Long-term Cardiovascular Disease Risk Among Firefighters After the World Trade Center Disaster

Exposure to the World Center Particulate Matter Alters the Gut-Brain Axis in Early Onset Alzheimer's Disease Mice

Background

The September 11, 2001, catastrophe unleashed widespread destruction beyond the World Center (WTC), with fires and toxic gases leaving lasting impacts. First responders at Ground Zero faced prolonged exposure to hazardous particulate matter (PM), resulting in chronic health challenges. Among the multitude of health concerns, the potential association between the WTCPM and Alzheimer's disease (AD) has emerged as an area of intense inquiry, probing the intricate interplay between environmental factors and neurodegenerative diseases.

Objective

We posit that a genetic predisposition to AD in mice results in dysregulation of the gut-brain axis following chronic exposure to WTCPM. This, in turn, may heighten the risk of AD-like symptoms in these individuals.

Methods

3xTg-AD and WT mice were intranasally administered with WTCPM collected at Ground Zero within 72 hours after the attacks. Working memory and learning and recognition memory were monitored for 4 months. Moreover, brain transcriptomic analysis and gut barrier permeability along with microbiome composition were examined.

Results

Our findings underscore the deleterious effects of WTCPM on cognitive function, as well as notable alterations in brain genes associated with synaptic plasticity, pro-survival, and inflammatory signaling pathways. Complementary, chronic exposure to the WTCPM led to increased gut permeability in AD mice and altered bacteria composition and expression of functional pathways in the gut.

Conclusions

Our results hint at a complex interplay between gut and brain axis, suggesting potential mechanisms through which WTCPM exposure may exacerbate cognitive decline. Identifying these pathways offers opportunities for tailored interventions to alleviate neurological effects among first responders.

The impacts of earthquakes on air pollution and strategies for mitigation: a case study of Turkey

This study delves into the repercussions of the 2023 earthquake in Turkey, particularity its impact on air pollution. A year post-event, it is evident that scientific literature has paid limited attention to monitoring the situation. However, the release of hazardous substances, such as asbestos, lead, and other toxins, from damaged structures poses a significant threat by contaminating nearby air, soil, and water sources, thereby jeopardizing ecosystems and public well-being. The improper disposal of waste post-earthquake and the presence of mining and oil refinery sites in the region contribute to potential air pollutants. These circumstances create challenging environments conducive to the spread of respiratory diseases, with potential long-term health and social consequences. Unfortunately, existing data gaps hinder a comprehensive understanding of the situation. This paper pioneers the reporting and analysis of data regarding potential sources of air pollution resulting from the earthquake in Turkey. It also pinpoints gaps in knowledge, outlining areas that demand further investigation. To effectively prevent and mitigate air pollution risks and associated health concerns linked to earthquakes, strategic recommendations are proposed. A key suggestion is the establishment of post-disaster air pollution monitoring systems capable of swiftly identifying emerging health issues, facilitating efficient responses, and curtailing potential long-term effects of the disaster. The paper underscores the necessity for continuous health monitoring of the affected population to mitigate possible adverse impacts on human health. These strategies play a pivotal role in reducing the likelihood of air pollution, supporting emergency response and recovery initiatives, and fostering new dedicated scientific studies.

Self-reported Cardiovascular Disease in Career Firefighters With and Without World Trade Center Exposure

OBJECTIVE

To assess the effect of World Trade Center (WTC) exposure on cardiovascular disease (CVD) in career firefighters. Methods: Firefighters from four US cities completed health questionnaires that provide information about demographics, CVD diagnoses, and CVD risk factors. Firefighters were also compared with respondents of the 2019 National Health Interview Survey. Results: Greater WTC exposure was positively associated with combined coronary artery disease, myocardial infarction, and angina (termed "CAD") when comparing WTC-exposed with non-WTC-exposed firefighters. Compared with the National Health Interview Survey population, firefighters had lower odds of CAD and stroke. Conclusions: An occupationally appropriate comparison is important to mitigate potential bias from the healthy worker effect. While the risk of CVD in WTC-exposed and non-WTC-exposed firefighters was significantly lower than a general US population, we observed an exposure gradient where greater WTC exposure was associated with greater odds of CVD.

Effects of Daily Posttraumatic Stress Disorder Symptoms on Heart Rate Variability

OBJECTIVE

Posttraumatic stress disorder (PTSD) is common, debilitating, and associated with an increased risk of health problems, including cardiovascular disease. PTSD is related to poor autonomic function indicated by reduced heart rate variability (HRV). However, very little work has tested the timescale or direction of these effects, given that most evidence comes from cross-sectional studies. Documentation of when effects occur and in what direction can shed light on mechanisms of cardiovascular disease risk and inform treatment. The present study of 169 World Trade Center responders, oversampled for PTSD, tested how daily PTSD symptoms were associated with autonomic function as reflected through HRV.

METHODS

Participants ( N = 169) completed surveys of PTSD symptoms three times a day at 5-hour intervals for 4 days while also wearing ambulatory monitors to record electrocardiograms to derive HRV (i.e., mean absolute value of successive differences between beat-to-beat intervals).

RESULTS

HRV did not predict PTSD symptoms. However, PTSD symptoms during a 5-hour interval predicted reduced HRV at the next 5-hour interval ( β = -0.09, 95% confidence interval = -0.16 to -0.02, p = .008). Results held adjusting for baseline age, current heart problems, and current PTSD diagnosis.

CONCLUSIONS

Findings underscore growing awareness that PTSD symptoms are not static. Even their short-term fluctuations may affect cardiovascular functioning, which could have more severe impacts if disruption accumulates over time. Research is needed to determine if momentary interventions can halt increases in PTSD symptoms or mitigate their impact on cardiovascular health.

Association of Lung Function Decline with All-Cause and Cancer-Cause Mortality after World Trade Center Dust Exposure

