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World Trade Center Disaster: Assessment of Responder Occupations, Work Locations, and Job Tasks

Department of Work Environment, University of Massachusetts Lowell, Lowell, Massachusetts 01854, USA.
American Journal of Industrial Medicine (Impact Factor: 1.74). 09/2011; 54(9):681-95. DOI: 10.1002/ajim.20997
Source: PubMed

ABSTRACT

To date there have been no comprehensive reports of the work performedby 9/11 World Trade Center responders.
18,969 responders enrolled in the WTC Medical Monitoring and Treatment Program were used to describe workers’ pre-9/11 occupations, WTC work activities and locations from September 11, 2001 to June 2002.
The most common pre-9/11 occupation was protective services (47%); other common occupations included construction, telecommunications, transportation, and support services workers. 14% served as volunteers. Almost one-half began work on 9/11 and >80% reported working on or adjacent to the ‘‘pile’’ at Ground Zero. Initially,the most common activity was search and rescue but subsequently, the activities of most responders related to their pre-9/11 occupations. Other major activities included security; personnel support; buildings and grounds cleaning; and telecommunications repair.
The spatial, temporal, occupational, and task-related taxonomy reported here will aid the development of a job-exposure matrix, assist in assessment of disease risk, and improve planning and training for responders in future urban disasters.

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AMERICAN JOURNAL OF INDUSTRIAL MEDICINE 54:681–695 (2011)
World Trade Center Disaster: Assessment of
Responder Occupations, Work Locations,
and Job Tasks
Susan R. Woskie, PhD, CIH,
1
Hyun Kim, ScD,
2
Alice Freund, CIH, MSPH,
2
Lori Stevenson, MPH,
2
Bo Y. Park, MPH,
2
Sherry Baron, MD, MPH,
3
Robin Herbert, MD,
2
Micki Siegel de Herna
´
ndez, MPH,
4
Susan Teitelbaum, PhD,
2
Rafael E. de la Hoz, MD, MPH,
2
Juan P. Wisnivesky, MD, DrPH,
2
and Phillip Landrigan, MD, MSc
2
Background To date there have been no comprehensive reports of the work per-
formed by 9/11 World Trade Center responders.
Methods 18,969 responders enrolled in the WTC Medical Monitoring and Treatment
Program were used to describe workers’ pre-9/11 occupations, WTC work activities
and locations from September 11, 2001 to June 2002.
Results The most common pre-9/11 occupation was protective services (47%); other
common occupations included construction, telecommunications, transportation, and
support services workers. 14% served as volunteers. Almost one-half began work on
9/11 and >80% reported working on or adjacent to the ‘pile’ at Ground Zero. Ini-
tially, the most common activity was search and rescue but subsequently, the activities
of most responders related to their pre-9/11 occupations. Other major activities includ-
ed security; personnel support; buildings and grounds cleaning; and telecommunica-
tions repair.
Conclusions The spatial, temporal, occupational, and task-related taxonomy reported
here will aid the development of a job-exposure matrix, assist in assessment of disease
risk, and improve planning and training for responders in future urban disasters. Am.
J. Ind. Med. 54:681–695, 2011.
ß 2011 Wiley-Liss, Inc.
KEY WORDS: World Trade Center; WTC; 9/11; emergency responder; disaster; task;
exposure; exposure assessment; emergency planning; occupational health
Additional Supporting Information may be found in the online version of this article.
1
Department of Work Environment,University of Massachusetts Lowell,Lowell,Massachusetts
2
Departments of Medicine & Preventive Medicine,Mount Sinai School of Medicine,NewYork,NewYork
3
National Institute for Occupational Safety and Health,Centersfor Disease Control and Prevention, Cincinnati,Ohio
4
CommunicationsWorkers ofAmerica, District1, AFL-CIO,NewYork, NewYork
Contract grant sponsor: Centers for Disease Control and NIOSH; Contract grant numbers: UIO 0H008232; U10 OH008225; U10 OH008239; U10OH008275; U10 OH008216; U10
OH008223;
Contract grant sponsor: Centers for Disease Control and Prevention/National Institute for Occupational Safety and Health (CDC/NIOSH); Contract grant number: 200-2002-0038.
Disclaimer: The findings and conclusions in this report are solely the responsibility of the authors and do not necessarily represent the views of the National Institute for
Occupational Safety and Health (CDC/NIOSH).
Disclosure Statement: The authors report no conflicts of interest.
*Correspondence to: ,Dr. Susan Woskie,PhD,CIH, One UniversityAve., Lowell,MA 01854.E-mail: susan_woskie@uml.edu
Accepted 8 July 2011
DOI10.1002/ajim.20997.Published online in Wiley Online Library
(wileyonlinelibrary.com).
ß 2011Wiley-Liss,Inc.
Page 1
INTRODUCTION
On Septemb er 11, 2001, over 15,000 people were in
the World Trade Center towers when the rst flight
crashed into the North Tower at 8:46 AM [Murphy, 2009].
As the WTC commission reports; ‘In the 17-minute
period between 8:46 and 9:03 AM on September 11, New
York City and the Port Authority of New York and New
Jersey (NJ) had mobilized the largest rescue operation in
the city’s history. Then the second plane hit. [National
Commission on Terrorist Attacks upon the United States,
2004]. In all, more than 70 engine, ladder, rescue, and
hazmat groups from the New York City Fire Department
(FDNY) and more than 2,000 New York City Police
Department (NYPD) officers were mobilized to the site by
9:15 AM [National Commission on Terrorist Attacks upon
the United States, 2004]. Within 2 hr the towers had col-
lapsed from structura l failures, and the area south of Canal
Street was evacuated [CNN, 2001; Bradt, 2003]. The Fed-
eral Response Plan was activated, bringing assistance to
the area from the Federal Emergency Management Agen-
cy, disaster medical assistance teams, and other resources.
The New York City Office of Emergency Management
had oversight of all emergency operations at Ground Zero
including work by the NYPD, National Guard, FDNY,
Port Authority of New York and New Jersey and 10 mu-
nicipal, 5 state, 15 federal, and 10 private agencies or
companies [Bradt, 2003]. Ultimately, tens of thousands of
workers and volunteers responded to the disaster, which
was one of the worst urban environmental disasters in
United States history.
The disaster response initially focused on locating
and evacuating survivors from collapsed and damaged
buildings. In subsequent weeks efforts moved to assessing
damage, searching for remains, restoring utilities, repair-
ing infrastructure, cleaning adjacent buildings, and remov-
ing debris from the site. Thus, the overall resp onse effort
had two phases: (1) crisis response and (2) management,
recovery, and restoration. There was also a transition peri-
od when the two types of work overlapped [Jederberg,
2005].
Prior studies have documented that WTC responders
were a very heterogeneous population who worked for dif-
ferent periods in varying locations [Herbert et al., 2006;
Wheeler et al., 2007]. In addition to traditional first res-
ponders, a diverse group of non-traditional responders also
were involved, and these non-traditional responders
worked in both the initial crisis response as well as in the
subsequent management and clean-up phases, often work-
ing alongside traditional first responders.
To date, there has been no detailed characterization of
the work of the WTC responder popul ation or of the mul-
tiple job tasks that they performed, often under harrowing
and heroic conditions. Previous studies have reported that
some of the health consequences among responders varied
depending on the time of arrival at the site, whether they
were entrapped in the dust cloud at the collapse, and their
duration of work [Banauch et al., 2006; Herbert et al.,
2006; Wheeler et al. 2007; Skloot et al., 2009].
