Nasal pathology and ultrastructure in patients with chronic airway inflammation (RADS and RUDS) following an irritant exposure

Occupational Rhinitis: An Update

PURPOSE OF REVIEW

Occupational rhinitis is an underdiagnosed disease with significant morbidity and implications in the workplace. Multiple factors associated with this disease continue to pose a challenge to investigators. This review aims to summarize recent literature in occupational rhinitis, including classifications, pathogenesis, diagnosis, and treatment, as well as the impact of occupational rhinitis on individuals. Additionally, it identifies areas in need of further research and investigation.

RECENT FINDINGS

We highlight current research on the association between occupational rhinitis and occupational asthma and the role of immunotherapy in this disease. Discussion includes the impact of social trends on workers and the wider consequences of occupational rhinitis including decreased work productivity, absenteeism, and socioeconomic burden. Occupational rhinitis remains a challenging disease entity due to the numerous potential causative factors, reduced recognition, morbidity in asthma, and therapeutic limitations. Additional research is needed to better identify disease predictors and develop effective management strategies.

Physiological Health and Physical Performance in Multiple Chemical Sensitivity-Described in the General Population

Multiple chemical sensitivity (MCS) is a multifactorial somatic disorder characterized by physical reactions triggered by even extremely low levels of different airborne chemicals. In most individuals with MCS, these reactions have substantial negative impact on social, occupational, and everyday life often including limited or no engagement in physical activities. The aim of this study was to explore associations between MCS and objective measurements of anthropometry, cardiorespiratory health, and physical performance. From the Danish population-based cohort DanFunD counting 9656 participants aged 18–76 years, 1.95% (n = 188) were categorized as MCS individuals (MCS All). Of those 188, 109 participants were subcategorized as having MCS without functional somatic disorders (FSD) (MCS with no comorbid FSD). The remaining study population without any FSD were regarded controls. We used adjusted multiple linear regression analyses to evaluate associations between MCS and anthropometry, cardiorespiratory fitness, and physical performance. Compared with the general population, MCS All had less optimal body composition, increased risk of obesity, impaired cardiorespiratory fitness, and physical performance which was not seen in MCS with no comorbid FSD. MCS individuals may be inhibited to maintain an active lifestyle which can increase risk of obesity and consequently have negatively impact on general health, which may not be the case among MCS with no comorbid FSD.

Occupational rhinitis

Occupational rhinitis (OR) has so far received little attention even though it shares common pathophysiological features and trigger factors and is closely associated with occupational asthma (OA). Work-related exposure to certain substances, such as animal dander, is considered to be the main factor for the development of OR. The new EAACI definition of OR stresses the causal relationship between workplace exposure and onset of rhinitis symptoms as opposed to previous definitions that mainly focused on a temporal relationship between workplace exposure and occurrence of nasal symptoms. Also, it has been suggested to use the term “work-related rhinitis” for classifying the different forms of rhinitis associated with the workplace. These forms can be subdivided into allergic or non-allergic OR, which is due to causes and conditions related to a particular work environment, as well as work-exacerbated rhinitis, which is defined as a pre-existing rhinitis exacerbated by exposure at the workplace. Even though taking a detailed patient history is especially important when it comes to diagnosing OR, the gold standard for confirming the diagnosis is nasal provocation testing. Best possible symptomatic relief and prevention of development of OA constitute the main therapeutic objectives in OR. Treatment options consist of total avoidance of trigger substances (main goal), reduction of exposure to certain substances, and pharmacotherapy. Furthermore, it is important to note that allergic OR is an occupational disease in Germany (Berufskrankheit No 4301) and needs to be reported to health authorities.

Rhinitis 2020: A practice parameter update

This comprehensive practice parameter for allergic rhinitis (AR) and nonallergic rhinitis (NAR) provides updated guidance on diagnosis, assessment, selection of monotherapy and combination pharmacologic options, and allergen immunotherapy for AR. Newer information about local AR is reviewed. Cough is emphasized as a common symptom in both AR and NAR. Food allergy testing is not recommended in the routine evaluation of rhinitis. Intranasal corticosteroids (INCS) remain the preferred monotherapy for persistent AR, but additional studies support the additive benefit of combination treatment with INCS and intranasal antihistamines in both AR and NAR. Either intranasal antihistamines or INCS may be offered as first-line monotherapy for NAR. Montelukast should only be used for AR if there has been an inadequate response or intolerance to alternative therapies. Depot parenteral corticosteroids are not recommended for treatment of AR due to potential risks. While intranasal decongestants generally should be limited to short-term use to prevent rebound congestion, in limited circumstances, patients receiving regimens that include an INCS may be offered, in addition, an intranasal decongestant for up to 4 weeks. Neither acupuncture nor herbal products have adequate studies to support their use for AR. Oral decongestants should be avoided during the first trimester of pregnancy. Recommendations for use of subcutaneous and sublingual tablet allergen immunotherapy in AR are provided. Algorithms based on a combination of evidence and expert opinion are provided to guide in the selection of pharmacologic options for intermittent and persistent AR and NAR.

