Risk factors for and consequences of persistent lower respiratory symptoms among World Trade Center Health Registrants 10 years after the disaster

Descriptive analysis to establish the prevalence of lead-associated chronic conditions among adult public health registry participants in Flint, Michigan: identifying disparities to support focused recovery efforts

Background

A population-level trauma, the Flint water crisis (FWC) exposed approximately 140 000 people to lead in water. In response, the Flint Registry (FR) was established by a local university in partnership with the community. Lead exposure has been linked to multiple adult-onset chronic diseases, and addressing the health needs of those exposed requires estimating the prevalence of these conditions. Our objective was to calculate the prevalence of chronic conditions among FR-enrolled adults and compare prevalence to state-wide surveillance estimates.

Methods

Data collection for the FR started 4.5 years after the onset of the FWC; this cross-sectional study included participants who completed their enrolment survey December 2018-July 2022. Participants reported if they had ever been diagnosed with 11 chronic conditions. We used crude and age-adjusted prevalence of the 11 chronic conditions and compared them to 2019-2021 Michigan Behavioral Risk Factor Surveillance System (MiBRFSS) estimates.

Results

We included 14 274 adult (≥18) participants in this study. Crude and age-adjusted prevalence was higher in FR participants than MiBRFSS estimates for 9 of the 11 chronic conditions, such as kidney disease. Age-adjusted results suggested that 8.1% of participants would have kidney disease if they had the same age distribution as the adult population of Michigan, whereas only 3.4% of the adult population in Michigan has a kidney disease diagnosis. Patterns for males, females, black and white participants were similar to the overall results, though differences between the black FR participants and MiBRFSS estimates were less extreme.

Conclusion

The FR is a resource for the Flint community and an example for other communities experiencing mass environmental disruptions. We cannot assert the FWC caused any cases of the health conditions evaluated, however, establishing the prevalence of lead-associated conditions among people exposed to the FWC is needed to prioritise secondary prevention efforts and demonstrate the utility of a university-run registry in response to events like the FWC.

World Trade Center-related asthma: clinical care essentials

Asthma is defined as a heterogeneous disease with respiratory symptoms (wheeze, shortness of breath, chest tightness and cough) that vary over time and intensity, and variable expiratory airflow limitation. Environmental and occupational exposures contribute to its causation. WTC-related or aggravated asthma is considered a World Trace Center (WTC) Health Program certifiable disease. Criteria include defined exposures to the WTC dust and fumes, the presence of symptoms, or aggravated symptoms that are present within 5 years after the last potential for WTC dust/fume exposures (the last 9/11 exposures occurred on July 31, 2002), and a WTC-provider diagnosis of asthma. Asthma is the 3^rd most common non-cancer certification among WTC responders and survivors. In this review we provide evidence-based information on the evaluation, diagnosis, and treatment of patients with WTC-related or aggravated asthma and include peer-reviewed research findings in WTC-exposed populations.

Long-Term Lower Respiratory Symptoms among World Trade Center Health Registry Enrollees Following Hurricane Sandy

Several studies showed an association between lower respiratory tract symptoms (LRS) and exposure to the 9/11 terrorist attack. However, few studies have examined the long-term impact of natural disasters on those with prior respiratory distress. The present study aims to assess the impact of Hurricane Sandy on persistent LRS among people exposed to the World Trade Center (WTC) terrorist attack. The analytic sample consisted of WTC Health Registry enrollees who completed survey waves 1, 3, and 4 and the Hurricane Sandy Survey and did not report LRS before the WTC terrorist attack. The log binomial was used to assess the association between the impact of Hurricane Sandy and persistent LRS. Of 3277 enrollees, 1111 (33.9%) reported persistent LRS post-Sandy. Participants of older age, males, lower household income, current smokers, and those with previous asthma were more likely to report persistent LRS. In separate adjusted models, multiple Sandy-related inhalation exposures (relative risk (RR): 1.2, 95% CI: 1.06-1.37), Sandy-related PTSD (RR: 1.27, 95% CI: 1.15-1.4), and Sandy LRS (RR: 1.64, 95% CI: 1.48-1.81) were associated with persistent LRS post-Sandy. Our findings suggest that respiratory protection is important for everyone performing reconstruction and clean-up work after a natural disaster, particularly among those with previous respiratory exposures.