The purpose of this study is to provide a comprehen-
sive description of the WTC responder population
including their demographics, pre-9/11 occupations, and
the types, locations, and timing of the job tasks that they
performed at Ground Zero. This information is essential
for developing a comprehensive exposure assessm ent,
building job-exposure matrices, informing interpretation
of health findings, and for future urban disaster planning.
METHODS
The study was conducted using data collected from 9/
11 responders as part of the structured interviewer-admin-
istered med ical and exposure questionnaires taken from
each of the responders participating in the WTC Medical
Monitoring and Treatment Program (MMTP) and was ap-
proved by the Mount Sinai School of Medicine Institution-
al Review Board. This progr am was establ ished in 2002 to
monitor eligible responders for physical and mental health
conditions possibly related to WTC work and exposures
[Herbert et al., 2006]. The target population for the
MMTP consisted of all non-FDNY workers and volunteers
who were engaged in rescue, recovery, restoration of ser-
vices, cleanup, or other support work on or after 9/11
[Savitz et al., 2008]. To be eligible, a responder had to
work for 4 hr on 9/11 to 9/14, 2001, 24 hr during the
month of September, 2001 or 80 hr total during the peri-
od of October through December, 2001. In addition,
employees of the Office of the Chief Medical Examiner
(OCME) who processed human remains after 9/11, Port
Authority Trans-Hudson Corporation wor kers who partici-
pated in the cleanup efforts for 24 hr from February to
July, 2002, or workers who drove, repaired, cleaned, or
maintained vehicles that handled WTC debris were eligi-
ble to participate in the program [Herbert et al., 2006;
Savitz et al., 2008]. New York City firefighters and offi-
cers, other FDNY civilian personnel such as Emergency
Medical Services (EMS) technicians and paramedics have
been monitored by a separate, parallel program coordinat-
ed by the FDNY and thus, are not included in this report.
Of approximately 31,000 persons who met eligibility
criteria for program participation, 20,843 completed their
baseline MMTP medical examination between July 16,
2002 and September 11, 2008 and consented to data ag-
gregation (approximately 77% of those eligible underwent
medical exam and about 90% of those who had medical
exams also consented to participa te in data aggregation).
The exposure assessment questionnaires for 1,874 of the
682 Woskie et al.
Page 2
20,843 did not contain information regarding WTC-r elated
activities, although when screened for admission to the
MMTP these responders answered affirmatively to partici-
pating in rescue, recovery, demolition, debris cleanup, or
other support services such as security or site monitoring
at the WTC, Staten Island La ndfill or barge loading piers.
Nevertheless, without the exposure assessment activity in-
formation, they were excluded from this analysis. There-
fore, the final cohort reported here includes 18,969 WTC
responders.
Demographic characteristics (age, gender, race, and
ethnicity) were collected via a self-administered question-
naire. Exposure-related information, including data about
pre-9/11 occupation, timing and location of WTC-related
work, work activities, whether work was conducted in
enclosed areas, and whether the responder was ‘directly
in the cloud of dust (or blackout) from the collapse of
the WTC buildings’ was collected via an interviewer-
administered survey. Pre-9/11 occupation was coded to the
first decimal of the Standard Occupational Classification
(SOC) 2000, although construction trades workers were
subsequently coded to the second decimal of the SOC
[Bureau of Labor Statistics, 2000]. Where appropriate,
SOC codes were then combined to create groups con-
taining similar job duties (Table I and Supplementary
Table I).
Information about the duration, shift, location of
work (using four broad categories); specific activities
performed; and whether the responder was a volunteer
or paid worker were obtained by trained interviewers
from each individual responder for four time periods:
September 2001, October 2001, November to December
of 2001, and January to June of 2002 [Herbert et al.,
2006; Moline et al., 2008]. Responders reported the most
common location for their work shift during each of these
time periods. Possible location choices were: (1) the
TABL E I. Standard Occupational Classification Coding Based onTrade or Profession Reported by Responders for September10, 2001
St andard occupational classifications (SOC)an d representative occupationaltitles n %
Protectiveservice occupations(33-0000) 8,941 47.1
NYClocal municipality, Port Authority and otherlawenforcement agenciesincludingcorrectionofficers,detectives,police officers,school safetyofficers,traffic officers,
NYPDand othermunicipal,regional, andfederal agencies;fireand EMS workersfromregional firedepartments and othercity agencies,excluding NYFD; body
guards,park rangers,security workers, animal controlworkers
Constructionoccupations (47-0000) 4,274 22.5
Foremen/supervisors;constructionworkers/demolitionworkers/laborers,carpenters/dockbuilders,electricians,heavy equipmentoperators,ironworkers/structural
iron and steel,ma sons,painters,plumbers/pipefitters;Asbestoshandlers/hazardousmaterialsremoval workers,asphaltpavers,buildingengineers/inspectors,
elevatorrepair workers,highwayrepair workers,track workers,fenceerectors
Electrical,telecommunications& other Installation & repair(49-0000) 1,342 7.1
Supervisors;Telecommunicationfieldtechnicians,telephoneinstallers,utility workers (electric),electrical repairer(powerhouse,substation,relay),telecommunications
and electrical powerequipmentrepairandinstall including line installer; cablesplicers,heating, airconditioning andrefrigeration mechanics and installers,signal
and track switchrepair,buildingmaintenance andrepair,vehicle andheavy equipmentmechanics
Transportation andmaterial movers(53-0000) 698 3.7
Supervisors;Busdrivers,delivery drivers,motor vehicle drivers(taxidrivers,personal drivers),truckdrivers, ambulance drivers; Sanitationworkers,conveyoroperators,
craneoperator,dredge/excavatoroperator, hoist/winch operator
Business,engineering& administration(11-000; 13-000; 17-000) 1,109 5.8
Project managers,human resourceand financial managers,Union Representatives,emergencymanagementspecialists,cl aims adjusters,examinersand appraisers
engineers,surveyors
Otheroccupations 2,605 13.7
Health & personal careprofessions(21-000;29-000;39-000) (2.7% ofcohort):Mental health counselors,social workers,clergy,physicians,veterinarians,nurses,
chiropractors; EMT,occupational health and safetyprofessional,funeralser vice workers,barbersand cosmetologist,fitnesstrainers
Building and groundscleaning andmaintenance occupations (37-0000) (2.6% ofcohort):janitors,housekeeping,building cleaners,groundskeepers
Hourly workersfromretail,factoryorfoodpreparationoccupations(35-000,41-000,and 51-000) (2.2%ofcohort): Cooks,waiters,salespersons,realestate agents,food
processingworkers,manufacturingtrades (metal,plastic,printing,textile,apparel wood),power& chemical plantworkers
Arts,design,entertainment,sports,and media occupations(27-0000) (1.1%ofcohort):Radio and TVannouncers,reportersand broadcast staff,photographers,actors,
dancers,musicians,designers
Miscellaneousoccupations(15- 000; 19-000; 25-000) (1.6%ofcohort): Computer analyst,programmer& support,environmentalhealth scientists,psychologists,
sociologists,urbanplanners,teachers,farming,fishingand forestry workers,health care supportworkers,legal occupations,military occupations
Unemployed& retired (2.0%ofcohort)
Unknown(1.7% ofcohort)
WTC Responder Jobs, Locations, Activities 683
Page 3
‘pile’ or ‘pit, terms that referred to the former location
of the twin towers of the WTC complex; (2) ‘adjacent to
the pile’ which included locations within approximately
four blocks of the pile (this was the secured area immedi-
ately surrounding the ‘pile’ and was the site for many
support, recovery and restoration activities, the location of
several field command centers including those of the NYC
Office of Emergency Management (OEM), the Port
Authority of NY/NJ, the NYC Department of Design &
Construction (DDC), the NYPD and FDNY); (3) the Fresh
Kills Landfill on Staten Island where WTC debris was
brought for investigation/screening for human remains
or personal items, stockpiling, and/or disposal [Bellew,
2004]; (4) ‘barges/piers, where material was transferred
to barges to go to the Landfill (transfer stations at 59th in
Manhattan and Hamilton Avenue in Brooklyn and, later
Piers 6 and 25 in lower Manhattan) ; (5) the OCME at 520
First Avenue in Manhattan, where human remains were
processed; and (6) elsewhere south of Canal Street which
included a large command center at Police Plaza (Fig. 1).
