Work-related Asthma Research Articles

Association between occupational exposure to irritant agents and a distinct asthma endotype in adults

AimThe biological mechanisms of work-related asthma induced by irritants remain unclear. We investigated the associations between occupational exposure to irritants and respiratory endotypes previously identified among never asthmatics (NA) and...

Surveillance of work-related asthma including the emergence of a cannabis-associated case series in Washington State

Objective We conducted surveillance for work-related asthma (WRA) in Washington State to identify the industry sectors and asthma exposures most commonly affecting injured workers and in need of prevention activities. Methods Using workers’ compensation data as the primary data source, valid cases were classified as work-aggravated asthma (WAA) or new onset asthma that includes occupational asthma (OA) and reactive airways dysfunction syndrome (RADS). The source of exposure that caused the worker’s asthma, their industry and occupation were determined. Results There were 784 valid work-related asthma cases identified for the period 2009–2016, WAA (n = 529) was most common followed by occupational asthma (n = 127) and RADS (n = 12). The Health Care and Social Assistance industry had the highest number of cases (n = 170) with 82% classified as WAA. The highest overall proportions of new onset asthma are occurring in Agriculture, Forestry, Fishing and Hunting (33% of work related asthma cases), Manufacturing (31%) and Construction (30%). The leading substances associated with new onset asthma across all industries include hop plant dust, wood and cedar dust, mineral and inorganic dust, mold, and cleaning materials. We describe ten cases of cannabis-associated asthma including seven from workers in the legalized cannabis industry, four of whom had OA. Conclusion State-based work-related asthma surveillance is critical in identifying the workers and exposures associated with this occupational disease, including the detection of a case-series in the cannabis industry.

Endotyping asthma related to 3 different work exposures

Work exposures play a significant role in adult-onset asthma, but the mechanisms of work-related asthma are not fully elucidated. We aimed to reveal the molecular mechanisms of work-related asthma associated with exposure to flour (flour asthma), isocyanate (isocyanate asthma), or welding fumes (welding asthma) and identify potential biomarkers that distinguish these groups from each other. We used a combination of clinical tests, transcriptomic analysis, and associated pathway analyses to investigate the underlying disease mechanisms of the blood immune cells and the airway epithelium of 61 men. Compared with the healthy controls, the welding asthma patients had more differentially expressed genes than the flour asthma and isocyanate asthma patients, both in the airway epithelia and in the blood immune cells. In the airway epithelia, active inflammation was detected only in welding asthma patients. In contrast, many differentially expressed genes were detected in blood cells in all 3 asthma groups. Disease-related immune functions in blood cells, including leukocyte migration and inflammatory responses, and decreased expression of upstream cytokines such as TNF and IFN-γ were suppressed in all the asthma groups. In transcriptome-phenotype correlations, hyperresponsiveness (R ∼ |0.6|) had the highest clinical relevance and was associated with a set of exposure group-specific genes. Finally, biomarker subsets of only 5genesspecifically distinguished each of the asthma exposure groups. This study provides novel data on the molecular mechanisms underlying work-related asthma. We identified a set of 5 promising biomarkers in asthma related to flour, isocyanate, and welding fume exposure to be tested and clinically validated in future studies.

Occupational rhinitis and asthma in bakers: a cross-sectional study in the former Katanga province of DR Congo.

Bakers are at high risk of rhinitis and asthma, but the prevalence of these occupational diseases is not well known in Sub-Saharan Africa. We investigated the prevalence of occupational rhinitis and asthma among industrial bakers in the former province of Katanga. In a cross-sectional study conducted in eight towns from October 2018 to September 2019, we included 276 male workers from 18 industrial bakeries and 113 male controls (35 butchers and 78 bread sellers), all nonsmokers. Participants replied to a validated questionnaire (European Community of Respiratory Health Survey II), administered face to face, and performed spirometry at the work place. In 15 bakers with symptoms of work-related asthma, records of self-measured peak expiratory flow (PEF) 4 times per day during 4weeks were analyzed by the OASYS (Occupational Asthma System) protocol. The bakers and controls did not differ by age (32.2 ± 7.3 y vs 32.8 ± 10.3 y). According to the questionnaire, work-related rhinitis and asthma were significantly more prevalent among bakers (31% and 5%, respectively) than among controls (2% and 0%, respectively). However, the groups did not differ significantly with regard to spirometric parameters. Based on PEF records, 10 out of 15 were positive for occupational asthma (OASYS score > 2.5), so the rate of occupational asthma was 3.6% in this study. This first study in DR Congo demonstrates the existence of occupational rhinitis and asthma among industrial bakers in Katanga. Further epidemiological studies are needed to clarify the extent and risk factors of baker's asthma in the area. In the meantime, advocacy and implementation of appropriate occupational hygiene measures are warranted to protect bakery workers in DR Congo.

