Airway responses to the inhalation of cotton dust and cotton bract extracts

Respiratory Symptoms and Lung Function among Greek Cotton Industry Workers: A Cross-Sectional Study

Background:

Workers in cotton industry are occupationally exposed to various dust-related hazards. The nature of these agents and the respective exposure levels depend on the cotton industry specific sector. These exposures could be associated with respiratory symptoms and changes in lung function parameters.

Objective:

To evaluate associations between occupational exposure and respiratory function as well as reported symptoms in several groups of workers at different stages of the cotton industry in a vertical approach that covers all the major sectors—from cotton ginning to weaving and fabric production.

Methods:

A questionnaire on respiratory symptoms and individual as well as workplace characteristics was completed by 256 workers at the cotton industry and 148 office workers (control group). Both groups underwent spirometry.

Results:

Workers in cotton industry reported a higher prevalence of severe dyspnea (p=0.002) and wheezing (p=0.004) compared to the control group. Also they were found to have a lower predicted FEV1% (p<0.029) and lower FEV1/FVC (p<0.001) values. In addition, a higher prevalence of FEV1% <80% (p<0.001) and FEV1/FVC <70% (p=0.041) were found among textile workers. Similar results were found for non-smoker textile workers compared to non-smoker control group workers. Those working in cotton ginning mills recorded the highest decrease of spirometric values. Duration of employment in cotton industry and smoking use were found to be predictors of lung function decline for cotton industry workers.

Conclusion:

Occupational exposure to cotton dust was associated with increased prevalence of respiratory symptoms and obstructive pattern in pulmonary function test.

Pulmonary effects of intermittent, seasonal exposure to high concentrations of cotton dust

AIM: To quantify the exposure levels and to assess pulmonary reactions associated with exposure to cotton dust and its biological contaminants.

METHODS: All employees (51 male workers) of a ginning industry as well as 51 referent unexposed subjects from clerical staff of an educational center were investigated. Atmospheric concentrations of cotton dust and bioaerosols were measured. Furthermore, bacterial and fungal genera and species were identified by an expert microbiologist and an experienced mycologist. A standard respiratory symptom questionnaire was filled out for the subjects and they underwent multiple spirometry tests, at the beginning and at the end of work season as well as prior to (pre-exposure base line values) and at end of the first shift of workweek (post exposure).

RESULTS: Gram negative bacteria including Enterobacter agglomerans and Pseudomonas spp. were found to be the dominant bacterial species and genera, respectively. Similarly, dominant fungi were identified to be Mucor sp. Rhizopus sp. and Aspergillus niger. Mean atmospheric concentrations of cotton dust in ginning and outdoor areas were found to be 35.2 and 6.8 mg/m³, respectively. The prevalence rates of cough, phlegm, wheezing, dyspenea and grade 1/2 byssinosis among the exposed subjects were significantly higher than their corresponding values for the unexposed employees (P < 0.05). Additionally, significant differences were noted in the mean baseline value (preshift) of vital capacity, forced expiratory volume in the first second (FEV1) and FEV1/forced vital capacity ratio of the exposed subjects when compared with those of their referent counterparts. Similarly, significant cross shift decrements were noted in most parameters of pulmonary function of the exposed subjects.

CONCLUSION: Seasonal exposure to cotton dust induces both acute, partially reversible, and chronic irreversible decrements in the lungs’ functional capacities as well as increased prevalence of respiratory symptoms.

Ventilatory functions in cotton textile workers and the role of some inflammatory cytokines

Exposure to cotton dust in industrial environments causes inflammation in the airways of the exposed workers. This may manifest as respiratory complaints and changes in the respiratory functions after work shift and in the baseline of their ventilatory functions. The study aimed to investigate the effect of occupational exposure to cotton dust on respiratory symptoms, ventilatory functions and pro-inflammatory cytokine levels (tumor necrosis factor α, interleukin 6 and interleukin 1β). The study was conducted on 63 textile workers and 65 nonexposed subjects. Both groups were matched for age, socioeconomic status and smoking habit. The respirable dust measured in the workplace did not exceed the permissible values of the Egyptian law 1994. The bacterial counts detected were within the occupational exposure limits of the industrial settings. The results revealed that the percentage of respiratory symptoms was higher in textile workers. Respiratory complaints were chronic cough (33.2%), chronic bronchitis (39.7%) and dyspnea (23.8%) in textile workers compared to (6.2%, 6.2% and 1.5%), respectively, in controls. There was a marked reduction in the ventilatory functions (forced vital capacity and forced expiratory volume in 1 s) in the textile workers compared to the controls. The additive effect of smoking on the ventilatory functions was not apparent. The ventilatory functions of the workers were significantly positively correlated with the duration of exposure. The cytokines were insignificantly higher in the textile workers compared to their controls. The textile workers with respiratory complaints showed significant decline in ventilatory functions and elevation in the cytokine levels compared to the nonsymtomatizing workers with significant difference in interleukin 1β and interleukin 6. In conclusion, the results supported the fact that exposure to cotton dust deteriorates ventilatory functions and elevates proinflammatory cytokine levels. Analysis of the release of cytokines can be used to evaluate the immune responses to organic dust-induced airway inflammation.

Working conditions and exposure to dust and bioaerosols in sisal processing factories in Tanzania

Information was collected on working conditions and personal exposures to dust, bacteria, and fungi in sisal fiber processing factories in Tanzania to identify health hazards and possible needs for preventive measures. Walkthrough surveys were performed in the brushing and decorticating departments of six sisal factories. The number of departments showing adequate scores for ergonomics and work organization, physical working environment, and occupational health items were determined. Personal thoracic dust samples were collected during sisal processing and analyzed for concentration of dust (n = 24) and for fungi and bacteria (n = 32). In both departments, most items considered to be a prerequisite for a good working environment were either missing or inadequate. Ergonomic and physical hazards were observed. Repetitive strenuous tasks, awkward work postures, and high noise levels were found. Visible dust and inadequate ventilation were seen in the brushing departments, and wet floors were observed in the decortication departments. Personal protective equipment was hardly used. The arithmetic mean exposure of sisal processors was 1.2 mg thoracic dust/m(3), 43 x 10(6) bacteria/ m(3), and 2.35 x 10(6) fungal spores/m(3). The highest exposure levels were measured in the decortication departments when machines were cleaned of waste. Significant differences were found for mean thoracic dust exposure and bacteria counts between the brushing and decortication departments and the security guards. Within individual departments, there were no significant differences in exposures between the different work tasks. A linear mixed effect model of thoracic dust including department as fixed effect explained 65% of the between-worker variability for thoracic dust exposure. The study shows that workers in sisal processing in Tanzania are exposed to bioaerosols, and suitable control measures should be implemented. More exposure studies are needed in this type of industry.

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.