An official American Thoracic Society proceedings: work-related asthma and airway diseases. Presentations and discussion from the Fourth Jack Pepys Workshop on Asthma in the Workplace

Occupational chronic obstructive pulmonary disorder: prevalence and prevention

INTRODUCTION

Occupational chronic obstructive pulmonary disorder, i.e. work-related asthma (WRA) and occupational chronic obstructive pulmonary disease (COPD), are the most common occupational lung diseases in the last decades worldwide. As in the case of the other occupational disorders, these diseases may be prevented.

AREAS COVERED

WRA is a heterogeneous entity that includes three subtypes, immunologic occupational asthma (OA), irritant-induced asthma (IIA), and work-exacerbated asthma (WEA), depending on the role of occupational exposures as a causing or aggravating factor of the disease. In addition, there is consistent evidence that a substantial proportion of COPD cases can be explained by exposure to noxious particles and gases other than tobacco smoke, such as workplace dusts, gases, fumes, and vapors. The articles cited in this paper were searched by keywords in several databases in the period up to May-July 2021.

EXPERT OPINION

The development of occupational chronic obstructive disorder is a matter of prevention. WRA and occupational COPD contribute significantly to the overall burden of asthma and COPD. Activities and measures targeted to elimination or reduction of harmful workplace exposures, as well as to early detection and early intervention in the course of the lung damage, can significantly reduce the burden caused by these diseases.

Transplantation for work-related lung disease in the USA

OBJECTIVES

Work-related lung diseases (WRLDs) are entirely preventable. To assess the impact of WRLDs on the US transplant system, we identified adult lung transplant recipients with a WRLD diagnosis specified at the time of transplant to describe demographic, payer and clinical characteristics of these patients and to assess post-transplant survival.

METHODS

Using US registry data from 1991 to 2018, we identified lung transplant recipients with WRLDs including coal workers' pneumoconiosis, silicosis, asbestosis, metal pneumoconiosis and berylliosis.

RESULTS

The frequency of WRLD-associated transplants has increased over time. Among 230 lung transplants for WRLD, a majority were performed since 2009; 79 were for coal workers' pneumoconiosis and 78 were for silicosis. Patients with coal workers' pneumoconiosis were predominantly from West Virginia (n=31), Kentucky (n=23) or Virginia (n=10). States with the highest number of patients with silicosis transplant were Pennsylvania (n=12) and West Virginia (n=8). Patients with metal pneumoconiosis and asbestosis had the lowest and highest mean age at transplant (48.8 and 62.1 years). Median post-transplant survival was 8.2 years for patients with asbestosis, 6.6 years for coal workers' pneumoconiosis and 7.8 years for silicosis. Risk of death among patients with silicosis, coal workers' pneumoconiosis and asbestosis did not differ when compared with patients with idiopathic pulmonary fibrosis.

CONCLUSIONS

Lung transplants for WRLDs are increasingly common, indicating a need for primary prevention and surveillance in high-risk occupations. Collection of patient occupational history by the registry could enhance case identification and inform prevention strategies.