Post-Traumatic Growth and Quality of Life among World Trade Center Health Registry Enrollees 16 Years after 9/11

A recent study of World Trade Center Health Registry enrollees found that about one-third experienced post-traumatic growth (PTG) in the wake of the 9/11 attacks and that PTG was associated with social support and social integration. However, the implications of PTG for the enrollees' overall quality of life are unknown. The present study investigated the prevalence of PTG and its association with the SF-12 physical and mental functioning quality of life scales in a sample of 4760 enrollees from the Registry's Health and Quality of Life Study (HQoL) who completed the first four surveys, were older than 18 on 9/11, reported English as their primary spoken language, and provided consistent self-report of 9/11 physical injury at the Registry's baseline and HQoL surveys. We employed multivariable linear regression to evaluate the association between PTG and the SF-12 physical and mental scales, controlling for sociodemographic and other variables. We found that 31% of the sample enrollees experienced PTG and that PTG exhibited a clinically and statistically significant association with the SF-12 mental scale but not the physical scale (physical: b = 0.15 (-0.45, 0.75), mental: b = 3.61 (2.85, 4.37)). Those who were physically injured during 9/11 showed larger improvements in mental functioning than those who were not. PTG has implications for the overall mental quality of life that should be further investigated.

Change in Asthma Is Associated with Change in PTSD in World Trade Center Health Registrants, 2011 to 2016

The WTC Health Registry (WTCHR) is a closed, longitudinal cohort of rescue/recovery workers and survivors exposed to the 11 September 2001 disaster. WTCHR enrollees diagnosed with asthma after 11 September 2001 continued to experience poor control despite treatment. Asthma is associated with mental problems, although their bidirectional movement has not been studied. This study tested whether a clinical change in mental problems was associated with a difference in asthma control, and whether a change in asthma control varied with a change in quality of life (QoL). Difference in the Asthma Control Test (ACT) on the WTCHR from 2011-12 to 2015-16 was compared with the change in the Post-traumatic Stress Disorder Checklist (PCL-17), the Patient Health Questionnaire depression scale, self-reported heartburn, and change of physical and mental QoL over this period. In adjusted multinomial multivariable logistic regression, improved PCL-17 was associated with a better ACT score, odds ratio (OR) = 1.42 (95% C.I. 1.01, 1.99), and a worsened PCL-17 score was associated with a worsened ACT score, OR = 1.77 (95% C.I. 1.26, 2.50). Decreased ACT was associated with poor physical QoL, OR = 1.97 (95% C.I. 1.48, 2.62). Change in mental health measures tracked with change in asthma control, which correlated with a change in QoL. Careful follow-up and treatment of all three are indicated to improve these inter-related issues.

Associations between self-reported respiratory symptoms and non-specific psychological distress following exposure to a prolonged landscape fire

We investigated the association between respiratory symptoms and psychological distress in the context of a prolonged smoke event, and evaluated whether smoke exposure, or pre-existing respiratory and mental health conditions, influenced the association. Three thousand ninety-six residents of a rural town heavily exposed to smoke from the 6-week Hazelwood coal mine fire, and 960 residents of a nearby unexposed town, completed Kessler's psychological distress questionnaire (K10) and a modified European Community Respiratory Health Survey. Logistic regression models evaluated associations between distress and respiratory symptoms, with interactions fitted to evaluate effect modification. Smoke exposed participants reported higher levels of distress than those unexposed, and participants reporting respiratory symptoms recorded higher levels of distress than participants without respiratory symptoms, irrespective of exposure. 5-unit increments in K10 scores were associated with 21%-48% increases in the odds of reporting respiratory symptoms. There were significant interactions with pre-existing asthma, chronic obstructive pulmonary disease and mental health conditions, but not with smoke exposure. Although participants with pre-existing conditions were more likely to report respiratory symptoms, increasing distress was most strongly associated with respiratory symptoms among those without pre-existing conditions. Communities exposed to landscape fire smoke could benefit from interventions to reduce both psychological and respiratory distress.

