World Trade Center Disaster Site Research Articles

Association of World Trade Center (WTC) Occupational Exposure Intensity with Chronic Obstructive Pulmonary Disease (COPD) and Asthma COPD Overlap (ACO).

Reported associations between World Trade Center (WTC) occupational exposure and chronic obstructive pulmonary disease (COPD) or asthma COPD overlap (ACO) have been inconsistent. Using spirometric case definitions, we examined that association in the largest WTC occupational surveillance cohort. We examined the relation between early arrival at the 2001 WTC disaster site (when dust and fumes exposures were most intense) and COPD and ACO in workers with at least one good quality spirometry with bronchodilator response testing between 2002 and 2019, and no physician-diagnosed COPD before 9/11/2001. COPD was defined spirometrically as fixed airflow obstruction and ACO as airflow obstruction plus an increase of ≥ 400ml in FEV1 after bronchodilator administration. We used a nested 1:4 case-control design matching on age, sex and height using incidence density sampling. Of the 17,928 study participants, most were male (85.3%) and overweight or obese (84.9%). Further, 504 (2.8%) and 244 (1.4%) study participants met the COPD and ACO spirometric case definitions, respectively. In multivariable analyses adjusted for smoking, occupation, cohort entry period, high peripheral blood eosinophil count and other covariates, early arrival at the WTC site was associated with both COPD (adjusted odds ratio [ORadj] = 1.34, 95% confidence interval [CI] 1.01-1.78) and ACO (ORadj = 1.55, 95%CI 1.04-2.32). In this cohort of WTC workers, WTC exposure intensity was associated with spirometrically defined COPD and ACO. Our findings suggest that early arrival to the WTC site is a risk factor for the development of COPD or of fixed airway obstruction in workers with pre-existing asthma.

Assembling the Career Firefighter Health Study cohort: A methods overview.

Studies of World Trade Center (WTC)-exposed rescue/recovery workers report the increased occurrence of health conditions after work at the WTC disaster site. However, the extent to which these associations are due to WTC exposure is unclear, in part due to the lack of suitable comparison groups. Accordingly, we identified a previously assembled National Institute for Occupational Safety and Health (NIOSH) cohort of career firefighters from three US cities (n = 29,992). Here, we document the challenges in establishing this non-WTC-exposed firefighter cohort for the goal of tracking and comparing cancer and chronic health conditions in WTC-exposed and non-WTC-exposed firefighters. Follow-up process included institutional review board applications, data use agreements, state cancer registry linkages and vital status determination for the NIOSH firefighter cohort. After completion of these steps, we undertook outreach to the three original city fire departments and union officials, before contact tracing and direct recruitment of 14,566 living firefighters to complete a confidential health survey. We staggered recruitment efforts by the city, using letters, postcards, emails, videos, and telephone outreach. Participants who completed the survey received $10. A total of 4962 of 14,566 alive firefighters responded to the baseline survey (34.1% response rate). Respondents were older and more likely to be non-Hispanic white than nonrespondents. We provide an overview of the process for the first survey to collect information on physical and mental health conditions among US firefighters. The data collected will have an important impact on studies of WTC rescue/recovery work, firefighting, and related health conditions.

