Work-related asthma.

Work-related asthma (WRA) is highly prevalent in the adult population. WRA includes occupational asthma (OA), which is asthma caused by workplace exposures, and work-exacerbated asthma (WEA), also known as work-aggravated asthma, which is preexisting or concurrent asthma worsened by workplace conditions. In adults, the estimated prevalence of OA is 16.0%, whereas that of WEA is 21.5%. An increasing number of chemicals used in industrial production, households, and services are associated with the incidence of adult-onset asthma attributable to exposure to chemicals. This review article summarizes the different types of WRA and describes diagnostic procedures, treatment, prevention, and approaches to patient management. It is not always easy to distinguish between OA and WEA. It is important to establish a diagnosis (of sensitizer-/irritant-induced OA or WEA) in order to prevent worsening of symptoms, as well as to prevent other workers from being exposed, by providing early treatment and counseling on social security and work-related issues.

Work-related asthma / Asma relacionada ao trabalho

ABSTRACT Work-related asthma (WRA) is highly prevalent in the adult population. WRA includes occupational asthma (OA), which is asthma caused by workplace exposures, and work-exacerbated asthma (WEA), also known as work-aggravated asthma, which is preexisting or concurrent asthma worsened by workplace conditions. In adults, the estimated prevalence of OA is 16.0%, whereas that of WEA is 21.5%. An increasing number of chemicals used in industrial production, households, and services are associated with the incidence of adult-onset asthma attributable to exposure to chemicals. This review article summarizes the different types of WRA and describes diagnostic procedures, treatment, prevention, and approaches to patient management. It is not always easy to distinguish between OA and WEA. It is important to establish a diagnosis (of sensitizer-/irritant-induced OA or WEA) in order to prevent worsening of symptoms, as well as to prevent other workers from being exposed, by providing early treatment and counseling on social security and work-related issues.

RESUMO A asma relacionada ao trabalho (ART) é um acometimento com elevada prevalência na população adulta. A ART inclui a asma ocupacional (AO), desencadeada pela exposição a um agente presente em um determinado ambiente de trabalho, e a asma agravada ou exacerbada pelo trabalho (AA/ET), que acomete indivíduos com antecedentes de asma ou que iniciaram um quadro de asma concomitante, mas sem relação causal com o ambiente de trabalho. Estima-se que 16,0% e 21,5% da asma no adulto sejam AO e AA/ET, respectivamente. O elevado e crescente número de substâncias químicas usadas na produção industrial, no uso domiciliar ou em serviços é responsável pela incidência de asma associada à exposição a agentes químicos na vida adulta. Este artigo de revisão descreve os principais tipos de ART, os procedimentos para seu diagnóstico, tratamento e prevenção e as condutas frente ao diagnóstico. Nem sempre é fácil a distinção entre AO e AA/ET. A importância do diagnóstico (AO ou AA/ET e asma induzida por sensibilizantes ou irritantes) tem relação com a adoção de medidas de prevenção para evitar que novos indivíduos sejam expostos e que os acometidos apresentem agravamento da doença, utilizando tratamento precoce e fornecendo orientação sobre aspectos previdenciários e trabalhistas.

A scoping review to identify strategies that work to prevent four important occupational diseases.

BACKGROUND: Despite being largely preventable, many occupational diseases continue to be highly prevalent and extremely costly. Effective strategies are required to reduce their human, economic, and social impacts. METHODS: To better understand which approaches are most likely to lead to progress in preventing noise-related hearing loss, occupational contact dermatitis, occupational cancers, and occupational asthma, we undertook a scoping review and consulted with a number of key informants. RESULTS: We examined a total of 404 articles and found that various types of interventions are reported to contribute to occupational disease prevention but each has its limitations and each is often insufficient on its own. Our principal findings included: legislation and regulations can be an effective means of primary prevention, but their impact depends on both the nature of the regulations and the degree of enforcement; measures across the hierarchy of controls can reduce the risk of some of these diseases and reduce exposures; monitoring, surveillance, and screening are effective prevention tools and for evaluating the impact of legislative/policy change; the effect of education and training is context-dependent and influenced by the manner of delivery; and, multifaceted interventions are often more effective than ones consisting of a single activity. CONCLUSIONS: This scoping review identifies occupational disease prevention strategies worthy of further exploration by decisionmakers and stakeholders and of future systematic evaluation by researchers. It also identified important gaps, including a lack of studies of precarious workers and the need for more studies that rigorously evaluate the effectiveness of interventions.