Rationale: In numerous cohorts, lung function decline is associated with all-cause and cardiovascular-cause mortality, but the association between the decrease in forced expiratory volume in 1 second (FEV1) and cancer-cause mortality, particularly after occupational/environmental exposure(s), is unclear. Exposure to dust/smoke from the World Trade Center (WTC) disaster caused inflammation and lung injury in Fire Department of the City of New York rescue/recovery workers. In addition, prior research found that >10% of the cohort experienced greater than twice the age-related decrease in FEV1 (⩾64 ml/yr). Objectives: To evaluate the association of longitudinal lung function with all-cause and cancer-cause mortality after exposure to the WTC disaster. Methods: We conducted a prospective cohort study using longitudinal prebronchodilator FEV1 data for 12,264 WTC-exposed firefighters and emergency medical service providers. All-cause and cancer-cause mortality were ascertained using National Death Index data from September 12, 2001, through December 31, 2021. Joint longitudinal survival models evaluated the association of baseline FEV1 and change in FEV1 from baseline with all-cause and cancer-cause mortality adjusted for age, race/ethnicity, height, smoking, work assignment (firefighters vs. emergency medical service providers), and WTC exposure. Results: By December 31, 2021, 607 of the 12,264 individuals in the cohort (4.9%) had died (crude rate = 259.5 per 100,000 person-years), and 190 of 12,264 (1.5%) had died from cancer (crude rate = 81.2 per 100,000 person-years). Baseline FEV1 was ⩾80% predicted in 10,970 of the 12,264 (89.4%); final FEV1 was ⩾80% in 9,996 (81.5%). Lower FEV1 at baseline was associated with greater risk for all-cause mortality (hazard ratio [HR] per liter = 2.32; 95% confidence interval [95% CI] = 1.98-2.72) and cancer-cause mortality (HR per liter = 1.99; 95% CI = 1.49-2.66). Longitudinally, each 100-ml/yr decrease in FEV1 was associated with an 11% increase in all-cause mortality (HR = 1.11; 95% CI = 1.06-1.15) and a 7% increase in cancer-cause mortality (HR = 1.07; 95% CI = 1.00-1.15). Compared with FEV1 decrease <64 ml/yr, those with FEV1 decrease ⩾64 ml/yr had higher all-cause (HR = 2.91; 95% CI = 2.37-3.56) and cancer-cause mortality (HR = 2.68; 95% CI = 1.90-3.79). Conclusions: Baseline FEV1 and longitudinal FEV1 decrease are associated with increased risk of all-cause and cancer-cause mortality in a previously healthy occupational cohort, the majority of whom had normal lung function, after intense exposure to dust/smoke. Further investigation is needed to define pathways by which lung function impacts mortality after an irritant exposure.

Weight Status and Binge Drinking Among Male and Female Florida Firefighters

OBJECTIVE

The aim of the study is to examine the association between weight status and binge drinking among Florida firefighters.

METHODS

Health survey data collected between 2015 and 2019 among Florida firefighters participating in the Annual Cancer Survey were analyzed for weight class (healthy, overweight, obese) and binge-drinking behaviors. Binary logistic regression models were fit and stratified by sex while controlling for sociodemographic and health characteristics.

RESULTS

Among 4002 firefighter participants, 45.1% binge drink, 50.9% are overweight, and 31.3% are obese. Among male firefighters, being overweight (adjusted odds ratio = 1.34; 95% confidence interval = 1.10-1.64) or obese (1.29; 1.04-1.61) was significantly associated with binge drinking compared with healthy weight counterparts. In female firefighters, being obese (2.25; 1.21-4.22) was significantly associated with binge drinking but being overweight was not.

CONCLUSIONS

Being overweight or obese is selectively associated with binge drinking among male and female firefighters.

A 15-year follow-up study of mortality in a pooled cohort of World Trade Center rescue and recovery workers

INTRODUCTION

Hazardous exposures from the World Trade Center (WTC) terrorist attacks have been linked to increased incidence of adverse health conditions, often associated with increased mortality. We assessed mortality in a pooled cohort of WTC rescue/recovery workers over 15 years of follow-up.

MATERIALS AND METHODS

We analyzed mortality through 2016 in a pooled and deduplicated cohort of WTC rescue/recovery workers from three WTC-exposed cohorts (N = 60,631): the Fire Department of the City of New York (FDNY); the WTC Health Registry (WTCHR); and the General Responder Cohort (GRC). Standardized mortality ratios (SMRs) were estimated to assess mortality vs. the US and NY state populations. Multivariable Cox proportional hazards models were used to examine associations of WTC exposures (date of first arrival, working on the WTC debris pile) with mortality risk.

RESULTS

There were 1912 deaths over 697,943.33 person-years of follow-up. The SMR for all-cause mortality was significantly lower-than-expected, both when using US (SMR 0.43, 95% confidence interval [CI] 0.42-0.45) and NYS (SMR 0.51, 95% CI 0.49-0.53) as reference populations. SMRs were not elevated for any of the 28 major causes of death. Arriving at the WTC site on 9/11-9/17/2001 vs. 9/18/2001-6/30/2002 was associated with 30-50% higher risk of all-cause, heart disease and smoking-related mortality in non-FDNY/non-GRC members. Conversely, arriving on 9/11/2001 vs. 9/18/2001-6/30/2002 was associated with 40% lower all-cause and smoking-related mortality risk in FDNY members. Working on vs. off the WTC pile was associated with an increased risk of all-cause mortality in non-FDNY/non-GRC members (adjusted hazard ratio [aHR] 1.25, 95% CI 1.04-1.50), and cancer-specific mortality in GRC members (aHR 1.39, 95% CI 1.05-1.84), but lower mortality risks were found in FDNY members.

CONCLUSIONS

We did not observe excess mortality among WTC rescue/recovery workers compared with general populations. However, significantly increased mortality risks among some sub-groups with high WTC exposure warrant further investigation.

Tracking diseases related to the terrorist attacks of September 11, 2001

Accurate, timely, and complete disease reporting is essential to understanding the extent and long-term consequences of diseases related to the terrorist attacks of September 11, 2001 (9/11). Although there are no public health disease reporting requirements that specifically mention 9/11, other mechanisms exist to track 9/11-related illnesses. These include the availability of 9/11-exposed cohorts, some open to new member recruitment and others closed. Record linkages of 9/11 cohorts to various data registries (eg statewide cancer registries and the National Death Index) are periodically performed. This paper describes these 9/11 cohorts and the efforts to track their health experience.

Association between Cardiovascular Disease Risk Factors and Cardiorespiratory Fitness in Firefighters: A Systematic Review and Meta-Analysis

Approximately 45% of on-duty related mortalities were due to sudden cardiac death, with many of these fatalities related to cardiovascular disease and overexertion, while performing emergency duties. Therefore, the aim of this systematic review was to determine the association between cardiovascular disease risk factors and cardiorespiratory fitness in firefighters. A literature search of PubMed, SCOPUS, Web of Science, Embase, EBSCOHost, and ScienceDirect was conducted; the Rayyan® intelligent systematic review tool was used to screen and select studies for inclusion. The appraisal tool for cross-sectional studies and the Critical Appraisal Skills Programme toolkit were used for methodological assessment of included studies. Data were analyzed using the Review Manager 5.3 and MedCalc® statistical softwares to determine the effects of obesity (Z = 10.29, p < 0.001) and aging (Z = 4.72, p < 0.001) on cardiorespiratory fitness. Furthermore, there was a significant effect for cardiorespiratory fitness level on systolic blood pressure (Z = 5.94, p < 0.001), diastolic blood pressure (Z = 2.45, p < 0.001), total cholesterol levels (Z = 3.80, p < 0.001), low-density lipoprotein cholesterol (Z = 4.44, p < 0.001), triglycerides (Z = 3.76, p < 0.001) and blood glucose concentration (Z = 4.78, p < 0.001). Cardiovascular disease risk factors and cardiorespiratory fitness were significantly and inversely associated in firefighters. Fire service departments should adopt behavioral intervention strategies to maintain optimum cardiovascular disease risk factor profiles and cardiorespiratory fitness among firefighters to ensure their occupational well-being.

