Lifetime occupational exposures and chronic obstructive pulmonary disease risk in the UK Biobank cohort.

BACKGROUND AND AIM: Occupational exposures are important, preventable causes of COPD. We previously found an increased risk of COPD among six occupations by analysing lifetime job histories and lung function data in the population-based UK Biobank cohort. We aimed to build on these findings and elucidate the underlying potential causal agents to focus preventive strategies. METHODS: We applied the ALOHA+job exposure matrix (JEM) based on the International Standard Classification of Occupations V.1988 codes, where exposure to 12 selected agents was rated as 0 (no exposure), 1 (low) or 2 (high). COPD was spirometrically defined as FEV1/FVC less than the lower limit of normal. We calculated semiquantitative cumulative exposure estimates for each agent by multiplying the duration of exposure and squared intensity. Prevalence ratio (PR) and 95% CI for COPD were estimated using robust Poisson regression adjusted for centre, sex, age, smoking and coexposure to JEM agents. Only associations confirmed among never-smokers and never-asthmatics were considered reliable. RESULTS: Out of 116 375 participants with complete job histories, 94 514 had acceptable/repeatable spirometry and smoking data and were included in the analysis. Pesticide exposure showed increased risk of COPD for ever exposure (PR=1.13, 95% CI 1.01 to 1.28) and high cumulative exposure (PR=1.32, 95% CI 1.12 to 1.56), with positive exposure-response trends (p trend=0.004), which were confirmed among never-smokers (p trend=0.005) and never-asthmatics (p trend=0.001). CONCLUSION: In a large population-based study, occupational exposure to pesticides was associated with risk of COPD. Focused preventive strategies for workers exposed to pesticides can prevent the associated COPD burden.

Occupational inhalant exposures and longitudinal lung function decline.

BACKGROUND: Airborne exposures at the workplace are believed to be associated with lung function decline. However, longitudinal studies are few, and results are conflicting. METHODS: Participants from two general population-based cohorts, the Copenhagen City Heart Study and the Copenhagen General Population Study, with at least two lung function measurements were followed for a mean of 9 years (range 3-27 years). Occupational exposure was assigned to each year of follow-up between the two lung function measurements by a job exposure matrix. Associations between mean occupational exposure per year and mean annual decline in forced expiratory volume in 1 s (FEV1) were investigated using linear mixed-effects models according to cohort and time period (1976-1983 and 2003-2015). We adjusted for sex, height, weight, education, baseline FEV1 and pack-years of smoking per year during follow-up. RESULTS: A total of 16 144 individuals were included (mean age 48 years and 43% male). Occupational exposure to mineral dusts, biological dusts, gases and fumes and a composite category was not associated with FEV1 decline in analyses with dichotomised exposure. In analyses with an indexed measure of exposure, gases and fumes were associated with an FEV1 change of -5.8 mL per unit per year (95% CI -10.8- -0.7 mL per unit per year) during 1976-1983, but not during 2001-2015. CONCLUSION: In two cohorts from the Danish general population, occupational exposure to dusts, gases and fumes was not associated with excess lung function decline in recent years but might have been of importance decades ago.

Understanding the impact of systemic lupus erythematosus on work amongst South Asian people in the UK: An explorative qualitative study.

SLE has a range of fluctuating symptoms affecting individuals and their ability to work. Although South Asian (SA) patients are at increased risk of developing SLE there is limited knowledge of the impact on employment for these patients in the UK. Understanding ethnicity and disease-specific issues are important to ensure patients are adequately supported at work. Semi-structured interviews were conducted with patients of SA origin to explore how SLE impacted on their employment. Thematic analysis was used to analyse the data which are reported following COREQ guidelines. Ten patients (8 female; 2 male) were recruited from three rheumatology centres in the UK and interviewed between November 2019 and March 2020. Patients were from Indian (n = 8) or Pakistani (n = 2) origin and worked in a range of employment sectors. Four themes emerged from the data: (1) Disease related factors; (2) Employment related factors; (3) Cultural and interpersonal factors impacting on work ability; (4) Recommendations for improvement. Patients' ability to work was affected by variable work-related support from their hospital clinicians, low awareness of SLE and variable support from their employers, and cultural barriers in their communities that could affect levels of family support received. These findings highlight the need for additional support for SA patients with SLE in the workplace.