Association of low FVC spirometric pattern with WTC occupational exposures

BackgroundA reduced forced vital capacity without obstruction (low FVC) is the predominant spirometric abnormality reported in workers and volunteers exposed to dust, gases, and fumes at the World Trade Center (WTC) disaster site in 2001–2002. While low FVC has been associated with obesity and metabolic syndrome, its association with WTC occupational exposures has not been demonstrated. We estimated the prevalence of this abnormality and examined its association with WTC exposure level. MethodsLongitudinal study of the relation between arrival at the WTC site within 48 h and FVC below the lower limit of normal (FVC < LLN, with normal FEV1/FVC ratio) at any time in 10,284 workers with at least two spirometries between 2002 and 2018. Logistic regression and linear mixed models were used for the multivariable analyses. ResultsThe prevalence of low FVC increased from 17.0% (95% CI 15.4%, 18.5%) in June 2003, to 26.4% (95% CI 24.8%, 28.1%) in June 2018, and exceeded at both times that of obstruction. The rate of FVC decline was −43.7 ml/year during the study period. In a multivariable analysis adjusting for obesity, metabolic syndrome indicators, and other factors, early arrival at the WTC disaster site was significantly associated with low FVC, but only among men (ORadj = 1.29, 95% CI 1.17, 1.43). Longitudinal FVC rate of decline did not differ by WTC site arrival time. ConclusionsAmong WTC workers, the prevalence of low FVC increased over a 16-year period. Early arrival to the WTC disaster site was significantly associated with low FVC in males.

Incidence and prevalence of antibody to hepatitis C virus in FDNY first responders before and after work at the World Trade Center disaster site.

The goals of this study were to assess the impact of work at the World Trade Center (WTC) site in relation to new, post-9/11/2001 (9/11) antibody to hepatitis C Virus (anti-HCV); and, evaluate secular trends in WTC-exposed male Fire Department of New York City (FDNY) Firefighters and Emergency Medical Services (EMS) responders. FDNY monitors responder health through physical exams and routine blood work. We used descriptive statistics to compare trans-9/11 and post-9/11 incidence and to assess trends in prevalence from 2000 to 2012. Trans-9/11 incidence of new anti-HCV was 0.42 per 100 persons compared with post-9/11 incidence of 0.34 (P = 0.68). Overall seroprevalence was 1.3%; rates declined from 1.79 per 100 to 0.49 per 100 over time (P < 0.0001). Work at the WTC was not associated with new infection. Biennial seroprevalence in responders declined over time, supporting the FDNY decision to discontinue routine annual testing in this cohort.

Multiple Myeloma and Its Precursor Disease Among Firefighters Exposed to the World Trade Center Disaster

The World Trade Center (WTC) attacks on September 11, 2001, created an unprecedented environmental exposure to known and suspected carcinogens suggested to increase the risk of multiple myeloma. Multiple myeloma is consistently preceded by the precursor states of monoclonal gammopathy of undetermined significance (MGUS) and light-chain MGUS, detectable in peripheral blood. To characterize WTC-exposed firefighters with a diagnosis of multiple myeloma and to conduct a screening study for MGUS and light-chain MGUS. Case series of multiple myeloma in firefighters diagnosed between September 11, 2001, and July 1, 2017, together with a seroprevalence study of MGUS in serum samples collected from Fire Department of the City of New York (FDNY) firefighters between December 2013 and October 2015. Participants included all WTC-exposed FDNY white, male firefighters with a confirmed physician diagnosis of multiple myeloma (n = 16) and WTC-exposed FDNY white male firefighters older than 50 years with available serum samples (n = 781). WTC exposure defined as rescue and/or recovery work at the WTC site between September 11, 2001, and July 25, 2002. Multiple myeloma case information, and age-adjusted and age-specific prevalence rates for overall MGUS (ie, MGUS and light-chain MGUS), MGUS, and light-chain MGUS. Sixteen WTC-exposed white male firefighters received a diagnosis of multiple myeloma after September 11, 2001; median age at diagnosis was 57 years (interquartile range, 50-68 years). Serum/urine monoclonal protein isotype/free light-chain data were available for 14 cases; 7 (50%) had light-chain multiple myeloma. In a subset of 7 patients, myeloma cells were assessed for CD20 expression; 5 (71%) were CD20 positive. In the screening study, we assayed peripheral blood from 781 WTC-exposed firefighters. The age-standardized prevalence rate of MGUS and light-chain MGUS combined was 7.63 per 100 persons (95% CI, 5.45-9.81), 1.8-fold higher than rates from the Olmsted County, Minnesota, white male reference population (relative rate, 1.76; 95% CI, 1.34-2.29). The age-standardized prevalence rate of light-chain MGUS was more than 3-fold higher than in the same reference population (relative rate, 3.13; 95% CI, 1.99-4.93). Environmental exposure to the WTC disaster site is associated with myeloma precursor disease (MGUS and light-chain MGUS) and may be a risk factor for the development of multiple myeloma at an earlier age, particularly the light-chain subtype.

