3 tables omitted
In the months after the September 11, 2001, attacks on the World Trade
Center (WTC), concerns grew about the health consequences of exposures sustained
by persons involved in the rescue and recovery response. In addition to the
estimated 10,000 Fire Department of New York (FDNY) personnel, an estimated
30,000 other workers and volunteers potentially were exposed to numerous psychological
stressors, environmental toxins, and other physical hazards. These concerns
prompted CDC’s National Institute for Occupational Safety and Health
(NIOSH) to support the WTC Worker and Volunteer Medical Screening Program,
which provided free, standardized medical assessments, clinical referrals,
and occupational health education for workers and volunteers exposed to hazards
during the WTC rescue and recovery effort. During July 16, 2002–August
6, 2004, the program evaluated 11,768 non-FDNY workers and volunteers. This
report summarizes data analyzed from a subset of 1,138 of the 11,768 participants
evaluated at Mount Sinai School of Medicine during July 16–December
31, 2002. These data indicated that a substantial proportion of participants
experienced new-onset or worsened preexisting lower and upper respiratory
symptoms, with frequent persistence of symptoms for months after their WTC
response work stopped. These findings underscore the need for comprehensive
health assessment and treatment for workers and volunteers participating in
rescue and recovery efforts.
The clinical program included a single screening evaluation consisting
of medical- and exposure-assessment questionnaires, physical examination,
pre- and post-bronchodilator (BD) spirometry, complete blood count, blood
chemistries, urinalysis, chest radiograph, and mental health screening questionnaires.
Participants were recruited through outreach that included community and union
meetings, mailings, and articles in the media. Eligibility for the screening
program was based on arrival date and duration of exposure to the site* rather
than on symptomatology. Institutional review board approval and informed consent
were obtained for data aggregation and analyses.
The subset of 1,138 program participants was predominantly male (91%)
and non-Hispanic white (58%), with a median age of 41 years (range: 21-74
years). Non-Hispanic blacks and Hispanics accounted for 11% and 15% of the
population, respectively. The largest occupational sectors represented in
this sample were technical and utilities (25%), law enforcement (21%), and
construction (18%). Numerous other occupational groups accounted for the remaining
36%; 89% were union members.
Of the 1,138 participants, 525 (46%) worked on WTC rescue and recovery
efforts on September 11, 2001, and 963 (84%) worked or volunteered during
September 11-14, when exposures were greatest. During that period, a total
of 239 (21%) participants reported using appropriate respiratory protection
(i.e., full- or half-face respirators).1 The
median length of time worked on the WTC effort was 966 hours (range 24-4,080
hours). Of the 610 examinees present in lower Manhattan on September 11, a
total of 313 (51%) reported being directly in the cloud of dust created by
the collapse of the WTC buildings, and an additional 191 (31%) reported exposure
to substantial amounts of dust.
A participant was considered to have a WTC-related symptom if the symptom
either first developed (incident) or worsened (exacerbated) while working
or volunteering on the WTC effort. WTC-related lower respiratory symptoms
were reported by 682 (60%) of the sample, and 836 (74%) reported WTC-related
upper respiratory symptoms. A total of 450 (40%) examinees had WTC-incident
lower respiratory symptoms that persisted to the month before screening, and
565 (50%) reported WTC-incident and persistent upper respiratory symptoms.
Among the 851 participants who reported persistent WTC-related symptoms, an
average of 32 weeks (range: 7-63 weeks) had elapsed since either they stopped
working at the site or since the end of May 2002, when site cleanup was officially
completed.† On examination, 527 (46%) had nasal mucosal inflammation.
Other respiratory abnormalities (e.g., abnormal nasal turbinates or sinuses,
rhonchi, and wheezing) were less common.
All participants underwent spirometry before and after an inhaled BD
using standard techniques.2 A total of 360
(33%) participants had abnormal spirometry findings, primarily because of
results suggesting restriction; 84 (23%) had a significant‡ post-BD
response. A total of 22 (27%) of those with airway obstruction had a significant
BD response consistent with asthma.
Compared with a general population sample of employed, adult, white
males (National Health and Nutrition Examination Surveys [NHANES III]),3 the 599 participants who had never smoked had a higher
prevalence of abnormalities on spirometry (31% versus 13%), which was attributable
to a higher prevalence of restriction (21% versus 4%).
Participants experienced numerous other symptoms, including a substantial
proportion with incident and persistent musculoskeletal symptoms, such as
low back pain (16%) and upper or lower extremity pain (16% and 13%, respectively).
Other incident and persistent symptoms included heartburn (15%), eye irritation
(14%), and frequent headache (13%). Overall, 364 (23%) of the sample reported
previously receiving medical care for WTC-related respiratory conditions.
A total of 214 (19%) of examinees reported missing work because of WTC-related
health problems (median: 10 days; range: 1-364 days).
SM Levin, MD, R Herbert, MD, JM Moline, MD, AC Todd, PhD, L Stevenson,
MPH, P Landsbergis, PhD, S Jiang, MS, G Skloot, MD, Mount Sinai School of
Medicine, New York, New York. S Baron, MD, P Enright, MD, Div of Surveillance,
Hazard Evaluations, and Field Studies, National Institute for Occupational
Safety and Health, CDC.
