposures were estimated from job titles. No asbestos fiber type is named. Parenchymal (lung-tissue) abnormalities alone were found in 45 workers (5.9%), pleural in 37 (4.9%), both in 19 (2.5%). Before adjustment, the highest asbestos category had higher odds of pleural abnormalities than the lowest-exposure-potential jobs (odds ratio 3.24, 95% CI 1.40 to 7.51). After adjustment for age, sex, race and smoking, no exposure was statistically significantly linked to abnormalities. Age was the strongest predictor. Abnormal breathing tests were associated with X-ray abnormalities, including isolated pleural ones. The 5.9% parenchymal rate was comparable to 5.4% in one other Department of Energy group and higher than 2.2% in another. The authors concluded this rate was elevated but that the effect of age or other causes could not be ruled out.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Cross-sectional analysis of data from a federally funded medical screening (surveillance) program for former Department of Energy workers
• Who was studied: Former workers of a single nuclear weapons assembly facility in the Midwest that worked under contract with the Department of Energy (formerly the Atomic Energy Commission) between 1949 and mid-1975. 1005 of an estimated 3617 eligible living former workers were screened, and 757 whose films were read by all three readers were included in the analysis.
• Exposure: Asbestos (fiber type not specified; the facility had asbestos-fitted steam pipes), beryllium, high explosives and barium. Exposure was ranked qualitatively from category 0 to 3 using a job-title exposure matrix. For asbestos, no jobs were assigned category 0, so category 1 was the lowest. Pipefitters, plumbers and carpenters were in the highest asbestos category.
• Main results:
  • Among the 757 workers: 45 (5.9%) had isolated parenchymal abnormalities, 37 (4.9%) had pleural abnormalities, and 19 (2.5%) had both parenchymal and pleural abnormalities.
  • Isolated parenchymal abnormalities were found in 45 workers (5.9%).
  • Unadjusted analysis: workers ever in the highest asbestos exposure category (category 3) were compared with workers in the lowest-exposure-potential jobs (category 1). Their odds ratios were 0.56 (0.13–2.39) for parenchymal, 2.19 (0.61–7.81) for parenchymal and pleural, and 3.24 (1.40–7.51) for pleural abnormalities.
  • After adjustment for age, sex, race and smoking, no exposure studied was statistically significantly associated with any type of X-ray abnormality.
  • Adjusted odds ratios for asbestos category 3 versus category 1 were 0.38 (0.09–1.65) for parenchymal, 1.20 (0.32–4.51) for parenchymal and pleural, and 2.21 (0.92–5.29) for pleural abnormalities. None was statistically significant.
  • Age was the strongest predictor of all types of X-ray abnormality in every regression analysis.
  • In adjusted models, restrictive breathing test results were associated with parenchymal and pleural abnormalities (OR 4.14, 1.32–13.01) and with isolated pleural abnormalities (OR 2.82, 1.28–6.20).
  • The 5.9% parenchymal rate was comparable with the 5.4% rate in another population of former Department of Energy production workers. It was higher than the 2.2% rate reported in construction and trade workers from three former sites.
• The authors' conclusion: The authors concluded that the rate of parenchymal abnormalities was elevated compared with other Department of Energy populations, but that the effect of age or other causes could not be ruled out. They also reported that isolated pleural abnormalities were associated with abnormal spirometry.
• Limitations the authors state:
  • Age was strongly associated with asbestos and beryllium exposure and with first date of hire, making it difficult to separate the effects of age from cumulative exposure.
  • Participants may have self-selected based on health status or concerns, and may have differed from nonparticipants.
  • Exposure misclassification was possible because exposures occurred decades earlier and no industrial hygiene records were available for quantitative estimates.
  • A detailed smoking history was not available for the whole cohort, and the smoking results likely lacked statistical power.
  • Variability between X-ray readers may have biased prevalence estimates in an unknown direction.
  • The spirometry reference equations were based on people aged 8 to 80, but 13% of participants were older than 80.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Pleural plaques and thickening.

Medical terms in this study, explained in our Lexicon: Chest X-Ray, Spirometry.

Related studies

• Yield of Low-Dose Computerized Tomography Screening for Lung Cancer in High-Risk Workers: The Case of 7189 US Nuclear Weapons Workers — S.B. Markowitz, A. Manowitz, et al. (2018)
• Comparison of x-ray films and low-dose computed tomographic scans: demonstration of asbestos-related changes in 2760 nuclear weapons workers screened for lung cancer — A. Miller, S.A. Widman, et al. (2013)
• Lung function and chest radiograph abnormalities among construction insulators — S.M. Kennedy, S. Vedal, et al. (1991)
• Findings from high resolution computed tomography of the lung and pleura of symptom free workers exposed to amosite who had normal chest radiographs and pulmonary function tests — S. Neri, A. Antonelli, et al. (1994)
• The relation among pulmonary function, chest roentgenographic abnormalities, and smoking status in an asbestos-exposed cohort — L. Rosenstock, S. Barnhart, et al. (1988)
• Chest radiographs in subjects with asbestos-related abnormalities: comparison between ILO categorizations and clinical reading — B. Hilt, A. Borgerson, et al. (1992)

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