Blood Leukocyte Concentrations, FEV1 Decline, and Airflow Limitation. A 15-Year Longitudinal Study of World Trade Center-exposed Firefighters.

Rescue/recovery work at the World Trade Center disaster site (WTC) caused a proximate decline in lung function in Fire Department of the City of New York firefighters. A subset of this cohort experienced an accelerated rate of lung function decline over 15 years of post-September 11, 2001 (9/11) follow-up. To determine if early postexposure blood leukocyte concentrations are biomarkers for subsequent FEV1 decline and incident airflow limitation. Individual rates of forced expiratory volume in 1 second (FEV1) change were calculated for 9,434 firefighters using 88,709 spirometric measurements taken between September 11, 2001, and September 10, 2016. We categorized FEV1 change rates into three trajectories: accelerated FEV1 decline (FEV1 loss >64 ml/yr), expected FEV1 decline (FEV1 loss between 0 and 64 ml/yr), and improved FEV1 (positive rate of change >0 ml/yr). Occurrence of FEV1/FVC less than 0.70 after 9/11 defined incident airflow limitation. Using regression models, we assessed associations of post-9/11 blood eosinophil and neutrophil concentrations with subsequent FEV1 decline and airflow limitation, adjusted for age, race, smoking, height, WTC exposure level, weight change, and baseline lung function. Accelerated FEV1 decline occurred in 12.7% of participants (1,199 of 9,434), whereas post-9/11 FEV1 improvement occurred in 8.3% (780 of 9,434). Higher blood eosinophil and neutrophil concentrations were each associated with accelerated FEV1 decline after adjustment for covariates (odds ratio [OR], 1.10 per 100 eosinophils/μl; 95% confidence interval [CI], 1.05-1.15; and OR, 1.10 per 1,000 neutrophils/μl; 95% CI, 1.05-1.15, respectively). Multivariable-adjusted linear regression models showed that a higher blood neutrophil concentration was associated with a faster rate of FEV1 decline (1.14 ml/yr decline per 1,000 neutrophils/μl; 95% CI, 0.69-1.60 ml/yr; P < 0.001). Higher blood eosinophil concentrations were associated with a faster rate of FEV1 decline in ever-smokers (1.46 ml/yr decline per 100 eosinophils/μl; 95% CI, 0.65-2.26 ml/yr; P < 0.001) but not in never-smokers (P for interaction = 0.004). Higher eosinophil concentrations were also associated with incident airflow limitation (adjusted hazard ratio, 1.10 per 100 eosinophils/μl; 95% CI, 1.04-1.15). Compared with the expected FEV1 decline group, individuals experiencing accelerated FEV1 decline were more likely to have incident airflow limitation (adjusted OR, 4.12; 95% CI, 3.30-5.14). Higher post-9/11 blood neutrophil and eosinophil concentrations were associated with subsequent accelerated FEV1 decline in WTC-exposed firefighters. Both higher blood eosinophil concentrations and accelerated FEV1 decline were associated with incident airflow limitation in WTC-exposed firefighters.