Occupational Rhinitis

There is convincing evidence that tight relationships between the upper and lower airways also apply to the workplace context. Most patients with occupational asthma (OA) also suffer from occupational rhinitis (OR), although OR is 2 to 3 times more common than OA. OR most often precedes the development of OA, especially when high-molecular-weight protein agents are involved, and longitudinal cohort studies have confirmed that OR is associated with an increased risk for the development of OA. The level of exposure to sensitizing agents at the workplace is the most important determinant for the development of IgE-mediated sensitization and OR. Atopy is a risk factor for the development of IgE-mediated sensitization only to high-molecular-weight agents. In workers with work-related rhinitis symptoms, documentation of IgE-mediated sensitization to a workplace agent via skin prick testing or serum specific IgE confirms a diagnosis of probable OR, whereas specific nasal provocation testing in the laboratory remains the reference method to establish a definite diagnosis of OR. Complete avoidance of exposure to the causal agent is the most effective therapeutic option for controlling work-related nasal symptoms and preventing the development of OA. If complete elimination of exposure is expected to induce meaningful adverse socioeconomic consequences, reduction of exposure can be considered as an alternative approach, but it is important to consider the individual risk factors for the development of OA to implement a more personalized management of OR.

Profile of Patients with Chemical Injury and Sensitivity, Part II

Exposures which can induce multiple chemical sensitivity (MCS) involve symptomatic, usually repeated, exposures to pesticides, solvents, combustion products, remodeling, sick buildings, carbonless copy paper (occupational heavy use) and other irritants and petrochemicals. Accompanying toxic injury often involves the immune, endocrine and nervous systems as well as impairments in detoxification, energy and neurotransmitter metabolism, protein, mineral, and other nutrient deficiencies and gastrointestinal changes such as Candida, parasites, reduced chymotrypsin (marker enzyme for reduced pancreatic enzyme function), gluten intolerance, and reduced Secretory IgA. Chronic cortisol elevation leading to adrenal insufficiency if not corrected is common. Such elevation can lead to protein and mineral deficiencies with increased osteoporosis and reduced steroid precursors for normal estrogen and testosterone production. Detoxification changes often involve reduction in one or more Phase II pathways which causes excess free radical production. Impaired digestive enzymes can reduce breakdown of foods, with larger more antigenic molecules being absorbed and consequent food intolerances. Many of these conditions are treatable. There is extensive overlap of MCS with Chronic Fatigue Syndrome and Fibromyalgia which may be one condition in many cases. Current occupational exposure limits are not health based and thus may not prevent MCS and are totally inadequate to accommodate sensitive persons. Warning symptoms indicating increased risk for MCS onset include repeated headache, eye and respiratory irritation and fatigue. Eliminating exposures which cause repeated symptoms is a critical strategy for preventing sensitization and MCS. It also significantly reduces the degree of disability in persons with MCS, the single most important factor from the literature. Affected persons with disability can utilize the Americans With Disability Act to request reasonable accommodations for work, home (condo, apartment), and school.

Nonallergic Rhinitis: Environmental Determinants

"Nonallergic rhinitis" (NAR) is defined by intermittent or persistent nasal symptoms without evidence of immunoglobulin E-mediated sensitization to relevant aeroallergens. The largest subgroup is idiopathic, and is characterized by nasal hyperreactivity to nonspecific environmental triggers, including temperature, humidity, and chemical exposures. As nonspecific nasal hyperreactivity is often found in the absence of mucosal inflammation, some clinicians refer to this condition as "nonallergic rhinopathy." Irritant rhinitis, can arise de novo after high-level and/or prolonged exposure to airborne irritant chemicals. We review the range of environmentally induced nonallergic nasal symptoms and signs, and explore issues of pathophysiology unique to environmental chemical exposures.