Chronic productive cough and inhalant occupational exposure-a study of the general population.

PURPOSE: Occupational inhalant exposures have been linked with a higher occurrence of chronic productive cough, but recent studies question the association. METHODS: We included participants from two general population studies, the Copenhagen City General Population Study and the Copenhagen City Heart Study, to assess contemporary (year 2003-2017) and historical (1976-1983) occupational inhalant hazards. Job titles one year prior to study inclusion and an airborne chemical job-exposure matrix (ACE JEM) were used to estimate occupational exposure. The association between occupational exposures and self-reported chronic productive cough was studied using generalized estimating equations stratified by smoking status and cohort. RESULTS: The population consisted of 5210 working individuals aged 20-65 from 1976 to 1983 and 64,279 from 2003 to 2017. In smokers, exposure to high levels of mineral dust, biological dust, gases & fumes and the composite variable vapours, gases, dusts or fumes (VGDF) were associated with chronic productive cough in both cohorts with odds ratios in the range of 1.2 (95% confidence interval, 1.0;1.4) to 1.6 (1.2;2.1). High levels of biological dust were only associated with an increased risk of a chronic productive cough in the 2003-2017 cohort (OR 1.5 (1.1;2.0)). In non-smokers, high levels of VGDF (OR 1.5 (1.0;2.3)) and low levels of mineral dust (OR 1.7 (1.1;2.4)) were associated with chronic productive cough in the 1976-1983 cohort, while no associations were seen in non-smokers in the 2003-2017 cohort. CONCLUSION: Occupational inhalant exposure remains associated with a modestly increased risk of a chronic productive cough in smokers, despite declining exposure levels during the past four decades.

Occupational exposure to inhaled pollutants and risk of airflow obstruction: a large UK population-based UK Biobank cohort.

BACKGROUND: Although around 10% to 15% of COPD burden can be attributed to workplace exposures, little is known about the role of different airborne occupational pollutants (AOP). The main aim of the study was to assess the effect size of the relationship between various AOP, their level and duration of exposure with airflow obstruction (AFO). METHODS: A cross-sectional analysis was conducted in 228 614 participants from the UK Biobank study who were assigned occupational exposure using a job exposure matrix blinded to health outcome. Adjusted prevalence ratios (PRs) and 95% CI for the risk of AFO for ever and years of exposure to AOPs were estimated using robust Poisson model. Sensitivity analyses were conducted for never-smokers, non-asthmatic and bi-pollutant model. RESULTS: Of 228 614 participants, 77 027 (33.7%) were exposed to at least one AOP form. 35.5% of the AFO cases were exposed to vapours, gases, dusts or fumes (VGDF) and 28.3% to dusts. High exposure to vapours increased the risk of occupational AFO by 26%. Exposure to dusts (adjusted PR=1.05; 95% CI 1.01 to 1.08), biological dusts (1.05; 1.01 to 1.10) and VGDF (1.04; 1.01 to 1.07) showed a significantly increased risk of AFO, however, statistically not significant following multiple testing. There was no significant increase in risk of AFO by duration (years) of exposure in current job. The results were null when restricted to never-smokers and when a bi-pollutant model was used. However, when data was analysed based on the level of exposure (low, medium and high) compared with no exposure, directionally there was increase in risk for those with high exposure to vapours, gases, fumes, mists and VGDF but statistically significant only for vapours. CONCLUSION: High exposure (in current job) to airborne occupational pollutants was suggestive of higher risk of AFO. Future studies should investigate the relationship between lifetime occupational exposures and COPD.

The occupations at increased risk of COPD: analysis of lifetime job-histories in the population-based UK Biobank Cohort.