Health-Related Quality of Life (HRQoL) of Residents with Persistent Lower Respiratory Symptoms or Asthma Following a Sulphur Stockpile Fire Incident

Background: This study evaluated health-related quality of life (HRQoL) in residents with persistent lower respiratory symptoms (PLRS) or asthma six years after exposure to sulphur dioxide vapours emanating from an ignited sulphur stockpile. Methods: A cross-sectional study was carried out, using interview data collected at three time points (prior to, one- and six-years post incident), medical history, respiratory symptoms and HRQOL using the Medical Outcomes Study Form 36 (SF-36). Results: A total of 246 records, 74 with and 172 without PLRS or asthma, were analysed. The mean age was 42 (SD:12) years in the symptomatic group and 41 (SD:13) years in the asymptomatic group. Mean SF-36 scores were significantly lower for the symptomatic group in the Physical Functioning (24 vs. 39), Role—Physical (33 vs. 48) and General Health (GH) domains (24 vs. 37). Symptomatic residents experienced a significant decline in their Role—Physical (OR = 1.97; CI 1.09, 3.55) and GH (OR = 3.50; CI 1.39, 8.79) at year 6 compared to asymptomatic participants. Residents with co-morbid reactive upper airways dysfunction syndrome demonstrated stronger associations for GH (OR = 7.04; CI 1.61, 30.7) at year 1 and at year 6 (OR = 8.58; CI 1.10, 65.02). Conclusions: This study highlights the long-term adverse impact on HRQoL among residents with PLRS or asthma following a sulphur stockpile fire disaster.

Lung function decline before and after treatment of World Trade Center associated obstructive airways disease with inhaled corticosteroids and long-acting beta agonists

Background

Greater than average loss of one‐second forced expiratory volume (FEV₁) is a risk factor for asthma, chronic obstructive pulmonary disease (COPD), and asthma/COPD overlap syndrome in World Trade Center (WTC)‐exposed firefighters. Inhaled corticosteroids and long‐acting beta agonists (ICS/LABA) are used to treat obstructive airways disease but their impact on FEV₁‐trajectory in this population is unknown.

Methods

The study population included WTC‐exposed male firefighters who were treated with ICS/LABA for 2 years or longer (with initiation before 2015), had at least two FEV₁ measurements before ICS/LABA initiation and two FEV₁ measurements posttreatment between September 11, 2001 and September 10, 2019. Linear mixed‐effects models were used to estimate FEV₁‐slope pre‐ and post‐treatment.

Results

During follow‐up, 1023 WTC‐exposed firefighters were treated with ICS/LABA for 2 years or longer. When comparing intervals 6 years before and 6 years after treatment, participants had an 18.7 ml/year (95% confidence interval [CI]: 11.3–26.1) improvement in FEV₁‐slope after adjustment for baseline FEV₁, race, height, WTC exposure, weight change, blood eosinophil concentration, and smoking status. After stratification by median date of ICS/LABA initiation (January 14, 2010), earlier ICS/LABA‐initiators had a 32.5 ml/year (95% CI: 19.5–45.5) improvement in slope but later ICS/LABA‐initiators had a nonsignificant FEV₁‐slope improvement (7.9 ml/year, 95% CI: −0.5 to 17.2).

Conclusions

WTC‐exposed firefighters treated with ICS/LABA had improved FEV₁ slope after initiation, particularly among those who started earlier. Treatment was, however, not associated with FEV₁‐slope improvement if started after the median initiation date (1/14/2010), likely because onset of disease began before treatment initiation. Research on alternative treatments is needed for patients with greater than average FEV₁‐decline who have not responded to ICS/LABA.

