Two-Phase Occupational Screening in Coal-Fired Power Plant Workers: Anamnestic Risk Stratification and Targeted Low-Dose CT Findings

Our plain-English summary of Two-Phase Occupational Screening in Coal-Fired Power Plant Workers: Anamnestic Risk Stratification and Targeted Low-Dose CT Findings, by A. Cranta, E. Osiac, D.I. Gheonea, et al (Diagnostics, 2026).

The study

• Authors: A. Cranta, E. Osiac, D.I. Gheonea, C.T. Streba, C.N. Oancea, I.A. Gheonea, M. Niculici, C. Ciofiac, D. Petrescu, M.S. Șerbănescu
• Journal: Diagnostics
• Published: 2026;16(19)
• Read it: PubMed · Publisher · Free full text

Abstract

Background: Employees at coal-fired power plants experience cumulative occupational exposure to respirable particulates alongside a high prevalence of smoking, both contributing to chronic respiratory disease and elevated lung cancer risk, and organized-screening implementation data remain scarce in this specific industrial setting outside asbestos-exposed cohorts. We evaluated a two-step occupational screening strategy integrating an anamnestic questionnaire with targeted low-dose CT (LDCT) imaging, assessing risk distribution, structured imaging findings, and the discriminative value of questionnaire-based triage relative to its underlying continuous predictors. Methods: In this cross-sectional study, all workers at a coal-fired power plant completed a structured questionnaire (F1) and were classified as high-risk or non-high-risk using a predefined eligibility rule (respiratory symptoms, or age ≥ 50 years with current/former smoking). All workers were invited to voluntary LDCT (F2), interpreted using Lung-RADS v2022 with structured emphysema and coronary artery calcium (CAC) assessment. Associations were assessed using Fisher's exact tests, multivariable logistic regression, and ROC analysis with DeLong's test; voluntary LDCT uptake was characterized with a multivariable propensity model. Results: Among 870 screened workers, 364 (41.8%) were high-risk. LDCT uptake was higher among high-risk workers (130/364, 35.7%) than non-high-risk workers (56/506, 11.1%), yielding 186 examinations. Only 14/186 (7.5%) had Lung-RADS ≥ 3. High-risk status was associated with higher prevalence of any nodule (80.8% vs. 62.5%; OR 2.52) and CAC (46.9% vs. 14.3%; OR 5.30); a composite abnormality outcome was present in 92.3% vs. 69.6% (OR 5.23). Only age (OR 1.11/year) and ever-smoking status (OR 4.38) independently predicted abnormalities on multivariable analysis; dichotomized risk classification showed reduced discrimination for CAC versus a continuous age-smoking model (AUC 0.647 vs. 0.779). Conclusions: Questionnaire-based triage effectively enriched the LDCT-screened population for smoking-related and cardiometabolic risk. Age and smoking history, rather than the full questionnaire, principally drove imaging abnormalities, supporting an integrated occupational model combining lung cancer screening with COPD and cardiovascular risk management.

In plain English

This cross-sectional study screened workers at one coal-fired power plant. It was not a study of asbestos exposure. The 870 workers completing a questionnaire were classed high-risk (364, 41.8%) or non-high-risk. High risk meant respiratory symptoms, or age 50 or over with current or former smoking. All were offered a voluntary low-dose CT chest scan; 186 took it (130 of 364 high-risk, 56 of 506 non-high-risk). Of the 186 scanned, 140 (75.3%) had a lung nodule and 14 (7.5%) were Lung-RADS category 3 or higher. Emphysema was seen in 42 (22.6%), coronary artery calcium in 69 (37.1%), and pleural abnormalities in 10 (5.4%). High-risk workers more often had any nodule (80.8% versus 62.5%) and coronary calcium (46.9% versus 14.3%). Clinically actionable findings did not differ significantly between the groups. Only age and ever-smoking were independently linked to having any nodule, emphysema or coronary calcium, in an analysis the authors called exploratory; ever-smoking was not significantly linked to the actionable findings modelled separately. Workplace exposure was recorded only as a yes/no question. The authors called the findings hypothesis-generating; no follow-up or cancer diagnosis data existed.

