York City Firefighters Research Articles

Cardiovascular disease in the World Trade Center Health Program General Responder Cohort.

Over 90,000 rescue and recovery responders to the September 2001 World Trade Center (WTC) attacks were exposed to toxic materials that can impair cardiac function and increase cardiovascular disease (CVD) risk. We examined WTC-related exposures association with annual and cumulative CVD incidence and risk over 17 years in the WTC Health Program (HP) General Responder Cohort (GRC). Post 9/11 first occurrence of CVD was assessed in 37,725 responders from self-reported physician diagnosis of, or current treatment for, coronary artery disease, myocardial infarction, stroke and/or congestive heart failure from WTCHP GRC monitoring visits. Kaplan-Meier estimates of CVD incidence used the generalized Wilcoxon test statistic to account for censored data. Cox proportional hazards regression analyses estimated the CVD hazard ratio associated with 9/11/2001 arrival in responders with and without dust cloud exposure, compared with arrival on or after 9/12/2001. Additional analyses adjusted for comorbidities. To date, 6.3% reported new CVD. In covariate-adjusted analyses, men's CVD 9/11/2001 arrival risks were 1.40 (95% confidence interval [CI] = 1.26, 1.56) and 1.43 (95% CI = 1.29, 1.58) and women's were 2.16 (95% CI = 1.49, 3.11) and 1.59 (95% CI = 1.11, 2.27) with and without dust cloud exposure, respectively. Protective service employment on 9/11 had higher CVD risk. WTCHP GRC members with 9/11/2001 exposures had substantially higher CVD risk than those initiating work afterward, consistent with observations among WTC-exposed New York City firefighters. Women's risk was greater than that ofmen's. GRC-elevated CVD risk may also be occurring at a younger age than in the general population.

Memory, stress, and the hippocampal hypothesis: Firefighters' recollections of the fireground

Nadel, Jacobs, and colleagues have postulated that human memory under conditions of extremely high stress is "special." In particular, episodic memories are thought to be susceptible to impairment, and possibly fragmentation, attributable to hormonally based dysfunction occurring selectively in the hippocampal system. While memory for highly salient and self-relevant events should be better than the memory for less central events, an overall nonmonotonic decrease in spatio/temporal episodic memory as stress approaches traumatic levels is posited. Testing human memory at extremely high levels of stress, however, is difficult and reports are rare. Firefighting is the most stressful civilian occupation in our society. In the present study, we asked New York City firefighters to recall everything that they could upon returning from fires they had just fought. Communications during all fires were recorded, allowing verification of actual events. Our results confirmed that recall was, indeed, impaired with increasing stress. A nonmonotonic relation was observed consistent with the posited inverted u-shaped memory-stress function. Central details about emergency situations were better recalled than were more schematic events, but both kinds of events showed the memory decrement with high stress. There was no evidence of fragmentation. Self-relevant events were recalled nearly five times better than events that were not self-relevant. These results provide confirmation that memories encoded under conditions of extremely high stress are, indeed, special and are impaired in a manner that is consistent with the Nadel/Jacobs hippocampal hypothesis.

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.

The role of serum amyloid A staining of granulomatous tissues for the diagnosis of sarcoidosis

BackgroundPrevious studies demonstrated that SAA staining of sarcoidosis granulomas was qualitatively and quantitatively different from other granulomatous diseases. These data suggest that positive SAA staining of granulomatous tissue may have adequate specificity to establish a diagnosis of sarcoidosis. Our objective was to determine the diagnostic specificity of SAA staining for sarcoidosis relative to other granulomatous disorders. MethodsPathological specimens demonstrating granulomatous inflammation were retrospectively identified at one institution, plus 4 specimens were obtained from New York City firefighters with biopsy-confirmed World Trade Center “sarcoidosis-like” pulmonary disease. Specimens were analyzed if specific diagnoses related to the granulomatous inflammation were confirmed through medical record review. SAA staining was performed using previously developed methods. Two pathologists, blinded to each other and the diagnoses, determined if the stained material was SAA positive or negative. Discordant results were adjudicated by the two pathologists. Measurements and main results106 specimens were analyzed from 100 patients, with 36 biopsies (34%) from sarcoidosis tissues and 70 (66%) from other granulomatous disorders. The Cohen Kappa correlation between the two pathologists for SAA staining positivity was excellent (0.85, 0.73–0.98). The overall specificity of SAA staining for the diagnosis of sarcoidosis was 84% (59/70). The sensitivity was 44% (16/36). ConclusionsAlthough SAA staining of various granulomatous tissues was fairly specific for the diagnosis of sarcoidosis, the specificity was inadequate for SAA staining to be used as a diagnostic test for sarcoidosis in isolation. These data suggest that SAA production may not be a universal mechanism in the development of sarcoidosis.