The Burden of Work-related Asthma in Michigan, 1988-2018

Rationale: Exposure to a variety of substances in the workplace can cause new-onset asthma or aggravate preexisting asthma, both of which are considered work-related asthma (WRA). Understanding trends in the nature and causes of WRA can assist in the diagnosis and management of adult patients with asthma.Objective: To describe trends over 31 years of WRA surveillance in Michigan.Methods: Michigan law requires reporting of all known or suspected cases of occupational disease. WRA was confirmed by review of a standardized telephone interview and patient medical records. Enforcement inspections at the workplaces of the WRA cases included air monitoring and evaluation for asthma and asthma symptoms among coworkers.Results: The Michigan surveillance program identified 3,634 WRA cases from 1988 to 2018, including nine deaths. The cumulative incidence rate of WRA decreased from 3.5 to 2.0 cases per 100,000 workers. Cases most frequently worked in manufacturing (56%), health care (12%), and education (4%). The cumulative incidence rate of WRA decreased in each of those three industries, while increasing in retail trade and accommodations and food services. The most common exposures to known asthma inducers were to cleaning agents and isocyanates; the percentage exposed to cleaning agents increased from 5% to 20%, and the percentage exposed to isocyanates decreased from 20% to 7%. Fifty-one percent had not applied for workers' compensation benefits. Only 5% of the 571 workplaces where air sampling was performed were above the allowable exposure limit. Fifteen percent (1,622 of 10,493) of coworkers of the index cases reported onset of asthma since beginning to work at the facility or being bothered at work by daily or weekly chest tightness, shortness of breath, or wheezing.Conclusions: The industries and exposures where Michigan adults develop WRA have changed during the past 31 years. The identification of WRA cases, including WRA deaths, underscores the need for continued vigilance to monitor changes in where and how workers are exposed to asthma-causing agents, physician consideration of workplace exposures in new-onset or worsening adult asthma, and adoption of workplace standards that reduce exposure and require workplace medical monitoring to prevent and reduce the morbidity and mortality of WRA.

Global and regional burden of chronic respiratory disease in 2016 arising from non-infectious airborne occupational exposures: a systematic analysis for the Global Burden of Disease Study 2016

OBJECTIVES

This paper presents detailed analysis of the global and regional burden of chronic respiratory disease arising from occupational airborne exposures, as estimated in the Global Burden of Disease 2016 study.

METHODS

The burden of chronic obstructive pulmonary disease (COPD) due to occupational exposure to particulate matter, gases and fumes, and secondhand smoke, and the burden of asthma resulting from occupational exposure to asthmagens, was estimated using the population attributable fraction (PAF), calculated using exposure prevalence and relative risks from the literature. PAFs were applied to the number of deaths and disability-adjusted life years (DALYs) for COPD and asthma. Pneumoconioses were estimated directly from cause of death data. Age-standardised rates were based only on persons aged 15 years and above.

RESULTS

The estimated PAFs (based on DALYs) were 17% (95% uncertainty interval (UI) 14%-20%) for COPD and 10% (95% UI 9%-11%) for asthma. There were estimated to be 519 000 (95% UI 441,000-609,000) deaths from chronic respiratory disease in 2016 due to occupational airborne risk factors (COPD: 460,100 [95% UI 382,000-551,000]; asthma: 37,600 [95% UI 28,400-47,900]; pneumoconioses: 21,500 [95% UI 17,900-25,400]. The equivalent overall burden estimate was 13.6 million (95% UI 11.9-15.5 million); DALYs (COPD: 10.7 [95% UI 9.0-12.5] million; asthma: 2.3 [95% UI 1.9-2.9] million; pneumoconioses: 0.58 [95% UI 0.46-0.67] million). Rates were highest in males; older persons and mainly in Oceania, Asia and sub-Saharan Africa; and decreased from 1990 to 2016.

CONCLUSIONS

Workplace exposures resulting in COPD, asthma and pneumoconiosis continue to be important contributors to the burden of disease in all regions of the world. This should be reducible through improved prevention and control of relevant exposures.