To assess responders various activities, a list of 55 job
codes was establ ished. For each time-period, information
on responders’ activity was collected using up to three of
these pre-selected codes. However, many (37 out of 55)
of these codes described occupational titles (e.g., police
officer, mason, custodian) rather than activities. A more
detailed description of activities was also collected by ask-
ing responders to describe their main activity at the WTC
site for each time period. Two certified industrial hygien-
ists (CIHs) reviewed the text and used the words to create
a dictionary of activities. A computer algorithm was
developed to identify text strings associated with specific
activities using the coding dictionary. Based on this
search, each subject was assigned up to 11 different activi-
ties for each time period. The resulting activity codes
were then validated via a CIH review of a 5% random
FIGURE 1. World Trade Center response and cleanup workforce locations.
684 Woskie et al.
Page 4
sample of the corresponding text field data. Overall, 95%
of codes matched. Combining the original codes and
those generated via the text fields resulted in a list of
97 activities. Because some activities overlapped (e.g.,
‘bucket brigade’ and ‘search and recovery, or ‘traffic
control’ and ‘perimeter security’’), and given that many
activities included a small number of responders, the final
categories of activities were collapsed into 15 activity
groups (Table II).
RESULTS
The median age of the 18,969 WTC responders was
39 9 years, and 86% were male. In terms of race, 60%
were White, 11% Black, and 29% from other races.
Approximately 24% reported Hispanic ethnicity.
Occupations
Almost one-half (47%) of the WTC responders in this
cohort were employed in the protective services (SOC 33)
before 9/11 (Tables I and III). Within the protective ser-
vices category, the majority (92%) of these workers were
law enforcement officers with the largest groups being
union members of the NYC Patrolmen’s Benevolent Asso-
ciation (PBA), the NYC Detectives’ Endowment Associa-
tion (DEA), and the NYC Sergeants Benevolent
Association (SBA). There were 280 firefighters from fire
departments other than FDNY, which has its own WTC
monitoring program. In addition, there were retired fire-
fighters who may be included under the category of
‘Other occupations. The remaining one-half of the WTC
responders were from pre-9/11 occupations not typically
TABL E II. Final Activity Groups and Corresponding Description
Activitygroup Description
Asbestos removal Insulationworkorany workactivity associated with‘‘asbestos’’
Building and groundscleaning Cleaningofbuildings,vehicles,ducork,furniture,sidewalks,handlingspoiledfood,garbage,and furniture
Debrisremoval Loadingandunloadingtrucks,boats,barges;loading or unloadingdebrisorsteel;transporting concrete or
cement; hauling debrisor material
Excavation Excavation
Heavy equipment/demolition and concretework Demolition;heavy equipmentorconstructionequipmentor machine operator;oiler; cutting a nd drilling of
concreteorgranite; pouring ofcementorconcrete
Inspection/supervision Assessingdamage;surveyingor monitoring;buildinginspection;supervisoror foreman
Miscellaneousconstruction Erectingordismantlingor boardingup entrances,openings,barricades; dustsuppressionwithwater;dredging
and dewatering;carpentry including dockconstruction;elevatorand escalatorinstallation and repair; installation
andrepairof windows;painting;roofinstallation and repair; bridgeandroad construction andrepair; track
maintenance andrepair
Miscellaneousutility work Sheetmetal and ventilationrepair; water service,gas, steam,sewerinstallation,restoration,maintenance and
repair;install ation,restorationand shuttingdownof lights and generators;electric work
Morguework Morguework;identifyingbodies or remains;DNAtesting
Personnel supportservices Religious supportservices;counselinga nd psychotherapy; physical therapy, chiropractics, andmassa ge;
medical treatment; emergencymedical technicians (EMT);respiratorfittestingand training and otherhealth
and safety training; airand environmental monitoring;health andsafetyinspections; administration and
planning; clerical work(answeringphones,paperwork,filing,etc.);interpreting;interviewing;preparing,
delivering, a nd distributingfoodandwater(canteenservices); animal care;bringing/transporting/
organizing/distributingsuppliesandmaterials,other than food and waterorsitedebris;legal activities
Search,rescueandrecovery Bodybaggingand bodyremoval; bucketbrigade; handlingthe search dogs;digging;rescue,search,andrecovery;
siftingand sortingofdebrisincludingon theconveyorbelt
Security Escortingpeopleorremains; dispatchingandroutingvehicles andequipment; traffic control;security; evacuating
people; perimetersecurity
Steelwork Erectingsteel; rigging; cutting and weldingofmetal; firewatch
Telephone,cable,computerrepair Installation,repair, maintenance and removal of telephoneservice; cable installation/repair/splicing; installation,
operation,restoration,andshuttingdowncomputers
Transportation Operatevehicles/boats/barges/planes/helicopters;towingmoving andremovingvehicles; truckdriving;
transportingpeople; vehicle driver, including ambulances vehicle and equipmentmaintena nce and repair;
fueling of vehicles and machines
WTC Responder Jobs, Locations, Activities 685
Page 5
identified as emergency responders (Table I). Among
these, construction workers (SOC 47) were the most com-
mon group (23% of responders). Within this SOC the pre-
dominant subgroup was construction trades worker s (SOC
47-2000, 13% of all responders). Also within SOC 47
there was a subgroup that was disproportionately Hispanic
(47% vs. 18% for trades workers) comprised of ‘other
construction and related workers’ (SOC 47-4000, 9% of
all WTC responders). This subgroup contained the asbes-
tos/hazardous materials removal workers, as well as fence
erectors, elevator repairers, building inspectors and other
jobs (Supplementary Table I).
