Documents chronic respiratory diseases 9 results

Results of a study of 55 occupational asthma patients indicate that the disease is disabling and probably irreversible for most patients, despite prolonged removal from causative agents. Women, industrial workers and those with severe asthma or lack of a college degree appear to be at risk for worse outcomes. Topics: asthma; degree of disability; handicapped workers; high-risk groups; occupation disease relation; sex-linked differences; sickness absenteeism; state of health; statistical evaluation; unemployment.

"Background: This study examines the possible effect of exposure to aerosols and gases on lung function in a fertilizer plant in Norway.Methods: Dynamic lung volumes (FVC and FEV1) of 383 workers were measured in 2007 and 2010. During the follow-up period, most workers performed tasks with low exposure levels of acid aerosols and inorganic gases. The overall median inhalable and thoracic aerosol exposure levels were 1·1 and 0·21 mg/m3, respectively. A questionnaire on respiratory symptoms was provided.Results: During the follow-up period, there was an adjusted decrease of FEV1 of 18 ml/year (P<0·001). The respiratory symptoms score was low during follow-up.Conclusions: Work in this fertilizer industry may lead to an excessive lung function decline. We have, however, not been able to find any plausible exposure related explanation for the overall lung function decline."

"BACKGROUND: This study focused on respiratory symptoms due to occupational exposures in a contemporary general population cohort. Subjects were from the Dutch Monitoring Project on Risk Factors for Chronic Diseases (MORGEN). The composition of this population enabled estimation of respiratory risks due to occupation from the recent past for both men and women.
METHODS: The study subjects (aged 20-59) were all inhabitants of Doetinchem, a small industrial town, and came from a survey of a random sample of 1104 persons conducted in 1993. A total of 274 cases with respiratory symptoms (subdivided in asthma and bronchitis symptoms) and 274 controls without symptoms were matched for age and sex. Relations between industry and occupation and respiratory symptoms were explored and adjusted for smoking habits and social economic status.
RESULTS: Employment in the 'construction' (OR = 3.38; 95%CI 1.02 - 11.27), 'metal' (OR = 3.17; 95%CI 0. 98 - 10.28), 'rubber, plastics and synthetics' (OR = 6.52; 95%CI 1.26 - 53.80), and 'printing' industry (OR = 3.96; 95%CI 0.85 - 18.48) were positively associated with chronic bronchitis symptoms. In addition, the 'metal' industry was found to be weakly associated with asthma symptoms (OR = 2.59; 95%CI 0.87 - 7.69). Duration of employment within these industries was also positively associated with respiratory symptoms.
CONCLUSION: Respiratory symptoms in the general population are traceable to employment in particular industries even in a contemporary cohort with relatively young individuals. "

Background: To evaluate the relationship between long-term exposure to cotton dust and Gram-negative bacterial endotoxin on lung function, we conducted an 11-year follow-up study of cotton textile workers in Shanghai, China. Methods: Workers at a nearby silk-thread manufacturing mill were used as a referent population. Ninety percent of the original cohort of 445 cotton and 467 silk textile workers - both active and retired - were identified for testing in the 11th year. Questionnaires and spirometric testing were performed, as well as cotton dust and endotoxin sampling at three points over the 11-year follow-up period: at baseline, at Year 5, and at Year 11. After excluding deaths and subjects on sick-leave, 84% of the original cohort had complete health and environmental data. Results: The data were reanalyzed using generalized estimating equations feedback model which allow for subject transfer over time between work areas, various exposure levels to dust and endotoxin, and FEV1. Cotton workers had a larger loss of FEV1 during the first 5 years of study (-40 mls/yr) as compared with the second 6 years of follow-up (-18 mls/yr). During the same periods, the average decline among silk workers was slightly higher in the first period, but was more consistent (-30 mls/yr vs. -27 mls/yr), and these differences could not be explained by worker selection or dropout. When cumulative exposure to dust and endotoxin were estimated and used in a multivariate model (GEE) for FEV1 loss, cumulative dust, but not endotoxin, was associated with 11-year loss in FEV1 after adjustments for confounders. There was evidence of feedback between dust-exposure levels and FEV1, indicating the existence of a healthy-worker survivor effect. After accounting for a healthy-worker survivor effect, we found a significant relationship between dust exposure and FEV1 decline. Conclusions: Our results suggest that cotton dust is more strongly associated with chronic airflow limitation than associated endotoxins. Further work is needed to clarify potential reversibility after cessation of exposure, and the relative contributions of dust, endotoxin, and tobacco to chronic respiratory impairment in cotton and other vegetable-exposed workers.

"Background A study of chronic obstructive pulmonary disease (COPD) among 7,579 current and former workers participating in medical screening programs at Department of Energy (DOE) nuclear weapons facilities through September 2008 was undertaken. Methods Participants provided a detailed work and exposure history and underwent a respiratory examination that included a respiratory history, respiratory symptoms, a posterior-anterior (P-A) chest radiograph classified by International Labour Office (ILO) criteria, and spirometry. Statistical models were developed to generate group-level exposure estimates that were used in multivariate logistic regression analyses to explore the risk of COPD in relation to exposures to asbestos, silica, cement dust, welding, paints, solvents, and dusts/fumes from paint removal. Risk for COPD in the study population was compared to risk for COPD in the general US population as determined in National Health and Nutrition Examination Survey (NHANES III).Results The age-standardized prevalence ratio of COPD among DOE workers compared to all NHANES III data was 1.3. Internal analyses found the odds ratio of COPD to range from 1.6 to 3.1 by trade after adjustment for age, race, sex, smoking, and duration of DOE employment. Statistically significant associations were observed for COPD and exposures to asbestos, silica, welding, cement dusts, and some tasks associated with exposures to paints, solvents, and removal of paints. Conclusions Our study of construction workers employed at DOE sites demonstrated increased COPD risk due to occupational exposures and was able to identify specific exposures increasing risk. This study provides additional support for prevention of both smoking and occupational exposures to reduce the burden of COPD among construction workers. "

