The legacy of World Trade Center dust

Our plain-English summary of The legacy of World Trade Center dust, by J.M. Samet, A.S. Geyh, M.J. Utell (The New England Journal of Medicine, 2007).

The study

• Authors: J.M. Samet, A.S. Geyh, M.J. Utell
• Journal: The New England Journal of Medicine
• Published: 2007;356(22):2233-6
• Cited by: 14 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Summary of the article

In this Perspective article, published more than 5 years after the World Trade Center disaster of September 11, 2001, the authors reviewed evidence on the health risks of inhaling dust from the collapse of the twin towers, the fires, and the cleanup. Air was not sampled immediately after the collapse. Settled dust contained combustion-related carcinogens, building materials, and some asbestos. Most Environmental Protection Agency samples had asbestos content below the clearance threshold used for schools. The authors judged that some site workers probably inhaled asbestos fibers. They judged that exposure among nearby residents and workers was probably too low to cause asbestosis or a measurable rise in lung cancer risk, although it might slightly increase mesothelioma risk, which would not become evident for decades. Firefighters developed "World Trade Center cough." Those on site the first morning had three times the bronchial hyperreactivity of later arrivals. In the year after the disaster, firefighters lost about 320 ml in forced expiratory volume in 1 second, compared with an expected 30 ml. Residents within 1.5 km of the site reported more respiratory symptoms than people in a control area. The authors concluded that uncertainty about exposure will not be reduced. They stated that cancer risks will not be apparent for decades. They said prospective studies, including the World Trade Center Health Registry of more than 71,000 registrants, will be needed, though some questions may never be answered.

PubMed has no abstract for this study, and the article doesn't print one. We wrote this summary from the full article with the help of AI. It is not the authors' wording.

In plain English

This article was a short commentary (a "Perspective" piece), not an original study. Writing more than five years after the September 11, 2001 attacks, the authors reviewed published work on the health risks of dust from the World Trade Center collapse for first responders, tower occupants, cleanup workers and nearby residents. They noted that air was not sampled right after the collapse. In their view, some workers at the site probably inhaled asbestos fibers, especially without protective equipment. Exposure among people living and working nearby was probably lower and unlikely to cause asbestosis or a measurable rise in lung cancer risk, though it might slightly increase mesothelioma risk that would not show for decades. Citing earlier firefighter studies, they described lung-function losses and persistent breathing problems among early responders. The authors concluded that decades of registry follow-up and monitoring of responders will be needed. They cautioned that even a registry of more than 71,000 people may not detect uncommon effects unless the added risks are very high.

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: Commentary (Perspective article) reviewing published research; not an original study
• Who was studied: No study population of its own. The commentary discussed people exposed to World Trade Center dust in New York after September 11, 2001: first responders such as firefighters, occupants of the towers, cleanup workers, and neighborhood residents.
• Exposure: Inhaled dust from the collapse of the twin towers, the fires and the cleanup. The authors described settled dust as containing combustion-related carcinogens, building materials and some asbestos (no fiber type named). They also discussed particles, PAHs, dioxins and other combustion products.
• Main results:
  • The authors described Environmental Protection Agency sampling of airborne and settled dust: the majority of samples had an asbestos content below the clearance threshold used for schools.
  • The authors judged that some workers at the site probably inhaled asbestos fibers, particularly if they were not wearing protective equipment.
  • The authors judged that asbestos exposure among people living and working around the site was probably lower. In their view it was unlikely to cause asbestosis or a measurable increase in lung cancer risk. It might slightly increase mesothelioma risk, but any excess would not become evident for decades.
  • Citing an earlier follow-up study of firefighters (not this article's own data), the authors reported a drop in FEV1 (forced expiratory volume in 1 second) of approximately 320 ml in the year after the disaster. The normally anticipated drop is 30 ml.
  • The authors concluded that some responders who were at the site in the first hours and days have persistent respiratory abnormalities consistent with airway injury from inhaled particles and gases.
  • According to the authors, any increased risk of respiratory tract cancer and most other cancers among responders will not become apparent for decades.
• The authors' conclusion: The authors concluded that decades of commitment to the World Trade Center Health Registry, along with continued monitoring of responders, will be needed to learn the longer-term consequences of inhaling the dust. They added that some questions may never be answered.
• Limitations the authors state:
  • Air was not sampled immediately after the collapse, so the identity and concentrations of contaminants at that time are unknown.
  • Settled dust samples were dominated by larger particles. The smaller particles that reach the deep lung were probably not captured.
  • The size of the exposed population is not known with any certainty.
  • Although the registry has more than 71,000 registrants, it will not reveal relatively infrequent consequences unless the additional risks are very high.

Topics

Medical terms in this study, explained in our Lexicon: Settled Dust, Lung Cancer, Mesothelioma.

Related studies

• Health consequences of the September 11 World Trade Center attacks: a review — J. Moline, R. Herbert, et al. (2006)
• 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)
• 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)
• Occupational exposures during the World Trade Center disaster response — K.M. Wallingford, E.M. Snyder (2001)
• Potential carcinogenic effects of world trade center dust after intratracheal instillation to Sprague-Dawley rats: first observation — M. Soffritti, L. Falcioni, et al. (2013)
• Health and environmental consequences of the world trade center disaster — P.J. Landrigan, P.J. Lioy, et al. (2004)

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