Chest CT scan findings in World Trade Center workers

Our plain-English summary of Chest CT scan findings in World Trade Center workers, by R.E. de la Hoz, J. Weber, D. Xu, et al (Archives of Environmental & Occupational Health, 2019).

The study

• Authors: R.E. de la Hoz, J. Weber, D. Xu, J.T. Doucette, X. Liu, D.A. Carson, J.C. Celedón
• Journal: Archives of Environmental & Occupational Health
• Published: 2019;74(5):263-270
• Cited by: 17 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

We examined the chest CT scans of 1,453 WTC responders using the International Classification of High-resolution CT for Occupational and Environmental Respiratory Diseases. Univariate and bivariate analyses of potential work-related pleural abnormalities were performed with pre-WTC and WTC-related occupational exposure data, spirometry, demographics and quantitative CT measurements. Logistic regression was used to evaluate occupational predictors of those abnormalities. Chest CT scans were performed first at a median of 6.8 years after 9/11/2001. Pleural abnormalities were the most frequent (21.1%) across all occupational groups In multivariable analyses, significant pre-WTC occupational asbestos exposure, and work as laborer/cleaner were predictive of pleural abnormalities, with prevalence being highest for the Polish subgroup (n = 237) of our population. Continued occupational lung disease surveillance is warranted in this cohort.

In plain English

This study looked at the first available chest CT scans of 1,453 workers from the rescue, recovery, cleanup and service restoration at the World Trade Center site after September 11, 2001. Firefighters were not included. The scans were taken at Mount Sinai in New York a median of 6.8 years after the attack. Radiologists who did not know the workers' identities re-read them using a standard international classification. Pleural abnormalities (changes in the lining around the lungs) were the most common finding, seen in 307 workers (21.1%). In an adjusted analysis, workers who reported asbestos exposure at least a few times a week in their jobs before 9/11 had 1.42 times the odds of pleural abnormalities compared with workers who did not (95% confidence interval 1.06 to 1.89). Laborers and cleaners, a group that included asbestos handlers, also had higher odds. Time worked at the WTC site and early arrival were not significantly associated. Among 237 first-generation Polish immigrant laborers, 77 had pleural abnormalities. No worker in the series had been diagnosed with asbestosis. The authors noted that their asbestos exposure measures were crude, and they called for continued surveillance of exposed workers.

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 each worker's first available chest CT scan. The scans were re-read by radiologists blinded to worker identity, using the ICOERD classification. Logistic regression was used to look for occupational predictors of pleural abnormalities.
• Who was studied: 1,453 WTC rescue, recovery, cleanup and service restoration workers (excluding firefighters). They were drawn from a sub-cohort of 1,641 evaluated by the WTC Pulmonary Evaluation Unit at Mount Sinai, New York, from 2003 to 2012. They were mostly male, with a median age of 42 on 9/11/2001.
• Exposure: The main exposure was self-reported occupational asbestos exposure before 9/11, counted when it happened from 'a few times per week' to 'daily'. 355 workers (24.4%) reported it. The authors also studied pre-WTC occupational group and WTC exposure (arrival within 48 hours; more than 60 days at the site).
• Main results:
  • In all 1,453 workers, pleural abnormalities were the most frequent CT finding: 307 (21.1%). Visceral pleural abnormalities were found in 13.8% and parietal in 9.5%.
  • Workers with significant pre-WTC occupational asbestos exposure had increased odds of pleural abnormalities compared with those without such exposure in the adjusted Model 1: OR 1.42, 95% CI 1.06 to 1.89 (Table 4).
  • Laborers/building cleaners had increased odds of pleural abnormalities compared with management/services workers in the adjusted Model 2. The text gives 1.65-fold; Table 4 lists OR 1.61, 95% CI 1.10 to 2.39.
  • Neither WTC exposure duration nor early arrival at the WTC site was significantly associated with pleural abnormalities.
  • In the adjusted models, older age was associated with pleural abnormalities. Per 10-year increase in age on 9/11/2001, the odds rose by about 18% in Model 1 and 16% in Model 2.
  • Among the 237 first-generation Polish immigrant laborers/asbestos handlers/building cleaners, 77 had pleural abnormalities. They made up 25.1% (77/307) of all workers with that finding.
  • 70% of the Polish laborers reported significant pre-WTC asbestos exposure. They accounted for 166 of the 355 workers reporting such exposure.
  • In an exploratory analysis, a non-Latino White/Polish category was added to both models. It was then the only significant predictor of pleural abnormalities. The data were not shown.
  • No worker in the series had been diagnosed with asbestosis.
• The authors' conclusion: The authors concluded that their findings underscore the need for continued prevention of asbestos-related diseases and for surveillance of exposed workers in all categories, with particular attention to the most intensely exposed.
• Limitations the authors state:
  • Asbestos exposures were not ascertained in detail, and the available exposure indicators were relatively crude.
  • Disagreement between CT readers is almost as common as with chest X-rays.
  • Pleural findings must be interpreted with caution, especially in people with no clear exposure history or with only visceral pleural abnormalities.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Construction.

Medical terms in this study, explained in our Lexicon: CT Scan, High-Resolution CT (HRCT), Occupational Exposure, Spirometry, Asbestos Exposure, Occupational Lung Disease.

Related studies

• Case report: Lung disease in World Trade Center responders exposed to dust and smoke: carbon nanotubes found in the lungs of World Trade Center patients and dust samples — M. Wu, R.E. Gordon, et al. (2010)
• Assessing truck driver exposure at the World Trade Center disaster site: personal and area monitoring for particulate matter and volatile organic compounds during October 2001 and April 2002 — A.S. Geyh, S. Chillrud, et al. (2005)
• The legacy of World Trade Center dust — J.M. Samet, A.S. Geyh, et al. (2007)
• Development of an exposure assessment method for epidemiological studies of New York State personnel who responded to the World Trade Center disaster — M.L. Herdt-Losavio, M.P. Mauer, et al. (2008)
• Summary of the development of a signature for detection of residual dust from collapse of the World Trade Center buildings — H.A. Lowers, G.P. Meeker, et al. (2009)
• Evaluation of vacuum and wet-wipe methods for removal of World Trade Center dust from indoor environments — K.M. Tang, C.G. Nace, et al. (2004)

Browse more research in Archives of Environmental & Occupational Health, or return to medical research.