Editorial introductions.

Editorial introductions.

Pulmonary Function Testing in Work-Related Asthma: An Overview from Spirometry to Specific Inhalation Challenge.

Work-related asthma (WRA) is a very frequent condition in the occupational setting, and refers either to asthma induced (occupational asthma, OA) or worsened (work-exacerbated asthma, WEA) by exposure to allergens (or other sensitizing agents) or to irritant agents at work. Diagnosis of WRA is frequently missed and should take into account clinical features and objective evaluation of lung function. The aim of this overview on pulmonary function testing in the field of WRA is to summarize the different available tests that should be considered in order to accurately diagnose WRA. When WRA is suspected, initial assessment should be carried out with spirometry and bronchodilator responsiveness testing coupled with first-step bronchial provocation testing to assess non-specific bronchial hyper-responsiveness (NSBHR). Further investigations should then refer to specialists with specific functional respiratory tests aiming to consolidate WRA diagnosis and helping to differentiate OA from WEA. Serial peak expiratory flow (PEF) with calculation of the occupation asthma system (OASYS) score as well as serial NSBHR challenge during the working period compared to the off work period are highly informative in the management of WRA. Finally, specific inhalation challenge (SIC) is considered as the reference standard and represents the best way to confirm the specific cause of WRA. Overall, clinicians should be aware that all pulmonary function tests should be standardized in accordance with current guidelines.

Work-related asthma.

ABSTRACTWork-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.

Cleaners and airway diseases.

Evidence for adverse respiratory effects of occupational exposure to disinfectants and cleaning products (DCPs) has grown in the last two decades. The relationship between DCPs and asthma is well documented but questions remain regarding specific causal agents. Beyond asthma, associations between DCPs and COPD or chronic rhinitis are plausible and have been examined recently. The purpose of this review is to summarize recent advances on the effect of occupational exposure to DCP and chronic airway diseases. Recent epidemiological studies have often focused on healthcare workers and are characterized by efforts to improve assessment of exposure to specific DCPs. Despite increasing knowledge on the effect of DCPs on asthma, the burden of work-related asthma caused by DCPs has not decreased in the past decade, emphasizing the need to strengthen prevention efforts. Novel data suggest an association between occupational exposure to DCPs and other chronic airway diseases, such as rhinitis, COPD, and poor lung function. Epidemiological and experimental data showed that many chemicals contained in DCPs are likely to cause airway damage, indicating that prevention strategies should target multiple products. Further research is needed to evaluate the impact of DCP exposure on occupational airway diseases beyond asthma.

Combined forced oscillation and fractional-order modeling in patients with work-related asthma: a case\u2013control study analyzing respiratory biomechanics and diagnostic accuracy

BackgroundFractional-order (FrOr) models have a high potential to improve pulmonary science. These models could be useful for biomechanical studies and diagnostic purposes, offering accurate models with an improved ability to describe nature. This paper evaluates the performance of the Forced Oscillation (FO) associated with integer (InOr) and FrOr models in the analysis of respiratory alterations in work-related asthma (WRA).MethodsSixty-two individuals were evaluated: 31 healthy and 31 with WRA with mild obstruction. Patients were analyzed pre- and post-bronchodilation. The diagnostic accuracy was evaluated using the area under the receiver operating characteristic curve (AUC). To evaluate how well do the studied models correspond to observed data, we analyzed the mean square root of the sum (MSEt) and the relative distance (Rd) of the estimated model values to the measured resistance and reactance measured values.Results and discussionInitially, the use of InOr and FrOr models increased our understanding of the WRA physiopathology, showing increased peripheral resistance, damping, and hysteresivity. The FrOr model (AUC = 0.970) outperformed standard FO (AUC = 0.929), as well as InOr modeling (AUC = 0.838) in the diagnosis of respiratory changes, achieving high accuracy. FrOr improved the curve fitting (MSEt = 0.156 ± 0.340; Rd = 3.026 ± 1.072) in comparison with the InOr model (MSEt = 0.367 ± 0.991; Rd = 3.363 ± 1.098). Finally, we demonstrated that bronchodilator use increased dynamic compliance, as well as reduced damping and peripheral resistance.ConclusionsTaken together, these results show clear evidence of the utility of FO associated with fractional-order modeling in patients with WRA, improving our knowledge of the biomechanical abnormalities and the diagnostic accuracy in this disease.

