Health and environmental consequences of the world trade center disaster

Our plain-English summary of Health and environmental consequences of the world trade center disaster, by P.J. Landrigan, P.J. Lioy, G. Thurston, et al (Environmental Health Perspectives, 2004).

The study

• Authors: P.J. Landrigan, P.J. Lioy, G. Thurston, G. Berkowitz, L.C. Chen, S.N. Chillrud, S.H. Gavett, P.G. Georgopoulos, A.S. Geyh, S. Levin, F. Perera, S.M. Rappaport, C. Small, NIEHS World Trade Center Working Group
• Journal: Environmental Health Perspectives
• Published: 2004;112(6):731-9
• Type of article: Review
• Cited by: 279 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

The attack on the World Trade Center (WTC) created an acute environmental disaster of enormous magnitude. This study characterizes the environmental exposures resulting from destruction of the WTC and assesses their effects on health. Methods include ambient air sampling; analyses of outdoor and indoor settled dust; high-altitude imaging and modeling of the atmospheric plume; inhalation studies of WTC dust in mice; and clinical examinations, community surveys, and prospective epidemiologic studies of exposed populations. WTC dust was found to consist predominantly (95%) of coarse particles and contained pulverized cement, glass fibers, asbestos, lead, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and polychlorinated furans and dioxins. Airborne particulate levels were highest immediately after the attack and declined thereafter. Particulate levels decreased sharply with distance from the WTC. Dust pH was highly alkaline (pH 9.0-11.0). Mice exposed to WTC dust showed only moderate pulmonary inflammation but marked bronchial hyperreactivity. Evaluation of 10,116 firefighters showed exposure-related increases in cough and bronchial hyperreactivity. Evaluation of 183 cleanup workers showed new-onset cough (33%), wheeze (18%), and phlegm production (24%). Increased frequency of new-onset cough, wheeze, and shortness of breath were also observed in community residents. Follow-up of 182 pregnant women who were either inside or near the WTC on 11 September showed a 2-fold increase in small-for-gestational-age (SGA) infants. In summary, environmental exposures after the WTC disaster were associated with significant adverse effects on health. The high alkalinity of WTC dust produced bronchial hyperreactivity, persistent cough, and increased risk of asthma. Plausible causes of the observed increase in SGA infants include maternal exposures to PAH and particulates. Future risk of mesothelioma may be increased, particularly among workers and volunteers exposed occupationally to asbestos. Continuing follow-up of all exposed populations is required to document the long-term consequences of the disaster.

In plain English

This workgroup report from six research centers summarized research on chemical exposures from the World Trade Center (WTC) destruction on 11 September 2001 and their health effects. Many of the findings came from separately published studies. Settled dust samples were highly alkaline (pH 9.0 to 11.0) and contained 0.8% to 3.0% asbestos by mass. Asbestos, primarily chrysotile, had been used as North Tower fire insulation. Of more than 10,000 U.S. EPA air samples tested, more than 8,000 also by electron microscopy, 22 exceeded an asbestos clearance standard based on that method. No 8-hour average worker exposures exceeded the OSHA asbestos standard, though the authors noted short-term peak exposures. Among firefighters, persistent "WTC cough" rose with exposure level, from 1% to 8%. Among 183 rubble removal workers, 32.8% reported new cough. Mice given a high dose of WTC fine dust showed airway hyperresponsiveness. Women in or near the WTC had more small-for-gestational-age infants than a comparison group (8.2% vs 3.8%). The authors concluded that future mesothelioma risk appeared greatest among first responders, Ground Zero workers, and workers cleaning asbestos-laden dust.