Submicron Particle Monitoring of Paving and Related Road Construction Operations

This study identified activities and sources that contribute to ultrafine and other submicron particle exposure that could trigger respiratory symptoms in highway repair workers. Submicron particle monitoring was conducted for paving, milling, and pothole repair operations in a major metropolitan area where several highway repair workers were identified as symptomatic for respiratory illness following exposures at the 2001 World Trade Center disaster site. Exposure assessments were conducted for eight trades involved in road construction using a TSI P-Trak portable condensation particle counter. Direct readings near the workers’ breathing zones and observations of activities and potential sources were logged on 7 days on 27 workers using four different models of pavers and two types of millers. Average worker exposure levels ranged from 2 to 3 times background during paving and from 1 to 4 times background during milling. During asphalt paving, average personal exposures to submicron particulates were 25,000–60,000, 28,000–70,000, and 23,000–37,000 particles/ cm3 for paver operators, screed operators, and rakers, respectively. Average personal exposures during milling were 19,000–111,000, 28,000–81,000, and 19,000 particles/cm3 for the large miller operators, miller screed operators, and raker, respectively. Personal peak exposures were measured up to 467,000 and 455,000 particles/cm3 in paving and milling, respectively. Several sources of submicron particles were identified. These included the diesel and electric fired screed heaters; engine exhaust from diesel powered construction vehicles passing by or idling; raking, dumping, and paving of asphalt; exhaust from the hotbox heater; pavement dust or fumes from milling operations, especially when the large miller started and stopped; and secondhand cigarette smoke. To reduce the potential for health effects in workers, over 40 recommendations were made to control exposures, including improved maintenance of paver ventilation systems; diesel fume engineering controls; reduced idling; provision of cabs for the operators; and improved dust suppression systems on the milling machine. [Supplementary materials are available for this article. Go to the publisher's online edition of Journal of Occupational and Environmental Hygiene for the following free supplemental resource: a PDF file containing recommendations for controlling fumes and dust during road repair and a report on an investigation of the New York City Department of Transportation road repair operations.]

Assessment of acute injuries, exposure to environmental toxins, and five-year health surveillance of New York Police Department working dogs following the September 11, 2001, World Trade Center terrorist attack

To determine deployment logistics of New York Police Department (NYPD) working dogs that assisted in relief efforts at the World Trade Center (WTC) site following the September 11, 2001, terrorist attack; establish types and rates of related acute injuries and illnesses; identify environmental toxin exposures; and determine long-term (ie, 5-year) health effects of deployment. Prospective cohort study. 27 working dogs. Deployment logistics for the period from September 11, 2001, through May 30, 2002, were determined, and acute health disorders were identified by means of physical examination; a questionnaire; interviews with dog handlers; and toxicologic (blood and hair samples), clinicopathologic, microbiologic (nasal swab specimens submitted for Bacillus anthracis culture), and radiographic methods. Long-term health surveillance ended September 21, 2006. Dogs worked a total of 1,428 days (15,148 hours) at the site. Seventeen of the 27 (62.9%) dogs had health disorders during the first week. Specific conditions included fatigue (incidence rate [events/1,000 active deployment hours], 13.1), conjunctival irritation (13.1), respiratory tract problems (12.4), decreased appetite (10.8), dehydration (10), and cuts (9.3). Only minor hematologic and serum biochemical abnormalities were identified. Bacterial culture of nasal swab specimens did not yield B anthracis. Only mild and infrequent health conditions were identified during the 5-year follow-up period. None of the dogs were identified as having chronic respiratory tract disease. Six dogs died of various causes. Results suggested that acute injuries and illnesses were common among NYPD working dogs deployed to the WTC disaster site, but that longterm health complications were minimal.

Potential for diffuse parenchymal lung disease after exposures at World Trade Center Disaster site