Occupational exposures are important, preventable causes of chronic obstructive pulmonary disease (COPD). Identification of COPD high-risk jobs is key to focus preventive strategies, but a definitive job-list is unavailable.We addressed this issue by evaluating the association of lifetime job-histories and lung function data in the population-based UK Biobank cohort, whose unprecedented sample size allowed analyses restricted to never-smokers to rule out the most important confounder, tobacco smoking. COPD was spirometrically defined as forced expiratory volume in 1 s/forced vital capacity ratio below the lower limit of normal. Lifetime job-histories were collected via OSCAR (Occupations Self-Coding Automatic Recording), a new validated online tool that automatically codes jobs into the UK Standard Occupational Classification v.2000. Prevalence ratios for COPD by employment duration in each job compared to lifetime office workers were estimated using robust Poisson regression adjusted for age, sex, centre and smoking. Only associations confirmed among never-smokers and never-asthmatics were considered reliable.From the 116 375 participants with complete job-histories, 94 551 had acceptable/repeatable spirometry data and smoking information and were included in the analysis. Six occupations showed an increased COPD risk among never-smokers and never-asthmatics; most of these also with positive exposure-response trends. Interesting new findings included sculptors, gardeners and warehouse workers.COPD patients, especially never-smokers, should be asked about their job-history for better disease management. Focussed preventive strategies in COPD high-risk jobs are warranted.

Factors in Removing Job Restrictions for Cancer Survivors in the United Kingdom Royal Air Force.

Purpose To identify personal, occupational and clinical factors associated with the lifting of restrictions on duties among Royal Air Force (RAF) personnel who have returned to work after surviving primary cancer treatment. Methods A retrospective cohort of 205 RAF personnel aged 18-58 with cancer diagnosed between 2001 and 2011 was followed-up until May 2012. Personal, occupational, and clinical information was extracted from occupational health and primary care records. Predictors of the lifting of (a) employment restrictions on UK duties at 18 months after diagnosis and (b) the lifting of all deployment restrictions at the end of the study were analysed using logistic and Cox regression models. Results At 18 months, 62% of the cancer survivors had restrictions on their UK duties lifted. The positive independent predictors of unrestricted UK duties are testicular cancer (OR 5.34; 95% CI 1.21-23.6) and no treatment being required (16.8; 1.11-255.2). The lifting of all employment restrictions and return to full deployability was achieved by 41% of the participants (median time 2.1 years), with testicular cancer (HR 2.69; 95% CI 1.38-5.26) and age at diagnosis (1.05; 1.01-1.09) being the positive independent predictors of faster lifting of all restrictions. Conclusion Diagnostic group, prognosis and type of treatment are not the only predictor of employment outcome after cancer. Patient-centred factors such as smoking, age, fatigue, job status, job type and length of employment are also important predictors of return to pre-morbid job function in cancer survivors in the RAF.

Factors associated with work productivity among people with COPD: Birmingham COPD Cohort.

BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) are more likely to take time off work (absenteeism) and report poor performance at work (presenteeism) compared to those without COPD. Little is known about the modifiable factors associated with these work productivity outcomes. AIM: To assess the factors associated with work productivity among COPD patients. METHODS: Cross-sectional analysis of baseline data from a subsample (those in paid employment) of the Birmingham COPD Cohort study. Absenteeism was defined by self-report over the previous 12 months. Presenteeism was assessed using the Stanford Presenteeism Scale. Logistic regression analysis was used to assess the effects of sociodemographic, clinical and occupational characteristics on work productivity. RESULTS: Among 348 included participants, increasing dyspnoea was the only factor associated with both absenteeism and presenteeism (p for trend<0.01). Additionally, increasing history of occupational exposure to vapours, gases, dusts or fumes (VGDF) was independently associated with presenteeism (p for trend<0.01). CONCLUSIONS: This is the first study to identify important factors associated with poor work productivity among patients with COPD. Future studies should evaluate interventions aimed at managing breathlessness and reducing occupational exposures to VGDF on work productivity among patients with COPD.

