Respiratory effects of long-term exposure to cotton dust

Risk of chronic obstructive pulmonary disease in a large cohort of Ontario, Canada workers

Although several occupational exposures have been linked to the risk of COPD; limited data exists on sex-specific differences. This study aimed to identify at-risk occupations and sex differences for COPD risk. Cases were identified in a large surveillance system established through the linkage of former compensation claimants' data (non-COPD claims) to physician visits, ambulatory care data, and hospital inpatient data (1983-2020). Cox proportional hazard models were used to estimate hazard ratios (HRs) and corresponding 95% confidence intervals (CI) for occupation groups (occupation at time of claim), stratified by sex. HRs were indirectly adjusted for cigarette smoking using another population dataset. A total of 29,445 male and 14,693 female incident cases of COPD were identified. Increased risks were observed in both sexes for construction (HRmale 1.15, 95% CI 1.12-1.19; HRfemale 1.54, 95% CI 1.29-1.83) transport/equipment operating (HRmale 1.32, 95% CI 1.28-1.37; HRfemale 1.53, 95% CI 1.40-1.68) farming (HRmale 1.23, 95% CI 1.15-1.32; HRfemale 1.19, 95% CI 1.04-1.37) and janitors/cleaners (HRmale 1.31, 95% CI 1.24-1.37; HRfemale 1.40, 95% CI 1.31-1.49). Increased risks were observed for females employed as chefs and cooks (HR 1.44, 95% CI 1.31-1.58), bartenders (HR 1.38, 95% CI 1.05-1.81), and those working in food/beverage preparation (HR 1.34, 95% CI 1.24-1.45) among other occupations. This study demonstrates elevated risk of COPD among both male and female workers potentially exposed to vapours, gases, dusts, and fumes, highlighting the need for occupational surveillance of COPD.

The effect of organic dust exposure on long-term change in lung function: a systematic review and meta-analysis

Lung function is a predictor of morbidity and mortality, and the chronic nature of lung function decline allows for preventive initiatives. Proinflammatory constituents of organic dust are considered a possible cause of compromised respiratory health. The aim of this systematic review was to reveal the impact of organic dust exposure on long-term change in lung function. The literature search was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. Predefined criteria concerned study design: longitudinal, ≥1 year follow-up, ≥50 exposed; exposure measures: organic dust, measured or estimated, in different occupational settings; and outcome measures: change in lung function measured by spirometry. Based on these criteria, 1580 potentially relevant publications were narrowed down to 20 included publications. Quality was evaluated and discussed based on six objectively defined criteria. Overall, 14 studies found some type of association between exposure to organic dust and long-term change in lung function. However, the results were inconsistent and no specific work exposure showed more clear associations to change in lung function. Meta-analysis revealed an overall small significant excess loss in forced expiratory volume in the 1st s for exposed compared with controls of 4.92 mL/year (95% CI 0.14 to 9.69). No significant association was seen overall for forced vital capacity. 12 studies revealed a significant exposure-response relation between organic dust and change in lung function. The results were inconsistent across varying study design and different exposure measures and outcomes. We therefore conclude that there is limited evidence of a causal association between general exposure to organic dust and long-term excess decline in lung function.

Respiratory problems among cotton textile workers

Background:

Long term occupational exposure to cotton dust is associated with respiratory symptoms and loss of pulmonary function.

Aim:

This study was conducted to explore respiratory symptoms, pulmonary function tests and chest radiography of workers, and to evaluate the findings of high resolution computed tomographyand its correlation with pulmonary function tests (PFT).

Material and Methods:

The study was conducted on 100 cotton workers as exposed group and 100 unexposed subjects. Smokers were excluded from the study. All workers were interviewed and examined by the pulmonologist. PFT and chest radiography were conducted for all subjects. HRCT was performed for those with abnormal PFT or chest radiography.

Results:

A total of 51% and 31% of the cotton textile workers had one or more respiratory symptoms and respiratory signs respectively. 28% of subjects in the exposed group and 5% of subjects in unexposed group had obstructive pattern. Bronchia wall thickening and air trapping were the most frequent chest radiography and HRCT abnormalities respectively. There was a significant correlation between HRCT and the results of PFT.

Conclusion:

We conclude that long term exposure to cotton dust is associated with obstructive disease that increase with duration of exposure (history of working years), also use of HRCT as a sensitive tool in the assessment of pathologic changes and it's correlation with PFT, confirms the expected pathophysiology of airway obstruction in cotton workers.

Longitudinal pulmonary functional loss in cotton textile workers: a 5-year follow-up study

BACKGROUND

Occupational exposure to cotton dust causes several diseases affecting the lungs, but only limited information is available on effects of long-term exposure. In this study, we aimed to evaluate longitudinal changes in selected parameters of pulmonary function in textile workers.

MATERIAL AND METHODS

This prospective cohort study began with 196 textile workers in 2006 and was completed in 2011 with 49 workers. We used standardized tests for pulmonary function on participants on the first day of the workweek in June of 2006 and 2011. Environmental samples of cotton dust were gathered with a vertical elutriator. Loss of pulmonary function was assessed based on gender and smoking status.