Post-9/11 cancer incidence in World Trade Center-exposed New York City firefighters as compared to a pooled cohort of firefighters from San Francisco, Chicago and Philadelphia (9/11/2001-2009).

We previously reported a modest excess of cancer in World Trade Center (WTC)-exposed firefighters versus the general population. This study aimed to separate the potential carcinogenic effects of firefighting and WTC exposure by comparing to a cohort of non-WTC-exposed firefighters. Relative rates (RRs) for all cancers combined and individual cancer subtypes from 9/11/2001 to 12/31/2009 were modeled using Poisson regression comparing 11,457 WTC-exposed firefighters to 8,220 urban non-WTC-exposed firefighters. Compared with non-WTC-exposed firefighters, there was no difference in the RR of all cancers combined for WTC-exposed firefighters (RR = 0.96, 95%CI: 0.83-1.12). Thyroid cancer was significantly elevated (RR = 3.82, 95%CI: 1.07-20.81) from 2001 to 2009; this was attenuated (RR = 3.43, 95%CI: 0.94-18.94) and non-significant when controlling for possible surveillance bias. Prostate cancer was elevated during the latter half (2005-2009; RR = 1.38, 95%CI: 1.01-1.88). Further follow-up is needed to assess the relationship between WTC exposure and cancers with longer latency periods. Am. J. Ind. Med. 59:722-730, 2016. © 2016 Wiley Periodicals, Inc.

Agreement Between Self-Reported and Confirmed Cancer Diagnoses in New York City Firefighters and EMS Workers, 2001-2011.

Because of the delay in availability of cancer diagnoses from state cancer registries, self-reported diagnoses may be valuable in assessing the current cancer burden in many populations. We evaluated agreement between self-reported cancer diagnoses and state cancer registry-confirmed diagnoses among 21,437 firefighters and emergency medical service workers from the Fire Department of the City of New York. We also investigated the association between World Trade Center (WTC) exposure and other characteristics in relation to accurate reporting of cancer diagnoses. Participants self-reported cancer status in questionnaires from October 2, 2001, to December 31, 2011. We obtained data on confirmed cancer diagnoses from nine state cancer registries, which we used as our gold standard. We calculated sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), comparing self-reported cancer diagnoses with confirmed cancer diagnoses. We used multivariable logistic regression models to assess the association between WTC exposure and correct self-report of cancer status, false-positive cancer reports, and false-negative cancer reports. Sensitivity and specificity for all cancers combined were 90.3% and 98.7%, respectively. Specificities and NPVs remained high in different cancer types, while sensitivities and PPVs varied considerably. WTC exposure was not associated with accurate reporting. We found high specificities, NPVs, and general concordance between self-reported cancer diagnoses and registry-confirmed diagnoses. Given the low population prevalence of cancer, self-reported cancer diagnoses may be useful for determining non-cancer cases. Because of the low sensitivities and PPVs for some individual cancers, however, case confirmation with state cancer registries or medical records remains critically important.

Estimating the time interval between exposure to the World Trade Center disaster and incident diagnoses of obstructive airway disease.

Respiratory disorders are associated with occupational and environmental exposures. The latency period between exposure and disease onset remains uncertain. The World Trade Center (WTC) disaster presents a unique opportunity to describe the latency period for obstructive airway disease (OAD) diagnoses. This prospective cohort study of New York City firefighters compared the timing and incidence of physician-diagnosed OAD relative to WTC exposure. Exposure was categorized by WTC arrival time as high (on the morning of September 11, 2001), moderate (after noon on September 11, 2001, or on September 12, 2001), or low (during September 13–24, 2001). We modeled relative rates and 95% confidence intervals of OAD incidence by exposure over the first 5 years after September 11, 2001, estimating the times of change in the relative rate with change point models. We observed a change point at 15 months after September 11, 2001. Before 15 months, the relative rate for the high- versus low-exposure group was 3.96 (95% confidence interval: 2.51, 6.26) and thereafter, it was 1.76 (95% confidence interval: 1.26, 2.46). Incident OAD was associated with WTC exposure for at least 5 years after September 11, 2001. There were higher rates of new-onset OAD among the high-exposure group during the first 15 months and, to a lesser extent, throughout follow-up. This difference in relative rate by exposure occurred despite full and free access to health care for all WTC-exposed firefighters, demonstrating the persistence of WTC-associated OAD risk.