Exposure to World Trade Center Dust Exacerbates Cognitive Impairment and Evokes a Central and Peripheral Pro-Inflammatory Transcriptional Profile in an Animal Model of Alzheimer's Disease

BACKGROUND

The terrorist attacks on September 11, 2001, on the World Trade Center (WTC) led to intense fires and a massive dense cloud of toxic gases and suspended pulverized debris. In the subsequent years, following the attack and cleanup efforts, a cluster of chronic health conditions emerged among First Responders (FR) who were at Ground Zero for prolonged periods and were repeatedly exposed to high levels of WTC particulate matter (WTCPM). Among those are neurological complications which may increase the risk for the development of Alzheimer's disease (AD) later in life.

OBJECTIVE

We hypothesize that WTCPM dust exposure affects the immune cross-talking between the periphery and central nervous systems that may induce brain permeability ultimately promoting AD-type phenotype.

METHODS

5XFAD and wild-type mice were intranasally administered with WTCPM dust collected at Ground Zero within 72 h after the attacks. Y-maze assay and novel object recognition behavioral tests were performed for working memory deficits and learning and recognition memory, respectively. Transcriptomic analysis in the blood and hippocampus was performed and confirmed by RT qPCR.

RESULTS

Mice exposed to WTCPM dust exhibited a significant impairment in spatial and recognition short and long-term memory. Furthermore, the transcriptomic analysis in the hippocampal formation and blood revealed significant changes in genes related to immune-inflammatory responses, and blood-brain barrier disruption.

CONCLUSION

These studies suggest a putative peripheral-brain immune inflammatory cross-talking that may potentiate cognitive decline, identifying for the first time key steps which may be therapeutically targetable in future studies in WTC FR.

Circulating galectin-3 levels are inversely associated with subclinical cardiovascular disease in obese adults

BACKGROUND

Galectin-3 is a new cytokine that is mainly secreted by activated macrophages. It is involved in apoptosis, inflammation and may play a role in the development of cardiovascular disease (CVD). However, there is little information about the association between circulating galectin-3 and subclinical atherosclerosis in humans.

METHODS AND RESULTS

We measured serum galectin-3 in 483 obese adult subjects (aged 40 years and over) who had the measurement of carotid intima-media thickness (CIMT) recruited from the community. Adults with lower levels of circulating galectin-3 had increased CIMT (p < 0.05). In multivariable linear regression analyses, circulating galectin-3 was independently associated with CIMT. The risks of increased CIMT were significantly decreased by 65.1% (OR (95% CI): 0.349 (0.165-0.739)), adjusting for possible confounding factors. Notably, individuals in the lowest quartile of serum galectin-3 were 1.80 times (p < 0.05) more likely to have increased CIMT than those in the highest quartile in multivariable logistic regression analyses; however, such associations with circulating galectin-3 were not noted for carotid plague.

CONCLUSIONS

These findings propose that circulating galectin-3 concentrations are inversely associated with increased CIMT in obese adults, which may be a potential biomarker of CVD.

Mutagenicity of the organic fraction of World Trade Center dust

Most studies of the health effects and chemical characterization of the dust resulting from the catastrophic collapse of the World Trade Center (WTC) on September 11, 2001, have focused on the large inorganic fraction of the dust; however, chemical analyses have identified mutagens and carcinogens in the smaller organic fraction. Here, we determined the mutagenicity of the organic fraction of WTC dust in Salmonella. Only 0.74% of the mass of the particulate matter (PM) <53 μm in diameter was extractable organic matter (EOM). Because the EOM was 10 times more mutagenic in TA100 +S9 than in TA98 +S9 and was negative in TA98 -S9, we inferred, respectively, that polycyclic aromatic hydrocarbons (PAHs) played a role in the mutagenicity and not nitroarenes. In TA98 +S9, the mutagenic potency of the EOM (0.1 revertant/μg EOM) was within the range of EOMs from air and combustion emissions. However, the EOM-based mutagenic potency of the particles (0.0007 revertants/μg PM) was 1-2 orders of magnitude lower than values from a review of 50 combustion emissions and various air samples. We calculated that 37 PAHs analyzed previously in WTC EOM were 5.4% of the EOM mass and 0.04% of the PM mass; some air contained 0.3 μg WTC EOM/m³ (0.02 μg PAHs/m³ ). Populations exposed to WTC dust have elevated levels of prostate and thyroid cancer but not lung cancer. Our data support earlier estimates that PAH-associated cancer risk among this population, for example, PAH-associated lung cancer, was unlikely to be significantly elevated relative to background PAH exposures.

Lifestyle and environmental factors may induce airway and systemic inflammation in firefighters

Health status depends on multiple genetic and non-genetic factors. Nonheritable factors (such as lifestyle and environmental factors) have stronger impact on immune responses than genetic factors. Firefighters work is associated with exposure to air pollution and heat stress, as well as: extreme physical effort, mental stress, or a changed circadian rhythm, among others. All these factors can contribute to both, short-term and long-term impairment of the physical and mental health of firefighters. Increased levels of some inflammatory markers, such as pro-inflammatory cytokines or C-reactive protein (CRP) have been observed in firefighters, which can lead to local, acute inflammation that promotes a systemic inflammatory response. It is worth emphasizing that inflammation is one of the main hallmarks of cancer and also plays a key role in the development of cardiovascular and respiratory diseases. This article presents possible causes of the development of an inflammatory reaction in firefighters, with particular emphasis on airway inflammation caused by smoke exposure.

Risk Factors for COVID-19 in a Retired FDNY WTC-Exposed Cohort

We evaluated the incidence and risk factors for COVID-19 in a prospectively followed cohort of Fire Department of the City of New York (FDNY) World Trade Center (WTC)-exposed workers, thus reducing the potential for selection bias, a limitation in published studies of hospitalized individuals. Participants were retired FDNY WTC-exposed rescue/recovery workers with ≥1 medical visit between 1 March 2020 and 1 August 2021. The cumulative incidence was calculated using self-reported COVID-19 diagnoses. Cox regression was performed to evaluate the association of WTC-exposure and COVID-19, adjusting for history of comorbidities, age, race, work assignment (emergency medical service providers vs. firefighter), and sex. The cumulative incidence of COVID-19 was 130 per 1000. The adjusted models showed the risk of infection was greater in those with highest WTC exposure versus less exposure (hazard ratio (HR) = 1.14 (95% CI 1.00–1.31)). Older age was associated with a lower risk of infection HR = 0.97 (95% CI 0.96–0.98). WTC-associated diseases (obstructive airways disease and interstitial lung disease) were not COVID-19 risk factors. This study is the first to show an association between WTC exposure and the risk of COVID-19. While participants are retired from FDNY work, the youngest individuals may still be in the workforce, explaining why younger age was a significant risk for COVID-19.