Occupational Rhinitis

Occupational rhinitis (OR) involves nasal congestion, rhinorrhea, nasal itching, and/or sneezing resulting from workplace exposures. OR can have a significant negative effect on quality of life and productivity. OR can be divided into allergic or nonallergic subgroups based on the underlying pathogenesis. Certain occupational exposures place employees at greater risk for developing disease. Primary treatment is avoidance of implicated exposures. Antihistamines, saline rinses, and nasal steroids may be useful. OR can coexist with occupational asthma, and rhinitis symptoms have been reported to precede those of the lower respiratory tract. OR is has both medical and socioeconomic implications.

No acute effects of an exposure to 50 ppm methyl methacrylate on the upper airways

PURPOSE

The German MAK value of methyl methacrylate has been fixed at 50 ppm. The aim of this study was to evaluate possible acute effects of an exposure to 50 ppm methyl methacrylate on the upper airways of human subjects.

METHODS

Twenty healthy subjects were exposed to 50 ppm methyl methacrylate and to air (sham) in an exposure chamber for 4 h according to a crossover design. Symptoms were assessed by the SPES questionnaire. Olfactory thresholds for n-butanol and mucociliary transport time were measured before and after exposure. Concentrations of interleukin 1ß and interleukin 8 were determined in nasal secretions taken after exposure. mRNA levels of interleukins 1ß, 6 and 8, tumor necrosis factor α, granulocyte-macrophage colony-stimulating factor, monocyte chemotactic protein 1, and cyclooxygenases 1 and 2 were measured in nasal epithelial cells, obtained after exposure. Possible effects were investigated by semiparametric and parametric crossover analyses.

RESULTS

The score of the item "irritation to the nose" was slightly elevated following exposure to methyl methacrylate (p ≤ 0.01). Olfactory functioning was not impaired. Mucociliary transport time did not change. Neither concentrations of interleukins in nasal secretions nor mRNA levels were elevated.

CONCLUSION

Only minor irritating effects on the nose were observed. The acute exposure to 50 ppm methyl methacrylate did not cause any adverse effects. However, the results cannot be extrapolated to chronic exposure.

Occupational irritant and allergic rhinitis

The upper airway (extending from the nares to larynx) fulfills essential physiologic functions, including sensation, air conditioning, filtration, and communication. As the portal of entry for the respiratory tract, the upper airway's sentinel function is performed by the olfactory and trigeminal nerves. Sensory (eye, nose and throat) irritation figures prominently in symptom reporting in so-called "problem buildings," as well as in industrial exposures to irritant gases, vapors, and smokes. Both irritants and allergens can alter function in the upper airway, leading to loss of air conditioning and filtering due to airflow obstruction and hypersecretion. Increasing evidence points to a "unified airway" model of pathogenesis (in which rhinitis may precede the development of asthma). The spectrum of occupational irritant- and allergen-related upper airway health effects-including sensory irritation, olfactory dysfunction, rhinitis, sinusitis, nasal septal perforation, and sinonasal cancer-is reviewed in this article.

Occupational upper airway disease: how work affects the nose

Chronic inflammation of the upper airways is common and can arbitrarily be divided into rhinitis and rhinosinusitis. Infection and allergy represent two well-characterized and most frequently diagnosed etiologies of upper airway inflammation. Persistent upper airway inflammation caused by agents inhaled in the work environment represents a diagnostic challenge in clinical practice, and its pathophysiology has been little studied. Occupational rhinitis is a recognized medical condition with diagnostic and therapeutic guidelines. In contrast, only limited evidence is available about the relationship between work exposures and rhinosinusitis. This review aims at providing a comprehensive overview of the available literature on occupational upper airway disease with a focus on pathophysiological mechanisms and with an emphasis on the current unmet needs in work-related upper airway disease.

EAACI Position Paper on assessment of cough in the workplace

Cough is a nonspecific and relatively common symptom that can present difficulties in diagnosis and management, particularly when it is reported to be associated with the workplace. The present consensus document, prepared by a taskforce of the Interest Group on Occupational Allergy of the European Academy of Allergy and Clinical Immunology by means of a nonsystematic review of the current literature, is intended to provide a definition and classification of work-related chronic cough (WRCC) to assist the daily practice of physicians facing with this symptom. The review demonstrates that several upper and lower airway work-related diseases may present with chronic cough; hence, the possible link with the workplace should always be considered. Due to the broad spectrum of underlying diseases, a multidisciplinary approach is necessary to achieve a definite diagnosis. Nevertheless, more epidemiological studies are necessary to estimate the real prevalence and risk factors for WRCC, the role of exposure to environmental and occupational sensitizers and irritants in its pathogenesis and the interaction with both upper and lower airways. Finally, the best management option should be evaluated in order to achieve the best outcome without adverse social and financial consequences for the worker.