The diffuse parenchymal lung diseases (DPLDs) are a heterogeneous group of disorders that result from damage to the lung parenchyma. While the cause of most DPLDs remains unknown, extensive epidemiological and experimental evidence has linked exposure to environmental toxins to the pathogenesis of some of those diseases. The purpose of this review is to examine the potential relation between exposure to toxins released from the World Trade Center (WTC) collapse on September 11th, 2001 and the development of DPLD based on published evidence up to date. We examine such evidence from two points of view, (1) exposure, and (2) histopathogenesis. Analyses of WTC-dust and particle size demonstrate that some portion of the dust was composed of particles small enough to penetrate deep into the lungs, reaching distal airways and alveoli. The presence of such particles has been confirmed in studies of induced sputum and bronchoalveolar lavage in WTC-exposed firefighters. Histopathogenesis: In vitro and animal experiments and patient evidence suggest that WTC dust is capable of inducing a pulmonary interstitial inflammatory response. To date, there have been limited clinical reports documenting the development of diffuse parenchymal responses following exposure to WTC dust. No single common pathologic response has been described. The one common denominator in the reports is that the individuals who developed disease were heavily exposed either during the disaster or during the initial 2-to-3 days following the disaster. DLPDs are probably associated with heavy or extended exposure to the toxins released at the WTC disaster site. Coupled with the historical experience with exposures to occupational toxins this mandates continued long-term clinical observation of this cohort.

Development of an Exposure Assessment Method for Epidemiological Studies of New York State Personnel who Responded to the World Trade Center Disaster

An exposure assessment method was developed for use in assigning an exposure score to New York State personnel who responded to the World Trade Center disaster site after the 11 September 2001 terrorist attacks. The method consists of an algorithm with two instantiations. Each represents a major component of the overall exposures at the site: dust and smoke. The algorithm uses US Environmental Protection Agency air monitoring data collected between 23 September 2001 and 28 February 2002, as well as information on duration, location and time period of work assignment and type and frequency of personal protective respiratory equipment (PPE) use, collected by a self-administered mailed questionnaire. These data were used to calculate an overall exposure score for each participant. For each time period/location combination, individuals provided average number of hours and number of days worked. This was multiplied by a weighting factor derived from the median of the air monitoring data for the time period/location. Calcium was chosen as a surrogate for the dust exposure, so the weighting factors for the dust instantiation were calculated from calcium air monitoring data. Total hepta-chlorinated dibenzo-p-dioxin was chosen as a surrogate for the smoke exposure and was similarly used in the smoke instantiation. More individuals in the highest exposure score category performed tasks such as search/rescue and hand digging than those in the lowest exposure category. Also, those in the highest exposure category had a higher mean number of hours at the site than other exposure groups. The exposure assessment method presented accounts for PPE use, amount of time at the site, proximity to the site and ambient air monitoring results taken in the immediate vicinity. The algorithm can be used to rank individuals in the same study with very different patterns of exposure, such as high-level, short-term exposures and low-level, long-term exposures. The concepts could be modified for use in other epidemiological studies where long-term chronic exposure is a concern.

Vocal cord dysfunction in former World Trade Center (WTC) rescue and recovery workers and volunteers

Vocal cord dysfunction (VCD) is a condition characterized by paradoxical partial adduction of the vocal cords on inspiration. It has been associated with exposures to irritants, as well as with psychological illnesses and conditions. Workers who participated in the recovery of the WTC disaster site were exposed to a large amount of irritants as well as considerable psychological stressors. We describe the clinical characteristics of 10 symptomatic former WTC workers diagnosed with this condition, as well as the frequency of spirometric findings suggestive of variable extrathoracic obstruction. Workers who became symptomatic after their WTC work experience have been evaluated clinically by a multidisciplinary team at an academic medical center. The evaluation included history, physical examination, chest radiograph, blood tests, and pre- and post-bronchodilator spirometry in all patients. Additional evaluations and diagnostic tests included otolaryngological evaluation with flexible rhinolaryngoscopy and stroboscopy, gastroenterological and psychiatric evaluations. A randomly selected sample of 172 spirometry results were reviewed for evidence of inspiratory flow limitation. Variable extrathoracic obstruction was found in 18.6% of the spirometries. Ten patients were diagnosed with VCD. In addition to symptoms suggestive of co-morbid conditions (particularly rhinitis and acid reflux disease), most of the 10 patients had (1) hoarseness, (2) dyspnea that was not associated with bronchial hyperreactivity, or (3) dyspnea associated with asthma, with either mild bronchial hyperreactivity and/or poor response to asthma treatment. VCD appears to be part of the spectrum of airway disorders caused by occupational exposures at the WTC disaster site. Further study of this association is warranted.