THU0387 Refractory Sarcoid Arthritis in World Trade Center- Exposed New York City Firefighters Necessitating Anti-TNF Alpha Therapy

BackgroundSarcoidosis is characterized by multisystem granulomatous inflammation, predominantly of the lungs. Acute joint manifestations occur in 25–40% of cases and are usually self-limited with only 1–4% developing chronic arthritis. We...

MMP-2 and TIMP-1 predict healing of WTC-lung injury in New York City firefighters

RationaleAfter 9/11/2001, most FDNY workers had persistent lung function decline but some exposed workers recovered. We hypothesized that the protease/anti-protease balance in serum soon after exposure predicts subsequent recovery.MethodsWe performed a nested case–control study measuring biomarkers in serum drawn before 3/2002 and subsequent forced expiratory volume at one second (FEV1) on repeat spirometry before 3/2008. Serum was assayed for matrix metalloproteinases (MMP-1,2,3,7,8,9,12 and 13) and tissue inhibitors of metalloproteinases (TIMP-1,2,3,4). The representative sub-cohort defined analyte distribution and a concentration above 75th percentile defined elevated biomarker expression. An FEV1 one standard deviation above the mean defined resistance to airway injury. Logistic regression was adjusted for pre-9/11 FEV1, BMI, age and exposure intensity modeled the association between elevated biomarker expression and above average FEV1.ResultsFEV1 in cases and controls declined 10% of after 9/11/2001. Cases subsequently returned to 99% of their pre-exposure FEV1 while decline persisted in controls. Elevated TIMP-1 and MMP-2 increased the odds of resistance by 5.4 and 4.2 fold while elevated MMP-1 decreased it by 0.27 fold.ConclusionsResistant cases displayed healing, returning to 99% of pre-exposure values. High TIMP-1 and MMP-2 predict healing. MMP/TIMP balance reflects independent pathways to airway injury and repair after WTC exposure.

Early Elevation of Serum MMP-3 and MMP-12 Predicts Protection from World Trade Center-Lung Injury in New York City Firefighters: A Nested Case-Control Study

ObjectiveAfter 9/11/2001, some Fire Department of New York (FDNY) workers had excessive lung function decline. We hypothesized that early serum matrix metalloproteinases (MMP) expression predicts World Trade Center-Lung Injury (WTC-LI) years later.MethodsThis is a nested case-control analysis of never-smoking male firefighters with normal pre-exposure Forced Expiratory Volume in one second (FEV1) who had serum drawn up to 155 days post 9/11/2001. Serum MMP-1, 2,3,7,8, 9, 12 and 13 were measured. Cases of WTC-LI (N = 70) were defined as having an FEV1 one standard deviation below the mean (FEV1≤77%) at subspecialty pulmonary evaluation (SPE) which was performed 32 months (IQR 21–53) post-9/11. Controls (N = 123) were randomly selected. We modeled MMP's ability as a predictor of cases status with logistic regression adjusted for time to blood draw, exposure intensity, weight gain and pre-9/11 FEV1.ResultsEach log-increase in MMP-3 and MMP-12 showed reduced odds of developing WTC-LI by 73% and 54% respectively. MMP-3 and MMP-12 consistently clustered together in cases, controls, and the cohort. Increasing time to blood draw significantly and independently increased the risk of WTC-LI.ConclusionsElevated serum levels of MMP-3 and MMP-12 reduce the risk of developing WTC-LI. At any level of MMP-3 or 12, increased time to blood draw is associated with a diminished protective effect.

Chitotriosidase is a biomarker for the resistance to World Trade Center lung injury in New York City firefighters.