The findings in this report indicate that a substantial proportion of
program participants had new-onset and persistent upper and lower airway symptoms,
musculoskeletal symptoms, and gastrointestinal symptoms. In addition, a substantial
proportion of participants had respiratory abnormalities on spirometry. This
preliminary analysis is consistent with earlier reports from WTC screening
programs conducted by FDNY,4,5 which
documented a substantial proportion of respiratory symptoms in emergency response
workers. These findings suggest a need for continued monitoring and appropriate
treatment of WTC responders.
NIOSH recently funded a program that will provide continued medical
screening of responders for an additional 5 years. Through philanthropic sources,
a WTC Health Effects Treatment Program was established to provide further
clinical evaluation and treatment to responders at no cost. Thus far, this
program has provided approximately 3,587 services to 844 responders, 40% of
whom lacked health insurance.
A substantial proportion of workers evaluated in this program had low
forced vital capacity (FVC). Restrictive lung diseases (low FVC) typically
develop during a long period and are not the consequence of airway irritant
exposures such as those experienced by WTC workers. Reduction in FVC might
be attributable to air trapping rather than true restriction (i.e., pseudo-restriction),
a hypothesis supported by the increase of FVC into the normal range after
inhaled BD in 29% of the workers with low FVC. Further analyses that include
lung volume measurement might clarify the implications of these findings.
The destruction of the WTC towers resulted in the release of high levels
of airborne contaminants.6 The Environmental
Protection Agency estimated that potential dust exposures ranged from 1,000
μg/m3 to >100,000 μg/m3 in the hours after the
towers’ collapse. Exposures were attributed primarily to smoldering
fires (until December 2001), dust resuspension, and diesel exhaust from heavy
equipment. WTC dust contained pulverized (alkaline) cement, glass fibers,
asbestos, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls
(PCBs), and polychlorinated furans and dioxins. WTC dust was highly alkaline
(pH: 9.0-11.0).7 The deposit of larger particles
in the upper respiratory tract might have resulted in persistent upper airway
inflammation. Highly irritant, respirable particles are likely to have accounted
for lower airway symptoms and clinical findings. Administration of respirable
particulate (particles <2.5 μm in diameter) WTC dust to rodents resulted
in lower airway hyper-responsiveness.8 Thus,
the findings in WTC examinees are consistent with current understanding of
WTC exposures; however, the persistence of symptoms for >1 year after the
9/11 event is a new finding and requires further study.
The findings in this report are subject to at least three limitations.
First, no reliable statistics exist on the size or composition of the exposed
worker/volunteer population, so determining participation rates for the screening
program is not possible, and generalizations to all WTC-exposed workers should
be made with caution. Second, the screened population might overrepresent
those most affected; those screened earlier might not be representative of
all persons screened with regard to WTC exposures or health outcomes, and
persons examined earlier might have had more severe health problems and sought
out the program for that reason. However, preliminary analyses of exposure
data among all persons examined through January 2, 2004, demonstrate similar
patterns of acute and longer-term WTC exposures. Additional analyses of data
for the remainder of the cohort will address concerns regarding health outcomes
of persons screened later in the program. Finally, because of the absence
of pre-9/11 symptom prevalence and pulmonary function tests (PFTs) for these
participants, the ability to measure accurately the impact of WTC exposures
on responders’ health is limited. Because of the absence of an unexposed
control group, spirometry data from this sample were compared with those of
This report underscores the need for comprehensive occupational health
assessment and treatment for rescue workers and volunteers as part of all
emergency preparedness programs. Guidelines for professional emergency response
workers have been developed.1 The results
described in this report suggest that disaster preparedness also should include
(1) planning for rapid provision of suitable respiratory and other protective
gear and (2) provision of medical care for first responders and nontraditional
responders (e.g., persons from construction trades, utility workers, and other
The findings in this report are based, in part, on contributions by
S Carroll, H Juman-James, D Stein, J Weiner, K Leitson, N Nguyen, other staff,
and patients of the World Trade Center Worker and Volunteer Medical Screening
Program; labor, community, and volunteer organizations.
*Minimum of 24 hours working/volunteering during September 11-30, 2001,
or >80 hours during September 11–November 30, 2001, either south of
Canal Street, the Staten Island landfill, or the barge loading piers. Employees
of the Office of the Chief Medical Examiner also were eligible, regardless
of hours worked. FDNY and State of New York employees had access to other
screening programs and were not eligible for this program.
†After official site closure, exposure levels were reduced markedly.
‡Defined by using the American Thoracic Society criteria or an
increase in either forced expiratory volume in 1 second (FEV1) or forced vital
capacity (FVC) of >12% and >0.2 L, respectively.
Physical Health Status of World Trade Center Rescue and Recovery Workers and Volunteers—New York City, July 2002–August 2004. JAMA. 2004;292(15):1811-1813. doi:10.1001/jama.292.15.1811