Acute effects of an exposure to 100 ppm 1-methoxypropanol-2 on the upper airways of human subjects

The German MAK value of 1-methoxypropanol-2 has been fixed at 100 ppm. The aim of this study was to evaluate possible acute effects of an exposure to 100 ppm 1-methoxypropanol-2 on the upper airways of human subjects. Twenty subjects were exposed in a crossover design to 100 ppm 1-methoxypropanol-2 and to air in an exposure chamber for 4h. Subjective symptoms were assessed by questionnaire. Olfactory thresholds for n-butanol and mucociliary transport time were measured before and after exposure. Concentrations of interleukin 1β and interleukin 8 were determined in nasal secretions taken after exposure. mRNA levels of interleukins 1β, 6 and 8, tumor necrosis factor α, granulocyte-macrophage colony-stimulating factor, monocyte chemotactic protein 1, and cyclooxygenases 1 and 2 were measured in nasal epithelial cells, obtained after exposure. Possible effects were investigated by semiparametric and parametric cross-over analyses. Subjects did not have any subjective irritating symptoms. The olfactory threshold was slightly elevated following exposure to 1-methoxypropanol-2. Mucociliary transport time did not change. Neither concentrations of interleukins in nasal secretions nor mRNA levels except for interleukin 1β were higher after exposure to 1-methoxypropanol-2. In conclusion, the acute exposure to 100 ppm 1-methoxypropanol-2 did not cause clear-cut adverse effects in test subjects.

Occupational rhinitis and other work-related upper respiratory tract conditions

The nose and upper airways form the initial area of impact for air pollutants and allergens. The development of nasal allergies in the workplace (occupational rhinitis) may herald subsequent development of occupational asthma. Exposure controls, periodic surveillance, and early intervention may circumvent work-related airways disease and prevent unnecessary worker impairment and disability.

Negative impact of occupational exposure on surgical outcome in patients with rhinosinusitis

BACKGROUND

Chronic rhinosinusitis (CRS) is a frequent condition that is treated by functional endoscopic sinus surgery (FESS) when medical treatment fails. Endogenous as well as exogenous factors may be responsible for persisting symptoms after FESS. The role of occupational exposures on success of FESS has never been investigated.

METHODS

In this case-control study, we tested the hypothesis that the outcome of FESS procedures is related to exposures at work. Questionnaires were sent to 890 patients who had undergone one or more FESS procedures and to 182 controls. Three independent experts assessed blindly the reported work exposures to inhaled agents. The relationship between exposure and the number of FESS procedures was analyzed.

RESULTS

Relevant occupational exposure was reported by 25% of all responding patients undergoing FESS (n = 467) and 12% of controls (n = 69). The prevalence of occupational exposures increased linearly with the number of FESS procedures from 21% in those who had one FESS to 44% in those who had four or more FESS (χ(2)  = 12.74, P < 0.001). Logistic regression analysis with adjustments for potential confounders, including smoking, atopy, and asthma, confirmed that the odds ratio (OR) for reporting occupational exposures was significantly higher in those needing more than one FESS (OR = 1.64) or more than two FESS (OR = 1.97). These results were mainly driven by exposure to low molecular weight agents.

CONCLUSION

Exposure at work appears to be a risk factor for the occurrence of CRS and for its recurrence or persistence, as evidenced by the need for revision surgery.

Diabetes-related alteration of occludin expression in rat blood-spinal cord barrier

Occludin is an essential component of tight junctions, which are involved in controlling the integrity of the blood-brain barrier and blood-spinal cord barrier (BSCB). Diabetes-induced alteration of occludin in rat BSCB and the relationship between occludin level and disease course was examined. Diabetes was induced using streptozotocin. Occludin rat spinal cord mRNA levels were assessed by real-time quantitative RT-PCR. Protein levels were examined by western blot. Occludin expression in 1-month diabetic rats was significantly reduced compared to the controls (0.20 ± 0.01 vs 1.00 ± 0.01, respectively; P < 0.05). Expression was also significantly lower in the 3-month diabetic group (0.06 ± 0.02; P < 0.01). Occludin protein levels of 1-month (0.53 ± 0.01) and 3-month (0.31 ± 0.01) diabetic rats were also significantly reduced compared to controls (0.91 ± 0.06; P < 0.01 for both). Diabetes decreased BSCB occludin expression at the mRNA and protein level. This down-regulation appears to correlate with the course of the disease, and may be a causal factor of diabetes-induced increase of BSCB permeability.