The next most common SOC codes comprised in total
less than 20% of the responders (Table I and Supplemen-
tary Table I). They were SOC 49 (7% of responders),
which included a diverse group of installation, mainte-
nance, and repair occupations. Although the majority of
these workers were involved in telecommunications or
electrical repair work, 10% of the workers in this SOC
were listed as vehicle mechanics (SOC 49-3000). We have
titled thi s group (SOC 49) electrical, telecommunications
& other installation & repair. In the transportation and
material moving group, SOC 53 (4% of total cohort), one-
half of the workers (51%) were truck, ambulance or bus
TABL E III. Demographic Characteristics of Responders According to Pre-9/11Occupation
Characterist i c
Protective
services
(SOC 33)
Construction
(SOC 47)
Electrical,
telec ommunications
&otherinstallation
& repair (SOC 49)
Transportation
& material
movers (SOC 53)
Business,
engineeringand
adminis t rativ e
(SOC11,13,17) Othe r occupations Total
n% n % n % n % n % n % n %
Total numberofresponders 8,941 47.1 4,274 22.5 1,342 7.1 698 3.7 1,109 5.9 2,605 13.7 18,969 100
Age
<30 1,196 13.4 533 12.5 195 14.5 53 7.6 96 8.7 412 15.8 2,485 13.1
30-39 5,049 56.5 1,494 35 461 34.4 223 32 347 31.3 798 30.6 8,372 44.1
40-49 2,321 25.96 1,491 34.9 431 32.1 282 38.5 427 38.5 809 31.1 5,761 30.4
50-59 348 3.9 652 15.3 230 17.1 126 18.2 202 18.2 449 17.2 2,007 10.6
>60 27 0.3 104 2.4 25 1.9 14 3.3 37 3.3 137 5.3 344 1.8
Malegender 7,625 85.3 4,033 94.4 1,261 94 669 95.9 909 82 1,729 66.4 16,226 85.5
Race/ethnicity
White 5,624 62.9 2,411 56.4 832 62 375 53.7 790 71.2 1,327 50.9 11,359 59.9
Black 1,033 11.6 374 8.8 200 14.9 112 16.1 91 8.2 225 8.6 2,035 10.7
Other 2,284 25.6 1,489 34.8 310 23.1 211 30.2 228 20.6 1,053 40.4 5,575 23.4
Hispanic 1,878 21.0 1,227 28.7 209 15.6 139 20.0 167 15.1 941 36.1 4,561 24.0
TimefirstbeganWTC-relatedwork
11Sep.2001
Inthedustcloud 2,595 29 378 8.8 163 12.2 78 11.2 210 18.9 410 15.7 3,834 20.2
Not in the dustcloud 2,797 31.3 589 13.8 234 17.4 126 18.1 237 21.4 419 16.1 4,402 23.2
Do not know 49 0.6 12 0.3 3 0.2 2 0.3 9 0.8 15 0.6 90 0.5
12^14 Sep.2001 2,640 29.5 1,826 42.7 570 42.5 329 47.1 412 37.2 802 30.8 6,579 34.7
15^30 Sep. 2001 622 7 941 22 269 20 112 16.1 166 15 663 25.5 2,773 14.6
Onorafter1Oct. 140 1.6 479 11.2 71 5.3 34 4.9 65 5.9 258 9.9 1,047 5.5
Numberofrespondersduringthetime period
September,2001 8,698 49.3 3,731 21.1 1,253 7.1 650 3.7 1,020 5.8 2,299 13 17,651 100
October, 2001 7,209 52.1 2,761 20 1,041 7.5 478 3.5 696 5 1,662 12 13,847 100
November^December,2001 6,196 51 2,539 21 929 7.6 424 3.5 601 4.9 1,470 12.1 12,159 100
January^June,2002 4,305 51.1 1,771 21 616 7.3 315 3.7 445 5.3 978 11.6 8,430 100
Average days worked (mean, SD)
September,2001 13.2 6.4 11.8 6.2 14.2 5.3 13 6.3 11.7 6.4 10.3 6.1 12.5 6.3
October, 2001 17.1 9.5 22.8 8.8 23.7 8.2 22.4 9.3 19.9 9.5 19.8 9.4 19.4 9.6
November^December,2001 27 17.8 38.3 18.1 38.5 16.9 38.4 18.5 33.6 18.4 34.3 18 31.9 18.6
January^June,2002 49.6 46.1 77.7 52.6 84.5 52.7 84.6 55.1 82.5 54.1 70.7 50.5 63.5 51.4
All periods 72.2 66.2 86.6 77.8 101.5 78.8 95.3 85.8 81.7 83.3 72.5 73.9 79.0 73.3
686 Woskie et al.
Page 6
drivers, and 35% mater ial moving workers, which includes
sanitation and other material moving workers. The busi-
ness, engineering and administrative group (6% of total
cohort) included the SOC categories 11 (management
occupations), 13 (business and financial,) and 17 (architec-
ture and engineering). The ‘other occupations’ group
(combined <3% of the workforce) included a variety of
SOCs. Those with over 45 people included the health pro-
fessions (SOC 21, 29, and 39), building and grounds
maintenance workers (SOC 37), hourly workers from re-
tail, factory or food preparation occupations (SOC 35, 41,
and 51), broadcast/media personnel and artists (SOC 27),
and miscellaneous occupations such as teacher/librarian
(SOC 25), computer programmers/analysts (SOC 15), psy-
chologist, sociologist, and environmental health scient ists
(SOC 19) as well as retired/unemployed and other unclas-
sified individuals. Within ‘other occupations’ some of the
subgroups had high percentages of Hispanic workers in-
cluding the building and grounds maintenance workers
(75%), the retired and unemployed responders (45%) and
the hourly workers from retail, factory or food preparation
occupations (37%).
Volunteers, not including those who were both
employed on site and volunteered, comprised approxi-
mately 14% of the WTC responders. The most common
pre-9/11 occupations for volunteers included construction
(27%) followed by law enforcement (21%), business,
engineering and administration (12%), retired and unem-
ployed workers (7%), and health care workers (8%). It
should be noted that many responders both worked for
pay and also volunteered at the WTC, especially during
September when search, rescue and recovery work was
ongoing.
Public sector workers made up 61% of the total work-
force. These responders can be further subdivided with the
majority (45.5% of the total workforce) in the ‘protective
services’ group employed in the public sector, mostly the
NYPD. The remaining public sector responders (15.5%
of the total workforce) were comprised of workers
from many NYC agencies, some construction trades’ civil
service divisions, and other government workers.
Overall, the number of workers at the WTC decreased
with time (Table III). However, the percentage of the over-
all workforce comprised of each occupational group
remained relatively stable over time.
Timeline of Recovery Activities
The total number of responders in our program wen t
from a peak of 17,651 in September, 2001 to 8,430 in the
period ending in June, 2002 (Table III). Approximately
one-half (44%) of WTC responders began their response
work on 9/11. Of these, 46% reported being ‘directly in
the dust cloud (blackout) created from the WTC collapse.
Another 35% of the cohort arrived at the site between 9/
12 and 9/14, 2001. Overall, 93% of responders began to
work at the site sometime during the month of September,
2001 (Table III).
The majority of responders arriving on 9/11 were in
the protective services (65% n ¼ 5,441), followed by
workers in construction occupations (12% n ¼ 979),
‘other occupations’ (23%; including business, engineer-
ing and administrative professionals (n ¼ 456), electrical,
telecommunications & other installation & repair workers
(n ¼ 400), and transportation & material movers (n ¼
206)). Among the protective service workers who arrived
on September 11th, 29% were present ‘directly in the
dust cloud (blackout) created from the WTC collapse.
Among business, engineering and administrative profes-
sionals 19% were pres ent at the collapse, while for
all other occupational groups 9–16% were present at the
collapse. Protective service continued to be the most com-
mon occupation among responders arriving during 9/12
and 9/14, 2001. From September 15–30, 2001 new res-
ponders continued to arrive but at a slower rate.