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: Research workgroup report summarizing environmental sampling, plume imaging and modeling, a mouse study, and clinical and epidemiologic studies by a consortium of research centers, many published separately
• Who was studied: Lower Manhattan environment after 11 September 2001; New York City firefighters (10,116 evaluated); 183 rubble removal workers; 2,166 residents within 1.6 km of the WTC and 200 living 1.6 to 8.0 km away; mice; pregnant women in two cohorts (Mount Sinai, 187 recruited; Columbia, 329)
• Exposure: WTC dust and smoke: pulverized cement, glass fibers, asbestos (primarily chrysotile, used as fire insulation in the North Tower up to the 40th floor), lead, PAHs, PCBs, dioxins and other combustion products
• Main results:
  • Settled dust samples (from Lioy et al. 2002) contained asbestos at 0.8% to 3.0% of mass and had a pH of 9.0 to 11.0
  • More than 10,000 ambient air samples from lower Manhattan were tested for asbestos by the U.S. EPA using phase-contrast microscopy, and more than 8,000 of these were also examined by transmission electron microscopy
  • Twenty-two of the U.S. EPA air samples were found to contain asbestos above the clearance standard; most elevated levels were in the earliest days after 11 September
  • The clearance standard was 70 fibers/mm2 under the Asbestos Hazard Emergency Response Act and uses the transmission electron microscopy technique
  • No 8-hour time-weighted average worker asbestos exposures exceeded the OSHA standard of 0.1 fiber/cm3
  • In air monitoring of cleanup and recovery workers, airborne asbestos concentrations were generally low and fibers were mostly very short
  • Among firefighters (Prezant et al. 2002), WTC cough occurred in 128 (8%) of 1,636 with high exposure, 187 (3%) of 6,958 with moderate exposure, and 17 (1%) of 1,320 with low-level exposure
  • Among 183 rubble removal workers, 32.8% reported cough that began after starting work at the WTC site
  • Among the same 183 workers, 24.0% reported new phlegm production and 17.5% new wheeze; mean predicted FEV1 was 96.3% and FVC 98.8%
  • In the community survey, preliminary data showed that previously healthy residents near Ground Zero (2,166 enrolled, compared with 200 more distant residents) had a greater increase in symptoms, mainly cough, wheeze and shortness of breath; symptoms were not associated with abnormal screening spirometry (52 residents tested)
  • In mice (Gavett et al. 2003), a 100 µg dose of WTC fine dust caused mild to moderate lung inflammation and striking airway hyperresponsiveness that did not diminish significantly 1 to 3 days after exposure; lower doses caused neither
  • In the Mount Sinai cohort (Berkowitz et al. 2003), small-for-gestational-age infants occurred in 8.2% of the WTC group (187) vs 3.8% of controls (2,367), p less than 0.01; preterm birth and low birth weight did not differ significantly
  • In the Columbia study, birth weight did not differ, but gestation was significantly shorter in the exposed group (274.3 vs 275.9 days)
• The authors' conclusion: The authors stated that the greatest future risk of mesothelioma would appear to exist among first responders caught in the dust cloud, other workers at Ground Zero, and workers cleaning asbestos-laden dust from buildings
• Limitations the authors state:
  • Air sampling sites were not directly in the plume's path, so actual particulate levels may have been higher
  • Workers had short-term peak asbestos exposures not reflected in 8-hour averages
  • Community resident findings were preliminary
  • Whether the airway hyperresponsiveness seen in mice persists was not yet known

Topics

Medical terms in this study, explained in our Lexicon: Environmental Exposure, Air Sampling, Settled Dust, Inflammation, Mesothelioma.

Related studies

• Characterization of the dust/smoke aerosol that settled east of the World Trade Center (WTC) in lower Manhattan after the collapse of the WTC 11 September 2001 — P.J. Lioy, C.P. Weisel, et al. (2002)
• Occupational exposures during the World Trade Center disaster response — K.M. Wallingford, E.M. Snyder (2001)
• Mind and matter: OEM and the World Trade Center — H.M. Kipen, M. Gochfeld (2002)
• Health consequences of the September 11 World Trade Center attacks: a review — J. Moline, R. Herbert, et al. (2006)
• The legacy of World Trade Center dust — J.M. Samet, A.S. Geyh, et al. (2007)
• Health effects of World Trade Center (WTC) Dust: An unprecedented disaster's inadequate risk management — M. Lippmann, M.D. Cohen, et al. (2015)

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