Issue 3-The occupational burden of respiratory diseases, an update

INTRODUCTION AND AIMS

Workplace exposures are widely known to cause specific occupational diseases such as silicosis and asbestosis, but they also can contribute substantially to causation of common respiratory diseases. In 2019, the American Thoracic Society (ATS) and the European Respiratory Society (ERS) published a joint statement on the occupational burden of respiratory diseases. Our aim on this narrative review is to summarise the most recent evidence published after the ATS/ERS statement as well as to provide information on traditional occupational lung diseases that can be useful for clinicians and researchers.

RESULTS

Newer publications confirm the findings of the ATS/ERS statement on the role of workplace exposure in contributing to the aetiology of the respiratory diseases considered in this review (asthma, COPD, chronic bronchitis, idiopathic pulmonary fibrosis, hypersensitivity pneumonitis, infectious pneumonia). Except for COPD, chronic bronchitis and infectious pneumonia, the number of publications in the last 5 years for the other diseases is limited. For traditional occupational lung diseases such as silicosis and asbestosis, there are old as well as novel sources of exposure and their burden continues to be relevant, especially in developing countries.

CONCLUSIONS

Occupational exposure remains an important risk factor for airways and interstitial lung diseases, causing occupational lung diseases and contributing substantially in the aetiology of common respiratory diseases. This information is critical for public health professionals formulating effective preventive strategies but also for clinicians in patient care. Effective action requires shared knowledge among clinicians, researchers, public health professionals, and policy makers.

Occupational exposure and the risk of new-onset chronic rhinosinusitis â€" a prospective study 2013-2018

BACKGROUND

The aetiology behind chronic rhinosinusitis (CRS) is still poorly understood. The aim of this study was to investigate the association between the onset of CRS and several common occupational exposures over time.

METHODOLOGY

An adult random population from Telemark, Norway, comprising 7,952 subjects, who answered a comprehensive respiratory questionnaire including questions on CRS and occupational exposure first in 2013 and again in 2018.

RESULTS

New-onset CRS during the five-year follow-up was independently associated with occupational exposure to hair-care products, cleaning agents among women, super glue, strong acids, cooking fumes and wood dust.

CONCLUSION

In this random population cohort from Norway, exposure to several common occupational agents, such as hair-care products, super glue and wood dust, was associated with the onset of CRS. It is important that physicians who see patients with CRS inquire about workplace exposure.

P5297Body weight in adolescent men in Sweden and risk of an early acute coronary event

Background

To improve cardiovascular disease (CVD) prevention, knowledge of early key risk factors, especially those that are modifiable such as overweight and obesity, is essential.

Purpose

We aimed to determine whether body mass index (BMI) at age 18 predicted early acute coronary events among men in Sweden.

Methods

Population-based Swedish cohort study of conscripts (n=1,668,921; mean age at baseline, 18.3 years) who enlisted during 1968–2005. Follow-up was done through linkage to the nationwide Swedish patient- and death registries. Risk of an acute coronary event (hospitalization for acute myocardial infarction or coronary death) during follow-up (5–46 years) was calculated with Cox proportional hazards models. Objective baseline measures of fitness and cognition were included in the models in a second set of analyses.

Results

During follow-up there were 22,412 acute coronary events (mean age at diagnosis, 50.2 (SD 7.4) years, maximum 64 years). Compared with men with BMI of 18.5 to 20.0 kg/m2, men with BMI 20 to <22.5 and 22.5 to <25.0 kg/m2 had hazard ratios (HR) of 1.17 (1.12–1.43) and 1.51 (1.44–1.59), respectively, for an acute coronary event, after adjustment for age, year of conscription, comorbidities at baseline, parental education, blood pressure, IQ, muscle strength, and fitness. Those with a BMI of ≥35 kg/m2 had an HR of 3.47 (2.75–4.39) for an event before the age of 65. The multiple-adjusted risk per 1-unit increase in BMI was 1.10 (95% CI, 1.09–1.10).

Conclusion

We found a rise in risk of an early acute coronary event detectable already at normal levels of body weight at age 18, and rising to more than 3-fold in the highest weight category. Given increasing levels of body weight, and prevalence of overweight and obesity in young adults, the current decrease in coronary heart disease incidence in Sweden may flatten or even reverse in the near future.