Serum Th-2 cytokines and FEV1 decline in WTC-exposed firefighters: A 19-year longitudinal study

Background

Accelerated‐FEV₁‐decline, defined as rate of decline in FEV₁ > 64 ml/year, is a risk factor for asthma and chronic obstructive pulmonary disease in World Trade Center (WTC)‐exposed firefighters. Accelerated‐FEV₁‐decline in this cohort is associated with elevated blood eosinophil concentrations, a mediator of Th‐2 response. We hypothesized that an association exists between Th‐2 biomarkers and FEV₁ decline rate in those with accelerated‐FEV₁‐decline.

Methods

Serum was drawn from Fire Department of the City of New York (FDNY) firefighters 1–6 months (early) (N = 816) and 12–13 years (late) (N = 983) after 9/11/2001. Th‐2 biomarkers IL‐4, IL‐13, and IL‐5 were assayed by multiplex Luminex. Individual FEV₁ decline rates were calculated using spirometric measurements taken: (1) between 9/11/2001 and 9/10/2020 for the early biomarker group and (2) between late measurement date and 9/10/2020 for the late biomarker group. Associations of early and late Th‐2 biomarkers with subsequent FEV₁ decline rates were analyzed using multivariable linear regression controlling for demographics, smoking status, and other potential confounders.

Results

In WTC‐exposed firefighters with accelerated‐FEV₁‐decline, IL‐4, IL‐13, and IL‐5 measured 1–6 months post‐9/11/2001 were associated with greater FEV₁ decline ml/year between 9/11/2001 and 9/10/2020 (−2.9 ± 1.4 ml/year per IL‐4 doubling; −8.4 ± 1.2 ml/year per IL‐13 doubling; −7.9 ± 1.3 ml/year per IL‐5 doubling). Among late measured Th‐2 biomarkers, only IL‐4 was associated with subsequent FEV₁ decline rate (−4.0 ± 1.6 ml/year per IL‐4 doubling).

Conclusions

In WTC‐exposed firefighters with accelerated‐FEV₁‐decline, elevated serum IL‐4 measured both 1–6 months and 12–13 years after 9/11 is associated with greater FEV₁ decline/year. Drugs targeting the IL‐4 pathway may improve lung function in this high‐risk subgroup.

Long-term impact of coal mine fire smoke on lung mechanics in exposed adults

BACKGROUND AND OBJECTIVE

In 2014, a 6-week-long fire at the Hazelwood coal mine exposed residents in the adjacent town of Morwell to high concentrations of fine particulate matter with an aerodynamic diameter < 2.5 μm (PM_2.5 ). The long-term health consequences are being evaluated as part of the Hazelwood Health Study.

METHODS

Approximately 3.5-4 years after the mine fire, adults from Morwell (n = 346) and the comparison town Sale (n = 173) participated in the longitudinal Respiratory Stream of the Study. Individual PM_2.5 exposure was retrospectively modelled. Lung mechanics were assessed using the forced oscillation technique (FOT), utilizing pressure waves to measure respiratory system resistance (Rrs) and reactance (Xrs). Multivariate linear regression was used to evaluate associations between PM_2.5 and transformed Rrs at 5 Hz, area under the reactance curve (AX5) and Xrs at 5 Hz controlling for key confounders.

RESULTS

There were clear dose-response relationships between increasing mine fire PM_2.5 and worsening lung mechanics, including a reduction in post-bronchodilator (BD) Xrs5 and an increase in AX5. A 10 μg/m³ increase in mine fire-related PM_2.5 was associated with a 0.015 (95% CI: 0.004, 0.027) reduction in exponential (Xrs5) post-BD, which was comparable to 4.7 years of ageing. Similarly, the effect of exposure was associated with a 0.072 (0.005, 0.138) increase in natural log (lnAX5) post-BD, equivalent to 3.9 years of ageing.