Occupational airborne exposure in relation to Chronic Obstructive Pulmonary Disease (COPD) and lung function in individuals without childhood wheezing illness: A 50-year cohort study.

BACKGROUND: Evidence from longitudinal population-based studies relating occupational exposure to the full range of different forms of airborne pollutants and lung function and airway obstruction is limited. OBJECTIVE: To relate self-reported COPD and lung function impairment to occupational exposure to different forms of airborne chemical pollutants in individuals who did not have childhood wheeze. METHODS: A prospective cohort study was randomly selected in 1964 at age 10-15 years and followed up in 1989, 1995, 2001 and 2014 (aged 58-64) by spirometry and respiratory questionnaire. Occupational histories were recorded in 2014 and occupational exposures assigned using an airborne chemical job exposure matrix. The risk of COPD and lung function impairment was analyzed in subjects, who did not have childhood wheeze, using logistic and linear regression and linear mixed effects models. RESULTS: 237 subjects without childhood wheeze (mean age 60.6 years, 47% male) were analyzed. There was no association between any respiratory outcomes and exposure to gases, fibers, mists or mineral dusts and no consistent associations with exposure to fumes. Reduced FEV1 was associated with longer duration (years) of exposure to any of the six main pollutant forms - vapors, gases, dusts, fumes, fibers and mists (VGDFFiM) with evidence of a dose-response relationship (p-trend=0.004). Exposure to biological dusts was associated with self-reported COPD and FEV1

Occupations associated with COPD risk in the large population-based UK Biobank cohort study.

OBJECTIVES: Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide. Exposure to occupational hazards is an important preventable risk factor but the contribution of specific occupations to COPD risk in a general population is uncertain. Our aim was to investigate the association of COPD with occupation in the UK population. METHODS: In 2006-2010, the UK Biobank cohort recruited 502 649 adults aged 40-69 years. COPD cases were identified by prebronchodilator forced expiratory volume in 1 s/forced vital capacity

Predictors of return to work in cancer survivors in the Royal Air Force.

PURPOSE: Return to work (RTW) is beneficial for cancer survivors, employers and society. However, little is known about predictors of RTW in the military environment. METHODS: A cohort of 194 Royal Air Force (RAF) personnel aged 18-58 who survived primary cancer treatment between 2001 and 2011 were followed up for 18 months. Information was obtained from occupational health and primary care records. Personal, occupational and clinical predictors of RTW were identified by Cox proportional hazards regression. RESULTS: The median sickness absence before RTW was 107 days. Six months after diagnosis 54 % of participants had RTW, and reached 80 % by 12 months. Time taken to RTW was predicted by age at diagnosis, rank, trade group, pre-diagnosis sickness absence, site of cancer, treatment modality, and prognosis. RTW at 18 months were predicted by higher rank (HR = 2.31; 95 % CI 1.46-3.65), and having melanoma (9.75; 4.97-19.13). Those receiving chemotherapy were significantly less likely to have RTW compared to other treatment modalities (0.18; 0.10-0.32). CONCLUSIONS: Rank, cancer diagnostic group, and treatment modality are the most important predictors of RTW in cancer survivors in the RAF. These predictors can be used to inform rehabilitation programmes and decisions on RTW.

The effect of exposure to biomass smoke on respiratory symptoms in adult rural and urban Nepalese populations.