EAACI position paper on occupational rhinitis

The present document is the result of a consensus reached by a panel of experts from European and non-European countries on Occupational Rhinitis (OR), a disease of emerging relevance which has received little attention in comparison to occupational asthma. The document covers the main items of OR including epidemiology, diagnosis, management, socio-economic impact, preventive strategies and medicolegal issues. An operational definition and classification of OR tailored on that of occupational asthma, as well as a diagnostic algorithm based on steps allowing for different levels of diagnostic evidence are proposed. The needs for future research are pointed out. Key messages are issued for each item.

Determinants of whether or not mixtures of disinfection by-products are similar

Reactive chemicals have been used to disinfect drinking waters for over a century. In the 1970s, it was first observed that the reaction of these chemicals with the natural organic matter (NOM) in source waters results in the production of variable, complex mixtures of disinfection by-products (DBP). Because limited toxicological and epidemiological data are available to assess potential human health risks from complex DBP mixture exposures, methods are needed to determine when health effects data on a specific DBP mixture may be used as a surrogate for evaluating another environmental DBP mixture of interest. Before risk assessors attempt such efforts, a set of criteria needs to be in place to determine whether two or more DBP mixtures are similar in composition and toxicological potential. This study broadly characterizes the chemical and toxicological measures that may be used to evaluate similarities among DBP mixtures. Variables are discussed that affect qualitative and quantitative shifts in the types of DBP that are formed, including disinfectants used, their reactions with NOM and with bromide/iodide, pH, temperature, time, and changes in the water distribution system. The known toxicological activities of DBP mixtures and important single DBPs are also presented in light of their potential for producing similar toxicity. While DBP exposures are associated with a number of health effects, this study focuses on (1) mutagenic activity of DBP mixtures, (2) DBP cancer epidemiology, and (3) toxicology studies to evaluate similarity among DBP mixtures. Data suggest that further chemical characterization of DBP mixtures and more systematic study of DBP toxicology will improve the quality and usefulness of similarity criteria.

Chronic cough – occupational considerations

Chronic cough is a common symptom in a wide range of respiratory conditions, and may also occur as a result of upper airway or gastro-esophageal problems. Whilst chronic cough of any cause may be exacerbated by work, in some cases it has a direct occupational cause, resulting from a harmful acute or chronic workplace exposure. Such occupational conditions may only be suspected by taking a detailed occupational history, and directly asking employed patients whether their cough improves away from work. Early and accurate diagnosis, linked with tailored drug therapy, modification of workplace exposures, and expert compensation advice is likely to offer the best outcome for this group of patients.

No acute effects of an exposure to 50 ppm acetaldehyde on the upper airways

OBJECTIVE

German MAK value of acetaldehyde has been fixed at 50 ppm to prevent from irritating effects. The threshold value is mainly based on animal experiments. The aim of this study was to evaluate acute effects of an exposure to 50 ppm acetaldehyde on the upper airways of human subjects.

METHODS

Twenty subjects were exposed to 50 ppm acetaldehyde and to air in an exposure chamber for 4 h according to a crossover design. Subjective symptoms were assessed by questionnaire. Olfactory threshold for n-butanol and mucociliary transport time were measured before and after exposure. Concentrations of interleukin 1beta and interleukin 8 were determined in nasal secretions taken after exposure. mRNA levels of interleukins 1beta, 6 and 8, tumour necrosis factor alpha, granulocyte-macrophage colony-stimulating factor, monocyte chemotactic protein 1, and cyclooxygenases 1 and 2 were measured in nasal epithelial cells, gained after exposure. Possible effects were investigated by semiparametric and parametric crossover analyses.

RESULTS

Exposure to acetaldehyde did not cause any subjective irritating symptoms. Olfactory threshold did not change. Mucociliary transport time increased insignificantly after exposure to acetaldehyde. Neither concentrations of interleukins in nasal secretions nor mRNA levels of inflammatory factors were higher after exposure to acetaldehyde.

CONCLUSION

An acute exposure to 50 ppm acetaldehyde did not cause any adverse effects in test subjects.

Occupational rhinitis

The present document is the result of a consensus reached by a panel of experts from European and nonEuropean countries on Occupational Rhinitis (OR), a disease of emerging relevance, which has received little attention in comparison to occupational asthma. The document covers the main items of OR including epidemiology, diagnosis, management, socio-economic impact, preventive strategies and medicolegal issues. An operational definition and classification of OR tailored to that of occupational asthma, as well as a diagnostic algorithm based on steps allowing different levels of diagnostic evidence, are proposed. The needs for future research are pointed out. Key messages are issued for each item.