Assessment and Management of Occupational Asthma

Exposures at work can give rise to different phenotypes of "work-related asthma." The focus of this review is on the diagnosis and management of sensitizer-induced occupational asthma (OA) caused by either a high- or low-molecular-weight agent encountered in the workplace. The diagnosis of OA remains a challenge for the clinician because there is no simple test with a sufficiently high level of accuracy. Instead, the diagnostic process combines different procedures in a stepwise manner. These procedures include a detailed clinical history, immunologic testing, measurement of lung function parameters and airway inflammatory markers, as well as various methods that relate changes in these functional and inflammatory indices to workplace exposure. Their diagnostic performances, alone and in combination, are critically reviewed and summarized into evidence-based key messages. A working diagnostic algorithm is proposed that can be adapted to the suspected agent, purpose of diagnosis, and available resources. Current information on the management options of OA is summarized to provide pragmatic guidance to clinicians who have to advise their patients with OA.

Gender and occupational allergy: Report from the task force of the EAACI Environmental and Occupational Allergy Interest Group.

Women's work has traditionally been considered less hazardous to health in comparison with men's work. The increased women's participation in the workforce has led to an increased attention to women's working conditions. Women and men are unequally represented in individual professions or sectors (horizontal segregation), with women also under-represented in leadership positions (vertical segregation). The selection of specific occupations can result in differences between types and levels of occupational exposures among women and men and can affect prevalence of occupational allergy. Gender distribution of work-related asthma appears to vary across countries without clear global difference. Occupational rhinitis tends to be higher in women, although is not clear if this is related to a sex/gender effect or to differences in work exposure. Women are more likely to have occupational contact dermatitis, mainly due to wet work. No clear effects of gender on rates of hypersensitivity pneumonitis have been shown. Besides variation in exposures, physical and physiological characteristics, different behaviours and health consciousness have an impact on the occupational health hazards of women and men. Occupational allergy health promotion strategies need to consider approaches for women and men adjusted by gender, and legislative actions similarly could be implemented in a more gender-sensitive way.

Work-related Symptoms and Asthma among Fish Processing Workers

ABSTRACT After observing several clinical patients with respiratory symptoms, we initiated a questionnaire survey to assess prevalence of and predictors for asthma and work-related symptoms among workers in fish processing plants. A questionnaire with items on work conditions, work-related symptoms, and respiratory symptoms/diseases was sent to 916 fish processing workers, the 1836 licenced fishermen in Sweden, and 1965 controls; of those, 43%, 57%, and 53%, respectively, responded. Risks, hazard ratios (HRs), and prevalence ratios (PRs) were calculated with Cox regression, and 95% confidence intervals (CIs) were computed. The risk of asthma among fish filleting workers was increased during the years working in the fish processing industry when compared to the other fish processing workers and controls (HR 3.6, 95% CI 1.6–8.1, adjusted for atopy, gender, and ever smoking). The filleters had an increased PR for most of the work-related respiratory symptoms investigated. All fish processing workers had a higher PR for flu-like symptoms. Use of a pressure sprayer was identified as a risk for asthma and respiratory symptoms among both fish processing workers and controls. Filleters had changed work tasks because of respiratory symptoms more often (Fisher’s exact test, p = 0.02) than other fish processing workers. In conclusion the fish filleters and pressure sprayer users reported more adult asthma and cough with phlegm compared to the other fish processing workers and controls. The use of pressure sprayers must be reduced and machinery should be completely encased to reduce workers’ exposure to bioaerosols and its effects on the respiratory tract.

CE Module: Work-Related Asthma Among Certified Nurse Aides in Texas.