Association Between Atrial Fibrillation and Occupational Exposure in Firefighters Based on Self-Reported Survey Data

Background Exposure to inhaled smoke, pollutants, volatile organic compounds, and polycyclic aromatic hydrocarbons in the firefighting environment has been associated with detrimental respiratory and cardiovascular effects, making firefighters a unique population with both personal and occupational risk factors for cardiovascular disease. Some of these exposures are also associated with development of atrial fibrillation. We aimed to study the association of atrial fibrillation and occupational exposure in firefighters. Methods and Results A cross-sectional survey was conducted between October 2018 and December 2019. Data were gathered electronically and stored in a secure REDCap database through Louisiana State University Health Shreveport. Firefighters who were members of at least 1 of 5 preselected professional organizations were surveyed via electronic links distributed by the organizations. The survey queried the number of fires fought per year as a measure of occupational exposure, as well as self-reported cardiovascular disease. A total of 10 860 active firefighters completed the survey, of whom 93.5% were men and 95.5% were aged ≤60 years. Firefighters who fought a higher number of fires per year had a significantly higher prevalence of atrial fibrillation (0-5 fires per year 2%, 6-10 fires per year 2.3%, 11-20 fires per year 2.7%, 21-30 fires per year 3%, 31 or more fires per year 4.5%; P<0.001). Multivariable logistic regression showed that a higher number of fires fought per year was associated with an increased risk of atrial fibrillation (odds ratio 1.14 [95% CI, 1.04-1.25]; P=0.006). Conclusions Firefighters may have an increased risk of atrial fibrillation associated with the number of fires they fight per year. Further clinical and translational studies are needed to explore causation and mechanisms.

High burden of clonal hematopoiesis in first responders exposed to the World Trade Center disaster

The terrorist attacks on the World Trade Center (WTC) created an unprecedented environmental exposure to aerosolized dust, gases and potential carcinogens. Clonal hematopoiesis (CH) is defined as the acquisition of somatic mutations in blood cells and is associated with smoking and exposure to genotoxic stimuli. Here we show that deep targeted sequencing of blood samples identified a significantly higher proportion of WTC-exposed first responders with CH (10%; 48 out of 481) when compared with non-WTC-exposed firefighters (6.7%; 17 out of 255; odds ratio, 3.14; 95% confidence interval, 1.64-6.03; P = 0.0006) after controlling for age, sex and race/ethnicity. The frequency of somatic mutations in WTC-exposed first responders showed an age-related increase and predominantly affected DNMT3A, TET2 and other CH-associated genes. Exposure of lymphoblastoid cells to WTC particulate matter led to dysregulation of DNA replication at common fragile sites in vitro. Moreover, mice treated with WTC particulate matter developed an increased burden of mutations in hematopoietic stem and progenitor cell compartments. In summary, the high burden of CH in WTC-exposed first responders provides a rationale for enhanced screening and preventative efforts in this population.

Psychological and traumatic stress and the risk of developing diabetes and psychiatric disorders after a disaster-relief mission: An eight-year longitudinal study of Japan Maritime Self-Defense Force personnel dispatched for the 2011 Great East Japan Earthquake disaster-relief mission

The Great East Japan Earthquake caused triple disasters-the earthquake itself, tsunamis, and nuclear leakage. Japan Maritime Self-Defense Force (JMSDF) personnel engaged in disaster-relief suffered various degrees of psychological stress, which is associated with psychiatric as well as physical disorders, such as diabetes. This study aimed to assess the effect of mission-related stress on the development of diabetes and psychiatric disorders in these personnel using JMSDF annual physical check-up data from 2010 to 2018 and Impact of Events Scale-Revised (IES-R) and Kessler Psychological Distress Scale (K-10) questionnaire data. Cox proportional hazard models were used to assess the hazard ratios (HRs) of developing diabetes and psychiatric disorders in the dispatched (N = 3686) vs. non-dispatched (N = 13,953) groups and high IES-R (score ≥25) vs. low IES-R score and high K-10 (score ≥25) vs. low K-10 score subgroups. We found a significantly higher HR of developing diabetes in the high IES-R score subgroup (2.02; 95% confidence interval [CI], 1.08-3.80). However, the HRs were not significant when comparing dispatched vs. non-dispatched groups and high vs. low K-10 score subgroups. Although the HR of developing psychiatric disorders was significantly lower in the dispatched group (0.64; 95% CI, 0.48-0.84), it was significantly higher in the high IES-R (7.95; 95% CI, 3.38-18.74) and high K-10 (8.76; 95% CI, 4.34-17.68) score subgroups. Thus, this study indicates the importance of paying closer attention to the risk of diabetes and psychiatric disorders in individuals with high IES-R or K-10 scores after disaster-relief activities.

Functional Effects of Cardiomyocyte Injury in COVID-19

COVID-19 affects multiple organs. Clinical data from the Mount Sinai Health System show that substantial numbers of COVID-19 patients without prior heart disease develop cardiac dysfunction. How COVID-19 patients develop cardiac disease is not known. We integrated cell biological and physiological analyses of human cardiomyocytes differentiated from human induced pluripotent stem cells (hiPSCs) infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the presence of interleukins (ILs) with clinical findings related to laboratory values in COVID-19 patients to identify plausible mechanisms of cardiac disease in COVID-19 patients. We infected hiPSC-derived cardiomyocytes from healthy human subjects with SARS-CoV-2 in the absence and presence of IL-6 and IL-1β. Infection resulted in increased numbers of multinucleated cells. Interleukin treatment and infection resulted in disorganization of myofibrils, extracellular release of troponin I, and reduced and erratic beating. Infection resulted in decreased expression of mRNA encoding key proteins of the cardiomyocyte contractile apparatus. Although interleukins did not increase the extent of infection, they increased the contractile dysfunction associated with viral infection of cardiomyocytes, resulting in cessation of beating. Clinical data from hospitalized patients from the Mount Sinai Health System show that a significant portion of COVID-19 patients without history of heart disease have elevated troponin and interleukin levels. A substantial subset of these patients showed reduced left ventricular function by echocardiography. Our laboratory observations, combined with the clinical data, indicate that direct effects on cardiomyocytes by interleukins and SARS-CoV-2 infection might underlie heart disease in COVID-19 patients. IMPORTANCE SARS-CoV-2 infects multiple organs, including the heart. Analyses of hospitalized patients show that a substantial number without prior indication of heart disease or comorbidities show significant injury to heart tissue, assessed by increased levels of troponin in blood. We studied the cell biological and physiological effects of virus infection of healthy human iPSC-derived cardiomyocytes in culture. Virus infection with interleukins disorganizes myofibrils, increases cell size and the numbers of multinucleated cells, and suppresses the expression of proteins of the contractile apparatus. Viral infection of cardiomyocytes in culture triggers release of troponin similar to elevation in levels of COVID-19 patients with heart disease. Viral infection in the presence of interleukins slows down and desynchronizes the beating of cardiomyocytes in culture. The cell-level physiological changes are similar to decreases in left ventricular ejection seen in imaging of patients' hearts. These observations suggest that direct injury to heart tissue by virus can be one underlying cause of heart disease in COVID-19.