Acknowledgement/Funding

The Swedish Heart and Lung Foundation [2015-0438]; the Swedish Research Council [2013-5187,2013-4236]

4949Diverging secular trends in cardiovascular disease 21-year incidence in Swedish men born in 1950–1978

Background

Cardiovascular disease (CVD) mortality is decreasing in Western countries, including Sweden. However, there are reports of increases in incidence in young people with respect to heart failure (HF) and atrial fibrillation (AF). The magnitude and causes of these changes are only partly known.

Aims

We investigated secular trends in incidence in CVD outcomes and their attenuation by changes in body mass index (BMI). The outcomes were risk of acute myocardial infarction (AMI), heart failure (HF) and atrial fibrillation (AF) as well as cardiovascular and all-cause death in a population of Swedish adolescents.

Methods

We followed a cohort of Swedish men enrolled for military service conscription in 1969–1996 (n=1,326,082; mean age=18.3) until December 2016, collected from the national inpatient (IPR) and outpatient registries (OPR). Cox-proportional hazard models were used to analyse the longitudinal change in incidence by with respect to early (0–21 years) of follow-up for subgroups with conscription 1968–1971, 1971–1976, 1976–1981, 1981–1986, 1986–1991, 1991–1996 (with the group born 1971–1976 as reference). Adjustments for potential confounders including BMI were performed.

Results

We found that CVD and all-cause mortality and MI decreased progressively during the follow-up with hazard ratios (HR) of 0.51, 95% confidence interval (CI) 0.43–0.62, HR 0.51 CI 0.57–0.62, and 0.60 CI 0.50–0.72, respectively. In contrast, we found increases in the incidence of HF (HR 1.86, CI 1.48–2.33], and AF (HR 8.26, CI 6.87–9.92). Adjustments for changes in BMI partly attenuated the changes in secular trends. Cubic spline models showed where the changes in secular trends were most prominent.

Conclusion

The incidences of cardiovascular outcomes show diverging secular changes. While MI and cardiovascular mortality are continually decreasing, there is an increase in HF and AF. The associations appear to be partly explained by changes in index BMI over time.

Acknowledgement/Funding

grants from the Swedish Government and the county councils, the ALF–GBG-719761, ALFGBG-751111, Swedish Stroke Association, Göteborg Medical Society

The Swedish CArdioPulmonary BioImage Study: objectives and design

Cardiopulmonary diseases are major causes of death worldwide, but currently recommended strategies for diagnosis and prevention may be outdated because of recent changes in risk factor patterns. The Swedish CArdioPulmonarybioImage Study (SCAPIS) combines the use of new imaging technologies, advances in large-scale 'omics' and epidemiological analyses to extensively characterize a Swedish cohort of 30 000 men and women aged between 50 and 64 years. The information obtained will be used to improve risk prediction of cardiopulmonary diseases and optimize the ability to study disease mechanisms. A comprehensive pilot study in 1111 individuals, which was completed in 2012, demonstrated the feasibility and financial and ethical consequences of SCAPIS. Recruitment to the national, multicentre study has recently started.

The relation of airway obstruction to asthma, chronic rhinosinusitis and age: results from a population survey of adults

RATIONALE

There is conflicting evidence on whether patients with asthma experience an accelerated decline in lung function with age. We examined the association between postbronchodilator lung function, asthma, chronic rhinosinusitis (CRS), and atopy with age using a large European sample.

METHODS

In 17 centers in 11 European countries, case-control studies were nested within representative cross-sectional surveys of adults aged less than 75 years. Representative samples of participants with asthma, CRS or both and controls were assessed for postbronchodilator ventilatory function, smoking history, atopy, and treatment. Multiple regression was used to assess the interactive effects of age and diagnostic group on decline in postbronchodilator ventilatory function.

RESULTS

A total of 3337 participants provided adequate data (778 with asthma, 399 with CRS, 244 with both asthma and CRS and 1916 controls who had neither asthma nor CRS). Participants with asthma had lower FEV1 /FVC (-4.09% (95% CI: -5.02, -3.15, P < 0.001) and a steeper slope of FEV1 /FVC against age (-0.14%/annum [95%CI: -0.19, -0.08]) equivalent to smoking 1-2 packs of cigarettes per day. Those with atopy had a slope equivalent to controls.