BACKGROUND: Half of the world's population is exposed to household air pollution from biomass burning. This study aimed to assess the relationship between respiratory symptoms and biomass smoke exposure in rural and urban Nepal. METHODS: A cross-sectional study of adults (16+ years) in a rural population (n = 846) exposed to biomass smoke and a non-exposed urban population (n = 802) in Nepal. A validated questionnaire was used along with measures of indoor air quality (PM2.5 and CO) and outdoor PM2.5. RESULTS: Both men and women exposed to biomass smoke reported more respiratory symptoms compared to those exposed to clean fuel. Women exposed to biomass were more likely to complain of ever wheeze (32.0 % vs. 23.5%; p = 0.004) and breathlessness (17.8% vs. 12.0%, p = 0.017) compared to males with tobacco smoking being a major risk factor. Chronic cough was similar in both the biomass and non-biomass smoke exposed groups whereas chronic phlegm was reported less frequently by participants exposed to biomass smoke. Higher PM2.5 levels (≥2 SDs of the 24-hour mean) were associated with breathlessness (OR = 2.10, 95% CI 1.47, 2.99) and wheeze (1.76, 1.37, 2.26). CONCLUSIONS: The study suggests that while those exposed to biomass smoke had higher prevalence of respiratory symptoms, urban dwellers (who were exposed to higher ambient air pollution) were more at risk of having productive cough.

Effect of exposure to biomass smoke from cooking fuel types and eye disorders in women from hilly and plain regions of Nepal.

BACKGROUND/AIM: To study the association between exposure to biomass smoke from cooking fuels andi cataract, visual acuity and ocular symptoms in women. METHODS: We conducted a community-based cross-sectional study among women (≥20 years and without a previous diagnosis of cataract, ocular trauma or diabetes or those taking steroids) from hilly and plain regions of Nepal. Eligible participants received an interview and a comprehensive eye assessment (cataract development, visual acuity test and ocular symptoms). Participants' data on demographics, cooking fuel type and duration of use, and cooking habits were collected. We addressed potential confounders using the propensity score and other risk factors for ocular diseases through regression analysis. RESULTS: Of 784 participants, 30.6% used clean fuel (liquefied petroleum gas, methane, electricity) as their primary current fuel, and the remaining 69.4% used biomass fuels. Thirty-nine per cent of the total participants had cataracts-about twofold higher in those who currently used biomass fuel compared with those who used clean fuel (OR=2.27; 95% CI 1.09 to 4.77) and over threefold higher in those who always used biomass. Similarly, the nuclear cataract was twofold higher in the current biomass user group compared with the clean fuel user group (OR=2.53; 95% CI 1.18-5.42) and over threefold higher among those who always used biomass. A higher proportion of women using biomass had impaired vision, reported more ocular symptoms compared with those using clean fuel. Severe impaired vision and blindness were only present in biomass fuel users. However, the differences were only statistically significant for symptoms such as redness, burning sensation, a complaint of pain in the eye and tear in the eyes. CONCLUSIONS: Cataract was more prevalent in women using biomass for cooking compared with those using clean fuel.

Enhancing the health of NHS staff: eTHOS - protocol for a randomised controlled pilot trial of an employee health screening clinic for NHS staff to reduce absenteeism and presenteeism, compared with usual care.

BACKGROUND: Staff absenteeism and presenteeism incur high costs to the NHS and are associated with adverse health outcomes. The main causes are musculoskeletal complaints and mental ill-health, which are potentially modifiable, and cardiovascular risk factors are also common. We will test the feasibility of an RCT to evaluate the clinical and cost-effectiveness of an employee health screening clinic on reducing sickness absenteeism and presenteeism. METHODS: This is an individually randomised controlled pilot trial aiming to recruit 480 participants. All previously unscreened employees from four hospitals within three UK NHS hospital Trusts will be eligible. Those randomised to the intervention arm will be invited to attend an employee health screening clinic consisting of a screening assessment for musculoskeletal (STarT MSK and STarT Back), mental (PHQ-9 and GAD-7) and cardiovascular (NHS Health Check if aged ≥ 40, lifestyle check if < 40 years) health. Screen positives will be given advice and/or referral to recommended services. Those randomised to the control arm will receive usual care. Participants will complete a questionnaire at baseline and 26 weeks; anonymised absenteeism and staff demographics will also be collected from personnel records. The co-primary outcomes are as follows: recruitment, referrals and uptake of recommended services in the intervention arm. Secondary outcomes include the following: results of screening assessments, uptake of individual referrals, reported changes in health behaviours, acceptability and feasibility of intervention, indication of contamination and costs. Outcomes related to the definitive trial include self-reported and employee records of absenteeism with reasons. Process evaluation to inform a future trial includes interviews with participants, intervention delivery staff and service providers receiving referrals. Analyses will include presentation of descriptive statistics, framework analysis for qualitative data and costs and consequences presented for health economics. DISCUSSION: The study will provide data to inform the design of a definitive RCT which aims to find an effective and cost-effective method of reducing absenteeism and presenteeism amongst NHS staff. The feasibility study will test trial procedures, and process outcomes, including the success of strategies for including underserved groups, and provide information and data to help inform the design and sample size for a definitive trial. TRIAL REGISTRATION: ISRCTN reference number 10237475 .