All occupational groups reported a wide range of days
worked (median 56, mean 79, range 1–293 days). One-
half (51%) of responders worked <60 days, while only
23% worked >130 days. Responders in the ‘other occu-
pations’ subgroup of buildings and grounds cleaning and
maintenance (SOC 37) as well as the electrical, telecom-
munications & other installation & repair group (SOC 49)
had the largest average time on the site (108 and
102 days, respectively), as the utilities infrastructure re-
covery and repair continued well after the work on the
‘pile’ ended. Conversely, those in protective services and
the overall ‘other occupa tions’ group had the lowest
average number of days (72 days) working at the site
(Table III).
Many responders worked night shifts as well as day
shifts. Data on work shift were available only for the
October 2001–June 2002 period. Forty eight percent of
responders who worked at any time between
October 2001–June 2002 reported working both day and
night shifts, with about one-half of protective services
workers (56%) reporting work during both shifts (not nec-
essarily back to back). From October through June, 3–5%
of the responders reported always or mainly sleeping on-
site. The average hours per day worked varied somewhat
by time period: September mean 12.3 hr/day (SD 3.3);
October mean 11.5 hr/day (SD 2.8); November-December
mean 11.1 hr/day (SD 2.6); January–June mean 10.5 hr/
day (SD 2.6).
Location of Responders
The most common work location was ‘adjacent to
the pile’ followed by ‘on the pile or pit’ (Fig. 2). These
WTC Responder Jobs, Locations, Activities 687
Page 7
two locations com prised the secured zone referred to as
‘Ground Zero. In September, protective service workers
represented the largest group of responders in both of
these locations (41% ‘adjacent to the pile’ and 57% on
the ‘pile’’). Construction workers comprised the next larg-
est group (24% ‘adjacent to the pile’ and 21% on the
‘pile’’). Over time, the number of resp onders working on
the ‘pile’ decreased as work was completed (from 39%
in September to <9% in the January–June 2002 period).
Likewise, over the same time frame, the number of res-
ponders working in the area ‘adjacent to the pile’
decreased from 51% to 35%. In September 62%
(n ¼ 1,352) of all of the volunteers at the WTC reported
working on the ‘pile’’, decreasing to <23% (n ¼ 60) in
the January–June period. On the other hand, the percent
working at the landfill increased over time. Thirty percent
of the volunteers worked ‘adjacent to the pile’ in
September, but this increased in the subsequent time peri-
ods to >50% of all the volunteers.
At the landfill, loading piers/barges, and elsewhere
south of Canal Street, protective services workers were
again the largest fraction of the workforce (47–80%) in
September. Other groups that had an important presence
elsewhere south of Canal Street in the four time periods
were construction workers (11–13% of workforce), electri-
cal, telecommunications & other installation & repair
(11–13% of workforce) and the ‘other occupations’
group (12–14% of workforce). Between 3% and 9% of the
volunteers were present elsewhere south of Canal Street
between September 2001 and June 2002.
For each of the four time periods, responders were
asked if they performed work in an enclosed area, de-
scribed as ‘any subgrade level like a tunnel, basement or
building or any area not open to the general atmosphere.
In September, 54% of responders repor ted working in an
enclosed area when they also reported spending the major-
ity of their work shift ‘adjacent to the pile, 42% reported
working in an enclosed area when they also reported their
location as ‘elsewhere south of Canal Street, 41% when
on ‘the pile, 33% when at the OCME, 25% when at the
barges/piers, and 16% when at the landfill. Overall, the
percentage of responders reporting working in an enclosed
area decreased slightly during the months after September.
Electrical, telecommunications, and other installation and
repair workers were the group more likely to report work-
ing in an enclosed area (72% of workers), followed by
construction workers (59%) and business, engineering,
and administration (53% ).
Types of Activities by Pre-9/11
Occupation
Activities reported by WTC responders over the dif-
ferent time periods are shown in Figure 3. In Septemb er,
FIGURE 2. Number of workers at each location from September 2001 until June 2002.
688 Woskie et al.
Page 8
the most frequently reported activity across all occupation-
al groups was search, rescue and recovery (32% of all
reported activities). The next most commonly reported ac-
tivities in September were security (22%), building and
grounds cleaning (10%), personnel support (7%), and tele-
phone, cable, and computer repair (4%).
During the month of October, security related activi-
ties became the most commonly reported task (27%), fol-
lowed by search, rescue and recovery (23%), and building
and grounds cleaning (12%). In most categories the per-
centage of responders involved in the activity remained
relatively stable over time. However, search, rescue, and
recovery declined after September to about 20%, while
security work stayed at about 25% of responders after
September.
The percent of responders in the SOC groups that
reported performing each activity during the four time
periods is shown in Figure 4. Overall, all occupa tional
groups reported search, rescue and recovery activities.
Moreover, this was the most commonly reported activity
in September for protective services, business, engineer-
ing, and administrative workers (6,010 responders). After
September, most responders engaged in activities related
to their pre-9/11 occupations. Yet, all groups (except pro-
tective services workers) had a substantial percentage of
workers that reported being engaged in building and
grounds cleaning. In addition, security activities were
reported not only by protective services workers, but also
by transportation and retired and unemployed workers
(‘‘other occupations’ group). Asbestos removal was most-
ly limited to construction workers, as this SOC group
includes the hazardous materials removal workers. Debris
removal was reported by construction and transportation
workers and business, engineering and administrative
workers. Miscellaneous construction activities were con-
ducted by construction and transportation workers and by
the ‘other occupations’ group. Telephone, cable, and
computer repair was performed by the electrical, telecom-
munications & other installation & repair SOC group as
well as by the business, engineering and administrative
SOC group. Miscellaneous utility work was reported by
construction SOC group as well as the electrical, telecom-
munications & other installation & repair SOC group.
Among those who reported volunteering in September,
0
1,000
2,000
3,000
4,000
5,000
6,000
7,000
8,000
9,000
Sep
Oct Nov
-Dec Jan-Jun
Number of Responders
Personnel support services
Debris removal
Asbestos removal
Steelwork Heavy equipment/demolion/concrete
Excavaon
Misc. construcon
Inspecon/supervision
Transportaon
Misc. ulity
work
Telephone/cable/computer repair
Search, rescue and recovery
Morgue
work
Security
Building & grounds cleaning
FIGURE 3. Number of responders by activity and time period.
WTC Responder Jobs, Locations, Activities 689
Page 9
64% report search, rescue, and recovery activities and
30% reported personnel support activities. These two
activities were also most commonly reported by volunteers
in other time periods. However, in September other activi-
ties reported by volunteers included steelwork, building
and grounds cleani ng and debris removal over (170 per-
sons reported each).
The subcategories of the SOC groups were also exam-
ined to see if activity patterns varied within a SOC catego-
ry. Among the protective services SOC (33-000),
firefighters (SOC 33-2000) primarily did search, rescue,
and recovery activities in all time periods (88–53%
reported over time) (Supplementary Fig. 1). These res-
ponders in addition to searching the debris for remains,
acted as spotters and water sprayers for the operating engi-
neers moving debris and worked in the debris raking field
[Meyerwitz, 2006]. The activity pattern of the subgroup of
law enforcement responders (33-3000) reflected the over-
all SOC pattern since this was the predominant subgroup
in the SOC. Other protective services (33-9000) which in-
cluded security guards and animal control workers primar-
ily did security, although 45% also reported search rescue
and recovery and 25% reported personnel support activi-
ties in September.
