Asthma-specific Job Exposure Matrix Research Articles

Asthma control in severe asthma and occupational exposures to inhalable asthmagens

IntroductionWork-related asthma accounts for ≥25% of asthma in working-age populations, though the relationship between work exposures and symptoms is frequently missed, leading to poor health and employment outcomes. We hypothesised...

Development of a crosswalk to convert French PCS2003 into international ISCO88 occupational classifications. Application to the Occupational Asthma-specific Job-Exposure Matrix (OAsJEM).

The problem of transcoding is recurrent when researchers wish to link occupational data from cohorts to Job-Exposure Matrices (JEMs) which were not set up in the same classifications. The Occupational Asthma-specific JEM (OAsJEM) is a JEM developed for assessing exposure to agents known at risk for asthma for jobs coded with ISCO88 occupation classification. To apply the OAsJEM in the CONSTANCES cohort, in which jobs and industries were coded with French PCS2003 and NAF2008 classifications respectively, we developed a crosswalk to convert jobs from PCS2003 into ISCO88 classification. This work was carried out by 2 skilled coders and 1 novice coder who have worked independently by using different tools and transcoding strategies defined a priori. Consensus meetings were organized with skilled coders to define the final crosswalk. This work was elaborated in 2 steps: (i) for 38 ISCO88 codes classified as potentially exposed to cleaning and disinfection products by the OAsJEM, and (ii) for all jobs from the ISCO88 classification. A comparison between the 3 initial coder's crosswalk proposals and the final crosswalk was made for the 38 ISCO codes in step (i). The final crosswalk provided 998 matches between the 482 4-digit PCS2003 codes, 308 4-digit ISCO88 codes, and 31 3-digit ISCO88 codes. Information regarding the NAF2008 industry classification was also used in some cases to improve the final crosswalk. For the selected 38 ISCO88 codes, the final crosswalk provided 110 combinations, but the number of proposed ISCO88-PCS2003 couples by each of the 3 coders varied greatly from 68 to 153. In addition, an important variability between the 3 coders were observed among the number of common combinations between the initial coder's proposals and the final crosswalk (from 47% to 78%). We have developed a crosswalk specifically for an application of the OAsJEM in population-based surveys using the PCS2003 occupation classification. The development of this crosswalk is of great interest for the use of OAsJEM on the data of the CONSTANCES cohort and on any other survey with occupational data coded according to the French classifications. This OAsJEM crosswalk could be used by other teams to evaluate occupational exposures known to be at risk of asthma from occupational calendars coded with French classifications.

Chronic occupational exposures to irritants and asthma in the CONSTANCES cohort

ObjectivesThe impact of chronic occupational exposures to irritants on asthma remains discussed. We studied the associations between occupational exposures and asthma, with specific interest for chronic exposure to irritants, including...

Exploration of associations between occupational exposures and current adult eczema

ObjectivesThere is a scarcity of evidence on occupational exposures that may increase eczema in adults. We aimed to investigate potential associations between occupational exposures and eczema in middle-aged adults.MethodsA lifetime...

Application of the New Asthma-Specific Job Exposure Matrix: A Study in Quebec Apprentice Cohort Exposed to Isocyanates

Background: Recently, the first asthma-specific Job Exposure Matrix (JEM) was updated to occupational asthma-specific JEM (OAsJEM). Our study aimed to evaluate the association between continued exposure to isocyanates and incident work-related chest symptoms in former car-painting apprentices and to compare the associations using the first and new OAsJEMs.Methods: We used data from an inception cohort of male car-painting apprentices. Post-apprenticeship exposure to isocyanate during follow-up was evaluated using the first asthma-specific JEM (“exposed”=1 or “not exposed”=0) and the new OAsJEM (high=2, medium=1, and none=0). Association between occupation exposure to isocyanate and incidence of work-related rhinoconjunctival and chest symptoms were evaluated through cox regression models, adjusted for age, smoking, wheezing, and non-specific bronchial hyperresponsiveness. Results: The agreement between the two JEMs (exposed vs non-exposed to isocyanate) was perfect (kappa coefficient=0.946, p<0.001). There were only five subjects who were classified as non-exposed based on the first JEM, but had a medium exposure to isocyanate based on the new OAsJEM. Exposure to isocyanate increased the risk of occupational chest symptoms in the high-exposure category (hazard ratio [HR] 2.7, 95% CI 1.1 – 6.6) and the medium category (HR 2.9, 95% CI 0.3 – 30.0) compared to the reference group based on the new OAsJEM, whereas an HR of 2.5 (95% CI 1.0-6.2) was observed from the first JEM. Both JEMs yielded an inconclusive association between exposure to isocyanates and the risk for work-related rhino-conjunctivitis. Conclusion: The asthma-specific JEM and OAsJEM consistently showed that isocyanate exposure increased the risk of incident work-related chest symptoms.