Health effects following exposure to dust from the World Trade Center disaster: An update

Exposure to dust, smoke, and fumes containing volatile chemicals and particulate matter (PM) from the World Trade Center (WTC) towers' collapse impacted thousands of citizens and first responders (FR; firefighters, medicals staff, police officers) of New York City. Surviving FR and recovery workers are increasingly prone to age-related diseases that their prior WTC dust exposures might expedite or make worse. This review provides an overview of published WTC studies concerning FR/recovery workers' exposure and causal mechanisms of age-related disease susceptibility, specifically those involving the cardiopulmonary and neurological systems. This review also highlights the recent findings of the major health effects of cardiovascular, pulmonary, and neurological health sequelae from WTC dust exposure. To better treat those that risked their lives during and after the disaster of September 11, 2001, the deleterious mechanisms that WTC dust exposure exerted and continue to exert on the heart, lungs, and brain of FR must be better understood.

Longitudinal Impact of WTC Dust Inhalation on Rat Cardiac Tissue Transcriptomic Profiles

First responders (FR) exposed to the World Trade Center (WTC) Ground Zero air over the first week after the 9/11 disaster have an increased heart disease incidence compared to unexposed FR and the general population. To test if WTC dusts were causative agents, rats were exposed to WTC dusts (under isoflurane [ISO] anesthesia) 2 h/day on 2 consecutive days; controls received air/ISO or air only. Hearts were collected 1, 30, 240, and 360 d post-exposure, left ventricle total RNA was extracted, and transcription profiles were obtained. The data showed that differentially expressed genes (DEG) for WTC vs. ISO rats did not reach any significance with a false discovery rate (FDR) < 0.05 at days 1, 30, and 240, indicating that the dusts did not impart effects beyond any from ISO. However, at day 360, 14 DEG with a low FDR were identified, reflecting potential long-term effects from WTC dust alone, and the majority of these DEG have been implicated as having an impact on heart functions. Furthermore, the functional gene set enrichment analysis (GSEA) data at day 360 showed that WTC dust could potentially impact the myocardial energy metabolism via PPAR signaling and heart valve development. This is the first study showing that WTC dust could significantly affect some genes that are associated with the heart/CV system, in the long term. Even > 20 years after the 9/11 disaster, this has potentially important implications for those FR exposed repeatedly at Ground Zero over the first week after the buildings collapsed.

Twenty-Year Reflection on the Impact of World Trade Center Exposure on Pulmonary Outcomes in Fire Department of the City of New York (FDNY) Rescue and Recovery Workers

After the terrorist attacks on September 11, 2001 (9/11), many rescue/recovery workers developed respiratory symptoms and pulmonary diseases due to their extensive World Trade Center (WTC) dust cloud exposure. Nearly all Fire Department of the City of New York (FDNY) workers were present within 48 h of 9/11 and for the next several months. Since the FDNY had a well-established occupational health service for its firefighters and Emergency Medical Services workers prior to 9/11, the FDNY was able to immediately start a rigorous monitoring and treatment program for its WTC-exposed workers. As a result, respiratory symptoms and diseases were identified soon after 9/11. This focused review summarizes the WTC-related respiratory diseases that developed in the FDNY cohort after 9/11, including WTC cough syndrome, obstructive airways disease, accelerated lung function decline, airway hyperreactivity, sarcoidosis, and obstructive sleep apnea. Additionally, an extensive array of biomarkers has been identified as associated with WTC-related respiratory disease. Future research efforts will not only focus on further phenotyping/treating WTC-related respiratory disease but also on additional diseases associated with WTC exposure, especially those that take decades to develop, such as cardiovascular disease, cancer, and interstitial lung disease.

Dynamic Metabolic Risk Profiling of World Trade Center Lung Disease: A Longitudinal Cohort Study

Rationale: Metabolic syndrome (MetSyn) increases the risk of World Trade Center (WTC) lung injury (LI). However, the temporal relationship of MetSyn, exposure intensity, and lung dysfunction is not well understood. Objective: To model the association of longitudinal MetSyn characteristics with WTC lung disease to define modifiable risk. Methods: Firefighters, for whom consent was obtained (N = 5,738), were active duty on September 11, 2001 (9/11). WTC-LI (n = 1,475; FEV₁% predicted <lower limit of normal [LLN]) and non-WTC-LI (n = 4,263; FEV₁% predicted ⩾LLN at all exams) was the primary outcome, and FVC% predicted <LLN and FEV₁/FVC <0.70 were secondary outcomes. We assessed 1) the effect of concurrent MetSyn on longitudinal lung function by linear mixed models, 2) the temporal effect of MetSyn and exposure by Weibull proportional hazards, 3) the effects of MetSyn's rate of change by two-stage models, and 4) the nonlinear joint effect of longitudinal MetSyn components by a partially linear single-index model (PLSI). Measurements and Main Results: WTC-LI cases were more often ever-smokers, arrived in the morning (9/11), and had MetSyn. Body mass index ⩾30 kg/m² and high-density lipoprotein <40 mg/dl were most contributory to concurrent loss of FEV₁% predicted and FVC% predicted while conserving FEV₁/FVC. Body mass index ⩾30 kg/m² and dyslipidemia significantly predicted WTC-LI, FVC% predicted <LLN in a Weibull proportional hazards model. Dynamic risk assessment of WTC-LI on the basis of MetSyn and exposure showed how reduction of MetSyn factors further reduces WTC-LI likelihood in susceptible populations. PLSI demonstrates that MetSyn has a nonlinear relationship with WTC lung disease, and increases in cumulative MetSyn risk factors exponentially increase WTC-LI risk. An interactive metabolic-risk modeling application was developed to simplify PLSI interpretation. Conclusions: MetSyn and WTC exposure contribute to the development of lung disease. Dynamic risk assessment may be used to encourage treatment of MetSyn in susceptible populations. Future studies will focus on dietary intervention as a disease modifier.

The World Trade Center Health Program: Twenty years of health effects research

It has been 20 years since the devastating terrorist attacks on September 11, 2001. Thousands were injured or killed during the attacks and many more are at risk of adverse health stemming from physical, psychological, and emotional stressors born out of the attacks. Private, federal, state, and local resources were gathered soon after the attacks to address impacts to the community, including the health and well-being of both responders and survivors. Many of these efforts are now largely consolidated under the federally mandated World Trade Center (WTC) Health Program. This program provides medical monitoring and treatment of qualifying conditions among the 9/11-exposed population and supports related physical and mental health research. In this commentary, we describe the WTC Health Program, with emphasis on the health-effects research it has funded since inception in 2011. We describe sentinel research publications, and how science has impacted the program. We provide examples relating studies in this special issue to important roles in the WTC Health Program research agenda. Finally, we provide a perspective on future research needs.