CE Module: Work-Related Asthma Among Certified Nurse Aides in Texas.

Characterization of Occupational Eosinophilic Bronchitis in a Multicenter Cohort of Subjects with Work-Related Asthma Symptoms

Occupational eosinophilic bronchitis (OEB) has been described only as anecdotal case reports. We investigated the clinical and inflammatory characteristics of subjects with OEB identified in a cohort of subjects who completed a specific inhalation challenge (SIC) with occupational agents. In this retrospective multicenter study, OEB was defined by (1) a fall in FEV1 less than 15% during the SIC and the absence of nonspecific bronchial hyperresponsiveness both before and after the SIC and (2) a postchallenge increase of 3% or more in sputum eosinophils. The subjects who fulfilled these criteria were compared with 226 subjects with a negative SIC and 30 subjects with a positive SIC who failed to show baseline nonspecific bronchial hyperresponsiveness. An isolated increase in postchallenge sputum eosinophils was documented in 33 of 259 subjects (13%) with a negative SIC. These subjects reported significantly more often an isolated cough at work compared with the negative and positive SIC controls. When compared with positive SIC controls, the subjects with OEB experienced less frequently work-related wheezing and reported a shorter duration of symptoms at work. The sensitivity of the post-SIC increase in fractional exhaled nitric oxide in identifying OEB among subjects with a negativeSIC was low, ranging from 43% to 24% using cutoff values of 8 ppb to 17.5 ppb, whereas the specificity was high (90%-97%). This study highlights the relevance of induced sputum analysis in the investigation of work-related asthma symptoms to identify isolated increases in sputum eosinophils that are consistent with a diagnosis of OEB.

Work-related Asthma in Crop Farmers

AIM: The objective of the study was to evaluate the influence of occupational exposure on asthma development among crop farmers. METHODS: A cross-sectional study was performed, comprising 87 crop farmers, and 80 office workers, matched by gender and age. Evaluation of subjects included completion of a standard questionnaire on chronic respiratory symptoms, spirometry tests, histamine challenge, serial peak expiratory flow rates (PEFR) measurements, and skin prick tests to occupational and common inhalant allergens. RESULTS: The prevalence of chronic respiratory symptoms in the past 12 months was higher, while the mean values of spirometric parameters were lower in crop farmers. Sensitization to workplace and common inhalant allergens was similar in both groups, whereas frequencies of bronchial hyperresponsiveness (BHR) and asthma were non-significantly higher in crop farmers. The prevalence of allergic was significantly higher compared to non-allergic asthma in both groups. Asthma was registered in 8% of crop farmers and was significantly associated with atopy, and positive family history of asthma. Occupational allergic asthma (OA) was registered in 2.3% of crop farmers, while the frequency of work-aggravated asthma was 5.7%. A causal relationship between workplace and asthma, suggesting allergic OA, was documented in two crop farmers with asthma, based on serial PEFR monitoring, but specific workplace agent causing asthma in the affected subjects was not identified. CONCLUSION: The obtained results can contribute in the detection of critical points for action, and serve as a predictive factor in the development of work-related asthma, indicating the need for reduction of adverse occupational exposures through adequate preventive measures, regular health examinations, obligatory use of respiratory protective equipment, and implementation of engineering controls.

Shorter time to clinical decision in work-related asthma using a digital tool.

PEF curves are a useful but cumbersome tool in diagnosing work-related asthma. Using a digital spirometer and smartphone app, time to clinical decision could be shortened by 6–7 weeks. Physician's time spent analysing PEF data is also shortened. https://bit.ly/3d5SY78

Causes and Phenotypes of Work-Related Asthma.

Work-related asthma (WRA) includes heterogeneous conditions, which have in common (i) symptoms and signs compatible with asthma and (ii) a relationship with exposures in the workplace. The types of WRA described in this review are distinguished by their etiology, comprising of work-exacerbated asthma (WEA), irritant-induced asthma (IIA), and immunologic occupational asthma (OA). There have been significant advances in the definition and characterization of the different forms of WRA by international panels of experts. The present review provides a comprehensive and updated view of the current knowledge on causes and phenotypes of WRA. Health care practitioners should consider WRA in any case of adult asthma, given that one fifth of workers with asthma report symptoms of WEA and it has been estimated that OA represents 10% to 25% of asthma in adulthood. The information provided in this review will facilitate the physician in the recognition of the different forms of WRA, since it has been established that five categories of agents are responsible for at least 60% of WEA cases and seven groups of agents are the cause of 70% of immunologic OA. In addition, there is agreement that IIA can be elicited not only by a single massive irritant exposure, but also by low/moderate repeated irritant exposures.