Occupational Exposures to Irritants and Sensitizers, Asthma and Asthma Control in the Nutrinet-Santé Cohort

The role of chronic occupational exposures to irritants in asthma remains not well-defined. Few studies have examined their associations with asthma and its control. To study the associations of occupational exposures with asthma and its control, with specific interest for irritants, including disinfectants and cleaning products (DCPs) and solvents. Analyses included 4,469 adults (3,792 with neither asthma nor respiratory symptoms, 677 with current asthma; 75.9% women, mean age 54 years) of a case-control study (2018) from the French NutriNet-Santé cohort. Current asthma was defined by ever asthma with symptoms, medication or asthma attacks in the past 12 months, adult-onset asthma by age at first asthma attack older than 16 years, and uncontrolled asthma was defined by an Asthma Control Test score less than 20. Ever/current exposures were assessed with the Occupational Asthma-specific Job Exposure Matrix. Associations were evaluated by multinomial logistic regressions adjusted for sex, age, smoking status, and body mass index. Ever exposures to sensitizers (high molecular weight [HMW]: OR 1.53, 95% CI 1.18-2.00; and low molecular weight [LMW]: OR 1.42; 95% CI 1.09-1.87), irritants (OR 1.32; 95% CI 1.03-1.68), and DCPs (OR 1.43; 95% CI 1.10-1.85) were associated with current adult-onset asthma. Significant associations between ever exposures and uncontrolled adult-onset asthma were observed for high molecular weight (OR 2.69; 95% CI 1.52-4.78) and low molecular weight (OR 2.27; 95% CI 1.24-4.37) sensitizers, irritants (OR 2.32; 95% CI 1.36-3.95), and DCPs (OR 2.59; 95% CI 1.48-4.54). Results were similar for current exposures, with higher ORs. No association was observed with solvents. Occupational exposures to both sensitizers and irritants were associated with current adult-onset asthma and uncontrolled asthma. Irritant and sensitizing agents should be carefully considered in asthma management.

Maternal preconception occupational exposure to cleaning products and disinfectants and offspring asthma

Emerging research suggests health effects in offspring after parental chemical exposures before conception. Many future mothers are exposed to potent chemicals at work, but potential offspring health effects are hardly investigated. We sought to investigate childhood asthma in relation to mother's occupational exposure to cleaning products and disinfectants before conception. The multicenter Respiratory Health In Northern Europe/Respiratory Health In Northern Europe, Spain and Australia generation study investigated asthma and wheeze starting at age less than 10 years in 3318 mother-offspring pairs. From an asthma-specific Job-Exposure Matrix and mothers' occupational history, we defined maternal occupational exposure to indoor cleaning agents (cleaning products/detergents and disinfectants) starting before conception, in the 2-year period around conception and pregnancy, or after birth. Never-employed mothers were excluded. Exposed groups include cleaners, health care workers, cooks, and so forth. Associations were analyzed using mixed-effects logistic regression and ordinary logistic regression with clustered robust SEs and adjustment for maternal education. Maternal occupational exposure to indoor cleaning starting preconception and continuing (n= 610) was associated with offspring's childhood asthma: odds ratio 1.56 (95% CI, 1.05-2.31), childhood asthma with nasal allergies: 1.77 (1.13-2.77), and childhood wheeze and/or asthma: 1.71 (95% CI, 1.19-2.44). Exposure starting around conception and pregnancy (n=77) was associated with increased childhood wheeze and/or asthma: 2.25 (95% CI, 1.03-4.91). Exposure starting after birth was not associated with asthma outcomes (1.13 [95% CI, 0.71-1.80], 1.15 [95% CI, 0.67-1.97], 1.08 [95% CI, 0.69-1.67]). Mother's occupational exposure to indoor cleaning agents starting before conception, or around conception and pregnancy, was associated with more childhood asthma and wheeze in offspring. Considering potential implications for vast numbers of women in childbearing age using cleaning agents, and their children, further research is imperative.