Occupational asthma from tafenoquine in the pharmaceutical industry: implications for QSAR.

We report occupational asthma and rhinitis in a formulation pharmacist, employed in the development of tafenoquine. Tafenoquine is a new anti-malarial drug in development; the pure drug substance has an asthma hazard index of zero and previously was not known to be a respiratory sensitizing agent. The implications of this finding for the refinement of quantitative structural analysis of asthmagenic chemicals are discussed.

Redemption of asthma pharmaceuticals among stainless steel and mild steel welders: a nationwide follow-up study.

PURPOSE: The purpose was to examine bronchial asthma according to cumulative exposure to fume particulates conferred by stainless steel and mild steel welding through a proxy of redeemed prescribed asthma pharmaceuticals. METHODS: A Danish national company-based historical cohort of 5,303 male ever-welders was followed from 1995 to 2011 in the Danish Medicinal Product Registry to identify the first-time redemption of asthma pharmaceuticals including beta-2-adrenoreceptor agonists, adrenergic drugs for obstructive airway diseases and inhalable glucocorticoids. Lifetime exposure to welding fume particulates was estimated by combining questionnaire data on welding work with a welding exposure matrix. The estimated exposure accounted for calendar time, welding intermittence, type of steel, welding methods, local exhaustion and welding in confined spaces. Hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated using a Cox proportional hazards model adjusting for potential confounders and taking modifying effects of smoking into account. RESULTS: The average incidence of redemption of asthma pharmaceuticals in the cohort was 16 per 1,000 person year (95% CI 10-23 per 1,000 person year). A moderate nonsignificant increased rate of redemption of asthma medicine was observed among high-level exposed stainless steel welders in comparison with low-level exposed welders (HR 1.54, 95% CI 0.76-3.13). This risk increase was driven by an increase risk among non-smoking stainless steel welders (HR 1.46, 95% CI 1.06-2.02). Mild steel welding was not associated with increased risk of use asthma pharmaceuticals. CONCLUSION: The present study indicates that long-term exposure to stainless steel welding is related to increased risk of asthma in non-smokers.

Clinical aspects of work-related asthma: past achievements, persistent challenges, and emerging triggers.

OBJECTIVE: The aim of this article was to address common clinical questions pertaining to work-related asthma (WRA). METHODS: This review is based on a presentation on WRA at the American College of Chest Physicians Course on Clinical Aspects of Occupational and Environmental Lung Disease, held in Toronto in 2013, and supplemented by a PubMed search of publications to 2013. RESULTS: Seven clinical questions are addressed in relation to definitions, causes, diagnosis, management and emerging triggers, and challenges of WRA. CONCLUSIONS: Although knowledge is expanding in this area, there remain challenges and uncertainties, particularly in the prevention of WRA.

Respiratory disease associated with occupational inhalation to hop (Humulus lupulus) during harvest and processing.