Progress in Occupational Asthma.

Occupational asthma (OA) represents one of the major public health problems due to its high prevalence, important social and economic burden. The aim of this review is to summarize current data about clinical phenotypes, biomarkers, diagnosis and management of OA, a subtype of work-related asthma. Most studies have identified two phenotypes of OA. One is sensitizer-induced asthma, occuring after a latency period and caused by hypersensitivity to high- or low-molecular weight agents. The other is irritant-induced asthma, which can occur after one or more exposures to high concentrations of irritants without latency period. More than 400 agents causing OA have been identified and its list is growing fast. The best diagnostic approach for OA is a combination of clinical history and objective tests. An important tool is a specific inhalation challenge. Additional tests include assessments of bronchial hyperresponsiveness to methacholine/histamine in patients without airflow limitations, monitoring peak expiratory flow at- and off-work, sputum eosinophil count, exhaled nitric oxide measurement, skin prick tests with occupational allergens and serum specific IgE. Treatment of OA implies avoidance of exposure, pharmacotherapy and education. OA is a heterogeneous disease. Mechanisms of its different phenotypes, their diagnosis, role of new biomarkers and treatment require further investigation.

Allergic and Respiratory Symptoms in Employees of Indoor Cannabis Grow Facilities.

While little is known about the occupational hazards associated with Cannabis cultivation, both historical research in the hemp industry and preliminary data from modern grow houses, suggest that Cannabis workers may be at increased risk of respiratory and allergic diseases. We sought to investigate the association between workplace exposures and health symptoms in an indoor Cannabis grow facility in Washington State, USA. We performed a cross-sectional study with all consenting employees in an indoor Cannabis grow facility in Seattle, WA using a questionnaire. The questionnaire gathered data on respiratory, ocular, nasal, and dermal symptoms. A subset of employees with work-related symptoms underwent repeated cross-shift and cross-week measurement of spirometry, fractional exhaled nitrogen oxide (FeNO), and skin prick testing for Cannabis sensitization. Exposure to Cannabis dust was classified based on self-described tasks, expert opinion, and exposure monitoring of particulate matter. Multivariable logistic regression was undertaken to examine associations between exposure to Cannabis dust (classified as low, medium, and high) and health symptoms. Linear mixed effects models examined the relationship between cross-shift and cross-week changes in spirometry and FeNO. Ninety-seven percent (97%) of the employees (n = 31) surveyed were recreational cannabis users, with 81% (n = 25) smoking cannabis multiple times per day. Twenty-two (71%) employees reported one or more work-related symptoms: 65% respiratory, 39% ocular, 32% nasal, and 26% dermal symptoms. There was a trend toward increased likelihood of work-related symptoms with increasing exposure to Cannabis dust, although none of these results were statistically significant. Of the 10 employees with work-aggravated symptoms, 5 had borderline-high or high FeNO, 7 had abnormal spirometry, and 5 had evidence of Cannabis sensitization on skin prick testing. FeNO increased by 3.78 ppb (95% confidence interval 0.68-6.88 ppb) across the work-week and there was a trend toward cross-week and cross-shift reduced airflow. We found a high prevalence of work-related allergic- and particularly respiratory symptoms in the employees of one indoor Cannabis grow facility in Washington State. A high proportion of employees with work-aggravated symptoms had findings consistent with probable work-related asthma based on high FeNO, airflow obstruction on spirometry, and Cannabis sensitization on skin prick testing. However, due to the high incidence of recreational cannabis use among these workers, the relative influence of occupational versus recreational exposure to Cannabis dust on the respiratory health and sensitization status of these workers could not be resolved in this study.

Work-related asthma in the USA: nationally representative estimates with extended follow-up

ObjectiveWe studied the associations of working in occupations with high asthma trigger exposures with the prevalence and incidence of asthma, and with ever reporting an asthma diagnosis throughout working life.MethodsWe...