The influence of occupational exposures on respiratory health with a specific focus on agriculture in low- and middle-income countries

Chronic respiratory disease, particularly chronic obstructive pulmonary disease (COPD) is reported to be a major cause of morbidity and mortality worldwide. While smoking is the main cause of the disease, previous studies have shown associations between COPD and socioeconomic status and occupations. Many of the industries historically associated with occupational respiratory diseases have been transferred to low- and middle-income countries (LMICs) where workers’ health protection is generally limited. As farming is a common economic activity in LMICs and has been associated in previous epidemiological studies with adverse respiratory health effects, I hypothesise that this occupation, and the underlying exposures in particular pesticide exposure, could be an important cause of chronic lung disease in these countries. This doctoral thesis aims to examine the relationships between chronic respiratory disease (lung function and chronic respiratory symptoms) and occupational exposure specific to agricultural contexts especially in LMICs. It comprises: first, a systematic review and meta-analysis of pesticide use and lung function; second, a cross-sectional study in Nan province, Thailand examining the relationship between agricultural exposures and respiratory health; and third, a data analysis of the large multinational Burden of Obstructive Lung Disease (BOLD) study focusing on high risk occupational exposures, primarily farming, and respiratory outcomes. The first study is a systematic review and meta-analysis exploring the available literature on the relationship between occupational exposure to pesticides and lung function. Of the 2,356 articles I retrieved, 56 were included in the systematic review and were pooled in meta-analyses of the ratio of forced expiratory volume in the first second to forced vital capacity (FEV1/FVC), FVC and FEV1. There was tentative evidence that exposure to cholinesterase (ChE) inhibiting pesticides reduced FEV1/FVC but no evidence that paraquat exposure affected lung function in farmers. The second study is a cross-sectional survey of adults aged 40 to 65 that I conducted in the agricultural Nan province, Thailand. The aim of this survey was to improve knowledge on the relationship of chronic airflow obstruction and respiratory health problems with several exposures related to farming activities, particularly pesticide use. I found that chronic airflow obstruction was uncommon in the studied villages; as with other studies in developing countries, farming villagers had a low smoking prevalence. Nan farmers had a high percentage of pesticide applicators but farming activities and pesticide use (duration, intensity and lifetime cumulative hours of spraying classified by pesticide types) were unlikely to be a major cause of respiratory problems there. In the final study, I analysed data from the multinational population-based BOLD study of 28,823 adults aged ≥40 years. The aim of this analysis was to examine the relationship between occupational exposures and respiratory health in both high-income countries (HICs) and LMICs. I found that people working in any of three occupational exposure categories (organic dusts; inorganic dusts; and fumes) and 11 high-risk occupations (farming; flour, feed or grain milling; cotton or jute processing; hard-rock mining; coal mining; sandblasting; working with asbestos; chemical or plastics manufacturing; foundry or steel milling; welding; and firefighting) were more likely to report respiratory symptoms than those who did not work in any of those occupations. There were no consistent associations of FEV1/FVC or FVC with any high-risk occupations, particularly farming. The associations between occupational categories and lung function varied by gross national income.Open Acces

Association of respiratory symptoms and lung function with occupation in the multinational Burden of Obstructive Lung Disease (BOLD) study