RESULTS

The mean number of years participants worked in the textile factory was 7.61 ± 1.83 years, and the mean age was 35.3+5.8 years. The annual FEV1 loss of all workers was 53.2 ml, giving a ratio of annual FEV1 loss to baseline FEV1 of 1.4%. Pulmonary function parameters of all participants in 2011 were significantly lower than those in 2006 (for all, p<0.05). In both surveys, pulmonary function in current smokers was lower, but this difference was not significant (p>0.05).

CONCLUSIONS

This study provides the first data on pulmonary functional loss in Turkish textile workers and supports the findings of other cohort studies that workers with long-term exposure to cotton dust may lose some pulmonary function. The ratio of annual FEV1 loss to baseline FEV1 appears to be a more accurate and comparable method than annual FEV1 loss for evaluating pulmonary functional loss.

Unexpected excessive chronic obstructive pulmonary disease mortality among female silk textile workers in Shanghai, China

OBJECTIVE

To investigate chronic obstructive pulmonary disease (COPD) mortality among textile workers.

METHODS

A total of 267,400 Chinese female textile employees were monitored for COPD mortality from 1989 to 2000. Textile factories in the cohort were classified into 10 industrial sectors. Age-adjusted mortality, standardized mortality ratios (SMRs) and 95% CIs were calculated by sector. In addition, RRs (HRs) adjusted for smoking and age were calculated for exposure to cotton and silk textile work compared with the other sectors in the cohort.

RESULTS

A majority of textile sectors had lower or similar COPD mortality (age-adjusted SMRs=0.58-1.15) compared with the general female population in the city of Nanjing, China. SMRs for cotton and silk workers were, respectively, 1.02 (95% CI: 0.81 to 1.28) and 2.03 (95% CI: 1.13 to 3.34). Compared with all other textile sectors in the cohort, there was greater COPD mortality among cotton workers (HR=1.40, 95% CI: 1.03 to 1.89) and silk workers (HR=2.54, 95% CI: 1.47 to 4.39).

CONCLUSION

Elevated COPD mortality among cotton workers is consistent with previous reports of adverse respiratory effects of cotton dust. The higher rate of COPD deaths among silk workers was unexpected.

Chronic LPS inhalation causes emphysema-like changes in mouse lung that are associated with apoptosis

Lipopolysaccharide (LPS) is ubiquitous in the environment. Recent epidemiologic data suggest that occupational exposure to inhaled LPS can contribute to the progression of chronic obstructive pulmonary disease. To address the hypothesis that inhaled LPS can cause emphysema-like changes in mouse pulmonary parenchyma, we exposed C57BL/6 mice to aerosolized LPS daily for 4 weeks. By 3 days after the end of the 4-week exposure, LPS-exposed mice developed enlarged airspaces that persisted in the 4-week recovered mice. These architectural alterations in the lung are associated with enhanced type I, III, and IV procollagen mRNA as well as elevated levels of matrix metalloproteinase (MMP)-9 mRNA, all of which have been previously associated with human emphysema. Interestingly, MMP-9-deficient mice were not protected from the development of LPS-induced emphysema. However, we demonstrate that LPS-induced airspace enlargement was associated with apoptosis within the lung parenchyma, as shown by prominent TUNEL staining and elevated cleaved caspase 3 immunoreactivity. Antineutrophil antiserum-treated mice were partially protected from the lung destruction caused by chronic inhalation of LPS. Taken together, these findings demonstrate that inhaled LPS can cause neutrophil-dependent emphysematous changes in lung architecture that are associated with apoptosis and that these changes may be occurring through mechanisms different than those induced by cigarette smoke.

Work-related respiratory symptoms among cotton-fabric sewing workers

OBJECTIVES

An inspection of the sewing unit in a 700-bed hospital revealed that workers employed in this unit complained of cough, shortness of breath, and tightness in the chest. The aim of this cross-sectional study was to assess the prevalence of respiratory symptoms in the sewing workers and dust concentration in the workplace. The obtained results were compared with the control group.

MATERIALS AND METHODS

The sewing workers (n = 22, including 19 current and 3 former employees) and 22 housekeepers as controls were included in the study. All the participants responded to the respiratory questionnaire and underwent spirometric measurements, skin prick test, chest X-ray, and methacholine inhalation test. Environmental dust was measured using both an air pump and a vertical elutriator.

RESULTS

The sewing workers reported more symptoms of phlegm, chest tightness and eye irritation than persons of the control group. Neither clinical investigations nor respiratory disorders under study provided evidence for a significant difference between the sewing workers and the control group. Of the 22 subjects, 2 (9.1%) showed occupational asthma and 4 (18.2%) mucous membrane irritation and organic dust toxic symptoms. The total and respiratory dust was within normal limits, but the dust concentration measured by the elutriator was above the limit value of 0.34 +/- 0.09 mg/m. After ventilation improvements, the dust level decreased to 0.19 +/- 0.06 mg/m.