[Occupational rhinitis]

INTRODUCTION

Rhinitis is one of the most common occupational diseases. It is often neglected by those affected because it causes little disability. It is poorly understood by doctors who have insufficient experience of occupational diseases and their causes. However it is often the first manifestation of a respiratory disorder that may cause physical complications and socio-economic disability.

BACKGROUND

Numerous diverse agents are potential causes of rhinitis. The diagnosis of occupational rhinitis should be considered when sneezing, rhinorrhoea or nasal obstruction are associated with work. The causal agent can be identified by ta-king a careful history. When the mechanism of the disease is immunologic the suspected antigen can be confirmed by skin testing, specific IgE or nasal provocation. The respiratory disorder of which rhinitis is the first manifestation may progress to asthma if the exposure continues. The prevention of occupational rhinitis depends on the reduction of exposure to allergens and/or irritants. When it has developed removal of the causative agent is essential to prevent progression to asthma.

Occupational upper airway disease

PURPOSE OF REVIEW

This article reviews recent findings concerning occupational upper airway diseases, which, although very frequent, are usually not considered serious. However, the concept of the 'united airway', evoked during recent years, should change our attitude regarding these diseases. Moreover, new agents in the occupational environment must be characterized. Furthermore, exposure to carcinogens has changed over the years, and in most cases risk should be reassessed.

RECENT FINDINGS

Recent findings concerning work-related upper airway diseases caused by allergens and irritants, and their relationship to lower airway diseases, are reviewed. Findings of studies aimed at characterizing occupational allergens of plant and animal origin are presented. Recognition of work-related upper airway diseases both in clinic and in epidemiological studies is discussed. Current evidence on occupational cancer of the upper airways, its risk factors and changes in them over the years resulting from preventative measures are also described.

SUMMARY

There is significant evidence that occupational allergic diseases of the upper airways can pose important health problems because they represent an early stage of allergy throughout the respiratory system. However, how to detect those rhinitic patients who will develop asthma remains unresolved. New occupational health problems due to irritants were recently reported, and both follow-up studies and evaluations of their implications for the lower airways are warranted. Although preventative measures have been effective to some extent, risk for occupational cancer of the upper airways persists and more targeted epidemiological studies in this area are needed.

A 5-year follow-up of airway symptoms after nitrogen dioxide exposure in an indoor ice arena

The authors investigated whether exposure to high levels of nitrogen dioxide (NO2) in an indoor ice hockey arena might be associated with airway symptoms 5 yr later. A follow-up questionnaire was answered by 71 subjects who had experienced such an exposure, accompanied by acute respiratory illness, in Stockholm in 1994. The same questionnaire was answered by 40 reference subjects. The overall response rate for both groups was 71%. Information was obtained regarding various background factors, such as smoking and respiratory symptoms since 1994. For those who had stopped playing ice hockey during the follow-up period, the exposure to high NO2 levels appeared to be associated with an increase in upper airways symptoms (i.e., nasal blockage or rhinitis) (odds ratio = 3.1, 95% confidence interval = 1.1, 8.8), after adjustment for age, smoking, and family history of allergy. These data suggest that exposure to high NO2 levels in an indoor ice arena may be associated with increased airway symptoms several years later.

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.

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.

Acute toxicity of marking pen emissions

To evaluate complaints of adverse reactions to marking pen emissions, groups of mice were exposed for 1 h to the emissions of 8 brands of felt-tip markers or white-board cleaner. Pneumotachographs and a computerized version of ASTM E-981 test method were used to measure changes in respiration. Sensory irritation (SI), pulmonary irritation (PI), and/or air flow limitation (AFL) of differing intensities were documented with each of the eight brands tested. At the peak of the effects, the largest SI was observed with pen F (72% of the breaths); the largest PI occurred with pen D (13% of the breaths), and the largest AFL was seen with pen F (25% of the breaths). Pens G and H produced minimal SI, PI, or AFL. A functional observational battery was used to screen for signs of neurotoxicity. Emissions from all eight of the pens produced behavioral abnormalities such as altered posture and gait, tremors, falling, and hyperactivity. The exposure concentrations were similar to the total volatile organic compounds (TVOC) values near marking pens in actual use. Gas chromatography identified mixtures of alcohols, acetates, and/or ketones. Exposures to white-board cleaner solution resulted in similar toxicity ( SI, PI, AFL, and neurotoxicity). These results document that some marking pens and white-board cleaner emit mixtures of chemicals that can produce acute respiratory toxicity and acute behavioral abnormalities in normal mice. These results provide a toxicological explanation for some of the human complaints concerning respiratory and neurological reactions to marking pen emissions.