CONCLUSIONS

People with asthma have a steeper decline in postbronchodilator lung function with age, but neither CRS nor atopy alone were associated with such decline.

What can we learn about asthma and allergy from the follow-up of the RHINE and the ECRHS studies?

OBJECT

The international population-based studies RHINE and ECRHS have provided new insight in the epidemiology and management of asthma, allergy and rhinitis in young adults. The aim of the present review is to focus on longitudinal results with regard incidence and net change of asthma and asthma-like symptoms, risk factors and management of asthma, with special reference to the Nordic-Baltic countries.

RESULTS

Asthma and rhinitis are common conditions that are important in a public health perspective. There are gender differences in incidence and remission. A socio-economic gradient that non-atopic asthma is more strongly related to poverty seems to have developed in the last decade. These findings will challenge our welfare states in the future. In addition, occupational, as well as indoor and outdoor environmental exposures, influenced the onset of asthma. The population-attributable risk for adult asthma because of occupational exposures is equivalent to an incidence of new-onset asthma of 250-300 cases per million per year. Genetic factors, allergic sensitisation, gastro-oesophageal reflux, habitual snoring, diet and other factors may also contribute to the onset of asthma and rhinitis. Even though management of asthma has improved, there are still great variations throughout Europe. These findings highlight the key role doctors and nurses play in educating and reviewing management of patients.

Occupational exposures and COPD: an ecological analysis of international data

The occupational contribution to chronic obstructive pulmonary disease (COPD) has yet to be put in a global perspective. In the present study, an ecological approach to this question was used, analysing group-level data from 90 sex-specific strata from 45 sites of the Burden of Obstructive Lung Disease study, the Latin American Project for the Investigation of Obstructive Lung Disease and the European Community Respiratory Health Survey follow-up. These data were used to study the association between occupational exposures and COPD Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage II or above. Regression analysis of the sex-specific group-level prevalence rates of COPD at each site against the prevalence of occupational exposure and ever-smoking was performed, taking into account mean smoking pack-yrs and mean age by site, sex, study cohort and sample size. For the entire data set, the prevalence of exposures predicted COPD prevalence (0.8% increase in COPD prevalence per 10% increase in exposure prevalence). By comparison, for every 10% increase in the proportion of the ever-smoking population, the prevalence of COPD GOLD stage II or above increased by 1.3%. Given the observed median population COPD prevalence of 3.4%, the model predicted that a 20% relative reduction in the disease burden (i.e. to a COPD prevalence of 2.7%) could be achieved by a 5.4% reduction in overall smoking rates or an 8.8% reduction in the prevalence of occupational exposures. When the data set was analysed by sex-specific site data, among males, the occupational effect was a 0.8% COPD prevalence increase per 10% change in exposure prevalence; among females, a 1.0% increase in COPD per 10% change in exposure prevalence was observed. Within the limitations of an ecological analysis, these findings support a worldwide association between dusty trades and chronic obstructive pulmonary disease for both females and males, placing this within the context of the dominant role of cigarette smoking in chronic obstructive pulmonary disease causation.

Occupation and adult onset of rhinitis in the general population

OBJECTIVES

Occupational exposures have been associated with an increased risk of new-onset rhinitis in apprentices. However, population-based prospective data are scarce and do not cover new onset of rhinitis later in life. The authors studied the association between occupational exposure and adult onset of rhinitis prospectively.

METHODS

The data of 4994 participants (age at follow-up 28-57 years) from 27 centres of the European Community Respiratory Health Survey II who were symptom-free at baseline were analysed. As outcome at follow-up self-reported (a) nasal allergies ("allergic rhinitis") and (b) runny, blocked nose for 12 months a year ("perennial rhinitis") were used. Occupational exposures at any time during follow-up were defined by job title.

RESULTS

The cumulative incidence of allergic rhinitis, perennial rhinitis and both conditions was 12%, 11% and 3%, respectively. Compared to office workers, male medical professionals were at increased risk of new onset of allergic rhinitis (OR 3.0; 95% CI 1.4 to 6.4). Odds ratios were reduced in metal workers not involved in metal making or treating (0.3; 95% CI 0.1 to 0.7). For perennial rhinitis ORs were significantly increased in cleaners (1.4; 95% CI 1.0 to 2.1).