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...

Parental occupational exposure pre- and post-conception and development of asthma in offspring.

BackgroundWhile direct effects of occupational exposures on an individual’s respiratory health are evident, a new paradigm is emerging on the possible effects of pre-conception occupational exposure on respiratory health in offspring. We aimed to study the association between parental occupational exposure starting before conception and asthma in their offspring (at 0–15 years of age).MethodsWe studied 3985 offspring participating in the Respiratory Health in Northern Europe, Spain and Australia (RHINESSA) generation study. Their mothers or fathers (n = 2931) previously participated in the European Community Respiratory Health Survey (ECRHS). Information was obtained from questionnaires on parental job history pre- and post-conception which was linked to an asthma-specific job-exposure matrix (JEM). We assessed the association between parental occupational exposure and offspring asthma, applying logistic regression models, clustered by family and adjusted for study centre, offspring sex, parental characteristics (age, asthma onset, place of upbringing, smoking) and grandparents’ level of education.ResultsParental occupational exposure to microorganisms, pesticides, allergens or reactive chemicals pre-conception or both pre- and post-conception was not related to offspring asthma; in general, subgroup analyses confirmed this result. However, maternal exposure both pre- and post-conception to allergens and reactive chemicals was associated with increased odds for early-onset asthma in offspring (0–3 years of age); odds ratio 1.70 (95% CI: 1.02–2.84) and 1.65 (95% CI: 0.98–2.77), respectively.ConclusionsThis study did not find evidence that parental occupational exposure, defined by an asthma JEM before conception only or during pre- and post-conception vs non-exposed, was associated with offspring asthma.

Development of an Asthma-Specific Job Exposure Matrix for Use in the United States.

Existing asthma-specific job-exposure matrices (JEMs) do not necessarily reflect current working conditions in the USA and do not directly function with occupational coding systems commonly used in the USA. We initiated a project to modify an existing JEM to address these limitations, and to apply the new JEM to the entire US employed population to estimate quantitatively the extent of probable work-related asthma exposures nationwide. We started with an asthma-specific JEM that was developed for northern Europe (the N-JEM) and modified it to function with the 2010 US Standard Occupational Classification (SOC-2010) codes and to reflect working conditions in the USA during the post-2000 period. This involved cross walking from the 1988 International Standard Classification of Occupations (ISCO-88) codes used in the N-JEM to the SOC-2010 codes, transferring the N-JEM exposure assignments to the SOC-2010 codes, and modifying those assignments to reflect working conditions in the USA. The new US asthma JEM (USA-JEM) assigns exposures to 19 agents organized into five categories. The USA-JEM and N-JEM were applied to the same sample of working adults with asthma to compare how they performed, and the USA-JEM was also applied to the entire 2015 US working population to estimate the extent of occupational asthma exposures nationally. The USA-JEM assigns at least one asthma-related probable exposure to 47.5% and at least one possible exposure to 14.9% of the 840 SOC-2010 detailed occupations, and 9.0% of the occupations have both probable exposure to at least one agent and possible exposure to at least one other agent. The USA-JEM has greater sensitivity for cleaning products, highly reactive disinfectants and sterilants, and irritant peak exposures than the N-JEM. When applied to the entire 2015 US working population, the USA-JEM determined that 42.6% of workers had probable exposure to at least one type of occupational asthma agent. A new asthma-specific JEM for application in the USA was developed. Additional work is needed to compare its performance to similar JEMs and, if possible, to exposure assessments generated on a case-by-case basis.