Toxicology of nasal irritants

The upper airway, including nasal cavities, naso-, oro-, and hypopharynx, is the portal of entry for air pollutants. Upper airway (as well as eye) irritation figures prominently in symptom reporting in so-called problem buildings and with exposure to environmental tobacco smoke. Large particles and water-soluble gases and vapors are likely to have their initial irritant effects in the mucous membranes of the upper airway and eyes, giving warning to the exposed individual to minimize further exposure. The spectrum of irritant-related upper airway health effects is reviewed in this article.

Acute inhalation injury

Recent events have underscored the importance of proper diagnosis and management of patients with inhalation injury. Clinicians who care for individuals who have sustained inhalation damage to their respiratory tract need to take a careful exposure history and be alert to possibilities of delayed effects and clinical deterioration. Although supportive care and prevention remain the cornerstone of current approaches to this condition, better understanding of the mechanisms of cellular injury and repair may lead to improved treatments in the future.

Occupational upper airway disease

The upper airway plays a critical role in filtering and conditioning air for the lungs. It provides the first line of warning and defense against microbials, allergens, and toxic inhalants. Current evidence suggests that the upper airway is susceptible to many of the pathogenic processes that the agents cause in the lower respiratory tract. Work-related rhinosinusitis or vocal cord dysfunction should prompt physicians and employers to identify the injurious agent(s) and formulate strategies to eliminate or reduce such exposures. Improving the work environment will prevent the development of new cases and the worsening of symptoms in existing cases.

Clinical findings for residents near a polyurethane foam manufacturing plant

Clinical findings for 38 community residents who complained of symptoms they attributed to exposure to air emissions from nearby fiber processing and polyurethane foam manufacturing facilities are reported. Common complaints included headache, mucosal irritation, shortness of breath, chest tightness, and wheezing. Airway hyperreactivity, measured by methacholine challenge, was observed in 8 individuals (22% of those tested), who also reported temporal relationships between exposure to visible emissions or odors and symptoms consistent with environmentally induced asthma. Six individuals (18.2%) had antibodies to at least 1 of the 3 common industrial diisocyanates. The number of individuals with antibodies to diisocyanates, coupled with the absence of other diisocyanate exposure, was highly suggestive of environmental exposure. The findings raised concern that some residents may have become sensitized to toluene diisocyanate.

A multiple center study of multiple chemical sensitivity syndrome

The lack of widely accepted, standardized, clinical and epidemiologic criteria for Multiple Chemical Sensitivity syndrome has led to confusion about the identification of the condition and has slowed pertinent research. In this article, the authors evaluated the psychometric properties of 2 sets of clinical/epidemiologic criteria for Multiple Chemical Sensitivity syndrome. In this cross-sectional survey of 1,166 patients who visited outpatient occupational, otolaryngology, allergy, and clinical ecological clinics, the authors used the aforementioned sets of criteria to (a) estimate the prevalence of the syndrome in these varied samples and (b) compare the current diagnostic practices of traditional physician specialists with those of clinical ecologists. The authors used a patient-completed questionnaire to assess the medical, psychosocial, and psychological status of patients who reported multiple chemical sensitivities. This approach enabled the formulation of 6 domains, which represented commonly observed characteristics of the syndrome. The authors used a physician-completed questionnaire to collect diagnoses of Multiple Chemical Sensitivity syndrome and other medical conditions. Domains, which were operationalized by the questionnaire and comprised the 2 sets of criteria for identification of the Multiple Chemical Sensitivity syndrome, had test-retest reliabilities that exceeded .75 and estimates of internal consistency that ranged between .59 and .94. Evidence of construct and face validity was considered acceptable. The overall clinic-based prevalences of Multiple Chemical Sensitivity syndrome, based on 6 and 4 domains, were 7% and 23%, respectively. Regardless of the identifying set of criteria used, physicians' diagnoses had relatively low sensitivities (range = 6-50%) and relatively high specificities (range = 82-99%). The study data suggested that the domains operationalized by the questionnaire had reasonable psychometric characteristics. Study data also support the fact that Multiple Chemical Sensitivity syndrome is often overlooked--even by those physicians who treat it most frequently--and that use of both sets of objective criteria for identifying the syndrome would greatly improve the sensitivity of physician diagnoses.