CONCLUSIONS

This study indicated that respiratory and ocular disorders were related to organic dust produced during the sewing process of cotton fabric.

Cotton dust lung diseases

PURPOSE OF REVIEW

Although, in the industrialized world, there is a significant decline in the prevalence of cotton dust lung diseases, studies show an increasing incidence in the developing world. With rapid industrialization of the developing world, cotton dust-induced lung diseases are poised to become a global health problem. Discovery of other vegetable dusts causing similar conditions and appreciation of a wider variety of clinical features also make this an opportune time to review this topic.

RECENT FINDINGS

In addition to chronic exposure-related byssinosis and less common forms of acute byssinosis, recent reports describe the rare occurrence of cotton dust-induced pulmonary fibrosis. New data also relate long-term cotton dust exposure to symptoms and physiologic changes of chronic obstructive pulmonary disease. There have also been new developments relating the pathogenesis of cotton dust airway disease to endotoxin lipopolysaccharide found in cotton dust and bract extracts.

SUMMARY

Establishment of an association between prolonged exposure to cotton and other vegetable dusts and symptoms of chronic obstructive pulmonary disease widens the clinical implication of cotton dust exposure. In addition, accumulating knowledge of endotoxins will bring about promising new developments reshaping industrial safety standards and measures to prevent cotton dust exposure.

Role of Caveolae and Caveolins in Health and Disease

Although they were discovered more than 50 years ago, caveolae have remained enigmatic plasmalemmal organelles. With their characteristic “flasklike” shape and virtually ubiquitous tissue distribution, these interesting structures have been implicated in a wide range of cellular functions. Similar to clathrin-coated pits, caveolae function as macromolecular vesicular transporters, while their unique lipid composition classifies them as plasma membrane lipid rafts, structures enriched in a variety of signaling molecules. The caveolin proteins (caveolin-1, -2, and -3) serve as the structural components of caveolae, while also functioning as scaffolding proteins, capable of recruiting numerous signaling molecules to caveolae, as well as regulating their activity. That so many signaling molecules and signaling cascades are regulated by an interaction with the caveolins provides a paradigm by which numerous disease processes may be affected by ablation or mutation of these proteins. Indeed, studies in caveolin-deficient mice have implicated these structures in a host of human diseases, including diabetes, cancer, cardiovascular disease, atherosclerosis, pulmonary fibrosis, and a variety of degenerative muscular dystrophies. In this review, we provide an in depth summary regarding the mechanisms by which caveolae and caveolins participate in human disease processes.

Chronic obstructive pulmonary disease in women: exploring gender differences

PURPOSE OF REVIEW

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality throughout the world. This major public health threat is ranked twelfth as a worldwide burden of disease and is projected to rank fifth by the year 2020 as a cause of lost quantity and quality of life. The impact of this disease in women is significantly understudied but the evidence that does exist reveals potentially substantial gender differences in the susceptibility to, severity of, and response to management of COPD.

RECENT FINDINGS

The best known risk factor for the development of COPD is tobacco smoking. While smoking rates in women have largely stabilized in developed countries, the rates are continuing to climb in developing countries. While it is not clear whether women are more susceptible to the toxic effects of cigarette smoke than men, it is known that the incidence and prevalence of COPD will continue to climb as more women smoke. Other known risk factors for the development of COPD include air pollution, infections, occupational exposures, and genetic factors. Air pollution, particularly fine particulate indoor air pollution from biomass fuels disproportionately affects women. Infections such as human immunodeficiency virus (HIV) and tuberculosis (TB) disproportionately affect vulnerable populations such as poor women and occupational exposures to various dusts and toxins are often gender specific. Genetic factors are still being explored but there seems a preponderance of women who are affected by early-onset and non-smoking related COPD. Women with COPD also seem to be underdiagnosed by physicians and may have different responses to medical treatment, smoking cessation interventions, and pulmonary rehabilitation programs.

SUMMARY

Chronic obstructive pulmonary disease in women is an understudied subject but is gaining attention as a significant public health threat. In developed countries, efforts at preventing the initiation of tobacco smoking and targeting smoking cessation programs in women are needed. In developing countries, efforts to promote cleaner fuels, improved stoves, better home ventilation, reduce toxic dust and fume exposures, combat infectious diseases such as TB and HIV, and improve nutrition are all ways in which the lung health of women can be improved.

Women and occupational lung disease: sex differences and gender influences on research and disease outcomes

We have attempted to describe the current state of knowledge regarding occupational lung disease in women. A large section of this article was devoted to describing the methodologic challenges that face researchers when evaluating gender differences in occupational lung disease. The findings of the presented studies are likely limited by many of the methodologic problems that were identified earlier. To accurately identify the true risk of occupational lung disease in women workers, these findings must be replicated in future studies with special attention paid to the various aspects of occupational lung disease research that are susceptible to gender-related bias.