For the subgroups in the Construction Trades SOC
(47-0000), supervisors (47-1000) and trades workers
(47-2000) reported search, rescue, and recovery as their
most common activity in September (36% and 42%,
respectively) (Supplementary Fig. 2). Other common
activities reported by 20% or more of supervisors included
building and grounds cleaning, inspection/supervision, and
miscellaneous construction. The ‘other construction’
related workers (47-4000), which included hazardous ma-
terial (asbestos) removal workers, reported building and
grounds cleaning as their most common activity during all
time periods (58–65%). Asbestos removal and miscella-
neous construction were reported by over 30% of these
responders during all time periods.
Within the construction trades (47- 2000), search, res-
cue, and recovery was the most common activity reported
in September for the brick masons (47-2020), carpenters
(47-2-30), equipment operators (47-2070), plumbers/pipe-
fitters (47-2150), and ironworkers (47-2220) (Supplemen-
tary Fig. 3). For the electricians (47-2110), miscellaneous
utility work was the most common in September (51%),
while cleaning buildings and grounds was the most com-
mon for the painters (47-2140) (54% ) and laborers
(47-2060) (33%). These trades also did search, rescue and
recovery in September (23–30% reporting). Other activi-
ties reported by over 20% of responders were: telephone,
cable and computer repair by the electricians; debris re-
moval by brick masons and equipment operators; steel-
work by the plumbers/pipefitters, iron workers and brick
masons; miscellaneous construction work by the carpen-
ters and painters; building and grounds cleaning by brick
masons, carpenters, plumbers/pipefitter; heavy equipment/
demolition/concret e work and excavation by equipment
operators.
Among the overall SOC category of electrical, tele-
communications & other installation & repair workers
(49-0000), telephone, cable, and computer repair activities
were commonly reported for all groups except vehicle
mechanics (49-3000) who reported transportation activities
most commonly (Supplementary Fig. 4). All subgroups
0
10
20
30
40
50
60
70
80
Sep
Oct Nov-
Dec
Jan-
Jun
Sep
Oct
Nov-
Dec
Jan-
Jun
Sep Oct Nov-
Dec
Jan-
Jun
Sep Oct Nov-
Dec
Jan-
Jun
Sep Oct Nov-
Dec
Jan-
Jun
Sep Oct Nov-
Dec
Jan-
Jun
Protective Services (33-0000)
Construction (47-0000) Electric
al, Telecommunications &
Other Installation & Repai
r
(49-0000)
Transportation and Material
Movers (53-0000)
Business, Engineering and
A
dministration*
Other Occupation*
Personnel Support
Debris removal
A
sbestos removal
Steelwork
Heavy equipment/demoliton & concrete work Excavation
Misc. construction
Inspection/supervision Transportation
Misc. utility work Telephone, cable, computer repai
r
Search, rescue and recovery
Morgue work Security Building and grounds cleaning
Percent of Responders
FIGURE 4. Responders activity by pre-9/11 occupation and time period.
690 Woskie et al.
Page 10
reported search rescue and recovery activities in Septem-
ber (9–29%). However, vehicle mechanics and supervisors
(49-1000) had over 20% of workers reporting these activi-
ties in September. Other act ivities reported by over 20%
of the responders were buildings and grounds cleaning by
the vehicle mechanics and inspection/supervision by the
supervisors.
Among the overall SOC category of transportation
workers (53-0000) the most common activity was debris
removal for supervisors (53-1000) and motor vehicle oper-
ators (53–3000) (Supplementary Fig. 4). For the material
moving workers (53-7000) cleaning building and grounds
was the most common activity followed by debris remov-
al. Note that for all subgroups search, rescue and recovery
activities were reported by over 12% of the responders in
September.
For the business, engineering and administrative
SOCs (11-0000, 13-0000, 17-0000) the most common ac-
tivities were inspection & supervision by management
occupations (11–9000) and engineers (17-2000) and per-
sonnel support by the business operations specialists
(13-1000) (Supplementary Fig. 5). All SOC subgroups
engaged in search rescue and recovery in September
(over 30% reported). In all SOC subgroups building and
grounds cleaning and debris removal activities were
reported by at least 10% of responders during one of the
time periods.
For the ‘other occupations’ SOCs (29-0000,
39-0000, 21-0000, 37-0000, 35-0000, 41-0000, 51-0000;
27-000; 25-000, 15-000, 19-000 and retired/unemployed),
the activities varied widely. For retail occupations
(SOC 41), production occupations (SOC 51) and the
unemployed, the most common activity in September was
search rescue and recovery. For the health care SOCs (29,
21) media occupations (SOC 27), education occupations
(SOC 25), computer occupations (SOC 15), and science
occupations (SOC 19) the most common activity was
personnel support in all time periods. For building and
grounds maintenance workers (SOC 37) and personal care
occupations (SOC 39) the most common activity in all
time periods was building and grounds cleaning. Food
preparation occupations (SOC 35) reported commonly
doing both building and grounds cleaning and personnel
support.
Types of Activities by Location
Responder activities in relation to the location sites in
which they spent most of their work shift are shown in
Figure 5. On the ‘pile, the most common activity
throughout all time periods was search, rescue and recov-
ery (43–78%), followed by security (20–27%) and debris
removal (8–15%). Debris removal increased steadily over
time, while the fraction of responders reporting search,
rescue, and recovery decreased and security remained fair-
ly constant. One of the main search and rescue activities
reported in the text fields was working on the bucket bri-
gade. This activity involved extracting metal and concrete
0
10
20
30
40
50
60
70
80
90
100
Dec
Jan-
Jun Dec
Jan-
Jun
Dec
Jan-
Jun
Dec
Jan-
Jun Dec
Jan-
Jun Dec
Jan-
Nov-
OctSep
Nov-
OctSep
Nov-
OctSep
Nov-
OctSep
Nov-
OctSep
Nov-
OctSep
Jun
Adjacent to pile
South of Canal St.
OCME
Loading Piers
Landfill
On the pile
Personnel Support Debris removal Steelwork
Excavation
Misc. construction Inspection/supervision Transportation
Telephone, cable, computer repair
Search, rescue and recovery Morgue work Security
Building and grounds cleaning
Percent of Responders
FIGURE 5. Responders activity by location and time period.
WTC Responder Jobs, Locations, Activities 691
Page 11
debris by hand, filling a bucket and passing it back
through a line of responders stationed on the terrain.
Another search, rescue and recovery activity on the pile
was the raking field where debris was checked for remains
[Meyerwitz, 2006].
In the location ‘adjacent to the pile, security was
the most commonly reported activity, in part because
of the large proportion of law enforcement responders and
the need for security at the more than 30 entry points
for the WTC site. In addition to being a crime scene, there
were valuable documents and commodities still present
at the WTC site and adjacent buildings (including seven
Secret Service vaults with government documents and a
bank vault with 14,000 pounds of gold in the basement
of the collapsed WTC building 7 [Smith, 2002; Reissman
and Howard, 2008]). Analyses of the text fields showed
that a commonly reported security task was ‘escorting’
of individuals or human remains. Building and ground
cleaning was also a common activity in the area ‘adjacent
to the pile’ during all time periods given the extensive
dust contamination in buildings and enclosed spaces [Lioy
and Gochfeld, 2002]. Personnel support activities in this
location included provision of food, water, heal th and
safety training, supplies, and equipment. At the service
tables and tents that sprang up adjacent to the pile, volun-
teers handed out ‘everything from toothbrushes to hydrau-
lic jacks’ [Smith, 2002]. The most commonly reported
activities in the text fields were the preparation, delivery
or distribution of food and water, with many volunteers
working long hours at the food services including the
‘Green Tarp Cafe
´
and the ‘Taj Mahal’ [Smith, 2002;
Meyerwitz, 2006]. Other personnel support activities
included mental health or other types of counseling and
provision of medical care. The increasing telephone,
cable, and computer repair activities over time in the area
‘adjacent to the pile’ were related to the restoration of
the telecommunications hubs and associated infrastructure
that provided service to lower Manhattan, including
the New York Stock Exchange, City Hall, Federal Plaza,
1 Police Plaza and many other commercial and residential
sites. One such hub was the Verizon building on the north
side of the Ground Zero site which was heavily damaged
by debris from the collapse of the towers, the collapse of
WTC 7 against its east side, a diesel spill and flooding
of the sub-basements destroying critical components of
the voice and data network.