Asthma Diagnosed after 11 September 2001 among Rescue and Recovery Workers: Findings from the World Trade Center Health Registry

BackgroundStudies have consistently documented declines in respiratory health after 11 September 2001 (9/11) among surviving first responders and other World Trade Center (WTC) rescue, recovery, and clean-up workers.ObjectivesThe goal of this study was to describe the risk of newly diagnosed asthma among WTC site workers and volunteers and to characterize its association with WTC site exposures.MethodsWe analyzed 2003–2004 interview data from the World Trade Center Health Registry for workers who did not have asthma before 9/11 (n = 25,748), estimating the risk of newly diagnosed asthma and its associations with WTC work history, including mask or respirator use.ResultsNewly diagnosed asthma was reported by 926 workers (3.6%). Earlier arrival and longer duration of work were significant risk factors, with independent dose responses (p < 0.001), as were exposure to the dust cloud and pile work. Among workers who arrived on 11 September, longer delays in the initial use of masks or respirators were associated with increased risk of asthma; adjusted odds ratios ranged from 1.63 [95% confidence interval (CI), 1.03–2.56) for 1 day of delay to 3.44 (95% CI, 1.43–8.25) for 16–40 weeks delay.ConclusionsThe rate of self-reported newly diagnosed asthma was high in the study population and significantly associated with increased exposure to the WTC disaster site. Although we could not distinguish appropriate respiratory protection from inappropriate, we observed a moderate protective effect of mask or respirator use. The findings underscore the need for adequate and timely distribution of appropriate protective equipment and the enforcement of its use when other methods of controlling respiratory exposures are not feasible.

Rethinking First Response: Effects of the Clean Up and Recovery Effort on Workers at the World Trade Center Disaster Site

We sought to describe the physical and mental health effects of the cleanup and recovery effort on workers at the World Trade Center disaster site. A mailed survey was sent to truck drivers, heavy equipment operators, laborers, and carpenters. It assessed work-related exposures and somatic and mental health symptoms. In one open-ended question, respondents shared any aspect of their experiences they wished; these 332 narrative responses were analyzed using qualitative techniques. Respondents reported suffering debilitating consequences of their work, including depression, drug use, and posttraumatic stress disorder. They felt poorly prepared to work in a disaster, lacked protective equipment and training, and felt overwhelmed by the devastation they faced. These workers' experiences were qualitatively similar to the experiences of the first responders. To protect workers in the future, the focus on preparing "first" responders should be reconsidered more broadly.

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

The destruction of the World Trade Center (WTC) in New York City on September 11, 2001, created a 16-acre debris field composed of pulverized and burning material significantly impacting air quality. Site cleanup began almost immediately. Cleanup workers were potentially exposed to airborne contaminants, including particulate matter, volatile organic compounds, and asbestos, at elevated concentrations. This article presents the results of the exposure assessment of one important group of WTC workers, truck drivers, as well as area monitoring that was conducted directly on site during October 2001 and April 2002. In cooperation with a local labor union, 54 drivers (October) and 15 drivers (April) were recruited on site to wear two monitors during their 12-hour work shifts. In addition, drivers were administered a questionnaire asking for information ranging from “first day at the site” to respirator use. Area monitoring was conducted at four perimeter locations during October and three perimeter locations during April. During both months, monitoring was also conducted at one location in the middle of the rubble. Contaminants monitored for included total dust (TD), PM10, PM2.5, and volatile organic compounds. Particle samples were analyzed for mass, as well as elemental and organic carbon content. During October, the median personal exposure to TD was 346 μg/m3. The maximum area concentration, 1742 μg/m3, was found in middle of the debris. The maximum TD concentration found at the perimeter was 392 μg/m3 implying a strong concentration gradient from the middle of debris outward. PM2.5/PM10 ratios ranged from 23% to 100% suggesting significant fire activity during some of the sampled shifts. During April, the median personal exposure to TD was 144 μg/m3, and the highest area concentration, 195 μg/m3, was found at the perimeter. During both months, volatile organic compounds concentrations were low.