World Trade Center (WTC) exposure caused airflow obstruction years after exposure. Chitinases and IgE are innate and humoral mediators of obstructive airway disease. We investigated if serum expression of chitinases and IgE early after WTC exposure predicts subsequent obstruction. With a nested case-control design, 251 FDNY personnel had chitotriosidase, YKL-40 and IgE measured in serum drawn within months of 9/11/2001. The main outcome was subsequent Forced Expiratory Volume after 1 second/Forced Vital Capacity (FEV1/FVC) less than the lower limit of normal (LLN). Cases (N = 125) had abnormal FEV1/FVC whereas controls had normal FEV1/FVC (N = 126). In a secondary analysis, resistant cases (N = 66) had FEV1 (≥107%) one standard deviation above the mean. Logistic regression adjusted for age, BMI, exposure intensity and post-exposure FEV1/FVC modeled the association between early biomarkers and later lung function. Cases and Controls initially lost lung function. Controls recovered to pre-9/11 FEV1 and FVC while cases continue to decline. Cases expressed lower serum chitotriosidase and higher IgE levels. Increase in IgE increased the odds of airflow obstruction and decreased the odds of above average FEV1. Alternately, increasing chitotriosidase decreased the odds of abnormal FEV1/FVC and increased the odds of FEV1 ≥ 107%. Serum YKL-40 was not associated with FEV1/FVC or FEV1 in this cohort. Increased serum chitotriosidase reduces the odds of developing obstruction after WTC-particulate matter exposure and is associated with recovery of lung function. Alternately, elevated IgE is a risk factor for airflow obstruction and progressive lung function decline.

Shortfalls in imputing sarcoidosis to occupational exposures

The cause of sarcoidosis remains elusive. Reports of elevated sarcoidosis incidence in New York City firefighters and World Trade Center disaster responders have been advanced to support a causal relationship. This inference is open to question due to methodological differences in assessing and computing sarcoidosis incidence in populations versus putative occupational exposures. The magnitude of the odds ratio (OR; ca. 1.5) of causal candidates in the ACCESS case-control study of occupational and environmental exposures is sufficiently small that it might easily be attributable to confounders. Additionally, multiplicity of comparisons, difficulty in assembling a valid control population and the potential for recall bias critically limit causal inferences. A possible explanation for etiological elusiveness and multiplicity of elevated OR is that individuals with sarcoidosis, lacking components of efficient cellular immunity, respond with systemic granulomas to a variety of ubiquitous, frequently unidentifiable environmental antigens. Epidemiological methods for the identification of sarcoidosis causal candidates are potentially misleading and are unlikely to prove useful.

Early assessment of cancer outcomes in New York City firefighters after the 9/11 attacks: an observational cohort study

The attacks on the World Trade Center (WTC) on Sept 11, 2001 (9/11) created the potential for occupational exposure to known and suspected carcinogens. We examined cancer incidence and its potential association with exposure in the first 7 years after 9/11 in firefighters with health information before 9/11 and minimal loss to follow-up. We assessed 9853 men who were employed as firefighters on Jan 1, 1996. On and after 9/11, person-time for 8927 firefighters was classified as WTC-exposed; all person-time before 9/11, and person-time after 9/11 for 926 non-WTC-exposed firefighters, was classified as non-WTC exposed. Cancer cases were confirmed by matches with state tumour registries or through appropriate documentation. We estimated the ratio of incidence rates in WTC-exposed firefighters to non-exposed firefighters, adjusted for age, race and ethnic origin, and secular trends, with the US National Cancer Institute Surveillance Epidemiology and End Results (SEER) reference population. CIs were estimated with overdispersed Poisson models. Additional analyses included corrections for potential surveillance bias and modified cohort inclusion criteria. Compared with the general male population in the USA with a similar demographic mix, the standardised incidence ratios (SIRs) of the cancer incidence in WTC-exposed firefighters was 1·10 (95% CI 0·98-1·25). When compared with non-exposed firefighters, the SIR of cancer incidence in WTC-exposed firefighters was 1·19 (95% CI 0·96-1·47) corrected for possible surveillance bias and 1·32 (1·07-1·62) without correction for surveillance bias. Secondary analyses showed similar effect sizes. We reported a modest excess of cancer cases in the WTC-exposed cohort. We remain cautious in our interpretation of this finding because the time since 9/11 is short for cancer outcomes, and the reported excess of cancers is not limited to specific organ types. As in any observational study, we cannot rule out the possibility that effects in the exposed group might be due to unidentified confounders. Continued follow-up will be important and should include cancer screening and prevention strategies. National Institute for Occupational Safety and Health.