At the landfill, responders primarily reporte d search,
rescue, and recovery activities (80–87%), followed by se-
curity (22–28%) and morgue related work (9–16%). The
main activity described in the text fields was to manually,
or with the use of conveyor belts, sift through debris look-
ing for human remains, personal effects or crime scene
evidence. At the OCME, morgue-related work was the
most commonly reported task as expected (77–80%),
followed by search, rescue, and recovery (35–42%), and
security (23–27%).
At the loading piers and barges, responders mainly
reported security-related activities (44–54%) although in
September, search, rescue and recovery and personnel sup-
port services were also quite common (32% and 23%,
respectively). After September, the focus shifted to debris
removal as the operations moved from the rescue phase to
the recovery phase.
Finally, in the area elsewhere south of Canal Street,
security was the main activity (44–49%) due to the disas-
ter location in the heart of Wall Street as well as the pres-
ence of many other commercial and residential properties.
Personnel support (15%) was fairly constant across the
different time periods, while telecommunications, cable,
and computer repair activities increased with time (11–
15% of responders). Building and ground cleaning was
reported by about 12% of responders across all time peri-
ods because of the millions of square feet of residential
and commercial building space contaminated by the dust
cloud produced from the collapse and the fires that burned
for several months afterwards. In this area, there was a
great effort put into cleaning and reopening the major
financial centers in an attempt to lessen the economic
impact of the WTC collapse.
Female WTC Responders
Women responders were 15% (n ¼ 2,743) of the
WTC cohort. About 39% were white and 18% were black.
Compared to men, more women were Hispanic (41% vs.
21%). Like men, about one-half (48%) were protective
service workers, but fewer women worked in construction
occupations (9% vs. 25%) and in transportation occupa-
tions (1% vs. 4%). Women arrived at the sites slightly lat-
er than men. Seventeen percent (vs. 21%) arrived on 9/11
in the dust cloud and 69% of women versus 84% of men
arrived before 9/15. The duration of work for women was
the same as men (average 80 days vs. 79 days for men).
The majority of women worked adjacent to the pile (65%
in September and 64% in January–June). This is a higher
proportion than men (47% in September and 54% in
January–June). Only 6–8% of women worked on the pile
throughout September 2001–June 2002. In general, the ac-
tivities performed by women responders were not consid-
erably different than men. However, in September, 22% of
women reported personnel support activities versus 8% of
men; 40% reporte d security activities versus 30% of men
and 28% reported search, rescue and recovery versus 49%
for men. This may in part be because more women were
in white collar occupations such as media, administrative,
healthcare. There was little difference between males and
females in the fraction of WTC responders who were
volunteers (17% women vs. 14% men).
692 Woskie et al.
Page 12
DISCUSSION
The collapse of the WTC on September 11, 2001 was
a major urban disaster that required a complex and exten-
sive recovery effort. Large numbers of responders from
multiple occupations were involved in this effort. They
performed a myriad of recovery activities, often in stress-
ful and dangerous conditions. This study provides the first
comprehensive description of the pre-9/11 occupations,
and of the post-9/11 work locations and the types of activ-
ities performed by 18,969 responders who enrolled in the
WTC MMTP.
Our study showed that the response to the WTC di-
saster included workers from diverse occupations and
backgrounds. Almost one-half of the responders (exclud-
ing FDNY fire fighters/EMT’s) belonged to the protective
services, primarily police officers and mostly NYPD.
However, we found that a large number of workers
(>50% of the cohort) were not part of the typical emer-
gency/first responder groups. For example, 22% of the res-
ponders were from construction occupations. Due to the
major damage to the utility infrastructure in lower Man-
hattan, a substantial number of workers came from electri-
cal, telecommunications & other installation & repair
occupations. Public sector workers comprised more than
one-half (61%)of the total responder population and public
sector workers were include d in all occupational catego-
ries. For example, among the construction occupations
there were transit and city and municipal workers who are
in the construction trades. There were also many other
smaller groups of non-traditional emergency responders
such as business managers and administrators, clerks,
engineers, broadcast and media personnel, social workers,
and computer specialists. Although traditional responders
receive prior training and have experience in emergency
response, other groups were considerably less well pre-
pared for disaster response. Our findings point to the need
for prior emergency response planning and training of
non-traditional responders who will always be part of a
disaster response, such as the groups listed above. Early
on-site health and safety training and the provision of ap-
propriate personal protective equipment for these non-tra-
ditional responders can minimize potential toxic exposures
and decrease the risk of injury during recovery activities.
Assessing the type and extent of exposures is ex-
tremely important for understanding potential health con-
sequences among WTC responders. The findings reported
herein are a platform for the development of a matrix to
characterize exposures among WTC respo nders. Several
previous studies have found that the time of first arrival at
the WTC, a crude measure of exposure to the dust cloud
from the collapse, is one variable that can provide a tem-
poral differentiation in risk [Banau ch et al., 2006; Herbert
et al., 2006; Wheeler et al., 2007; Skloot et al., 2009]. In
this study, we found that a large number of responder s
(44%) began work on 9/11, with 46% of them present
directly in the cloud of dust from the WTC collapse. Since
in this cohort, those who arrived on September 11 were
predominately from the protective services group (65%) it
is likely that many of them arrived at the site as part of
the initial response to the crash of the planes. However,
among the remainder of the occupational groups who
arrived on 9/11, large proportions also reported being
present during the collapse. It should be noted that work-
ers were mobilized from the entire NY/NJ metropolitan
area throughout the day after the initial crash and that
there were three separ ate building collapses at different
times on that day (the South Tower at 9:59 AM, the North
Tower at 10:28 AM and WTC 7 at 5:20 PM).
Most responders (93%) began work in September.
This may explain the consistency in the average number
of days worked across all occupational groups (72–102
days). In addition, workers in several occupational groups
(e.g., construction, electrical, telecommunications and oth-
er installation, and repair workers among others) contin-
ued work after the time period covered by the exposure
assessment questionnaire (end date June 30, 2002).
Due to the added stresses of shift work, it is of partic-
ular interest that 48% of the WTC responders reported
working both day and night shift even in the period after
September, and 3–5% of the responders reporting always
or mainly sleeping onsite. By late September, a veritable
tent city had grown up adjacent to the pile, with many
responder organizations having their own tents [Smith,
2002].
The location and type of the responders’ wor k are
considered an important determinant of potential expo-
sures. Our findings show that the most common work
location was ‘adjacent to the pile’ followed by on the
‘pile or pit, although this varied for different occupa-
tions. Some of the work also occurred in enclosed spaces
within buildings and the relationship of indoor exposures
compared to outdoor exposures has yet to be assessed.