Prevalence of COPD among workers with work-related asthma

Objective: Concurrent asthma and chronic obstructive pulmonary disease (COPD) diagnoses occur in 15%-20% of patients, and have been associated with worse health outcomes than asthma or COPD alone. Work-related asthma (WRA), asthma that is caused or made worse by exposures in the workplace, is characterized by poorly controlled asthma. The objective of this study was to assess the proportion of ever-employed adults (≥18 years) with current asthma who have been diagnosed with COPD, by WRA status.Methods: Data from 23 137 respondents to the 2012-2014 Behavioral Risk Factor Surveillance System Asthma Call-back Survey from 31 states and the District of Columbia were examined. Logistic regression was used to calculate adjusted prevalence ratios (PRs), examining six disjoint categories of WRA-COPD overlap with non-WRA/no COPD as the referent category.Results: An estimated 51.9% of adults with WRA and 25.6% of adults with non-WRA had ever been diagnosed with COPD. Adults with WRA/COPD were more likely than those with non-WRA/no COPD to have an asthma attack (PR = 1.77), urgent treatment for worsening asthma (PR = 2.85), an asthma-related emergency room visit (PR = 4.21), overnight stay in a hospital because of asthma (PR = 6.57), an activity limitation on 1-13 days (PR = 2.01) or ≥14 days (PR = 5.02), and very poorly controlled asthma (PR = 3.22).Conclusions: COPD was more frequently diagnosed among adults with WRA than those with non-WRA, and adults diagnosed with both WRA and COPD appear to have more severe adverse asthma outcomes than those with non-WRA and no COPD.

[Guidelines for methacholine provocation testing]

Bronchial challenge with the direct bronchoconstrictor agent methacholine is commonly used for the diagnosis of asthma. The "Lung Function" thematic group of the French Pulmonology Society (SPLF) elaborated a series of guidelines for the performance and the interpretation of methacholine challenge testing, based on French clinical guideline methodology. Specifically, guidelines are provided with regard to the choice of judgment criteria, the management of deep inspirations, and the role of methacholine bronchial challenge in the care of asthma, exercise-induced asthma, and professional asthma.

Medical Monitoring for Occupational Asthma Among Toluene Diisocyanate Production Workers in the United States

OBJECTIVE

The aim of this study was to describe a study of medical monitoring methods and lessons learned in detecting health outcomes in U.S. plants producing toluene diisocyanate (TDI).

METHODS

A multidisciplinary team implemented a medical and environmental monitoring program in three TDI plants.

RESULTS

Of 269 eligible workers, 197 (73%) participated and 42 (21%) met symptom and/or lung function criteria that would trigger evaluation for possible asthma over 5 years of data collection. Subsequent evaluation was delayed for most, and a web-based data collection system improved timeliness.

CONCLUSION

Medical monitoring of TDI workers identified workers triggering further assessment per study protocol. Systems and/or personnel to ensure rapid follow-up are needed to highlight when triggering events represent potential cases of asthma needing further evaluation. Implementation of a research protocol requires resources and oversight beyond an occupational health program.

Can the ceramic industry be a new and hazardous sector for work-related asthma?

BACKGROUND

Work-related asthma (WRA) constitutes a significant proportion of all asthma cases and continues to be reported from different industries. The aim of the study was to identify the occupations that can be related to WRA and diagnostic steps used in suspected WRA patients.

METHODS

We retrospectively reviewed the clinical records of WRA suspected patients who were referred to Ankara Occupational and Environmental Diseases Hospital, Turkey from January 2015 to January 2017. Detailed occupational history, the diagnostic steps such as pulmonary function testing (PFT), peak expiratory flow (PEF) monitoring and nonspecific bronchial provocation tests (NSBPT) were recorded.

RESULTS

Among 160 patients, 148 were male and 12 were female. Only 2 of them were diagnosed as work-exacerbated asthma (WEA). Diagnosis of asthma was based on using reversible airflow limitation 28.8% (n = 46) or NSBPT 31.9% (n = 51). Toxicological analysis showed that 28 patients had heavy metal poisoning, 9 patients had solvent poisoning, 4 patients had both. According to occupations, 32 of them were ceramic workers (20.0%) and 27 of them were metal workers (16.9%). Plastic workers (4 ± 2.8 years), cleaners (6.2 ± 5.7 years), metal workers (7.4 ± 5.4 years), painters (10 ± 5.2 years), ceramic workers (10.8 ± 5.9 years) had the shortest exposure durations for development of occupational asthma (OA). An analysis of variance showed that the effect of heavy metal and solvent poisoning on mean time for onset of OA was not significant.