CONCLUSION

This is the first study using FOT in adults evaluating long-term respiratory outcomes after medium-term ambient PM_2.5 exposure to coal mine fire smoke. These results should inform public health policies and planning for future events.

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.

Injury Severity and Psychological Distress Sustained in the Aftermath of the Attacks of 11 September 2001 Predict Somatic Symptoms in World Trade Center Health Registry Enrollees Sixteen Years Later

The World Trade Center attacks of 11 September 2001 (9/11) have been associated with the subsequent development of chronic diseases. Few studies have investigated the burden of somatic symptoms on attack victims, or the association of such symptoms with exposure to the 9/11 attacks. World Trade Center Health Registry (Registry) enrollees who were present south of Chambers Street during or immediately after the 9/11 attacks and who provided consistent answers regarding injury sustained on 9/11 were followed prospectively for up to 16 years post-9/11/01. We employed linear regression to evaluate the associations between injury severity, psychological distress and somatic symptoms in 2322 persons who completed all four Registry surveys and a subsequent Health and Quality of Life survey. Twenty-one percent of subjects had a “very high” burden of somatic symptoms, greater than in populations not exposed to a disaster. Somatic symptoms exhibited a dose-response association separately with injury severity and psychological distress trajectories. Victims of the 9/11 attacks suffer from a substantial burden of somatic symptoms which are associated with physical and psychological consequences of exposure to the attacks. Physical and mental health professionals need to work together when treating those exposed to complex disasters such as 9/11.

Probable Posttraumatic Stress Disorder and Lower Respiratory Symptoms Among Rescue/Recovery Workers and Community Members After the 9/11 World Trade Center Attacks-A Longitudinal Mediation Analysis

OBJECTIVE

Posttraumatic stress disorder (PTSD) and lower respiratory symptoms (LRS) often coexist among survivors of the September 11, 2001 (9/11) World Trade Center (WTC) attacks. Research in police and nontraditional responders suggests that PTSD mediates the relationship between 9/11 physical exposures and LRS, but not vice versa. We replicated these findings in WTC rescue/recovery workers (R/R workers), extended them to exposed community members, and explored the interplay between both physical and psychological 9/11 exposures, probable PTSD, and LRS over a 10-year follow-up.

METHODS

Participants were 12,398 R/R workers and 12,745 community members assessed in three WTC Health Registry surveys (2003-2004, 2006-2007, and 2011-2012). LRS and 9/11 exposures were self-reported. Probable PTSD was defined as a PTSD Checklist score ≥44.

RESULTS

Probable PTSD predicted LRS (R/R workers: β = 0.88-0.98, p < .001; community members: β = 0.67-0.86, p < .001) and LRS predicted PTSD (R/R workers: β = 0.83-0.91, p < .001; community members: β = 0.68-0.75, p < .001) at follow-ups, adjusting for prior symptoms and covariates. In both R/R workers and community members, probable PTSD mediated the relationship between 9/11 physical exposures (dust cloud, long duration of work) and LRS (indirect effects, p = .001-.006), and LRS mediated the physical exposure-PTSD relationship (indirect effects, p = .001-.006). In R/R workers, probable PTSD mediated the psychological exposure (losing friends or loved ones, witnessing horrific events)-LRS relationship (indirect effect, p < .001), but LRS did not mediate the psychological exposure-PTSD relationship (indirect effect, p = .332). In community members, high 9/11 psychological exposure predicted both probable PTSD and LRS at follow-ups; probable PTSD mediated the psychological exposure-LRS relationship (indirect effect, p < .001), and LRS mediated the psychological exposure-PTSD relationship (indirect effect, p = .001).

CONCLUSIONS

Probable PTSD and LRS each mediated the other, with subtle differences between R/R workers and community members. A diagnosis of either should trigger assessment for the other; treatment should be carefully coordinated.