CONCLUSIONS

Cleaners and medical professionals may be at increased risk for adult-onset rhinitis.

Exhaled breath condensate: methodological recommendations and unresolved questions

Collection of exhaled breath condensate (EBC) is a noninvasive method for obtaining samples from the lungs. EBC contains large number of mediators including adenosine, ammonia, hydrogen peroxide, isoprostanes, leukotrienes, nitrogen oxides, peptides and cytokines. Concentrations of these mediators are influenced by lung diseases and modulated by therapeutic interventions. Similarly EBC pH also changes in respiratory diseases. The aim of the American Thoracic Society/European Respiratory Society Task Force on EBC was to identify the important methodological issues surrounding EBC collection and assay, to provide recommendations for the measurements and to highlight areas where further research is required. Based on the currently available evidence and the consensus of the expert panel for EBC collection, the following general recommendations were put together for oral sample collection: collect during tidal breathing using a noseclip and a saliva trap; define cooling temperature and collection time (10 min is generally sufficient to obtain 1-2 mL of sample and well tolerated by patients); use inert material for condenser; do not use resistor and do not use filter between the subject and the condenser. These are only general recommendations and certain circumstances may dictate variation from them. Important areas for future research involve: ascertaining mechanisms and site of exhaled breath condensate particle formation; determination of dilution markers; improving reproducibility; employment of EBC in longitudinal studies; and determining the utility of exhaled breath condensate measures for the management of individual patients. These studies are required before recommending this technique for use in clinical practice.

Health and socioeconomic impact of work-related asthma

There is accumulating evidence that the workplace environment contributes significantly to the general burden of asthma. The purpose of this review is to explore the respiratory health and socioeconomic consequences of work-related asthma by addressing a series of controversial issues: 1) what is the natural history of occupational asthma and in what ways does ongoing exposure to the causal agent impact clinical outcomes?; 2) how does the natural history of irritant-induced asthma differ in its health outcomes from immunologically-mediated occupational asthma?; 3) do working conditions have a significant impact on asthma regardless of the aetiology of the disease?; 4) what is the scope of work disability from work-related-asthma in social and economic terms?; 5) what is the clinician's role in reducing the respiratory health consequences of work-related asthma? 6) to what extent do existing compensation and other social insurance schemes successfully address occupational asthma and work-aggravated asthma?

How much adult asthma can be attributed to occupational factors?

PURPOSE

Many occupational factors can cause asthma or reactivate preexisting disease. We carried out a critical review and synthesis of the available literature to estimate the proportion of adult asthma that is attributable to workplace factors.

METHODS

We reviewed published citations from 1966 through May 1999 as well as recent abstracts of studies providing risk estimates for asthma among various occupations. We extracted published attributable risk estimates, derived others from published data, and extrapolated estimates from the incidence rates of occupational asthma. We used a semiquantitative score to rank studies based on their characteristics.

RESULTS

We obtained 43 attributable risk estimates from 19 different countries: 23 were published estimates, 8 were derived from published data, and 12 were extrapolated from incidence data. The median value for the attributable risk of occupationally associated asthma was 9%(25th to 75th interquartile range: 5% to 19%). The derived estimates (median attributable risk = 25%) were significantly greater than published values (median = 9%, P = 0.002), whereas the extrapolated estimates were significantly lower (median = 5%, P = 0.04). The 12 highest scored studies based on their characteristics yielded a median risk estimate of 15%.

CONCLUSION

Occupational factors are associated with about 1 in 10 cases of adult asthma, including new onset disease and reactivation of preexisting asthma.

Quantitative importance of asbestos as a cause of lung cancer in a Swedish industrial city: a case-referent study

We wanted to assess the quantitative importance of asbestos as a cause of lung cancer. In a case-referent study, the exposure to asbestos, tobacco smoke and some other occupational exposures were compared between 147 cases of lung cancer (100 men, 47 women), 111 hospital referents, and 109 population referents, all below the age of 75 yrs and living in an industrial city. The attributable risk of lung cancer due to asbestos exposure was 16% in men (95% confidence interval 1-31%). No woman had occupational exposure to asbestos. We conclude that in the mid 1980's tobacco smoking was the major attributable risk, being 95% for men and 78% for women, but that in men asbestos was an appreciable contributing factor in the general population of a Swedish industrial city.