ABSTRACT
BACKGROUND: We hypothesised that occupational exposures differently affect subtypes of adult-onset asthma. OBJECTIVE: We investigated potential relations between occupation and three subtypes of adult asthma, namely atopic asthma, non-atopic asthma and asthma-COPD overlap syndrome (ACOS). METHODS: This is a population-based case-control study of incident asthma among working-age adults living in Pirkanmaa Hospital District in Southern Finland. The determinant of interest was occupation at the time of diagnosis of asthma or the job that the subject had quit due to respiratory symptoms. Asthma was divided into three mutually exclusive subtypes on the basis of any positive IgE antibody (atopic and non-atopic asthma) and presence of persistent airways obstruction in spirometry (ACOS). We applied unconditional logistic regression analysis to estimate adjusted OR (aOR), taking into account gender, age and smoking. RESULTS: The following occupational groups showed significantly increased risk of atopic asthma: chemical industry workers (aOR 15.76, 95% CI 2.64 to 94.12), bakers and food processors (aOR 4.69, 95% CI 1.18 to 18.69), waiters (aOR 4.67, 95% CI 1.40 to 15.56) and those unemployed (aOR 3.06, 95% CI 1.52 to 6.17). The following occupations showed clearly increased risk of non-atopic asthma: metal workers (aOR 8.37, 95% CI 3.77 to 18.59) and farmers and other agricultural workers (aOR 2.36, 95% CI 1.10 to 5.06). Some occupational groups showed statistically significantly increased OR of ACOS: electrical and electronic production workers (aOR 30.6, 95% CI 6.10 to 153.35), fur and leather workers (aOR 16.41, 95% CI 1.25 to 215.85) and those retired (aOR 5.55, 95% CI 1.63 to 18.97). CONCLUSIONS: Our results show that different occupations are associated with different subtypes of adult-onset asthma.
Subject(s)
Asthma, Occupational/etiology , Adult , Age Factors , Asthma, Occupational/classification , Asthma, Occupational/epidemiology , Asthma-Chronic Obstructive Pulmonary Disease Overlap Syndrome/epidemiology , Asthma-Chronic Obstructive Pulmonary Disease Overlap Syndrome/etiology , Case-Control Studies , Chemical Industry , Farmers , Female , Finland/epidemiology , Food Industry , Humans , Male , Middle Aged , Restaurants , Risk Factors , Sex Factors , Smoking/adverse effects , Young AdultABSTRACT
OBJECTIVES: To study potential exposures to crystalline silica and the number of work-related cases of silicosis occurring in Alberta. METHODS: Exposure data comprising 343 occupational samples were collected at 40 worksites across 13 industries. To assess silicosis reporting, cases reported to the Alberta government, claims accepted by the Workers' Compensation Board for work-related silicosis, and billings to Alberta Health for medical services with a diagnostic code for silicosis during a similar time period were compared. RESULTS: Workers potentially over-exposed to airborne respirable crystalline silica were identified at most of the worksites evaluated. There were large discrepancies in the number of silicosis cases found. CONCLUSIONS: Many Alberta workers may be over-exposed to airborne respirable crystalline silica, and the incidence of work-related silicosis in Alberta may not be adequately represented by the official statistics.
Subject(s)
Asthma, Occupational/diagnosis , Disability Evaluation , Silicosis/diagnosis , Alberta , Asthma, Occupational/classification , Asthma, Occupational/prevention & control , Eligibility Determination/legislation & jurisprudence , Expert Testimony/legislation & jurisprudence , Humans , Male , Middle Aged , Respiratory Function Tests , Respiratory Protective Devices , Silicosis/classification , Workers' Compensation/legislation & jurisprudenceABSTRACT
The term irritant-induced (occupational) asthma (IIA) has been used to denote various clinical forms of asthma related to irritant exposure at work. The causal relationship between irritant exposure(s) and the development of asthma can be substantiated by the temporal association between the onset of asthma symptoms and a single or multiple high-level exposure(s) to irritants, whereas this relationship can only be inferred from epidemiological data for workers chronically exposed to moderate levels of irritants. Accordingly, the following clinical phenotypes should be distinguished within the wide spectrum of irritant-related asthma: (i) definite IIA, that is acute-onset IIA characterized by the rapid onset of asthma within a few hours after a single exposure to very high levels of irritant substances; (ii) probable IIA, that is asthma that develops in workers with multiple symptomatic high-level exposures to irritants; and (iii) possible IIA, that is asthma occurring with a delayed-onset after chronic exposure to moderate levels of irritants. This document prepared by a panel of experts summarizes our current knowledge on the diagnostic approach, epidemiology, pathophysiology, and management of the various phenotypes of IIA.
Subject(s)
Algorithms , Asthma, Occupational/classification , Asthma, Occupational/diagnosis , Humans , Irritants/adverse effects , Occupational Exposure/adverse effectsABSTRACT
The workplace can trigger or induce asthma and cause the onset of different types of work-related asthma (WRA). Based on current knowledge of clinical features, pathophysiologic mechanisms, and evidence supporting a causal relationship, the following conditions should be distinguished in the spectrum of WRA: (1) immunologic occupational asthma (OA), (2) nonimmunologic OA, (3) work-exacerbated asthma, and (4) variant syndromes, including eosinophilic bronchitis, potroom asthma, and asthmalike disorders caused by organic dusts. The rationale, issues, and controversies relating to this approach are critically reviewed to stimulate the development of a consensus on operational definitions of the various phenotypes of WRA.
Subject(s)
Asthma, Occupational/classification , Irritants/adverse effects , Occupational Exposure/prevention & control , Population Surveillance/methods , Airway Remodeling/immunology , Asthma, Occupational/etiology , Asthma, Occupational/immunology , Asthma, Occupational/pathology , Asthma, Occupational/physiopathology , Bronchial Hyperreactivity/etiology , Bronchial Hyperreactivity/immunology , Bronchial Hyperreactivity/pathology , Bronchial Hyperreactivity/physiopathology , Humans , Immunoglobulin E/immunology , Irritants/immunology , Risk FactorsABSTRACT
Occupational asthma (OA) is one of the most common forms of work-related lung disease in all industrialized nations. The clinical management of patients with OA depends on an understanding of the multifactorial pathogenetic mechanisms that can contribute to this disease. This article discusses the various immunologic and nonimmunologic mechanisms and genetic susceptibility factors that drive the inflammatory processes of OA.