Respiratory effects of inhalation exposure among workers during the clean-up effort at the World Trade Center disaster site

During December 2001 we conducted a field study of 183 clean-up and recovery workers at the World Trade Center (WTC) disaster site to assess respiratory health effects potentially resulting from their work at the site. On site, we administered a respiratory health questionnaire designed to assess upper respiratory symptoms and lower respiratory symptoms, including cough, phlegm, and wheeze, as well as indices of exposure, including number of days worked at the site and job category. Spirometry was conducted for 175 workers. Sixty-five percent of the workers surveyed arrived at the site without lower respiratory symptoms. Of this group, 34% developed cough, 24% developed phlegm, and 19% developed wheeze. Prevalence rates of these symptoms were related to the number of days spent working at the WTC, but not job category. The mean percentage predicted FEV 1 and FVC were 6% and 5% lower, respectively, for workers who developed new lower respiratory symptoms compared to those who remained symptom free. While the development of new wheeze suggested the presence of airway obstruction, the near-normal distribution of age-adjusted FEV 1/FVC ratios suggested that the degree of obstruction was mild. The prevalence rates of upper airway symptoms (nasal congestion, sore throat, hoarse throat) exceeded those of lower respiratory symptoms, however, it was not determined whether symptoms pre-dated arrival at the WTC site.

Respiratory Symptoms and Physiologic Assessment of Ironworkers at the World Trade Center Disaster Site

To characterize respiratory abnormalities in a convenience sample of ironworkers exposed at the World Trade Center (WTC) disaster site for varying lengths of time between September 11, 2001, and February 8, 2002. Cross-sectional study. The Mount Sinai Medical Center, a large tertiary hospital. Ninety-six ironworkers engaged in rescue and recovery with exposure onset between September 11, 2001, and September 15, 2001, who responded to an invitation to undergo respiratory evaluation. Medical and exposure history, physical examination, spirometry, forced oscillation (FO), and chest radiographs. The relationships of prevalence of respiratory symptoms and presence of obstructive physiology to smoking, exposure on September 11, duration of exposure, and type of respiratory protection were examined using univariate and linear and logistic regression analyses. Seventy-four of 96 workers (77%) had one or more respiratory symptoms (similar in smokers [49 of 63 subjects, 78%] and nonsmokers [25 of 33 subjects, 76%]). Cough was the most common symptom (62 of 96 subjects, 65%), and was associated with exposure on September 11. Chest examination and radiograph findings were abnormal in 10 subjects (10%) and 19 subjects (20%), respectively. FO revealed dysfunction in 34 of 64 subjects tested (53%), while spirometry suggested obstruction in only 11 subjects (17%). Lack of a respirator with canister was a risk factor for large airway dysfunction, and cigarette smoking was a risk factor for small airway dysfunction. No other relationships reached statistical significance. Respiratory symptoms occurred in the majority of ironworkers at the WTC disaster site and were not attributable to smoking. Exposure on September 11 was associated with a greater prevalence of cough. Objective evidence of lung disease was less common. Spirometry underestimated the prevalence of lung function abnormalities in comparison to FO. Continuing evaluation of symptoms, chest radiographs, and airway dysfunction should determine whether long-term clinical sequelae will exist.

Site management of health issues in the 2001 World Trade Center disaster.