BACKGROUND: There is little published evidence for occupational respiratory disease caused by hop dust inhalation. In the United States, hops are commercially produced in the Pacific Northwest region. OBJECTIVE: To describe occupational respiratory disease in hop workers. METHODS: Washington State workers' compensation claims filed by hop workers for respiratory disease were systematically identified and reviewed. Incidence rates of respiratory disease in hop workers were compared with rates in field vegetable crop farm workers. RESULTS: Fifty-seven cases of respiratory disease associated with hop dust inhalation were reported from 1995 to 2011. Most cases (61%) were diagnosed by the attending health care practitioner as having work-related asthma. Seven percent of cases were diagnosed as chronic obstructive pulmonary disease, and the remaining cases were diagnosed as allergic respiratory disorders (eg, allergic rhinitis) or asthma-associated symptoms (eg, dyspnea). Cases were associated with hop harvesting, secondary hop processing, and indirect exposure. The incidence rate of respiratory disease in hop workers was 15 cases per 10,000 full-time workers, which was 30 times greater than the incidence rate for field vegetable crop workers. A strong temporal association between hop dust exposure and respiratory symptoms and a clear association between an increase in hop dust concentrations and the clinical onset of symptoms were apparent in 3 cases. CONCLUSION: Occupational exposure to hop dust is associated with respiratory disease. Respiratory disease rates were higher in hop workers than in a comparison group of agricultural workers. Additional research is needed before hop dust can be confirmed as a causative agent for occupational asthma.

Asthma related to workplace dampness and impaired work ability.

PURPOSE: To examine the long-term effects on work ability among patients previously diagnosed with occupational asthma (OA) or work-exacerbated asthma (WEA) or symptoms in relation to workplace dampness. METHODS: A questionnaire follow-up was used to study 1,098 patients (of whom 87 % were female) examined because of a suspected occupational respiratory disease caused by building dampness and mold. Self-rated work ability and early withdrawal from work were the two outcomes of the study. As determinants, we investigated the influence of the asthma diagnosis given in the initial examinations (OA or WEA), the number of persistent indoor air symptoms, and the psychosocial factors at work. RESULTS: With a mean follow-up of 7.8 years, 40 % of the OA patients, under 65 years of age, were outside worklife versus 23 % of the WEA patients and 15 % of the patients with only upper respiratory symptoms at baseline. The diagnosis of OA was associated with a nearly sixfold risk for early withdrawal from work in a comparison with a reference group with upper respiratory symptoms. A perceived poor social climate at work and poor experiences with supervisory co-operation were associated with impaired work ability outcomes. Those with multiple, long-term indoor air symptoms considerably more often perceived their work ability to be poor when compared with those with less significant symptoms. CONCLUSIONS: Adverse work ability outcomes are associated with asthma in relation to workplace dampness. The study raises the need for effective preventive measures in order to help workers with indoor air symptoms sustain their work ability.

Isocyanate exposure assessment combining industrial hygiene methods with biomonitoring for end users of orthopedic casting products.

Previous studies have suggested a potential risk to healthcare workers applying isocyanate-containing casts, but the authors reached their conclusions based on immunological or clinical pulmonology test results alone. We designed a study to assess potential exposure to methylene diphenyl diisocyanate (MDI) among medical personnel applying orthopedic casts using two different application methods. Air, dermal, surface, and glove permeation sampling methods were combined with urinary biomonitoring to assess the overall risk of occupational asthma to workers handling these materials. No MDI was detected in any of the personal and area air samples obtained. No glove permeation of MDI was detected. A small proportion of surface (3/45) and dermal wipe (1/60) samples were positive for MDI, but were all from inexperienced technicians. Urinary metabolites of MDI [methylenedianiline (MDA)] were detected in three of six study participants prior to both a 'dry' and 'wet' application method, five of six after the dry method, and three of six after the wet method. All MDA results were below levels noted in worker or general populations. Our conclusion is that the risk of MDI exposure is small, but unquantifiable. Because there is some potential risk of dermal exposure, medical personnel are instructed to wear a minimum of 5-mil-thick (5 mil = 0.005 inches) nitrile gloves and avoid contact to unprotected skin. This could include gauntlets, long sleeves, and/or a laboratory coat.

Assessment of public health impact of work-related asthma.