Background Chronic obstructive pulmonary disease has been associated with exposures in the workplace. We aimed to assess the association of respiratory symptoms and lung function with occupation in the Burden of Obstructive Lung Disease study. Methods We analysed cross-sectional data from 28 823 adults (≥40 years) in 34 countries. We considered 11 occupations and grouped them by likelihood of exposure to organic dusts, inorganic dusts and fumes. The association of chronic cough, chronic phlegm, wheeze, dyspnoea, forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1)/FVC with occupation was assessed, per study site, using multivariable regression. These estimates were then meta-analysed. Sensitivity analyses explored differences between sexes and gross national income. Results Overall, working in settings with potentially high exposure to dusts or fumes was associated with respiratory symptoms but not lung function differences. The most common occupation was farming. Compared to people not working in any of the 11 considered occupations, those who were farmers for ≥20 years were more likely to have chronic cough (OR 1.52, 95% CI 1.19–1.94), wheeze (OR 1.37, 95% CI 1.16–1.63) and dyspnoea (OR 1.83, 95% CI 1.53–2.20), but not lower FVC (β=0.02 L, 95% CI −0.02–0.06 L) or lower FEV1/FVC (β=0.04%, 95% CI −0.49–0.58%). Some findings differed by sex and gross national income. Conclusion At a population level, the occupational exposures considered in this study do not appear to be major determinants of differences in lung function, although they are associated with more respiratory symptoms. Because not all work settings were included in this study, respiratory surveillance should still be encouraged among high-risk dusty and fume job workers, especially in low- and middle-income countries.publishedVersio

Sleep Quality and Associated Factors Among Firefighters in Bangkok, Thailand: A Cross-sectional Study

Objectives: Professional firefighters face various health hazards and are required to maintain both physical and mental fitness to effectively mitigate crises and respond to emergencies. Moreover, the long working hours and shift work of this profession impact sleep quality. This study investigated the quality of sleep and its associated factors among firefighters in Bangkok, Thailand. Methods: This was a cross-sectional study of firefighters affiliated with the Bangkok Fire and Rescue Department, Bangkok Metropolitan Administration, Thailand between January 2023 and March 2023. A cluster random sampling technique was utilized to distribute 600 questionnaires to firefighters in 15 fire stations. The questionnaire addressed demographic, work-related, and environmental factors. Sleep quality was assessed using the Thai version of the Pittsburgh Sleep Quality Index (PSQI). Data analysis involved both descriptive and inferential statistics. Bivariate and multiple logistic regressions were performed. Results: The response rate was 78.7% (n=472), and 44.1% of the firefighters reported poor sleep quality (PSQI score >5). Sleep quality was statistically associated with conflicting family relationships (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.1 to 2.9), additional part-time jobs (daytime, OR, 2.4; 95% CI, 1.3 to 4.4; or nighttime, OR, 4.3; 95% CI, 1.1 to 16.7), noisy sleeping areas (OR, 1.7; 95% CI, 1.1 to 2.8), and the availability of adequate bedding (OR, 3.0; 95% CI, 1.8 to 4.9). Conclusions: Poor sleep quality among firefighters was associated with various personal, work-related, and environmental factors. Organizations should promote policies that improve sleep quality through good sleep hygiene practices and facilities

Association of respiratory symptoms and lung function with occupation in the multinational Burden of Obstructive Lung Disease (BOLD) study

Chronic obstructive pulmonary disease has been associated with exposures in the workplace. We aimed to assess the association of respiratory symptoms and lung function with occupation in the Burden of Obstructive Lung Disease study. We analysed cross-sectional data from 28,823 adults (≥40 years) in 34 countries. Eleven occupations were considered and grouped by likelihood of exposure to organic dusts, inorganic dusts and fumes. The association of chronic cough, chronic phlegm, wheeze, dyspnoea, FEV1/FVC and FVC with occupation was assessed, per study site, using multivariable regression. These estimates were then meta-analysed. Sensitivity analyses explored differences between sexes and gross national income (GNI). Overall, working in settings with potentially high exposure to dusts or fumes was associated with respiratory symptoms but not lung function differences. The most common occupation was farming. Compared to people not working in any of the 11 considered occupations, those who were farmers for ≥20 years were more likely to have chronic cough (OR=1.52, 95%CI 1.19-1.94), wheeze (OR=1.37, 95%CI 1.16-1.63), and dyspnoea (OR=1.83, 95%CI 1.53-2.20), but not lower FVC (β=0.02L, 95%CI -0.02L to 0.06L) or lower FEV1/FVC (β=0.04%, 95%CI -0.49% to 0.58%). Some findings differed by sex and GNI. In summary, at a population level, the occupational exposures considered in this study do not appear to be major determinants of differences in lung function, although they associate with more respiratory symptoms. As not all work settings were included in this study, respiratory surveillance should still be encouraged among high-risk dusty and fume job workers, especially in low- and middle-income countries