CONCLUSIONS

The results demonstrate that besides the sectors known to cause WRA, ceramic and metal industries can be related to important exposures related to WRA. Medical surveillance of employees in this sector is important in early detection.

Respiratory disability and impairment: what is new?

PURPOSE OF REVIEW

This review summarizes recent advances concerning respiratory impairment and disability.

RECENT FINDINGS

The traditional impairment assessment approach, depending heavily on clinical pulmonary function testing to estimate the match between the patient's sustainable oxygen consumption and the workplace requirements, continues to be widely used. Recent work indicates the need to reassess underlying concepts for several reasons: The relationship between basic pulmonary function tests and sustainable oxygen consumption varies among patients and conditions. Studies of the respiratory demands of modern workplaces need to be updated. The concepts are less easily applied to asthma than other disorders. Research studies present differing definitions of 'disability', and therefore the methods of relating impairment (function loss) and disability require reassessment. Recent advances provide improved understanding of the large societal and personal impacts of respiratory impairment and disability.

SUMMARY

Clinicians, policymakers, and researchers should carefully consider how well the current highly specified impairment rating systems can be improved for accuracy and relevance to current home and work activities. In addition to measuring 'impairment', clinicians should consider factors affecting how impairments lead to disability.

Asthma and Wheeze Prevalence among Nursing Professionals in Western Japan: A Cross-Sectional Study

Although adult asthma is attributable to occupational factors, few reports are available on asthma prevalence among health care workers in Japan. The objective of this study was to estimate the prevalence of asthma and wheeze among Japanese nursing professionals. A cross-sectional study was conducted by postal survey using a translated version of the European Community Respiratory Health Survey questionnaire from April to June 2013. The analysis included 4634 nursing professionals (257 men and 4377 women) and the overall response rate was 84.8%. The prevalence of current asthma and wheeze were 10.7% (95% confidence interval (CI), 9.9%-11.7%) and 15.6% (95% CI, 14.5%-16.6%), respectively. More than one year of work experience as a nursing professional and more than one year of experience with bed-making tasks were associated with odds ratios (ORs) of 1.95 (95% CI, 1.12-3.39) and 1.64 (95% CI, 1.15-2.23) for wheeze, respectively. Current smoking was significantly associated with the presence of wheeze, with ORs of 2.27 for men (95% CI, 1.11-4.64) and 2.01 for women (95% CI, 1.54-2.64). Among female nurses, latex allergy was associated with wheeze (OR, 1.87; 95% CI, 1.56-2.23), as was body mass index ≥30 (OR, 2.76; 95% CI, 1.65-4.62). This study has provided the prevalence of asthma and wheeze among Japanese nursing professionals. Employment period, bed-making tasks, latex allergy, obesity, and smoking may be risk factors for prevalent wheeze among nursing professionals.

Managing the Risk of Occupational Allergy in the Enzyme Detergent Industry

Enzyme proteins have potential to cause occupational allergy/asthma. Consequently, as users of enzymes in formulated products, detergents manufacturers have implemented a number of control measures to ensure that the hazard does not translate into health effects in the workforce. To that end, trade associations have developed best practice guidelines which emphasize occupational hygiene and medical monitoring as part of an effective risk management strategy. The need for businesses to recognize the utility of this guidance is reinforced by reports where factories which have failed to follow good industrial hygiene practices have given rise to incidences of occupational allergy. In this article, an overview is provided of how the industry guidelines are actually implemented in practice and what experience is to be derived therefrom. Both medical surveillance and air monitoring practices associated with the implementation of industry guidelines at approximately 100 manufacturing facilities are examined. The data show that by using the approaches described for the limitation of exposure, for the provision of good occupational hygiene and for the active monitoring of health, the respiratory allergenic risk associated with enzyme proteins can be successfully managed. This therefore represents an approach that could be recommended to other industries contemplating working with enzymes.