Comparing life satisfaction and functioning 15 years after September 11, 2001 among survivors with and without injuries: a mixed-method study

PURPOSE

This study compares life satisfaction and limited activity days among 9/11 survivors with and without physical injuries using quantitative and qualitative approaches.

METHODS

The study population included World Trade Center Health Registry enrollees who reported being injured on 9/11 in 2003-2004 and a sample of non-injured enrollees who participated in a cross-sectional substudy. We used multivariable logistic regression to examine differences in life satisfaction and number of limited activity days in the last 30 days between those with and without injuries. The free-response section of the survey was analyzed qualitatively to compare themes of those with and without injuries.

RESULTS

The final sample consisted of 2821 adult enrollees. Compared to those who were not injured, those who were injured on 9/11 were more likely to report being unsatisfied with their life (adjusted odds ratio (AOR): 1.5, 95% confidence intervals (CI) 1.1-2.0) and have 14 or more limited activity days in the last 30 days (AOR: 1.4, 95% CI 1.0-1.9). Among those who were injured, being partially or completely prevented from working increased the odds of being unsatisfied with life and having 14 or more limited activity days. In qualitative analysis, the emotional trauma experienced from 9/11 was a major and common theme, regardless of injury status. Those with injuries were more likely to express anger/lack of recognition/appreciation, describe substance use/abuse, and have financial/health care access issues.

CONCLUSIONS

More than 15 years after 9/11, those who were injured continue to be impacted, reporting lower life satisfaction and more functional impairment.

Pulmonary Fibrosis among World Trade Center Responders: Results from the WTC Health Registry Cohort

Dust created by the collapse of the World Trade Center (WTC) towers on 9/11 included metals and toxicants that have been linked to an increased risk of pulmonary fibrosis (PF) in the literature. Little has been reported on PF among WTC responders. This report used self-reported physician diagnosis of PF with an unknown sub-type to explore the association between levels of WTC dust exposure and PF. We included 19,300 WTC responders, enrolled in the WTC Health Registry in 2003–2004, who were followed for 11 years from 2004 to 2015. Exposure was defined primarily by intensity and duration of exposure to WTC dust/debris and work on the debris pile. Stratified Cox regression was used to assess the association. We observed 73 self-reported physician-diagnosed PF cases, with a PF incidence rate of 36.7/100,000 person-years. The adjusted hazard ratio (AHR) of PF was higher in those with a medium (AHR = 2.5, 95% CI = 1.1–5.8) and very high level of exposure (AHR = 4.5, 95% CI = 2.0–10.4), compared to those with low exposure. A test for exposure—response trend was statistically significant (P_trend = 0.004). Future research on WTC dust exposure and PF would benefit from using data from multiple WTC Health Program responder cohorts for increased statistical power and clinically confirmed cases.

Factors Associated with Persistent Lower Respiratory Symptoms or Asthma among Residents Exposed to a Sulphur Stockpile Fire Incident

Introduction: Residents of Macassar, South Africa, were exposed to sulphur dioxide vapours (SO₂) caused by an ignited sulphur stockpile, which produced peak hourly SO₂ levels of 20–200 ppm. The aim of this study was to assess the risk factors associated with persistent lower respiratory symptoms (LRS) or asthma six years after acute exposure to high SO₂ levels. Methods: A case-control study of residents that presented for a health evaluation six years after the incident was conducted. Survey instruments included a questionnaire, clinical examination and medical record review by an expert panel. A “case” was defined as a resident with persistent LRS/asthma. The Industrial Source Complex Short Term Model (ISCST 3) was used to predict time-averaged hourly SO₂ levels. Results: A previous history of pulmonary tuberculosis (PTB) was associated with persistent LRS/asthma (OR_udj: 3.49, CI: 1.46–8.35). Cases were more likely to report chest tightness (OR_udj: 9.93; CI: 5.15–19.11) at the time of the incident. Peak exposure at hour 15 was associated with persistent LRS/asthma (OR_adj: 1.04; CI: 1.01–1.07). Conclusion: LRS/asthma persisted in some individuals six years after acute SO₂ exposure_. Aside from peak exposures, initial chest tightness and a previous history of PTB were the strong predictors of persistent LRS/asthma.