European Respiratory Society International Congress 2018: four shades of epidemiology and tobacco control

In this article, early career members and experienced members of the Epidemiology and Environment Assembly of the European Respiratory Society highlight and summarise a selection of six sessions from the Society's annual congress, which in 2018 was held in Paris, France. The topics covered in these sessions span from cutting-edge molecular epidemiology of lung function to clinical, occupational and environmental epidemiology of respiratory disease, and from emergent tobacco products to tobacco control

Association of respiratory symptoms and lung function with occupation in the multinational Burden of Obstructive Lung Disease (BOLD) study

Background Chronic obstructive pulmonary disease has been associated with exposures in the workplace. We aimed to assess the association of respiratory symptoms and lung function with occupation in the Burden of Obstructive Lung Disease study. Methods We analysed cross-sectional data from 28 823 adults (≥40 years) in 34 countries. We considered 11 occupations and grouped them by likelihood of exposure to organic dusts, inorganic dusts and fumes. The association of chronic cough, chronic phlegm, wheeze, dyspnoea, forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1)/FVC with occupation was assessed, per study site, using multivariable regression. These estimates were then meta-analysed. Sensitivity analyses explored differences between sexes and gross national income. Results Overall, working in settings with potentially high exposure to dusts or fumes was associated with respiratory symptoms but not lung function differences. The most common occupation was farming. Compared to people not working in any of the 11 considered occupations, those who were farmers for ≥20 years were more likely to have chronic cough (OR 1.52, 95% CI 1.19–1.94), wheeze (OR 1.37, 95% CI 1.16–1.63) and dyspnoea (OR 1.83, 95% CI 1.53–2.20), but not lower FVC (β=0.02 L, 95% CI −0.02–0.06 L) or lower FEV1/FVC (β=0.04%, 95% CI −0.49–0.58%). Some findings differed by sex and gross national income. Conclusion At a population level, the occupational exposures considered in this study do not appear to be major determinants of differences in lung function, although they are associated with more respiratory symptoms. Because not all work settings were included in this study, respiratory surveillance should still be encouraged among high-risk dusty and fume job workers, especially in low- and middle-income countries

Association of respiratory symptoms and lung function with occupation in the multinational Burden of Obstructive Lung Disease (BOLD) study

Chronic obstructive pulmonary disease has been associated with exposures in the workplace. We aimed to assess the association of respiratory symptoms and lung function with occupation in the Burden of Obstructive Lung Disease study. We analysed cross-sectional data from 28,823 adults (≥40 years) in 34 countries. Eleven occupations were considered and grouped by likelihood of exposure to organic dusts, inorganic dusts and fumes. The association of chronic cough, chronic phlegm, wheeze, dyspnoea, FEV1/FVC and FVC with occupation was assessed, per study site, using multivariable regression. These estimates were then meta-analysed. Sensitivity analyses explored differences between sexes and gross national income (GNI). Overall, working in settings with potentially high exposure to dusts or fumes was associated with respiratory symptoms but not lung function differences. The most common occupation was farming. Compared to people not working in any of the 11 considered occupations, those who were farmers for ≥20 years were more likely to have chronic cough (OR=1.52, 95%CI 1.19-1.94), wheeze (OR=1.37, 95%CI 1.16-1.63), and dyspnoea (OR=1.83, 95%CI 1.53-2.20), but not lower FVC (β=0.02L, 95%CI -0.02L to 0.06L) or lower FEV1/FVC (β=0.04%, 95%CI -0.49% to 0.58%). Some findings differed by sex and GNI. In summary, at a population level, the occupational exposures considered in this study do not appear to be major determinants of differences in lung function, although they associate with more respiratory symptoms. As not all work settings were included in this study, respiratory surveillance should still be encouraged among high-risk dusty and fume job workers, especially in low- and middle-income countries