Prognostic factors associated with small for gestational age babies in a tertiary care hospital of Western Nepal: A cross-sectional study.

BACKGROUND: Small for gestational age (SGA) is common among newborns in low-income countries like Nepal and has higher immediate mortality and morbidities. OBJECTIVES: To study the prevalence and prognostic factors of SGA babies in Western Nepal. METHODS: A cross-sectional study (November 2016-October 2017) was conducted in a tertiary care hospital in Western Nepal. Socio-demographic, lifestyle factors including diet, and exposures including smoking and household air pollution in mothers who delivered newborns appropriate for gestational age (AGA), SGA and large for gestational age (LGA) were recorded. Logistic regression was carried out to find the odds ratio of prognostic factors after adjusting for potential confounders. RESULTS: Out of 4000 delivered babies, 77% (n = 3078) were AGA, 20.3% (n = 813) were SGA and 2.7% (n = 109) were LGA. The proportion of female-SGA was greater in comparison to male-SGA (n = 427, 52.5% vs n = 386, 47.5%). SGA babies were born to mothers who had term, preterm, and postterm delivery in the following proportions 70.1%, 19.3%, and 10.6%, respectively. The average weight gain (mean ± SD) by mothers in AGA pregnancies was 10.3 ± 2.4 kg, whereas in SGA were 9.3 ± 2.4 kg. In addition to low socioeconomic status (OR 1.9, 95% CI 1.1, 3.2), other prognostic factors associated with SGA were lifestyle factors such as low maternal sleep duration (OR 5.1, CI 3.6, 7.4) and monthly or less frequent meat intake (OR 5.0, CI 3.2, 7.8). Besides smoking (OR 8.8, CI 2.1, 36.3), the other major environmental factor associated with SGA was exposure to household air pollution (OR 5.4, 4.1, 6.9) during pregnancy. Similarly, some of the adverse health conditions associated with a significantly higher risk of SGA were anemia, oligohydramnios, and gestational diabetes. CONCLUSIONS: SGA is common in Western Nepal and associated with several modifiable prognostic factors.

Carcinogenic risk assessment for emissions from clinical waste incineration and road traffic.

The most significant potentially carcinogenic substances arising from a state-of-the-art clinical waste incinerator (CWI) and vehicle emissions were identified as polychlorinated dibenzo-p-dioxins, polycyclic aromatic hydrocarbons (PAHs), benzene, 1-butadiene, arsenic, cadmium, chromium and nickel. Long-term exposures of the notional maximum exposed individual (MEI) in the local environment, together with aggregate emissions from transport of clinical waste, were estimated. Mass emission rates of PAHs from the CWI to air were compared with previously published estimates of mass emissions to land from CWI bottom ash. Aggregate emissions from road transport of clinical waste were of a similar order to stack emissions from incineration. Mass emissions of PAHs to landfill generally greatly exceeded those from stack emissions. Emissions associated with operation of the CWI present a negligible contribution to overall cancer risk from PAHs and other carcinogens. Uncertainty in the quantitative risk estimates presented here is discussed in the context of these findings.

Delay in seeking medical help in patients with rheumatoid arthritis in India: A qualitative study.

