An Overview of the Environmental Conditions and Human Exposures

Chapter 2

An Overview of the Environmental Conditions and Human Exposures That Occurred Post September 11,2001 1,2

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Paul J. Lioy , Panos G. Georgopoulos , and Clifford P. Weisel Downloaded by YORK UNIV on June 3, 2018 | https://pubs.acs.org Publication Date: November 15, 2005 | doi: 10.1021/bk-2006-0919.ch002

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Department of Environmental and Occupational Medicine and Environmental and Occupational Health Sciences Institute, Robert Wood Johnson Medical School (RWJMS) at UMDNJ and Rutgers, The State University of New Jersey, Piscataway, NJ 08854

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The events of 9-11-01 left a series of environmental and occupational health issues to be evaluated for short term and long term health effects. A time line for the post 9-11-01 events is provided based upon the types and intensity of the emissions of dust and smoke particles and gases that were released on that fateful day and/or through the last days of the fires on 12-20-01. Summaries are presented on the nature of the plume, the major components of the plume, and the types of exposures that may have occurred outdoors and indoors that will also be essential components of future risk assessments. This overview includes information from a number of published and unpublished studies and analyses. It must be remembered, however, that the situation was a response to a terrorist attack and the subsequent disaster. Thus, the acquisition of samples and the types of analyses conducted by various organizations on those samples must be evaluated within the context of that chaotic enviornment.

© 2006 American Chemical Society

Gaffney and Marley; Urban Aerosols and Their Impacts ACS Symposium Series; American Chemical Society: Washington, DC, 2005.

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Downloaded by YORK UNIV on June 3, 2018 | https://pubs.acs.org Publication Date: November 15, 2005 | doi: 10.1021/bk-2006-0919.ch002

Introduction The attack on the World Trade Center (WTC) was an unprecedented act of war on American soil. The terrorists, by virtue of colliding two commercial jets into the two massive buildings ignitedfiresthat eventually led to the collapse of both buildings producing a complex environmental disaster (7, 2). Because these towers collapsed at vertical speeds up to 120 miles per hour, a largefractionof millions of tons of material that composed each of the WTC towers were reduced to pulverized dust and smoke, and the debris were dispersed radially from the WTC site throughout southern Manhattan (Figure 1) (2). The collapse of the towers also produced an intense plume that moved southeast above Brooklyn during the rest of the day. The only fortunate part about this horrendous act of war was that the terrorists released no biological, chemical, or radiological agents during the attack. The materials that were once part of the WTC disintegrated into a large mass of particles that were primarily >10 pm in diameter and had a large variety of shapes, and fibers also >10 }xm diameter or length, which contained construction debris, cement, chrysotile, cotton fibers (lint), tarry products, charred wood, soot and glassfibers(3). The particles had a very alkaline pH and produced irritation of the upper respiratory system (3, 4). In some cases the inhalation of dust and smoke yielded a variety of symptoms and health outcomes (e.g. the exacerbation of asthmatic conditions among workers and some residents) (5-14). Most of the immediate effects were limited to individuals who spent many hours at Ground Zero during the first few days post 9-11 or re-entered a building before it was professionally cleaned for dust contamination. The general population of southern Manhattan and individuals who had commuted to New York City on that day did not show the same frequency of acute effects, as the rescue workers andfirefighters(5).

Nature of the Post 9-11 Problems It is clear that individuals who were in southern Manhattan during the event were acutely exposed to at least lifetime doses of inhalable and respirable particles (3,5). Photographs show individuals completely covered by the dust (Figure 2). These particles were primarily >10 jam in diameter (Figure 3), a size range not normally or traditionally measured by the U.S. Environmental Protection Agency (EPA). Further, the particles were composed of glass fibers, cement dust (high pH), other construction materials, and silica, (3,4) materials not typically present in ambient air. A summary of the major individual and classes of materials found in the initial dust and smoke is shown in Table I (3).



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Figure 1. Collapse of the WTC showing the dust cloud moving away from Ground Zero(15).

Figure 2. The suspended inhalable dust after the collapse of the WTC and exposed individuals (16).



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Figure 3. Micrograph of the WTC Dust (Analyses by J. Millette, MVA, Ga.; for P. J. Lioy).

However, it was, and still is, impossible to compare the exposures to these suspended and resuspendable materials with current environmental health based standards since impossible to compare the exposures to these suspended and resuspendable materials with current environmental health based standards since there are no standards for atmospheric mass loadings of particles >10 ]im in diameter and/or the types of materials that composed this very complex mixture. The basic reason is that all current National Ambient Air Quality Standards (NAAQS) for particles are focused on long term health effects caused by exposure to atmospheric particles 0.1 100's 100's 10's

An Overview of the Environmental Conditions and Human Exposures

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