Chronic obstructive pulmonary disease in nonsmokers by occupation and exposure: a brief review

Respiratory Diseases Associated With Organic Dust Exposure

Organic dusts are complex bioaerosol mixtures comprised of dust and par ticulate matter of organic origin. These include components from bacteria, fungi, pollen, and viruses to fragments of animals and plants commonplace to several environmental/occupational settings encompassing agriculture/farming, grain processing, waste/recycling, textile, cotton, woodworking, bird breeding, and more. Organic dust exposures are linked to development of chronic bronchitis, chronic obstructive pulmonary disease, asthma, asthma-like syndrome, byssinosis, hypersensitivity pneumonitis, and idiopathic pulmonary fibrosis. Risk factors of disease development include cumulative dust exposure, smoking, atopy, timing/duration, and nutritional factors. The immunopathogenesis predominantly involves Toll-like receptor signaling cascade, T-helper 1/T-helper 17 lymphocyte responses, neutrophil influx, and potentiation of manifestations associated with allergy. The true prevalence of airway disease directly attributed to organic dust, especially in a workplace setting, remains challenging. Diagnostic confirmation can be difficult and complicated by hesitancy from workers to seek medical care, driven by fears of potential labor-related consequence. Clinical respiratory and systemic presentations coupled with allergy testing, lung function patterns of obstructive versus restrictive disease, and radiological characteristics are typically utilized to delineate these various organic dust-associated respiratory diseases. Prevention, risk reduction, and management primarily focus on reducing exposure to the offending dust, managing symptoms, and preventing disease progression.

COPD in Never-Smokers: BOLD Australia Study

Purpose

Tobacco smoking is the major risk factor for COPD, and it is common for other risk factors in never-smokers to be overlooked. We examined the prevalence of COPD among never-smokers in Australia and identified associated risk factors.

Methods

We used data from the Australia Burden of Obstructive Lung Disease (BOLD) study, a cross-section of people aged ≥40 years from six sites. Participants completed interviews and post-bronchodilator spirometry. COPD was primarily defined as an FEV1/FVC ratio <0.70 and secondarily as the ratio less than the lower limit of normal (LLN).

Results

The prevalence of COPD in the 1656 never-smokers who completed the study was 10.5% (95% CI: 9.1-12.1%) [ratio

Conclusion

COPD was prevalent in this population of never-smokers aged 40 years and over. This finding highlights the significance of risk factors other than smoking in the development of COPD.

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Key Words

• BOLD
• LLN
• burden of obstructive lung disease
• lower limit of normal
• non-smokers
• prevalence
• spirometry

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MESH Headings

• Female
• Male
• Humans
• Adult
• Middle Aged
• Child
• Smokers
• Pulmonary Disease, Chronic Obstructive/diagnosis
• Pulmonary Disease, Chronic Obstructive/epidemiology
• Asthma
• Odds Ratio
• Australia/epidemiology

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Grants

• National Health and Medical Research Council (NHMRC) of Australia
• Thoracic Society of Australia and New Zealand
• Robert Pierce Grant-in-Aid for Indigenous Lung Health
• Air Liquide, AstraZeneca; GlaxoSmithKline; and Boehringer Ingelheim

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Affiliation(s)

Marsha A Ivey School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, 3004, Australia School of Medicine, Faculty of Medical Sciences, The University of the West Indies, St Augustine, Trinidad and Tobago
Sheree M Smith School of Nursing and Midwifery, Campbelltown Campus, Western Sydney University, Penrith, NSW, 2751, Australia Faculty of Medicine, University of Queensland, Brisbane, QLD, Australia
Geza Benke School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, 3004, Australia
Brett G Toelle Respiratory and Environmental Epidemiology Group, Woolcock Institute of Medical Research, Sydney, NSW, 2037, Australia Sydney Local Health District, Sydney, NSW, 2050, Australia
Michael L Hunter School of Population and Global Health, University of Western Australia, Perth, WA, 6009, Australia
Alan L James Department of Pulmonary Physiology and Sleep Medicine, Sir Charles Gairdner Hospital and Medical School, University of Western Australia, Perth, WA, 6009, Australia
Graeme P Maguire Curtin Medical School, Curtin University, Perth, WA, 6102, Australia
Richard Wood-Baker School of Medicine, University of Tasmania, Hobart, TAS, 7000, Australia
David P Johns Melbourne School of Population and Global Health, University of Melbourne, Melbourne, VIC, Australia
Guy B Marks Respiratory and Environmental Epidemiology Group, Woolcock Institute of Medical Research, Sydney, NSW, 2037, Australia School of Clinical Medicine, University of New South Wales, Sydney, NSW, 2052, Australia
Michael J Abramson School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, 3004, Australia

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City-scale assessment of long-term air quality impacts on the respiratory and cardiovascular health

Background

The impact of the urban environment on human health is a contemporary subject of environmental research. Air pollution is often considered a leading environmental driver. However, a plethora of other factors within the urban exposome may be involved. At the same time, the resolution of spatial data is also an important facet to consider. Generally, systematic tools for accurate health risk assessment in the urban environment are missing or are not implemented.