Asthma among World Trade Center First Responders: A Qualitative Synthesis and Bias Assessment

The World Trade Center (WTC) disaster exposed the responders to several hazards. Three cohorts i.e., the Fire Department of New York (FDNY), the General Responder Cohort (GRC), and the WTC Health Registry (WTCHR) surveyed the exposed responder population. We searched Pubmed and Web of Science for literature on a well-published association between the WTC exposures and asthma, focusing on new-onset self-reported physician-diagnosed asthma. The resulting five articles were qualitatively assessed for potential biases. These papers were independently reviewed by the co-authors, and conclusions were derived after discussions. While, the cohorts had well-defined eligibility criteria, they lacked information about the entire exposed population. We conclude that selection and surveillance biases may have occurred in the GRC and WTCHR cohorts, but were likely to have been minimal in the FDNY cohort. Health care benefits available to responders may have increased the reporting of both exposure and outcome in the former, and decreased outcome reporting in the FDNY cohort. Irrespective of the biases, the studies showed similar findings, confirming the association between WTC exposure and self-reported physician-diagnosed asthma among responders. This suggests that health data gathered under great duress and for purposes other than epidemiology can yield sound conclusions. Potential biases can, however, be minimized by having validated survey instruments and worker registries in place before events occur.

Comorbidity amplifies the effects of post-9/11 posttraumatic stress disorder trajectories on health-related quality of life

PURPOSE

The present study aims to examine the impact of physical and mental health comorbidities on the association between post-9/11 posttraumatic stress disorder (PTSD) trajectories over 10 years and health-related quality of life (HRQOL) among 9/11-exposed persons.

METHODS

30,002 responding adult World Trade Center Health Registry enrollees reporting no pre-9/11 PTSD were studied. PTSD trajectories (chronic, delayed, remitted, no PTSD) were defined based on a 17-item PTSD Checklist-Specific to 9/11 across three waves of survey data. Three indicators of poor HRQOL were defined based on CDC HRQOL-4 measures. We computed age-adjusted prevalence of physical and mental health comorbidity (depression/anxiety) by PTSD trajectory and used modified Poisson regression to assess the effect of PTSD trajectory on poor HRQOL prevalence, accounting for comorbidity.

RESULTS

Age-adjusted prevalence of overall comorbid conditions was 95.8 and 61.4% among the chronic and no-PTSD groups, respectively. Associations between 9/11-related PTSD trajectories and poor HRQOL were significant and became greater when comorbidity was included. Adjusted prevalence ratios were elevated for fair/poor health status (APR 7.3, 95% CI 6.5, 8.2), ≥ 14 unhealthy days (4.7; 95% CI 4.4, 5.1), and ≥ 14 activity limitation days during the last 30 days (9.6; 95% CI 8.1, 11.4) in the chronic PTSD group with physical and mental health comorbidity compared to those without PTSD and comorbidity; similar associations were observed for delayed PTSD.

CONCLUSIONS

Ten years post-9/11 physical and mental health comorbidities have a substantial impact on the PTSD trajectories and HRQOL association. The need for early identification and treatment of PTSD and comorbidity should be emphasized to potentially improve HRQOL.

Airway Disease in Rescue/Recovery Workers: Recent Findings from the World Trade Center Collapse

PURPOSE OF REVIEW

Our goal is to summarize the airway disease literature since September 11, 2001 (9/11), focusing on studies published since 2011 in World Trade Center-exposed rescue/recovery workers.

