Permanent respiratory impairment and upper airway symptoms despite clinical improvement in patients with reactive airways dysfunction syndrome

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.

RADS and its variants: asthma by another name

This article describes the different clinical variants of irritant-induced asthma, specifically focusing on high-dose irritant-induced asthma and irritant-induced work-exacerbated asthma, as well as reviews known causes, addresses the often adverse medical and socioeconomic outcomes of this complex condition, and considers issues of causation from an occupational and environmental medicine perspective.

Successful treatment of reactive airways dysfunction syndrome by high-dose vitamin D

Reactive airways dysfunction syndrome is a controversial and poorly understood condition produced by inhalational injury from gas, vapors, or fumes. The symptoms mimic asthma, but appear unresponsive to asthma treatments. If symptoms persist for more than 6 months, there is a risk that they can become chronic. For these cases, effective treatments are lacking and quality of life is poor. We describe the first use of high-dose vitamin D in a patient with this condition, who fulfilled the 1995 American College of Chest Physicians criteria for this syndrome. The patient we describe presented an extremely difficult management problem and was refractory to conventional treatments, but responded to high-dose oral vitamin D supplements.

Inhalation incidents and respiratory health: results from the European Community Respiratory Health Survey

BACKGROUND

Inhalation incidents are an important cause of acute respiratory symptoms, but little is known about how these incidents affect chronic respiratory health.

METHODS

We assessed reported inhalation incidents among 3,763 European Community Respiratory Health Survey (ECRHS) participants with and without cough, phlegm, asthma, wheezing or bronchial hyperresponsiveness. We then examined whether inhalation incidents during the 9-year ECRHS follow-up period were associated with a new onset of any of these respiratory outcomes among 2,809 participants who were free of all five outcomes at the time of the baseline ECRHS survey.

RESULTS

Inhalation incidents were reported by 5% of participants, with higher percentages reported among individuals with asthma-related outcomes at the time of the baseline survey. Among participants without symptoms at baseline, our analyses generated non-statistically significant elevated estimates of the risk of cough, phlegm, asthma and wheezing and a non-statistically significant inverse estimate of the risk of bronchial hyperresponsiveness among participants who reported an inhalation incident compared to those without such an event reported.

DISCUSSION

Our findings provide limited evidence of an association between inhalation incidents and asthma-related symptoms. These data could be affected by differences in the reporting of inhalation incidents according to symptom status at the time of the baseline survey; they should thus be interpreted with caution.

Upper and lower respiratory diseases after occupational and environmental disasters

Respiratory consequences from occupational and environmental disasters are the result of inhalation exposures to chemicals, particulate matter (dusts and fibers) and/or the incomplete products of combustion that are often liberated during disasters such as fires, building collapses, explosions and volcanoes. Unfortunately, experience has shown that environmental controls and effective respiratory protection are often unavailable during the first days to week after a large-scale disaster. The English literature was reviewed using the key words-disaster and any of the following: respiratory disease, pulmonary, asthma, bronchitis, sinusitis, pulmonary fibrosis, or sarcoidosis. Respiratory health consequences after aerosolized exposures to high-concentrations of particulates and chemicals can be grouped into 4 major categories: 1) upper respiratory disease (chronic rhinosinusitis and reactive upper airways dysfunction syndrome), 2) lower respiratory diseases (reactive [lower] airways dysfunction syndrome, irritant-induced asthma, and chronic obstructive airways diseases), 3) parenchymal or interstitial lung diseases (sarcoidosis, pulmonary fibrosis, and bronchiolitis obliterans, and 4) cancers of the lung and pleura. This review describes several respiratory consequences of occupational and environmental disasters and uses the World Trade Center disaster to illustrate in detail the consequences of chronic upper and lower respiratory inflammation.

Pulmonary disease in rescue workers at the World Trade Center site

PURPOSE OF REVIEW

The catastrophic collapse of the World Trade Center (WTC) towers on September 11, 2001 created a large-scale disaster site in a densely populated urban environment. Over the ensuing months, tens of thousands of rescue, recovery and cleanup workers, volunteers, and residents of the adjacent community were exposed to a complex mixture of airborne pollutants. This review focuses on currently described respiratory syndromes, symptoms, and physiologic derangements in WTC rescue, recovery, and cleanup workers, discusses potential long-term effects on respiratory health, and draws parallels to community findings.