Update of an occupational asthma-specific job exposure matrix to assess exposure to 30 specific agents

ObjectivesWe aimed to update an asthmagen job exposure matrix (JEM) developed in the late 1990s. Main reasons were: the number of suspected and recognised asthmagens has since tripled; understanding of...

Association of respiratory symptoms and asthma with occupational exposures: findings from a population-based cross-sectional survey in Telemark, Norway

ObjectivesThe aim of this study was to estimate the prevalence of respiratory symptoms and physician-diagnosed asthma and assess the impact of current occupational exposure.DesignCross-sectional analyses of the prevalence of self-reported...

Impact of occupational exposures on exacerbation of asthma: a population-based asthma cohort study.

BackgroundAsthma is a prevalent chronic disease and occupation contributes to approximately 15 % of cases among adults. However, there are still few studies on risk factors for work-exacerbated asthma. The current study investigated the association between asthma exacerbations and occupational exposures.MethodsThe study comprised all currently working adults (n = 1356) who reported ever asthma in prior population-based cohorts. All subjects completed a questionnaire about exposures, occupations and exacerbations of asthma. Exposure to high and low molecular weight agents, irritating agents and asthmagens were classified using the asthma-specific job exposure matrix for northern Europe (N-JEM). Severe exacerbation of asthma was defined as sought emergency care at a hospital, admitted to a hospital overnight, or made an urgent visit to a primary care physician or district medical office due to breathing problems during the last 12 months. Moderate exacerbation was defined as both being not severe exacerbation and an additional visit to a primary care physician or district medical office, or had extra treatments with corticosteroid tablets. Mild exacerbation was defined as being neither severe nor moderate exacerbation, and increasing usage of inhaled corticosteroids.Multiple logistic regression was applied to investigate the association between exacerbation of asthma and occupational exposures while adjusting for potential confounders.ResultsApproximately 26 % of the working asthmatics reported exacerbation, and more than two-thirds of them had moderate or severe exacerbation. From 23 to 49 % of the asthmatics reported occupational exposure to a variety of different types of agents. Exposure to any gas, smoke or dust (OR 1.7[95 % CI 1.2–2.6]) was associated with severe exacerbation of asthma, as were organic dust (OR 1.7[1.2–2.5]), dampness and mold (OR 1.8[1.2–2.7]), cold conditions (OR 1.7[1.1–2.7]), and a physically strenuous job (OR 1.6[1.03–2.3]). Asthmagens and low molecular weight agents classified by the N-JEM were associated with mild exacerbation, with OR 1.6[1.1–2.5] and OR 2.2[1.1–4.4], respectively.ConclusionsSelf-reported exposure to any gas, smoke or dust, organic dust, dampness and mold, cold conditions and physically strenuous work, and jobs handling low molecular weight agents were associated with exacerbation of asthma. Reduction of these occupational exposures may help to reduce exacerbation of asthma.

Breath-taking jobs: a case–control study of respiratory work disability by occupation in Norway

BackgroundThe current knowledge on respiratory work disability is based on studies that used crude categories of exposure. This may lead to a loss of power, and does not provide sufficient...

Occupational exposure to asthmagens and adult onset wheeze and lung function in people who did not have childhood wheeze: A 50-year cohort study