Trends in Probable PTSD in Firefighters Exposed to the World Trade Center Disaster, 2001–2010

We present the longest follow-up, to date, of probable posttraumatic stress disorder (PTSD) after the 2001 terrorist attacks on the World Trade Center (WTC) in New York City firefighters who participated in the rescue/recovery effort. We examined data from 11,006 WTC-exposed firefighters who completed 40,672 questionnaires and reported estimates of probable PTSD by year from serial cross-sectional analyses. In longitudinal analyses, we used separate Cox models with data beginning from October 2, 2001, to identify variables associated with recovery from or delayed onset of probable PTSD. The prevalence of probable PTSD was 7.4% by September 11, 2010, and continued to be associated with early arrival at the WTC towers during every year of analysis. An increasing number of aerodigestive symptoms (hazard ratio [HR] 0.89 per symptom, 95% confidence interval [CI] 0.86-.93) and reporting a decrease in exercise, whether the result of health (HR 0.56 vs no change in exercise, 95% CI 0.41-.78) or other reasons (HR 0.76 vs no change in exercise, 95% CI 0.63-.92), were associated with a lower likelihood of recovery from probable PTSD. Arriving early at the WTC (HR 1.38 vs later WTC arrival, 95% CI 1.12-1.70), an increasing number of aerodigestive symptoms (HR 1.45 per symptom, 95% CI 1.40-1.51), and reporting an increase in alcohol intake since September 11, 2001 (HR 3.43 vs no increase in alcohol intake, 95% CI 2.67-4.43) were associated with delayed onset of probable PTSD. Probable PTSD continues to be associated with early WTC arrival even 9 years after the terrorist attacks. Concurrent conditions and behaviors, such as respiratory symptoms, exercise, and alcohol use also play important roles in contributing to PTSD symptoms.

A Computerized, Self-Administered Questionnaire to Evaluate Posttraumatic Stress Among Firefighters After the World Trade Center Collapse

We sought to determine the frequency of psychological symptoms and elevated posttraumatic stress disorder (PTSD) risk among New York City firefighters after the World Trade Center (WTC) attack and whether these measures were associated with Counseling Services Unit (CSU) use or mental health-related medical leave over the first 2.5 years after the attack. Shortly after the WTC attack, a computerized, binary-response screening questionnaire was administered. Exposure assessment included WTC arrival time and "loss of a co-worker while working at the collapse." We determined elevated PTSD risk using thresholds derived from Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision, and a sensitivity-specificity analysis. Of 8487 participants, 76% reported at least 1 symptom, 1016 (12%) met criteria for elevated PTSD risk, and 2389 (28%) self-referred to the CSU, a 5-fold increase from before the attack. Higher scores were associated with CSU use, functional job impairment, and mental health-related medical leave. Exposure-response gradients were significant for all outcomes. This screening tool effectively identified elevated PTSD risk, higher CSU use, and functional impairment among firefighters and therefore may be useful in allocating scarce postdisaster mental health resources.

Trial of Prophylactic Inhaled Steroids to Prevent or Reduce Pulmonary Function Decline, Pulmonary Symptoms, and Airway Hyperreactivity in Firefighters at the World Trade Center Site

Inhaled corticosteroids (ICS) are the most effective anti-inflammatory treatment for asthmatics. This trial evaluated the effects of prophylactic ICS in firefighters exposed to the World Trade Center disaster. Inhaled budesonide via a dry powder inhaler (Pulmicort Turbuhaler, AstraZeneca, Wilmington, DE) was offered on-site to New York City firefighters between September 18 and 25, 2001. One to 2 years later, firefighters (n = 64) who completed 4 weeks of daily ICS treatment were evaluated and compared with an age- and exposure-matched comparison group (n = 72) who did not use ICS. When spirometry results at the final visit were compared with those from the weeks following the 9/11 disaster, the treatment group had a greater increase in forced vital capacity (P = .009) and possibly a slower decline in forced expiratory volume at 1 second (P = .11), as well as a greater improvement in perceived well-being as assessed by the St George's Respiratory Questionnaire (P < .01). There was no difference in airway hyperreactivity and no evidence of adverse effects from ICS. Because the potential for hazardous exposures is great at many disasters, disease prevention programs based on environmental controls and respiratory protection are warranted immediately. Our results suggest that, pending further study with a larger sample, prophylactic ICS should be considered, along with respiratory protection, to minimize possible lung insult.