Methods

The long-term impact of air quality (PM₁₀, PM_2.5, NO₂, benzene, and SO₂) on respiratory and cardiovascular health was assessed with a log-linear model. We used the most accurate health data in high city scale spatial resolution over the period 2010 to 2018. Selected external exposome parameters were also included in the analysis.

Results

Statistically significant associations between air pollution and the health of the urban population were found. The strongest association was between benzene and the incidence of bronchitis in the adult population [RR 1.552 95% CI (1.415-1.704) per 0.5 μg/m³ change in benzene concentration]. A similar relation was observed between NO₂ and the same health condition [RR 1.483 95% CI (1.227-1.792) per 8.9 μg/m³ of change in NO₂]. Other weaker associations were also found between asthma in children and PMs, NO₂, or benzene. Cardiovascular-related hospitalizations in the general population were linked with NO₂ [RR 1.218 95% CI (1.119-1.325) per 9.7 μg/m³ change in NO₂]. The remaining pollutants were slightly less but still significantly associated with cardiovascular-related hospitalizations.

Conclusion

Our findings are mostly highly statistically significant (p ≤ 0.001) and are in line with current literature on the adverse effects of air pollution on the human population. The results highlight the need for continual improvements in air quality. We propose the implementation of this approach as a systematic tool for the investigation of possible health risks over a long period of time. However, further research involving other variables is an essential step toward understanding the complex urban exposome and its implications for human health. An increase in data spatial resolution is especially important in this respect as well as for improving city health risk management.

Incident chronic obstructive pulmonary disease associated with occupation, industry, and workplace exposures in the Health and Retirement Study

BACKGROUND

Chronic health effects from accumulated occupational exposures manifest as the workforce ages. The Health and Retirement Study (HRS), a panel survey of U.S. adults nearing/in retirement, allows assessment of associations among industry and occupation (I/O), workplace exposures, and incident chronic obstructive pulmonary disease (COPD).

METHODS

The study population comprised respondents from the 1992 HRS cohort employed in 1972 or later and not diagnosed with COPD as of initial interview. We examined associations with incident COPD through 2016 and: (1) broad and selected detailed I/O, (2) workplace exposures, and (3) exposures within I/O. Given the cohort's baseline age (50-62), we calculated subhazard ratios (SHRs) for COPD accounting for competing risk of death.

RESULTS

SHRs for COPD were significantly elevated for several industries: mining; blast furnaces, steelworks, rolling and finishing mills; groceries and related products; and automotive repair shops. Occupations with significantly elevated SHRs were maids and housemen; farmworkers; vehicle/mobile equipment mechanics and repair workers; material moving equipment operators; and nonconstruction laborers. Significantly elevated COPD SHRs were observed for specific I/O-exposure pairs: blast furnace/steelworks/rolling/finishing mills and asbestos; automotive repair shops and aerosol paints; farmworkers and pesticide exposures; and both material moving equipment operators and nonconstruction laborers exposed to dust and ash.

CONCLUSIONS

Certain jobs and occupational exposures are associated with increased risk for developing COPD in late preretirement and during retirement. Given the disability and economic costs of COPD, these findings support focusing exposure prevention and medical monitoring resources on groups of workers at increased risk.

Occupational lung diseases in Australia

Occupational exposures are an important determinant of respiratory health. International estimates note that about 15% of adult-onset asthma, 15% of chronic obstructive pulmonary disease and 10-30% of lung cancer may be attributable to hazardous occupational exposures. One-quarter of working asthmatics either have had their asthma caused by work or adversely affected by workplace conditions. Recently, cases of historical occupational lung diseases have been noted to occur with new exposures, such as cases of silicosis in workers fabricating kitchen benchtops from artificial stone products. Identification of an occupational cause of a lung disease can be difficult and requires maintaining a high index of suspicion. When an occupational lung disease is identified, this may facilitate a cure and help to protect coworkers. Currently, very little information is collected regarding actual cases of occupational lung diseases in Australia. Most assumptions about many occupational lung diseases are based on extrapolation from overseas data. This lack of information is a major impediment to development of targeted interventions and timely identification of new hazardous exposures. All employers, governments and health care providers in Australia have a responsibility to ensure that the highest possible standards are in place to protect workers' respiratory health.