BackgroundThere are few prospective studies that relate the development of adult respiratory disease with exposure to occupational asthmagens. ObjectiveTo evaluate the risk of adult onset wheeze (AOW) and obstructive lung function associated with occupational exposures over 50years. MethodsA population-based randomly selected cohort of children who had not had asthma or wheezing illness, recruited in 1964 at age 10–15years, was followed-up in 1989, 1995, 2001 and 2014 by spirometry and respiratory questionnaire. Occupational histories were obtained in 2014 and occupational exposures determined with an asthma-specific job exposure matrix. The risk of AOW and lung function impairment was analysed in subjects without childhood wheeze using logistic regression and linear mixed effects models. ResultsAll 237 subjects (mean age: 61years, 47% male, 52% ever smoked) who took part in the 2014 follow-up had completed spirometry. Among those who did not have childhood wheeze, spirometry was measured in 93 subjects in 1989, in 312 in 1995 and in 270 subjects in 2001 follow-up. For longitudinal analysis of changes in FEV1 between 1989 and 2014 spirometry records were available on 191 subjects at three time points and on 45 subjects at two time points, with a total number of 663 records. AOW and FEV1<LLN were associated with occupational exposure to food-related asthmagens (adjusted odds ratios (adjORs) 95% CI: 2.7 [1.4, 5.1] and 2.9 [1.1, 7.7]) and biocides/fungicides (adjOR 95% CI: 1.8 [1.1, 3.1] and 3.4 [1.1, 10.8]), with evident dose-response effect (p-trends<0.05). Exposure to food-related asthmagens was also associated with reduced FEV1, FVC and FEF25–75% (adjusted regression coefficients 95% CI: −7.2 [−12.0, −2.4], −6.2 [−10.9, −1.4], and −13.3[−23.4, −3.3]). Exposure to wood dust was independently associated with AOW, obstructive lung function and reduced FEF25–75%. Excess FEV1 decline of 6-8ml/year was observed with occupational exposure to any asthmagen, biocides/fungicides and food-related asthmagens (p<0.05). ConclusionsThis longitudinal study confirmed previous findings of increased risks of adult onset wheezing illness with occupational exposure to specific asthmagens. A novel finding was the identification of food-related asthmagens and biocides/fungicides as potential new occupational risk factors for lung function impairment in adults without childhood wheeze.

Occupational exposures associated with severe exacerbation of asthma.

The exacerbation of asthma by workplace conditions is common, but little is known about which agents pose a risk. We used data from an existing survey of adults with asthma to identify occupational exposures associated with severe exacerbation of asthma. Questionnaires were completed by 557 working adults with asthma. Severe exacerbation of asthma in the past 12 months was defined as asthma-related hospitalization, or reports of both unplanned asthma care and treatment with a short course of oral corticosteroids. Occupational exposures for the same time period were assessed using an asthma-specific job exposure matrix. We modeled severe exacerbation to yield prevalence ratios (PRs) for exposures while controlling for potential confounders. A total of 164 participants (29%) were positive for severe exacerbation, and 227 (40.8%) were assessed as being exposed to asthma agents at work. Elevated PRs were observed for several specific agents, notably the irritant subcategories of environmental tobacco smoke (PR 1.84, 95%CI 1.34-2.51) among all participants, inorganic dusts (PR 2.53, 95%CI 1.37-4.67) among men, and the low molecular weight subcategory of other highly reactive agents (PR 1.97, 95%CI 1.08-3.60) among women. Among working adults with asthma, severe exacerbation was associated with several occupational agents.

Occupational exposures, smoking and airway inflammation in refractory asthma.

BackgroundThe influence of occupation and ex/passive smoking on inflammatory phenotype is not well understood. The aim of this study was to examine the relationship between occupation, past smoking and current passive smoking and airway inflammation in a population of adults with refractory asthma.MethodsSixty-six participants with refractory asthma were characterised. Occupational exposure to asthma causing or worsening agents were identified with an asthma-specific job exposure matrix. Exposure to passive cigarette smoke was determined by questionnaire and exhaled carbon monoxide assessment. The carbon content of macrophages was assessed in a sub-group of participants.ResultsNineteen participants had smoked previously with low smoking pack years (median 1.7 years). Ex-smokers more commonly lived with a current smoker (26% vs. 9%, p = 0.11) and were more likely to allow smoking inside their home (26% vs. 4%, p = 0.02) compared to never smokers. Twenty participants had occupations with an identified exposure risk to an asthmagen; thirteen had exposures to irritants such as motor vehicle exhaust and environmental tobacco smoke. Sputum neutrophils were elevated in participants with asthma who had occupational exposures, particularly those who were diagnosed with asthma at a more than 30 years of age.ConclusionsSputum neutrophils are elevated in refractory asthma with exposure to occupational asthmagens. In addition to older age, exposure to both environmental and occupational particulate matter may contribute to the presence of neutrophilic asthma. This may help explain asthma heterogeneity and geographical variations in airway inflammatory phenotypes in asthma.