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

We previously reported clinical findings for 19 patients who developed symptomatic airways hyperactivity following an acute exposure to an inhaled irritant and who were given the diagnosis of reactive airways dysfunction syndrome (RADS). We now report on nine of these patients who have been followed for a mean of 9 years, allowing assessment of function, symptoms, and comorbidity beyond the early phase of acute airway injury and inflammation. None of the patients have resolved their airway hyper-responsiveness and symptoms completely, although only in one subject, who had a premorbid history of asthma, has the condition progressed. A common feature has been sinusitis and other upper-airway symptoms. We conclude that in this group of patients, RADS presented in a consistent pattern regardless of the cause of airway injury, resolved only partially, even in subjects without a premorbid history of respiratory disease, and was associated with significant secondary morbidity, especially affecting the upper airway. This pattern was evident regardless of smoking status or age at time of exposure. We conclude that for these subjects, RADS was a distinct entity with a consistent natural history that conferred permanent impairment, but did generally improve somewhat over time.

The nose versus the environment: 1982 and today

A brief overview of recent publications dealing with the effects of environmental pollutants on upper respiratory tract mucosa is presented. It mainly focuses on airborne irritants, substances inducing epithelial hyperplasia, metaplasia, and epithelial damage, and on inflammatory changes of nasal mucosa associated with environmental pollutants. Data from epidemiologic surveys, human exposure studies, animal experiments, and in vitro studies have improved present concepts of the significance of environmental pollutants for upper respiratory diseases. Although various national and international initiatives have resulted in a considerable reduction of indoor and outdoor pollutants within recent years, environmental pollutants continue to affect upper respiratory tract health of the population in urban areas and industrialized regions. Continuing efforts to reduce emissions of air pollutants are indispensable.

Chronic rhinitis in workers at risk of reactive airways dysfunction syndrome due to exposure to chlorine

BACKGROUND

To assess the frequency of chronic upper airways symptoms and to relate the presence of these symptoms to accidental exposure to chlorine and changes in lower airways symptoms, airway function, and bronchial responsiveness in a cohort of workers at risk of sporadic occupational exposure to high concentrations of chlorine.

METHODS

Data were collected on symptom assessment, spirometry, and methacholine challenge tests from 211 workers seen twice at a 2 year interval (1992-4).

RESULTS

The proportion of workers reporting chronic rhinitis was 46.9% in 1992 and 42.2% in 1994. Chronic rhinitis reported in 1994 was significantly associated with acute exposure to chlorine (self reports, p = 0.02; first aid reports, p = 0.001). In a multivariate logistic regression analysis the presence of reported accidents at the first aid unit (one accident, odds ratio (OR) 3.1, 95% confidence interval (95% CI) 1.3 to 7.5; two or more accidents, OR 6.2, 1.1 to 35.8) and of personal atopy (OR 5.5, 2.2 to 10.8) were significant predictors of chronic rhinitis in 1994. Chronic lower airways symptoms were more frequent in 1994 among workers reporting chronic rhinitis on both assessments than in others (p = 0.03) and changes in bronchial responsiveness were more pronounced in those with persistent rhinitis (p = 0.09).

CONCLUSIONS

These results suggest that persistent nasal symptoms in workers at risk of reactive airways dysfunction syndrome could be a useful marker of lower respiratory tract abnormalities.

Development of multiple chemical sensitivities in laborers after acute gasoline fume exposure in an underground tunneling operation

In this article, investigators report on the presence and nature of chemical sensitivities and other indices of illness in a cohort of workers excavating a new subway tunnel located under a former gasoline station. The workers were exposed to gasoline fumes for up to approximately 2 mo when they inadvertently dug into soil contaminated by gasoline. The cohort was unique in several ways: (a) contact with gasoline was made by the workers at a time when no one had complained of multiple chemical sensitivities syndrome; (b) all were males of low socioeconomic status; (c) the exposure was well documented; (d) the cohort could be considered "naive" because, at the time of the study, the men were not members of support groups and were not being seen by clinical ecologists, and they were not labeled, either by self or others, as having multiple chemical sensitivities syndrome or any related diagnosis; and (e) at the time of interview, all workers we contacted appeared to be either gainfully employed or laid off temporarily and seeking gainful employment. We explored the health status of the workers at two different times: (1) soon after the tunnel was closed as a result of high, measured benzene-exposure levels and (2) 10-13 mo after the tunnel was closed. The workers were chronically overexposed to gasoline fumes, after which approximately one-fourth (26.7%) of our random sample of relatively naive, low-socioeconomic-status male laborers-although neither disabled nor generally litigious-reported the new onset of chemical hypersensitivities and other characteristics that fit conservative criteria for multiple chemical sensitivities syndrome.