Non-smoking Chronic Obstructive Pulmonary Disease Attributed to Occupational Exposure to Silica Dust

An 85-year-old, never-smoking man presented with exertional dyspnea. He had been exposed to silica dust in the work place. Chest computed tomography revealed bronchial wall thickening without emphysema. A pulmonary function test showed airflow obstruction without impaired gas transfer. Airway hyperresponsiveness and reversibility were not evident. A transbronchial lung biopsy showed findings suggestive of mineral dust exposure, such as fibrosis and slight pigmentation of bronchioles. He was diagnosed with non-smoking chronic obstructive pulmonary disease (COPD) due to occupational exposure to silica dust. His symptoms were improved using an inhaled long-acting bronchodilator. The clinical characteristics of non-smoking COPD are discussed in this report.

Pulmonary health effects of air pollution

PURPOSE OF THE REVIEW

Air pollution continues to be a major public health concern affecting nine out of 10 individuals living in urban areas worldwide. Exposure to air pollution is the ninth leading risk factor for cardiopulmonary mortality. The aim of this review is to examine the current literature for the most recent updates on health effects of specific air pollutants and their impact on asthma, chronic obstructive pulmonary disease, lung cancer, and respiratory infection.

RECENT FINDINGS

A total of 52 publications were reviewed to establish new insights as to how air pollution is associated with pulmonary morbidity and mortality. Considerable past evidence suggests that air pollution is an important factor that enhances pulmonary disease, while also causing greater harm in susceptible populations, such as children, the elderly, and those of low socio-economic status worldwide. Asthma, chronic obstructive pulmonary disease, lung cancer, and respiratory infections all seem to be exacerbated because of exposure to a variety of environmental air pollutants with the greatest effects because of particulate matter, ozone, and nitrogen oxides. New publications reviewed reaffirm these findings.

SUMMARY

Continued vigilance will be essential to lessen the effects of air pollution on human health and pulmonary disease. Cooperation at a multinational level will be required on the part of governments, industry, energy-based enterprises, and the public working together to solve our air quality issues at the local, national, and global level.

Drillers and mill operators in an open-pit gold mine are at risk for impaired lung function

BACKGROUND

Occupational studies of associations of exposures with impaired lung function in mining settings are built on exposure assessment and far less often on workplace approach, so the aim of this study was to identify vulnerable occupational groups for early lung function reduction in a cohort of healthy young miners.

METHODS

Data from annual screening lung function tests in gold mining company in Kyrgyzstan were linked to occupations. We compared per cent predicted forced expiratory volume in one second (FEV1), forced vital capacity (FVC) and FEV1/FVC between occupational groups and tested selected occupations in multivariate regression adjusted for smoking and work duration for the following outcomes: FEV1 < 80 %, FEV1/FVC < 70 % and both.

RESULTS

1550 tests of permanent workers of 41 occupations (mean age 40.5 ± 9.2 years, 29.8 % never smokers) were included in the analysis. The mean overall VC was 103.0 ± 12.9 %; FVC 109.1 ± 13.0 % and FEV1 100.2 ± 25.9 %. Drillers and smoking food handlers had the lowest FEV1%. In non-smokers, the lowest FEV1 was in drillers (94.9 ± 11.3 % compared to 115.2 ± 17.7 % in engineers). Drillers (adjusted odds ratio (OR) 1.53 (95 % confidence interval (CI) 1.11-2.09)) and mill operators (OR 2.01 (1.13-3.57)) were at greater risk of obstructive ventilation pattern (FEV1/FVC < 70 %).

CONCLUSIONS

Drilling and mill operations are the highest risk jobs in an open-pit mine for reduced lung function. Occupational medical clinic at site should follow-up workers in these occupations with depth and strongly recommend smoking cessation.

POPE study: rationale and methodology of a study to phenotype patients with COPD in Central and Eastern Europe

Introduction

Chronic obstructive pulmonary disease (COPD) constitutes a major health challenge in Central and Eastern European (CEE) countries. However, clinical phenotypes, symptom load, and treatment habits of patients with COPD in CEE countries remain largely unknown. This paper provides a rationale for phenotyping COPD and describes the methodology of a large study in CEE.

Methods/design

The POPE study is an international, multicenter, observational cross-sectional survey of patients with COPD in CEE. Participation in the study is offered to all consecutive outpatients with stable COPD in 84 centers across the CEE region if they fulfill the following criteria: age >40 years, smoking history ≥10 pack-years, a confirmed diagnosis of COPD with postbronchodilator FEV₁/FVC <0.7, and absence of COPD exacerbation ≥4 weeks. Medical history, risk factors for COPD, comorbidities, lung function parameters, symptoms, and pharmaceutical and nonpharmaceutical treatment are recorded. The POPE project is registered in ClinicalTrials.gov with the identifier NCT02119494.

Outcomes

The primary aim of the POPE study was to phenotype patients with COPD in a real-life setting within CEE countries using predefined classifications. Secondary aims of the study included analysis of differences in symptoms, and diagnostic and therapeutic behavior in participating CEE countries.

Conclusion

There is increasing acceptance toward a phenotype-driven therapeutic approach in COPD. The POPE study may contribute to reveal important information regarding phenotypes and therapy in real-life CEE.