In the future, these factors (timeline, location, indoor vs.
outdoor, along with activity) should be combined to create
an exposure assessment model that can be used in evaluat-
ing health risks among WTC responders.
In examining the geographic and temporal taxonomy
of activities, it becomes apparent that in a disaster of the
magnitude of the WTC collapse, the crisis response
requires most responders to engage initially in search, res-
cue and recovery, regardless of their pre-disaster occupa-
tion. In fact, for most of the occupational groups include d
in this study, search, rescue, and recovery were the most
commonly reported activities during the month of Septem-
ber, 2001. After this initial period, most responders were
engaged in activities related to their original, pre-9/11,
occupations. Nevertheless, building and grounds cleaning
WTC Responder Jobs, Locations, Activities 693
Page 13
was a commonly reported activity in most occupational
groups, due to the wide-spread contamination of dust and
debris from the collapse. Because protective services was
the most common occupation in this cohort, security work
was a very commonly reported activity. The WTC site
was considered a crime scene with only authorized per-
sonnel allowed access. In addition, this urban disaster was
located in a major financial center that also included a
dense concentration of residential and commercial proper-
ties that remained under heightened security due to a
threat of additional terrorist action.
This study provides a comprehensive description of
the different groups, work periods, and type of activities
performed by a large cohort of responders enrolled in the
WTC MMTP. However, NYC firefighters, emergency
medical technicians, and short term workers were not eli-
gible for this program and thus, are not represented in this
report. Moreover, not all potentially eligible WTC res-
ponders have enrolled in the MMTP. Thus, the distribution
of occupations may reflect in part the inclusion and exclu-
sion criteria of the WTC MMTP. Data for ou r study were
obtained from answers to a standardized questionnaire
routinely administered as part of the initial visit to the
WTC MMTP. Although the exposure assessment survey
includes detailed questions about activities, dates, times,
and locations of work, the information is based on self-
reports and thus, potentially subject to recall and other
types of biases.
Another limitation in our data is related to the use of
the SOC groups to describe a responder’s pre-9/11 occu-
pation. Unfortunately, the SOC groups often combine rela-
tively different occupations within a single category.
However, this is a validated system to classify workers
and is one of the most commonly employed coding sys-
tems in the literature as well as in the National Health
Interview Survey.
The structure of the MMTP questionnaire restricted
some analyses. For example, activity information was col-
lected for four time periods and the location of the majori-
ty of the responders work during each time period was
assessed separately. As a consequence, we are unable to
make a direct link between each task and a specific loca-
tion. Instead we have assumed that the activities reported
during a time period occurred at the location reported by
the responder as the site they spend the majority of their
shift during the time period. Similarly, there was no infor-
mation collected about activities on a daily basis following
the collapse of the twin towers. This inform ation would
have allowed us to describe in further detail how activity
patterns changed as the WTC site transitioned from crisis
response to the subsequent recovery phase . Additionally,
the WTC exposure questionnaire is limited to activities
performed through June 30, 2002. However, work in some
occupations, such as telecommunications, construction
and at some sites, such as the Fresh Kills landfill, contin-
ued well beyond this date.
Despite these limit ations, the exposure assessment
questionnaire provides a great deal of insight into the
work done by responders to the WTC disaster. The large
cohort size and the detail available from the questionnaire
provide the most comprehensive description to date of the
non-FDNY WTC responder population. Based on post-9/
11 experiences at the WTC site and surrounding areas, as
well as on experiences gained in the aftermath of hurri-
cane Katrina, the BP oil disaster in the Gulf, as well as
the tsunami and nuclear reactor disaster in Japan, the defi-
nition of a disaster responder has become much broader
and responders should be understood to include not only
conventional emergency responders involved in the imme-
diate response to the crisis, but also those workers who
participate in the restoration of vital services and recovery
activities which may last for years [Bradt, 2003]. This rec-
ognition makes planning for health, safety, exposure as-
sessment, and protectio n of all workers in the aftermath of
a disaster much more complex than previously conceived
[Bradt, 2003].
CONCLUSION
Our analysis described the spatial, temporal, occupa-
tional, and task-related taxonomy of the responders en-
rolled in our program. This study shows that the response
to the WTC disaster included a large number of traditional
as well as non-traditional workers, most of whom arrived
early after the collapse of the towers and were involved in
numerous recovery activities at multiple locations over
time. The most common pre-9/11 occupation in our pro-
gram was protective services (47%), but many were non-
traditional responders (construction, telecommunications,
transportation, and support services workers), and 14%
worked as volunteers. Public sector workers comprise
61% of the total responder population enrolled in this co-
hort. Almost one-half began work on 9/11a nd >80%
reported working on or adjacent to the ‘pile’ at Ground
Zero. Initially, the most common activity was search and
rescue but subsequently, the activities of most responders
related to their pre- 9/11 occupations. Other major activi-
ties include d security; personnel support; buildings and
grounds cleaning; and telephone, cable, and computer re-
pair. The results will aid development of a job-exposure
matrix, assist assessment of disease risk and improve plan-
ning for future urban disasters.
ACKNOWLEDGMENTS
Thanks to Hovi Nguyen for making the maps used in
this paper.
694 Woskie et al.
Page 14
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WTC Responder Jobs, Locations, Activities 695
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    • "Protective Services (e.g., law enforcement and emergency medical services workers); Construction; Buildings and Grounds Cleaning and Maintenance and Electrical, Telecommunications and Other Installation and Repair Groups (CM & IRG); and All Other Occupations (Woskie et al. 2011 "
    [Show abstract] [Hide abstract] ABSTRACT: Background: World Trade Center rescue and recovery workers were exposed to a complex mix of pollutants and carcinogens. The purpose of this investigation was to evaluate cancer incidence in responders during the first seven years after September 11, 2001. Methods: Cancers among 20,984 consented participants in the WTC Health Program were identified through linkage to state tumor registries in New York, New Jersey, Connecticut, and Pennsylvania. Standardized incidence ratios (SIRs) were calculated to compare cancers diagnosed in responders to predicted numbers for the general population. Multivariate regression models were used to estimate associations with degree of exposure. Results: A total of 575 cancers were diagnosed in 552 individuals. Increases over registry-based expectations were noted for all cancer sites combined (SIR 1.15; 95% CI: 1.06, 1.25), thyroid cancer (SIR 2.39; 95% CI: 1.70, 3.27), prostate cancer (SIR 1.21; 95% CI: 1.01, 1.44), combined hematopoietic and lymphoid cancers (SIR 1.36; 95% CI: 1.07, 1.71) and soft tissue cancers (SIR 2.26; 95% CI: 1.13, 4.05). When restricted to 302 cancers diagnosed six or more months after enrollment, the SIR for all cancers decreased to 1.06 (95% CI: 0.94, 1.18), but thyroid and prostate cancer diagnoses remained greater than expected. All cancers combined were increased in very highly exposed responders and among those exposed to significant amounts of dust compared with responders who reported lower levels of exposure. Conclusion: Estimates should be interpreted with caution given the short follow-up and long latency period for most cancers, the intensive medical surveillance of this cohort, and the small numbers of cancers at specific sites. However, our findings highlight the need for continued follow up and surveillance of WTC responders.
    Full-text · Article · Apr 2013 · Environmental Health Perspectives