Performing a lung disability evaluation: how, when, and why?

OBJECTIVES

The objective of this review is to present a case-based clinical discussion on this topic.

METHODS

The article represents part of the proceedings of the Occupational and Environmental Lung Disease conference held by the American College of Chest Physicians at Toronto, Ontario, Canada, in 2013, and is based upon a nonsystematic review of the current literature by the author.

RESULTS

Although the American Medical Association Guides to the Evaluation of Permanent Impairment is the mainstay for evaluating respiratory impairment, many other impairment schemata are currently available in the United States. Impairment evaluation for a case with chronic respiratory disease and a separate case with asthma is discussed.

CONCLUSIONS

Pulmonary function tests are the cornerstone for evaluating respiratory impairment. Impairment values differ between various impairment schemata. Impairment evaluation for asthma may be particularly difficult.

The prevalence of respiratory symptoms among mushroom workers in Ireland

BACKGROUND

Respiratory conditions such as asthma, bronchitis, hypersensitivity pneumonitis and upper airways symptoms have been ascribed to fungal exposures. Mushroom workers may be at risk of these as a consequence.

AIMS

To assess the prevalence of respiratory symptoms in mushroom workers.

METHODS

A cross-sectional study assessed 4 weeks of respiratory symptoms among mushroom workers divided into four categories of exposure, using a self-administered respiratory questionnaire and spirometry.

RESULTS

The population of 191 subjects was predominantly (66%) from Eastern Europe; 61% were women and 39% were under 30. It included 73 growers, 38 composters, 26 administrators and 52 packers. Among all workers, there was a high prevalence (67%) of one or more respiratory symptoms which did not appear to vary by age, gender, pack-years of smoking or duration of employment. There was a significant improvement in respiratory symptoms in workers during absence from the workplace (P < 0.001). Spirometry readings across all groups were within normal values. Symptom profiles suggest that as many as 22 workers had symptoms of airways disease; 18 (82%) of these were mushroom growers. Growers were significantly more likely to have symptoms consistent with airways disease than all other workers, odds ratio 9.2 (95% CI 3.0-28.4).

CONCLUSIONS

There was a high prevalence of respiratory symptoms among mushroom workers. Mushroom growers may be at high risk of airways disease, possibly from fungal antigens or related exposures.

Distribution of asthma by occupation: Washington State behavioral risk factor surveillance system data, 2006-2009

Objective

Objective: To estimate the prevalence of asthma in workers by occupation in Washington State. Methods: Data from the 2006–2009 Behavioral Risk Factor Surveillance System (BRFSS) and the BRFSS Asthma Call-Back Survey (ACBS) in Washington State (WA) were analyzed. Using state-added and coded Industry and Occupation questions, we calculated prevalence ratios (PRs) for 19 occupational groups. Results: Of the 41 935 respondents who were currently employed during 2006–2009, the prevalence of current asthma was 8.1% [95% confidence interval (CI) 7.8–8.5%] When compared with the reference group of executive, administration and managerial occupations, three occupational groups had significantly (p < 0.05) higher PRs of current asthma: “Teachers, all levels, and Counselors’ (PR 1.3, 95% CI 1.1–1. 6%); ‘Administrative Support, including Clerical” (PR 1. 5, 95% CI 1.2–1.9%); and “Other Health Services” (PR 1.5, 95% CI 1.2–1.9). Half of the 2511 ACBS respondent workers (55.1%) indicated that they believed exposure at work had caused or worsened their asthma, but only 10.7% had ever spoken with a health care professional about their asthma being work related. Conclusions: Some occupations have a higher prevalence of current asthma than other occupations. The systematic collection of industry and occupation data can help identify worker populations with a high burden of asthma and can be used to target disease prevention efforts as well as to aid clinician recognition and treatment. Workers indicated that work-related asthma exposures are not discussed with their health care provider and this communication gap has implications for asthma management.