The terrorist destruction of the World Trade Center led to the greatest loss of life from a criminal incident in the history of the United States. There were 2,801 persons killed or missing at the disaster site, including 147 dead on two hijacked aircraft. Hundreds of buildings sustained direct damage or contamination. Forty different agencies responded with command and control exercised by an incident command system as well as an emergency operations center. Dozens of hazards complicated relief and recovery efforts. Five victims were rescued from the rubble. Up to 1,000 personnel worked daily at the World Trade Center disaster site. These workers collectively made an average of 270 daily presentations to health care providers in the first month post-disaster. Of presentations for clinical symptoms, leading clinical diagnoses were ocular injuries, headaches, and lung injuries. Mechanical injury accounted for 39% of clinical presentations and appeared preventable by personal protective equipment. Limitations emerged in the site application of emergency triage and clinical care. Notable assets in the site management of health issues include action plans from the incident command system, geographic information system products, wireless application technology, technical consensus among health and safety authorities, and workers' respite care.

Clinical and Psychological Abnormalities in New York City Police Officers Who Served at the World Trade Center (WTC) Disaster Site

PURPOSE: Inhalation of dust and smoke can manifest as new symptoms, pulmonary function abnormalities or exacerbate existing conditions. Psychological trauma experienced at the WTC disaster site may also affect symptoms. This study's aim is to evaluate symptoms, pulmonary function and posttraumatic stress disorder (PTSD) in officers involved in the rescue effort at the WTC site.

Multisensor fusion over the World Trade Center disaster site

The immense size and scope of the rescue and clean-up of the World Trade Center site created a need for data that would provide a total overview of the disaster area. To fulfill this need, the New York State Office for Technology (NYSOFT) contracted with EarthData International to collect airborne remote sensing data over Ground Zero with an air- borne light detection and ranging (LIDAR) sensor, a high-resolution digi- tal camera, and a thermal camera. The LIDAR data provided a three- dimensional elevation model of the ground surface that was used for volumetric calculations and also in the orthorectification of the digital images. The digital camera provided high-resolution imagery over the site to aide the rescuers in placement of equipment and other assets. In addition, the digital imagery was used to georeference the thermal im- agery and also provided the visual background for the thermal data. The thermal camera aided in the location and tracking of underground fires. The combination of data from these three sensors provided the emer- gency crews with a timely, accurate overview containing a wealth of information of the rapidly changing disaster site. Because of the dynamic nature of the site, the data was acquired on a daily basis, processed, and turned over to NYSOFT within twelve hours of the collection. During processing, the three datasets were combined and georeferenced to al- low them to be inserted into the client's geographic information systems. © 2002 Society of Photo-Optical Instrumentation Engineers.

Health effects and occupational exposures among office workers near the World Trade Center disaster site.

The extent of health effects and exposure to environmental contaminants among workers and residents indirectly affected by the September 11, 2001, attack on the World Trade Center (WTC) is unknown. The objective of this study was to evaluate concerns related to health effects and occupational exposures three months after the WTC disaster among a population of employees working in a building close to the disaster site. A cross-sectional questionnaire survey was performed of Federal employees working near the WTC site in New York City (NYC) and a comparison group of Federal employees in Dallas, Texas. An industrial hygiene evaluation of the NYC workplace was conducted. Constitutional and mental health symptoms were reported more frequently among workers in NYC compared to those in Dallas; level of social support was inversely related to prevalence of mental health symptoms. Post-September 11th counseling services were utilized to a greater degree among workers in NYC, while utilization of other types of medical services did not differ significantly between the groups. No occupational exposures to substances at concentrations that would explain the reported constitutional symptoms were found; however, we were unable to assess potential occupational exposures in the time immediately after the WTC disaster. There is no evidence of ongoing hazardous exposure to airborne contaminants among the workers surveyed. Specific causes of reported constitutional health symptoms have not been determined. Health care providers and management and employee groups should be aware of the need to address mental health issues as well as constitutional symptoms among the large number of workers in the NYC area who have been indirectly affected by the WTC disaster.