Dose-response relationship between World Trade Center dust exposure and hepatic steatosis

BACKGROUND

The World Trade Center (WTC) attack exposed thousands of workers to toxic chemicals that have been linked to liver diseases and cancers. This study examined the relationship between the intensity of WTC dust exposure and the risk of hepatic steatosis in the WTC General Responders Cohort (GRC).

METHODS

All low-dose computed tomography (CT) scans of the chest performed on the WTC GRC between September 11, 2001 and December 31, 2018, collected as part of the World Trade Center Health Program, were reviewed. WTC dust exposure was categorized into five groups based on WTC arrival time. CT liver density was estimated using an automated algorithm, statistics-based liver density estimation from imaging. The relationship between the intensity of WTC dust exposure and the risk of hepatic steatosis was examined using univariate and multivariable regression analyses.

RESULTS

Of the 1788 WTC responders, 258 (14.4%) had liver attenuation less than 40 Hounsfield units (HU < 40) on their earliest CT. Median time after September 11, 2001 and the earliest available CT was 11.3 years (interquartile range: 8.0-14.9 years). Prevalence of liver attenuation less than 40 HU was 17.0% for arrivals on September 11, 2001, 16.0% for arrivals on (September 12, 2001 or September 13, 2001), 10.9% for arrivals on September 14-30, 2001, and 9.0% for arrivals on January 10, 2001 or later (p = 0.0015). A statistically significant trend of increasing liver steatosis was observed with earlier arrival times (p < 0.0001). WTC arrival time remained a significant independent factor for decreased liver attenuation after controlling for other covariates.

CONCLUSIONS

Early arrival at the WTC site was significantly associated with increasing hepatic steatosis.

Health Trends among 9/11 Responders from 2011-2021: A Review of World Trade Center Health Program Statistics

INTRODUCTION

In a single day, the September 11, 2001 US terrorist attacks (9/11) killed nearly 3,000 people, including 412 first responders. More than 91,000 responders were exposed to a range of hazards during the recovery and clean-up operation that followed. Various health programs track the on-going health effects of 9/11, including the World Trade Center (WTC) Health Program (WTCHP). The objective of this research was to review WTCHP statistics reported by the Centers for Disease Control and Prevention (CDC) to analyze health trends among enrolled responders as the 20-year anniversary of the terrorist attacks approaches.

METHODS

The WTCHP statistics reported by the CDC were analyzed to identify health trends among enrolled responders from 2011 through 2021. Statistics for non-responders were excluded.

RESULTS

A total of 80,745 responders were enrolled in the WTCHP as of March 2021: 62,773 were classified as general responders; 17,023 were Fire Department of New York (FDNY) responders; and 989 were Pentagon and Shanksville responders. Of the total responders in the program, 3,439 are now deceased. Just under 40% of responders with certified health issues were aged 45-64 and 83% were male. The top three certified conditions among enrolled responders were: aerodigestive disorders; cancer; and mental ill health. The top ten certified cancers have remained the same over the last five years, however, leukemia has now overtaken colon and bladder cancer as the 20-year anniversary approaches. Compared to the general population, 9/11 first responders had a higher rate of all cancers combined, as well as higher rates of prostate cancer, thyroid cancer, and leukemia.

DISCUSSION

Trends in these program statistics should be viewed with some caution. While certain illnesses have been linked with exposure to the WTC site, differences in age, sex, ethnicity, smoking status, and other factors between exposed and unexposed groups should also be considered. Increased rates of some illnesses among this cohort may be associated with heightened surveillance rather than an actual increase in disease. Still, cancer in general, as well as lung disease, heart disease, and posttraumatic stress disorder (PTSD), seem to be increasing among 9/11 responders, even now close to 20 years later.

CONCLUSION

Responders should continue to avail themselves of the health care and monitoring offered through programs like the WTCHP.

Relationship Between Various Coronary Artery Disease Risk Factors in Firefighters

OBJECTIVE

To determine the correlation between the various coronary artery disease risk factors in firefighters.

METHODS

The study used a quantitative, cross-sectional, and correlational study design. A total of 124 full-time firefighters were conveniently recruited to participate. Research procedures were based on the ACSM guidelines.

RESULTS

Significances were found between age and body mass index (BMI) (r = 0.42, P < 0.001), age and waist circumference (WC) (r = 0.52, P < 0.001), BMI and WC (r = 0.88, P < 0.001), BMI and diastolic blood pressure (DBP) (r = 0.48, P < 0.001), between WC and DBP (r = 0.48, P < 0.001) and between gender and cigarette smoking (χ2[1] = 5.66, P = 0.017).

CONCLUSION

There were significant strong relationships between BMI, SBP, DBP, dyslipidemia, and increasing age, especially in male firefighters. Reducing key risk factors should be emphasized.

Association between post-traumatic stress disorder and alcohol-related hospitalizations among World Trade Center Health Registry enrollees

BACKGROUND

We examined both the impact of 9/11-related exposures and repeated assessments of post-traumatic stress disorder (PTSD) on the risk of alcohol-related hospitalizations (ARH) among individuals exposed to the World Trade Center (WTC) disaster.

METHODS

9/11-related exposures (witnessing traumatic events, physical injuries, or both) were measured at baseline and PTSD symptoms were assessed at four time points (2003-2016) using the PTSD Checklist-17 among 53,174 enrollees in the WTC Health Registry. ICD-9-CM and ICD-10-CM codes were used to identify ARHs (2003-2016) through linked administrative data. For the effect of 9/11-related exposures on ARH, Cox proportional-hazards regression estimated hazard ratios (HR) and 95 % confidence intervals (CI); for time-varying PTSD, extended Cox proportional-hazards regression was used. Models were adjusted fora priori confounders and stratified by enrollee group (uniformed rescue and recovery worker (RRW), non-uniformed RRW, and community members). Person-time was calculated from baseline or 9/12/2001 to the earliest of ARH, withdrawal, death, or end of follow-up (12/31/2016).

RESULTS

Across all 9/11-related exposures, community members and non-uniformed RRWs were at increased risk of ARHs; uniformed RRWs were not. In adjusted models, PTSD was associated with an increased risk of hospitalization across all groups [HR, (95 % CI): uniformed RRWs: 2.6, (1.9, 3.6); non-uniformed RRWs: 2.1, (1.7, 2.7); and community members: 2.6, (2.1, 3.2)].

CONCLUSIONS

Among certain enrollee groups, 9/11-related exposures are associated with an increased risk of ARH and that PTSD is strongly associated with ARHs among all enrollee groups. Findings may assist the clinical audience in improving screening and treatment.

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

BACKGROUND

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).

METHODS

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.

RESULTS

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.

CONCLUSIONS

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 of men's. GRC-elevated CVD risk may also be occurring at a younger age than in the general population.