BACKGROUND: Asthma is among the most common chronic diseases in working-aged populations and occupational exposures are important causal agents. Our aims were to evaluate the best methods to assess occurrence, public health impact, and burden to society related to occupational or work-related asthma and to achieve comparable estimates for different populations. METHODS: We addressed three central questions: 1: What is the best method to assess the occurrence of occupational asthma? We evaluated: 1) assessment of the occurrence of occupational asthma per se, and 2) assessment of adult-onset asthma and the population attributable fractions due to specific occupational exposures. 2: What are the best methods to assess public health impact and burden to society related to occupational or work-related asthma? We evaluated methods based on assessment of excess burden of disease due to specific occupational exposures. 3: How to achieve comparable estimates for different populations? We evaluated comparability of estimates of occurrence and burden attributable to occupational asthma based on different methods. RESULTS: Assessment of the occurrence of occupational asthma per se can be used in countries with good coverage of the identification system for occupational asthma, i.e. countries with well-functioning occupational health services. Assessment based on adult-onset asthma and population attributable fractions due to specific occupational exposures is a good approach to estimate the occurrence of occupational asthma at the population level. For assessment of public health impact from work-related asthma we recommend assessing excess burden of disease due to specific occupational exposures, including excess incidence of asthma complemented by an assessment of disability from it. International comparability of estimates can be best achieved by methods based on population attributable fractions. CONCLUSIONS: Public health impact assessment for occupational asthma is central in prevention and health policy planning and could be improved by purposeful development of methods for assessing health benefits from preventive actions. Registry-based methods are suitable for evaluating time-trends of occurrence at a given population but for international comparisons they face serious limitations. Assessment of excess burden of disease due to specific occupational exposure is a useful measure, when there is valid information on population exposure and attributable fractions.

Air exposure assessment of TDI and biological monitoring of TDA in urine in workers in polyurethane foam industry.

OBJECTIVES: Toluene diisocyanate (TDI) is used in the manufacturing process of polyurethane (PU) foams and is a potent inducer of occupational asthma. The objective of this study was to evaluate the correlation between the exposure to total TDI (2,4- and 2,6-TDI) in air and the corresponding biomarker concentration of total TDA (2,4- and 2,6-TDA) in hydrolysed urine. The aim was also to propose an appropriate biological exposure limit for total TDA in urine. METHODS: 9 workers from two production lines in a PU foam producing plant were studied. Personal exposure to TDI during four representative production shifts was monitored by an active air sampling method (filter impregnated with 1-(2-methoxyphenyl)piperazine) and quantified by high-performance liquid chromatography and diode array detection (NIOSH n° 2535, 5521). In parallel, pre-shift and post-shift urinary samples were collected from the exposed workers, and TDA concentrations were determined by gas chromatography-mass spectrometry after alkaline hydrolysis. All samples were collected on four measuring days: two Fridays (end of workweek) and two Mondays (start of workweek) separated by a weekend without exposure. RESULTS: Strong correlations between the personal air concentrations of total TDI and the corresponding biomarker levels of total TDA in urine (r=0.816) were observed. An increase of 18.12 µg TDA/l (post-shift minus pre-shift concentration) corresponds to an exposure of 5 ppb (37 µg/m(3), the current American Conference of Governmental Industrial Hygienists threshold limit value) during the shift. CONCLUSIONS: The increase in TDA during the shift is a suitable biomarker for exposure to TDI during the same shift. Further research is needed to evaluate the use of start of week or end of week post-shift TDA in urine as biomarker since TDA was found to accumulate during the working week and thus the moment of sampling will clearly influence the result.

Work-related asthma: a case-based approach to management.

The management of work-related asthma has some differences from management of other asthma. Components of management include not only making as accurate a diagnosis as possible, identifying the causative agent or triggers at work, and managing the asthma with pharmacologic treatment as for other patients with asthma, but also advising on the appropriate work changes that may be needed, assisting the worker with appropriate compensation claims, and supporting protective measures for coworkers. This article discusses the approaches that may be taken for patients with different forms of work-related asthma.