RECENT FINDINGS

Since 2011, studies have confirmed relationships between initial World Trade Center exposure intensity, severity of symptoms, airway disease diagnoses, and biomarkers of disease progression. Studies continue to document ongoing morbidity in rescue/recovery workers over 10 years after 9/11. Future research should further identify correlates of symptom persistence and new airway disease diagnoses. The unique characteristics of the airway diseases in this population warrant ongoing monitoring and treatment.

Injury, intense dust exposure, and chronic disease among survivors of the World Trade Center terrorist attacks of September 11, 2001

Background

The World Trade Center attack of September 11, 2001 in New York City (9/11) exposed thousands of people to intense concentrations of hazardous materials that have resulted in reports of increased levels of asthma, heart disease, diabetes, and other chronic diseases along with psychological illnesses such as post-traumatic stress disorder (PTSD). Few studies have discriminated between health consequences of immediate (short-term or acute) intense exposures versus chronic residential or workplace exposures.

Methods

We used proportional hazards methods to determine adjusted hazard ratios (AHRs) for associations between several components of acute exposures (e.g., injury, immersion in the dust cloud) and four chronic disease outcomes: asthma, other non-neoplastic lung diseases, cardiovascular disease, and diabetes, in 8701 persons free of those conditions prior to exposure and who were physically present during or immediately after the World Trade Center attacks. Participants were followed prospectively up to 11 years post-9/11.

Results

Heart disease exhibited a dose-response association with sustaining injury (1 injury type: AHR =2.0, 95% CI (Confidence Interval) 1.1–3.6; 2 injury types: AHR = 3.1, 95% CI 1.2–7.9; 3 or more injury types: AHR = 6.8, 95% CI 2.0–22.6), while asthma and other lung diseases were both significantly associated with dust cloud exposure (AHR = 1.3, 95% CI 1.0–1.6). Diabetes was not associated with any of the predictors assessed in this study.

Conclusion

In this study we demonstrated that the acute exposures of injury and dust cloud that were sustained on 9/11/2001 had significant associations with later heart and respiratory diseases. Continued monitoring of 9/11 exposed persons’ health by medical providers is warranted for the foreseeable future.

Risk factors for persistence of lower respiratory symptoms among community members exposed to the 2001 World Trade Center terrorist attacks

OBJECTIVES

We studied the course of lower respiratory symptoms (LRS; cough, wheeze or dyspnoea) among community members exposed to the 9/11/2001 World Trade Center (WTC) attacks during a period of 12-13 years following the attacks, and evaluated risk factors for LRS persistence, including peripheral airway dysfunction and post-traumatic stress disorder (PTSD).

METHODS

Non-smoking adult participants in a case-control study of post-9/11-onset LRS (exam 1, 2008-2010) were recruited for follow-up (exam 2, 2013-2014). Peripheral airway function was assessed with impulse oscillometry measures of R5 and R5-20. Probable PTSD was a PTSD checklist score ≥44 on a 2006-2007 questionnaire.

RESULTS

Of 785 exam 1 participants, 545 (69%) completed exam 2. Most (321, 59%) were asymptomatic at all assessments. Among 192 participants with initial LRS, symptoms resolved for 110 (57%) by exam 2, 55 (29%) had persistent LRS and 27 (14%) had other patterns. The proportion with normal spirometry increased from 65% at exam 1 to 85% at exam 2 in the persistent LRS group (p<0.01) and was stable among asymptomatic participants and those with resolved LRS. By exam 2, spirometry results did not differ across symptom groups; however, R5 and R5-20 abnormalities were more common among participants with persistent LRS (56% and 46%, respectively) than among participants with resolved LRS (30%, p<0.01; 27%, p=0.03) or asymptomatic participants (20%, p<0.001; 8.2%, p<0.001). PTSD, R5 at exam 1, and R5-20 at exam 1 were each independently associated with persistent LRS.

CONCLUSIONS

Peripheral airway dysfunction and PTSD may contribute to LRS persistence. Assessment of peripheral airway function detected pulmonary damage not evident on spirometry. Mental and physical healthcare for survivors of complex environmental disasters should be coordinated carefully.