Severity of Myocardial Ischemia Is Related to Career Length Rather Than Age Among Professional Firefighters

BACKGROUND

Ischemic heart disease (IHD) is the major cause of duty-related fatalities in the fire service. Age and career length are not only important risk factors associated with IHD, but are also highly correlated. The aim of this secondary analyses was to assess the relationship between age, career length, and IHD, based on ischemic severity, to identify whether age or career length had a stronger relationship to IHD.

METHODS

This was a secondary, correlational analysis of on-duty firefighters without known cardiovascular or respiratory disease who underwent exercise treadmill testing with 12-lead electrocardiography. Ischemia was defined based on current guidelines. Maximum ST-segment depression was measured to determine IHD ischemic severity. Age, years of employment, demographics, weight, blood pressure were recorded. Multiple correlations were computed between age, career length, and IHD.

FINDINGS

Twenty-two firefighters were included (96% male, 82% White, 82% overweight or obese, 77% hypertensive). The partial correlation between maximum ST-segment depression and age controlled for career length was not significant (r = -.392, p = .079). The partial correlation between maximum ST-segment depression and career length controlled for age was statistically significant (r = .466, p = .033).

CONCLUSION/APPLICATION TO PRACTICE

Career length, not age, moderately correlates with IHD ischemic severity among firefighters. Career length is a proxy measure of occupational exposures which contributes to IHD. When assessing IHD risk in firefighters, health practitioners should consider incorporating the occupational exposure history (i.e., career length) in addition to age when providing risk reduction services.

Prevalence of coronary artery disease risk factors in firefighters in the city of Cape Town fire and rescue service - A descriptive study

Background: Over 45% of firefighter deaths are attributable to sudden cardiac death related to coronary artery disease (CAD), with many of these deaths attributed to comorbidities. The purpose of the study is to determine the prevalence of coronary artery disease (CAD) risk factors in firefighters in the City of Cape Town (CoCT). Design and Methods: The study used a quantitative, cross-sectional and descriptive design. A total of 124 full-time firefighters were conveniently recruited between September and November 2019 from the City of Cape Town Fire and Rescue Service. Results: The most prevalent CAD risk factors among firefighters were hypertension (33.1%), obesity (37.1%), cigarette smoking (39.5%) and dyslipidaemia (40.3%). A total of 41.9% of firefighters were categorized as low-risk, 54.8% as moderate-risk, and 3.2% as high-risk for CAD. Conclusion: The majority of firefighters had at least one CAD risk factor, with older males having the highest prevalence of multiple CAD risk factors. Compared to other regions of the world, the (CoCT) firefighters have higher prevalence of dyslipidaemia and cigarette smoking. Preventative behavioural strategies and education on CAD should be promoted to mitigate the development of CAD.

Cardiovascular effects of air pollution: current evidence from animal and human studies

Air pollution is a global health concern. Particulate matter (PM)_2.5, a component of ambient air pollution, has been identified by the World Health Organization as one of the pollutants that poses the greatest threat to public health. Cardiovascular health effects have been extensively documented, and these effects are still being researched to provide an overview of recent literature regarding air pollution-associated cardiovascular morbidity and mortality in humans. Additionally, potential mechanisms through which air pollutants affect the cardiovascular system are discussed based on human and additional animal studies. We used the strategy of a narrative review to summarize the scientific literature of studies that were published in the past 7 yr. Searches were carried out on PubMed and Web of Science using predefined search queries. We obtained an initial set of 800 publications that were filtered to 78 publications that were relevant to include in this review. Analysis of the literature showed significant associations between air pollution, especially PM_2.5, and the risk of elevated blood pressure (BP), acute coronary syndrome, myocardial infarction (MI), cardiac arrhythmia, and heart failure (HF). Prominent mechanisms that underlie the adverse effects of air pollution include oxidative stress, systemic inflammation, endothelial dysfunction, autonomic imbalance, and thrombogenicity. The current review underscores the relevance of air pollution as a global health concern that affects cardiovascular health. More rigorous standards are needed to reduce the cardiovascular disease burden imposed by air pollution. Continued research on the health impact of air pollution is needed to provide further insight.

Physiology of cardiomyocyte injury in COVID-19

COVID-19 affects multiple organs. Clinical data from the Mount Sinai Health System shows that substantial numbers of COVID-19 patients without prior heart disease develop cardiac dysfunction. How COVID-19 patients develop cardiac disease is not known. We integrate cell biological and physiological analyses of human cardiomyocytes differentiated from human induced pluripotent stem cells (hiPSCs) infected with SARS-CoV-2 in the presence of interleukins, with clinical findings, to investigate plausible mechanisms of cardiac disease in COVID-19 patients. We infected hiPSC-derived cardiomyocytes, from healthy human subjects, with SARS-CoV-2 in the absence and presence of interleukins. We find that interleukin treatment and infection results in disorganization of myofibrils, extracellular release of troponin-I, and reduced and erratic beating. Although interleukins do not increase the extent, they increase the severity of viral infection of cardiomyocytes resulting in cessation of beating. Clinical data from hospitalized patients from the Mount Sinai Health system show that a significant portion of COVID-19 patients without prior history of heart disease, have elevated troponin and interleukin levels. A substantial subset of these patients showed reduced left ventricular function by echocardiography. Our laboratory observations, combined with the clinical data, indicate that direct effects on cardiomyocytes by interleukins and SARS-CoV-2 infection can underlie the heart disease in COVID-19 patients.

Post-9/11 Mental Health Comorbidity Predicts Self-Reported Confusion or Memory Loss in World Trade Center Health Registry Enrollees

Numerous studies report elevated levels of chronic mental health conditions in those exposed to the World Trade Center attacks of 11 September 2001 (9/11), but few studies have examined the incidence of confusion or memory loss (CML) or its association with mental health in 9/11 attack survivors. We investigated the incidence of CML and its association with the number of post-9/11 mental health conditions (PTSD, depression, and anxiety) in 10,766 World Trade Center Health Registry (Registry) enrollees aged 35–64 at the time of the wave 4 survey (2015–2016) that completed all four-wave surveys and met the study inclusion criteria. We employed log-binomial regression to evaluate the associations between CML and the number of mental health conditions. A total of 20.2% of enrollees in the sample reported CML, and there was a dose-response relationship between CML and the number of mental health conditions (one condition: RR = 1.85, 95% CI (1.65, 2.09); two conditions: RR = 2.13, 95% CI (1.85, 2.45); three conditions: RR = 2.51, 95% CI (2.17, 2.91)). Survivors may be experiencing confusion or memory loss partly due to the mental health consequences of the 9/11 attacks. Clinicians treating patients with mental health conditions should be aware of potential cognitive impairment.