RECENT FINDINGS

Detailed qualitative and quantitative analyses of airborne pollutants with their changing composition during initial rescue/recovery and subsequent cleanup have been published. Major concerns include persistent aerodigestive tract inflammatory syndromes, such as reactive airways dysfunction syndrome (RADS), reactive upper airways dysfunction syndrome (RUDS), gastroesophageal reflux disease (GERD), and inflammatory pulmonary parenchymal syndromes, as well as respiratory tract and nonrespiratory malignancies. Aerodigestive tract inflammatory syndromes have now been documented in WTC exposed occupational groups, and syndrome incidence has been linked to WTC airborne pollutant exposure intensity. Community based investigations have yielded similar findings.

SUMMARY

While it is too early to ascertain long-term effects of WTC dust exposure, current studies already demonstrate a definite link between exposure to WTC-derived airborne pollutants and respiratory disease, both in the occupational and the community setting. A better understanding of causes and effects of this exposure will help in developing appropriate preventative tools for rescue workers in future disasters.

The World Trade Center residents' respiratory health study: new-onset respiratory symptoms and pulmonary function

The destruction of the World Trade Center (WTC) on 11 September 2001 in New York City resulted in the massive release of pulverized dust and combustion products. The dust and smoke settled in the surrounding area, which encompassed a large residential community. We hypothesized that previously normal residents in the community surrounding the former WTC would have an increased incidence of persistent respiratory symptoms and abnormalities in screening spirometry. A hybrid cross-sectional and retrospective cohort study using a symptom-based questionnaire and onsite screening spirometry in residents in an exposed area and in a control area was performed 12 +/- 4 months after the collapse. Surveys were analyzed from 2,812 residents. New-onset respiratory symptoms were described by 55.8% of residents in the exposed area, compared with 20.1% in the control area after the event. Persistent new-onset symptoms were identified in 26.4 versus 7.5% of residents in the exposed area versus control area, respectively. No differences in screening spirometry between the groups were detected. A small pilot study suggested the possibility of an increase in bronchial hyperresponsiveness in exposed participants with persistent symptoms. The data demonstrate an increased rate of new-onset and persistent respiratory health effects in residents near the former WTC compared with a control population.

Bronchial hyperreactivity and other inhalation lung injuries in rescue/recovery workers after the World Trade Center collapse

BACKGROUND

The collapse of the World Trade Center (WTC) on September 11, 2001 created a large-scale disaster site in a dense urban environment. In the days and months thereafter, thousands of rescue/recovery workers, volunteers, and residents were exposed to a complex mixture of airborne pollutants.

METHODS

We review current knowledge of aerodigestive inhalation lung injuries resulting from this complex exposure and present new data on the persistence of nonspecific bronchial hyperreactivity (methacholine PC20 < or =8 mg/mL) in a representative sample of 179 Fire Department of the City of New York (FDNY) rescue workers stratified by exposure intensity (according to arrival time) who underwent challenge testing at 1, 3, 6, and 12 months post-collapse.

RESULTS

Aerodigestive tract inflammatory injuries, such as declines in pulmonary function, reactive airways dysfunction syndrome (RADS), asthma, reactive upper airways dysfunction syndrome (RUDS), gastroesophageal reflux disease (GERD), and rare cases of inflammatory pulmonary parenchymal diseases, have been documented in WTC rescue/recovery workers and volunteers. In FDNY rescue workers, we found persistent hyperreactivity associated with exposure intensity, independent of airflow obstruction. One year post-collapse, 23% of highly exposed subjects were hyperreactive as compared with only 11% of moderately exposed and 4% of controls. At 1 yr, 16% met the criteria for RADS.

CONCLUSIONS

While it is too early to ascertain all of the long-term effects of WTC exposures, continued medical monitoring and treatment is needed to help those exposed and to improve our prevention, diagnosis, and treatment protocols for future disasters.