"Assesses the ways in which epidemiological research can be used to determine when factors in the workplace operate as causes of disease or accidents. Addressed to occupational safety and health personnel, the book serves as both a detailed guide to the application of different epidemiological methods and a review of what these methods have already contributed to knowledge about health risks in the work environment and methods of prevention. In view of the complexity of human and environmental factors that need to be elucidated, the book gives particular attention to questions of study design and methodology that can strengthen the capacity of epidemiolgical research to yield sensitive, specific, and reliable data. The first main chapter, devoted to work-related diseases, concentrates on chronic nonspecific respiratory disease, cardiovascular disease, and musculo-skeletal disorders, including low-back pain, neck and upper limb disorders, and osteo-arthrosis. These common disorders, which were selected because of their complex multifactorial etiology, are used to illustrate specific problems inherent in epidemiological research aimed at identifying and quantifying the etiology of work-related disorders. Readers are given a formula for computing the strength of a given etiological factor, advice on the selection of indicators and measures of exposure, and a comparison of the appropriateness of different methodological approaches and study designs for providing evidence for or against the causality of an observed association. Data indicating the work-relatedness of each of these disorders are also succinctly reviewed. Work-related accidents are covered in the second half of the book, which reminds readers that an estimated 180,000 deaths and 110 million injuries are attributed each year to accidents at the workplace. An outline of present recording systems and problems with the statistical collection of data is followed by a detailed discussion of the uses of epidemiology to focus attention on dangerous trades, occupations, or tasks, to identify the causes of accidents within particular occupational environments, and to test the effectiveness of preventive methods. Details range from criteria for reporting near-accidents and dangerous occurrences to features of plant design and operation associated with superior safety performance"

"Objectives
To study exposure-response relations between cumulative organic dust exposure and incident chronic obstructive pulmonary disease (COPD) among subjects employed in the Danish farming and wood industry.
Methods
We studied exposure-response relations between cumulative organic dust exposure and incident COPD (1997–2013) among individuals born during 1950–1977 in Denmark ever employed in the farming or wood industry (n=1 75 409). Industry-specific employment history (1964–2007), combined with time-dependent farming and wood industry-specific exposure matrices defined cumulative exposure. We used logistic regression analysis with discrete survival function adjusting for age, sex and calendar year. Adjustment for smoking status was explored in a subgroup of 4023 with smoking information available.
Results
Cumulative organic dust exposure was inversely associated with COPD (adjusted rate ratios (RRadj (95% CIs) of 0.90 (0.82 to 0.99), 0.76 (0.69 to 0.84) and 0.52 (0.47 to 0.58) for intermediate-low, intermediate-high and high exposure quartiles, respectively, compared with the lowest exposure quartile). Lagging exposure 10 years was not consistently suggestive of an association between cumulative exposure and COPD; RRadj (95% CI): 1.05 (0.94 to 1.16), 0.92 (0.83 to 1.02) and 0.63 (0.56 to 0.70). Additional stratification by duration of employment showed no clear association between organic dust exposure and COPD except for the longer exposed (15–40 years) where an inverse association was indicated. Subgroup analyses showed that smoking had no impact on exposure-response estimates.
Conclusions
Our findings show no increased risk of COPD with increasing occupational exposure to organic dust in the farming or wood industry. Potential residual confounding by smoking can, however, not be ruled out."

"Background
Miners are highly exposed to diesel exhaust emissions from powered equipment. Although biologically plausible, there is little evidence based on quantitative exposure assessment, that long-term diesel exposure increases risk of chronic obstructive pulmonary disease (COPD). To fill this gap, we examined COPD mortality and diesel exhaust exposure in the Diesel Exhaust in Miners Study (DEMS).
Methods
We fit Cox models to estimate hazard ratios (HRs) for COPD mortality and cumulative exposure (μg/m3-years) to respirable elemental carbon (REC), a key metric for diesel exhaust exposure. Separate models were fit for ever-underground and surface-only miners to allow for effect modification. Exposure was lagged by 0, 10 and 15 years. In a secondary analysis, we addressed the healthy worker survivor effect by applying the parametric g-formula to handle time-varying confounding affected by prior exposure among ever-underground workers.
Results
Based on 140 cases, the HRs for COPD mortality increased as categories of lagged REC exposure increased for all workers. Among surface-only workers, those in the middle exposure category (0 lag) had a significantly elevated hazard ratio of 2.34 (95% CI: 1.11–4.61) relative to those in the lowest category. Among the ever-underground, that ratio was 1.35, with wide confidence intervals. Using the g-formula, we estimated that the lifetime cumulative risk of COPD mortality would have been reduced from the observed 5.0%–3.1% under a hypothetical intervention where all ever-underground workers were always unexposed.
Conclusions
Our results suggest long term exposure to diesel exhaust may increase risk of COPD in miners, though power was limited."