World Trade Center Health Program: First Decade of Research

The terrorist attacks on 11 September 2001 placed nearly a half million people at increased risk of adverse health. Health effects research began shortly after and continues today, now mostly as a coordinated effort under the federally mandated World Trade Center (WTC) Health Program (WTCHP). Established in 2011, the WTCHP provides medical monitoring and treatment of covered health conditions for responders and survivors and maintains a research program aimed to improve the care and well-being of the affected population. By 2020, funds in excess of USD 127 M had been awarded for health effects research. This review describes research findings and provides an overview of the WTCHP and its future directions. The literature was systematically searched for relevant articles published from 11 September 2001 through 30 June 2020. Synthesis was limited to broad categories of mental health, cancer, respiratory disease, vulnerable populations, and emerging conditions. In total, 944 WTC articles were published, including peer-reviewed articles funded by the WTCHP (n = 291) and other sources. Research has focused on characterizing the burden and etiology of WTC-related health conditions. As the program moves forward, translational research that directly enhances the care of individuals with chronic mental and physical health conditions is needed.

Mortality among Fire Department of the City of New York Rescue and Recovery Workers Exposed to the World Trade Center Disaster, 2001-2017

The World Trade Center (WTC) attacks on 9/11/2001 have consistently been associated with elevated rates of physical and mental health morbidities, while evidence about mortality has been limited. We examined mortality between 9/12/2001 and 12/31/2017 among 15,431 WTC-exposed Fire Department of the City of New York (FDNY) firefighters and emergency medical service providers (EMS), specifically assessing associations between intensity of WTC-exposure and mortality risk. Standardized mortality ratios (SMR) and 95% confidence intervals (CI) compared FDNY cohort mortality with the US general population using life table analysis. Deaths were identified via linkage to the National Death Index. Cox proportional hazards regression models were used to identify associations between intensity of WTC-exposure and mortality, accounting for age, sex, race/ethnicity, smoking history, and other relevant confounders. We identified 546 deaths and a lower than expected all-cause mortality rate (SMR = 0.34; 95% CI, 0.31–0.37). No cause-specific SMRs were meaningfully elevated. Mortality hazard ratios showed no association or linear trend with level of WTC-exposure. Our results provide evidence of the healthy worker effect, despite exposure to the World Trade Center. More follow-up time may be needed to assess the full impact of WTC-exposure on mortality in this occupational population.

Association Between Posttraumatic Stress Disorder and Mortality Among Responders and Civilians Following the September 11, 2001, Disaster

IMPORTANCE

Posttraumatic stress disorder (PTSD) has been associated with increased mortality, primarily in studies of veterans. The World Trade Center Health Registry (Registry) provides a unique opportunity to study the association between PTSD and mortality among a population exposed to the World Trade Center attacks in New York, New York, on September 11, 2001 (9/11).

OBJECTIVES

To assess whether 9/11-related probable PTSD (PTSD) is associated with increased mortality risk, as well as whether this association differs when including repeated measures of PTSD over time vs a single baseline assessment.

DESIGN, SETTING, AND PARTICIPANTS

A longitudinal cohort study of 63 666 Registry enrollees (29 270 responders and 34 396 civilians) was conducted from September 5, 2003, to December 31, 2016, with PTSD assessments at baseline (wave 1: 2003-2004) and 3 follow-up time points (wave 2: 2006-2007, wave 3: 2011-2012, wave 4: 2015-2016). Data analyses were conducted from December 4, 2018, to May 20, 2019.

EXPOSURES

Posttraumatic stress disorder was defined using the 17-item PTSD Checklist-Specific (PCL-S) self-report measure (score ≥50) at each wave (waves 1-4). Baseline PTSD was defined using wave 1 PCL-S, and time-varying PTSD was defined using the PCL-S assessments from all 4 waves.

MAIN OUTCOMES AND MEASURES

Mortality outcomes were ascertained through National Death Index linkage from 2003 to 2016 and defined as all-cause, cardiovascular, and external-cause mortality.

RESULTS

Of 63 666 enrollees (38 883 men [61.1%]; mean [SD] age at 9/11, 40.4 [10.4] years), 6689 (10.8%) had PTSD at baseline (responders: 2702 [9.5%]; civilians: 3987 [12.0%]). Participants who were middle aged (2022 [12.5%]), female (3299 [13.8%]), non-Latino black (1295 [17.0%]), or Latino (1835 [22.2%]) were more likely to have PTSD. During follow-up, 2349 enrollees died (including 230 external-cause deaths and 487 cardiovascular deaths). Among all enrollees in time-varying analyses, PTSD was associated with all-cause, cardiovascular, and external-cause mortality, with adjusted hazard ratios (AHRs) of greater magnitude compared with analyses examining baseline PTSD. Among responders, time-varying PTSD was significantly associated with increased risk of all-cause (AHR, 1.91; 95% CI, 1.58-2.32), cardiovascular (AHR, 1.95; 95% CI, 1.25-3.04), and external-cause (AHR, 2.40; 95% CI, 1.47-3.91) mortality. Among civilians, time-varying PTSD was significantly associated with increased risk of all-cause (AHR, 1.54; 95% CI, 1.28-1.85), cardiovascular (AHR, 1.72; 95% CI, 1.15-2.58), and external-cause (AHR, 2.11; 95% CI, 1.06-4.19) mortality.

CONCLUSIONS AND RELEVANCE

The risk of mortality differed in examination of baseline PTSD vs repeated measures of PTSD over time, suggesting that longitudinal data should be used where possible. Comparable findings between responders and civilians suggest that 9/11-related PTSD is associated with an increased mortality risk.

The Physical and Mental Health Challenges Experienced by 9/11 First Responders and Recovery Workers: A Review of the Literature

Introduction:

In the years following the September 11, 2001 terrorist attacks in New York (USA), otherwise known as 9/11, first responders and recovery workers began experiencing a range of physical and mental health challenges. Publications documenting these provide an important evidence-base identifying exposure-related health challenges associated with environmental exposures from the World Trade Center (WTC) site and describe the key lessons learned regarding both physical and mental health challenges (including symptoms and defined conditions) from the 9/11 disaster response.

Methods:

A systematic literature review was conducted using the MEDLINE, PubMed, CINAHL, and PsychInfo databases (September 11, 2001 to September 11, 2018) using relevant search terms, truncation symbols, and Boolean combination functions. Publications were limited to journal articles that documented the physical or mental health challenges of 9/11 on first responders or recovery workers.

Results:

A total of 156 publications were retrieved by the search strategy. The majority (55%) reported a quantitative methodology, while only seven percent reported the use of a qualitative research methodology. Firefighters were the group of responders most frequently reported in the literature (35%), while 37% of publications reported on research that included a mix of first responders and recovery workers. Physical health was the focus of the majority of publications (57%). Among the challenges, respiratory issues were the physical health condition most frequently reported in publications, while posttraumatic stress disorder (PTSD) was the most frequent mental health condition reported on. Publications were published in a broad range of multi-disciplinary journals (n = 75).

Discussion:

These findings will go some way to filling the current gap in the 9/11 evidence-base regarding the understanding of the long-term health challenges for first responders and recovery workers.