9/11 and New York City Firefighters' Post Hoc Unit Support and Control Climates: A Context Theory of the Consequences of Involvement in Traumatic Work-Related Events

We generate and test a context theory of the impact of involvement in work-related critical incidents, positing that variation in units' postevent support and control climates explains cross-unit v...

Society's Use of the Hero Following a National Trauma

The terrorist nature of the attacks on September 11th, the number of deaths on American soil and the direct involvement of society as virtual eyewitnesses of the events of that day had a traumatizing impact on the cultural consciousness. The interpersonal, socio-cultural manifestations of traumatic grief are explored through an analysis of the creation and transformation of its national heroes, the New York City firefighters, in the public mind over time. Mechanisms of identification, dissociation and splitting were manifested through the erection of physical and social boundaries around 9/11, which allowed for idealization at a safe distance followed by de-cathexis when the collective sought to abort the mourning process and overcome the pain and helplessness of traumatic grief by going to war.

HEALTH RESPONSES OF NEW YORK CITY FIREFIGHTER SPOUSES AND THEIR FAMILIES POST-SEPTEMBER 11, 2001 TERRORIST ATTACKS

Much attention has been focused on New York City firefighters and their responses to the traumatic events of the September 11, 2001, terrorist attacks on the World Trade Center, given their extensive involvement in rescue efforts, and the overwhelming loss of life among the fire department employees. It quickly became evident that the impact of this horrendous event had resonated deeply not only on the families and children of the firefighters who gave their lives, but also on those who had survived. The goal of this study was to conduct semi-structured focus groups of women whose firefighter husbands were directly involved in rescue efforts at Ground Zero. We hoped to identify patterns in survivors' responses to the events as well as any coping mechanisms that the participants used to manage their exposure to the tragedy. An analysis of transcripts from interviews reveals the nature and extent of the impact of the trauma on these women, their husbands, and their children. There were two recurring themes that were apparent from the interview data. Women used patterns of connectedness to other spouses to cope with the emotional impact of the event. In addition, participants reported a constant need to be vigilant in helping their families cope. Issues related to the family's physical, mental, and spiritual health in the context of nursing practice are discussed.

Induced Sputum Assessment in New York City Firefighters Exposed to World Trade Center Dust

New York City Firefighters (FDNY-FFs) were exposed to particulate matter and combustion/pyrolysis products during and after the World Trade Center (WTC) collapse. Ten months after the collapse, induced sputum (IS) samples were obtained from 39 highly exposed FDNY-FFs (caught in the dust cloud during the collapse on 11 September 2001) and compared to controls to determine whether a unique pattern of inflammation and particulate matter deposition, compatible with WTC dust, was present. Control subjects were 12 Tel-Aviv, Israel, firefighters (TA-FFs) and 8 Israeli healthcare workers who were not exposed to WTC dust. All controls volunteered for this study, had never smoked, and did not have respiratory illness. IS was processed by conventional methods. Retrieved cells were differentially counted, and metalloproteinase-9 (MMP-9), particle size distribution (PSD), and mineral composition were measured. Differential cell counts of FDNY-FF IS differed from those of health care worker controls (p < 0.05) but not from those of TA-FFs. Percentages of neutrophils and eosinophils increased with greater intensity of WTC exposure (< 10 workdays or ≥ 10 workdays; neutrophils p = 0.046; eosinophils p = 0.038). MMP-9 levels positively correlated to neutrophil counts (p = 0.002; r = 0.449). Particles were larger and more irregularly shaped in FDNY-FFs (1–50 μm; zinc, mercury, gold, tin, silver) than in TA-FFs (1–10 μm; silica, clays). PSD was similar to that of WTC dust samples. In conclusion, IS from highly exposed FDNY-FFs demonstrated inflammation, PSD, and particle composition that was different from nonexposed controls and consistent with WTC dust exposure.