BACKGROUND: Rheumatoid arthritis (RA) is an autoimmune disease with varied articular and extra-articular manifestations. In developing countries such as India patients with RA often delay seeking medical advice which may impact prognosis and disease burden. AIM: To explore perceptions and experiences of patients living in India in seeking medical help for their RA symptoms. METHODS: Clinician-diagnosed RA participants from different socioeconomic backgrounds were interviewed using a semi-structured topic guide. Participants were purposively selected and interviewed following an iterative approach. All interviews were recorded and transcribed by an independent company and analyzed using a thematic framework. Findings were reported in accordance with consolidated criteria for reporting qualitative research guidelines. RESULTS: Twenty participants (13 male, 7 female) with median age 40 years (35.7-46.5) were recruited. Three overarching themes demonstrating participants' experiences and reasons for delay in seeking medical help were identified. (1) "Symptoms perspectives and delay in participants' journey" narrated participants' experiences of having RA symptoms, how these were perceived, rationalized and led to delay. (2) "Participants' experience of the healthcare system" illustrated delay in referral, reaching diagnosis and treatment initiation highlighting their experiences with the health system. (3) "Recommendations for improving care" where participants made recommendations for reducing the delay at local and national levels. CONCLUSION: This is the first qualitative study which explored perceptions and experiences of RA patients in India resulting in delay. Improved provision of rheumatology care, effective referral system and greater involvement of government at local and national levels are needed to improve the delay in seeking medical help for Indian patients.

Occupational exposure and the risk of airway obstruction and mortality.

OBJECTIVES: To identify occupational groups at high risk of airway obstruction (AO) and mortality and potential interactions with smoking. METHODS: Lung function data from the LuftiBus project were enriched with occupational and follow-up information from the Swiss National Cohort, resulting in a cohort of 10582 adults between 2000 and 2015. We assigned professions to occupational groups and estimated the risk of AO and mortality using adjusted logistic and Cox regression model. Additionally, we assessed multiplicative and additive interactions between occupational exposure and smoking. RESULTS: Chimney sweeps and male workers from the agriculture, construction and food industries had an increased risk of AO (odds ratios ranging from 1.43 to 2.21). The risk of mortality was increased among male workers from the food industry (hazard ratio 1.57, 95% CI 1.10-2.23). Interactions with smoking were present in most associations, but smoking had no effect on the increased risk of mortality in the food industry. CONCLUSIONS: Some occupational groups have a considerable risk of AO and mortality. The identification of the most affected occupations is of great importance enabling targeted risk reduction strategies.

Occupational exposures and exacerbations of asthma and COPD-A general population study.

PURPOSE: Recent studies suggest that occupational inhalant exposures trigger exacerbations of asthma and chronic obstructive pulmonary disease, but findings are conflicting. METHODS: We included 7,768 individuals with self-reported asthma (n = 3,215) and/or spirometric airflow limitation (forced expiratory volume in 1 second (FEV1)/ forced expiratory volume (FVC) <0.70) (n = 5,275) who participated in The Copenhagen City Heart Study or The Copenhagen General Population Study from 2001-2016. Occupational exposure was assigned by linking job codes with job exposure matrices, and exacerbations were defined by register data on oral corticosteroid treatment, emergency care unit assessment or hospital admission. Associations between occupational inhalant exposure each year of follow-up and exacerbation were assessed by Cox regression with time varying exposure and age as the underlying time scale. RESULTS: Participants were followed for a median of 4.6 years (interquartile range, IQR 5.4), during which 870 exacerbations occurred. Exacerbations were not associated with any of the selected exposures (high molecular weight sensitizers, low molecular weight sensitizers, irritants or low and high levels of mineral dust, biological dust, gases & fumes or the composite variable vapours, gases, dusts or fumes). Hazards ratios ranged from 0.8 (95% confidence interval: 0.7;1.0) to 1.2 (95% confidence interval: 0.9;1.7). CONCLUSION: Exacerbations of obstructive airway disease were not associated with occupational inhalant exposures assigned by a job exposure matrix. Further studies with alternative exposure assessment are warranted.