Work-related exacerbation of asthma among adults treated by pulmonary specialists

The most common chronic occupational lung disease is occupational asthma. This study aimed to assess the prevalence of work-related respiratory symptoms (WRS) in asthmatic adults at pulmonary clinics. A cross-sectional study was performed. Current employed subjects were subdivided into 2 groups by WRS status according to questionnaire mainly based on one developed by the National Institute for Occupational Safety and Health (NIOSH). Subjects’ occupation and workplace exposures were evaluated by asthma-specific job exposure matrix (JEM). Thirty-nine of 179 current employed asthmatics had WRS. Subjects with WRS were more likely to have self-reported allergy and exposure to low-molecular-weight antigens (prevalence ratio [PR]: 2.7). The 2 most frequent occupational classes for asthmatics with WRS were trades, transport and equipment operators, and processing and manufacturing. Self-reported allergy, high-risk exposures, and occupations unique to processing, manufacturing, and utilities were estimated to be risk factors of WRS.

Human leukocyte antigen class II variants and adult-onset asthma: does occupational allergen exposure play a role?

Recently, a locus centred on rs9273349 in the HLA-DQ region emerged from genome-wide association studies of adult-onset asthma. We aimed to further investigate the role of human leukocyte antigen (HLA) class II in adult-onset asthma and a possible interaction with occupational exposures. We imputed classical HLA-II alleles from 7579 single-nucleotide polymorphisms in 6025 subjects (1202 with adult-onset asthma) from European cohorts: ECRHS, SAPALDIA, EGEA and B58C, and from surveys of bakers and agricultural workers. Based on an asthma-specific job-exposure matrix, 2629 subjects had ever been exposed to high molecular weight (HMW) allergens. We explored associations between 23 common HLA-II alleles and adult-onset asthma, and tested for gene-environment interaction with occupational exposure to HMW allergens. Interaction was also tested for rs9273349. Marginal associations of classical HLA-II alleles and adult-onset asthma were not statistically significant. Interaction was detected between the DPB1*03:01 allele and exposure to HMW allergens (p = 0.009), in particular to latex (p = 0.01). In the unexposed group, the DPB1*03:01 allele was associated with adult-onset asthma (OR 0.67, 95%CI 0.53-0.86). HMW allergen exposures did not modify the association of rs9273349 with adult-onset asthma. Common classical HLA-II alleles were not marginally associated with adult-onset asthma. The association of latex exposure and adult-onset asthma may be modified by DPB1*03:01.

Occupational irritants and asthma: an Estonian cross-sectional study of 34,000 adults.

Occupational exposures make important contributions to asthma morbidity. The role of low/moderate level irritant exposures remains unclear. We aimed to determine which occupational exposures are associated with asthma in an eastern European country with low asthma prevalence. The Estonian Genome Center of University of Tartu collected data from 50 077 adults in 2002-2011. Asthma was assessed through a questionnaire regarding diagnosed diseases, current health status and medication. Exposures to 22 agents during the current and longest held jobs were estimated using an asthma-specific job-exposure matrix. Analyses included 34 015 subjects (aged 18-65 years, 67.0% females), of which 1209 (3.6%) reported asthma (608 with physician-confirmed diagnosis). After adjusting for age, sex and smoking habits, lifetime occupational exposure to known asthmagens (20.4%) was significantly associated with physician-diagnosed asthma (OR 1.28, 95% CI 1.03-1.59), especially high molecular weight agents (flour: OR 2.36, 95% CI 1.31-4.27; animals: OR 1.62, 95% CI 1.00-2.60). Exposure to low/moderate levels of irritants (17.4%) was associated with physician-diagnosed asthma (OR 1.88, 95% CI 1.48-2.37). More pronounced associations were observed in subjects reporting current treated asthma. Beyond confirming the effect of known asthmagens (which are well-known, mostly from observations in western countries), the results provide evidence for a role of low/moderate exposure to irritants. This finding, observed in a country with a low prevalence of asthma and atopy, provides new insight into the understanding of asthma heterogeneity.