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, two-step occupational screening study: a questionnaire for risk classification, then voluntary low-dose CT
• Who was studied: 870 workers at a single coal-fired power plant completed the questionnaire, and 186 of them had a low-dose CT scan. The article text does not name the plant's location or give the screening dates.
• Exposure: Occupational exposure to respiratory hazards was recorded as a single yes/no question, with no detail on job, duration or cumulative dose. 94.5% of respondents (810/857) said yes. Smoking status was also recorded. No asbestos or other fiber exposure was assessed.
• Main results:
  • Of the 870 questionnaire respondents, 364 (41.8%) were classified high-risk and 506 (58.2%) non-high-risk.
  • CT uptake was 130/364 (35.7%) among high-risk workers and 56/506 (11.1%) among non-high-risk workers, for 186 scans in total.
  • Among the 186 scanned workers, 14 (7.5%) were in Lung-RADS category 3 or higher: 10 in category 3 and 4 in category 4A.
  • Among the 186 scanned workers, emphysema was found in 42 (22.6%); 4 (2.2%) had moderate or confluent emphysema.
  • Among the 186 scanned workers, coronary artery calcification was seen in 69 (37.1%); 11 (5.9%) had moderate-to-severe calcification.
  • Free-text radiology reports noted pleural abnormalities in 10 of 186 scanned workers (5.4%) and fibrotic or scar-like changes in 18 (9.7%).
  • Among scanned workers, any nodule was found in 80.8% of high-risk versus 62.5% of non-high-risk workers (OR 2.52, 95% CI 1.26 to 5.05).
  • Among scanned workers, coronary calcium was found in 46.9% of high-risk versus 14.3% of non-high-risk workers (OR 5.30, 95% CI 2.33 to 12.09).
  • Lung-RADS category 3 or higher did not differ significantly between groups: 7.7% of high-risk versus 7.1% of non-high-risk scanned workers (OR 1.08, p = 1.000).
  • When findings were limited to clinically actionable levels (Lung-RADS category 3 or higher, moderate-to-severe coronary calcium, moderate-to-severe emphysema), none differed significantly between risk groups. For moderate-to-severe coronary calcium the OR was 4.58, with p = 0.178.
  • In the multivariable analysis of the composite outcome (any nodule, emphysema or coronary calcium) among the 186 scanned workers, age (OR 1.11 per year, 95% CI 1.03 to 1.20) and ever-smoking (OR 4.38, 95% CI 1.61 to 11.88) were independently associated.
  • In the same composite-outcome analysis, reported occupational exposure was not independently significant (OR 3.46, 95% CI 0.31 to 38.54).
  • In separate exploratory models for actionable findings, no predictor was significant for Lung-RADS category 3 or higher (ever-smoking OR 3.41, p = 0.25).
  • In the separate exploratory model for moderate-to-severe coronary calcium, age was associated (OR 1.16 per year, 95% CI 1.02 to 1.32) but ever-smoking was not (OR 2.89, p = 0.32).
• The authors' conclusion: The authors concluded that questionnaire triage enriched the scanned group for age- and smoking-related findings, but not for clinically actionable ones. In their view, age and smoking history, rather than the full questionnaire, drove the associations, and the findings are best regarded as hypothesis-generating.
• Limitations the authors state:
  • CT uptake was voluntary, so the scanned group was self-selected and not a random sample of the workforce.
  • Occupational exposure was a single yes/no item, so the study cannot establish that the power plant exposure caused the findings.
  • There were no follow-up outcome data, including confirmed cancer diagnoses, beyond the first screening round.
  • The study had a single-round, cross-sectional design.
  • The regression analyses had few events relative to the number of predictors and were considered exploratory.
  • All scans were read by a single radiologist, with no second reader.
  • There were no pack-year smoking data and no spirometry, and non-nodule findings relied on free-text reports.

Topics

Medical terms in this study, explained in our Lexicon: Occupational Exposure, Lung Cancer, Lung-RADS, Emphysema, Low-Dose CT Screening, COPD.

Related studies

• Occupational exposures during routine activities in coal-fueled power plants — M.J. Bird, D.L. MacIntosh, et al. (2004)
• 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)
• Health Effects of Occupational and Environmental Exposures to Nuclear Power Plants: A Meta-Analysis and Meta-Regression — R.T. Lin, H. Boonhat, et al. (2024)
• Occupational exposure to asbestos during renovation of oil-shale fuelled power plants in Estonia — M. Kangur (2007)
• Malignant mesothelioma in thermoelectric power plant workers in Italy — P. Crosignani, F. Forastiere, et al. (1995)
• Asbestos related health hazards among power plant workers — Y. Lerman, A. Finkelstein, et al. (1990)

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