The cotton textile manufacturing sector is a large industry with millions of workers worldwide. Prolonged exposure to cotton dust in such environments is associated with respiratory ailments, including byssinosis, chronic bronchitis and obstructive pulmonary disease.¹ Cotton dust consists of endotoxins, fungi, and bacterial impurities that cause an inflammatory response in the airways.² Occupational exposure can cause restrictive as well as obstructive patterns of impairment of lung function.³ Spirometry is a widely used method for evaluation of pulmonary function by measuring the lung volumes and airflow rates.⁴ Spirometry has been found to identify early pulmonary impairment in individuals at high risk such as workers in textile industry.⁵ Several studies have reported decreased values of pulmonary function parameters like Forced Vital Capacity (FVC), Forced Expiratory Volume in one second (FEV₁), and Peak Expiratory Flow Rate (PEFR) in workers exposed to cotton dust.⁶ The severity of impairment has also been found to correlate with exposure duration and lack of protective gear.⁷ The objective of the present study was to identify the pulmonary capacity among cotton industry workers through spirometry and compare it with a control panel of non-exposed individuals. The outcome would give an idea regarding occupational exposures and support preventive actions in protecting workers from respiratory ailments.⁸

Permission for the present study was obtained from the institutional ethics committee. The current cross-sectional study was conducted among 250 workers in spinning and weaving mills who were employed in cotton mills. The study comprised of an age and sex-matched control group of 100 office workers with no exposure to cotton dust at their work environment.⁹ Both male and female workers aged between 20 to 60 years; who were employed in the cotton mills for a duration of one year and above and willing to participate in the study were enrolled in the present study. Workers with underlying chronic pulmonary diseases such as asthma or tuberculosis, cigarette smokers and those with acute history of respiratory infections were excluded from the present study.

Spirometry Testing -

Pulmonary function was quantified using a computerized spirometer in accordance with American Thoracic Society (ATS) standards.¹⁰ The following results were obtained:

• Forced Vital Capacity (FVC) – volume of air expelled forcefullyf ollowing maximum Inspiration.
• Forced Expiratory Volume in One Second (FEV₁) – volume expired during the first second of forceful exhalation.
• FEV₁/FVC Ratio – obstructive lung disease indicator
• Peak Expiratory Flow Rate (PEFR) – maximum rate of exhalation

Table 1: Categorization of workers in groups based on exposure duration

Statistical Analysis:

Data were analyzed using SPSS software. ANOVA was used to compare spirometry parameters between groups, and a p-value of <0.05 was considered statistically significant.¹¹

Table 2: Pulmonary Function Parameters in Cotton Industry Workers

 Table 3: Distribution of Pulmonary Function Impairment Among Workers

 Table 4: Correlation of Cotton Dust Exposure Duration with FEV₁ Decline

Graph 1: The declining trend in FEV₁ and PEFR with increased duration of exposure to cotton dust

Table 5: Comparison of Respiratory Symptoms Among Workers

In the present study, a significant decline in pulmonary function was observed among workers with increasing exposure duration. The most affected parameters were FEV₁ and PEFR. Workers in Group C exhibited the highest decline in pulmonary function, indicating a dose-dependent relationship between cotton dust exposure and lung impairment (Table 2). Obstructive lung disease was observed in 53% workers where as restrictive lung disease was seen in 33% workers (Table 3). Mean FEV₁ and  PEFR declined with increased duration of exposure (Table 4) (Graph 1). Symptoms like chronic cough, breathlessness and wheezing increased proportionately with increased duration of exposure to cotton dust (Table 5).

The findings of this study confirm that long-term exposure to cotton dust results in mainly obstructive lung disease with some of the workers developing restrictive patterns. Obstructive pattern is characterized by a significant decline in FEV₁ and FEV₁/FVC ratio, which agrees with previous studies on byssinosis and chronic bronchitis.¹² Obstructive lung disease in cotton mill workers is primarily due to long-standing inflammation of the airway following the inhalation of endotoxined cotton dust along with fungi and other particles. Progressive narrowing of the airways, such as chronic obstructive pulmonary disease (COPD), was detected in workers from the textile industry, causing related respiratory signs and symptoms like persistent coughing, wheezing, and shortness of breath.¹³ A restrictive lung impairment pattern also occurred in certain studies, but particularly in the subjects exposed for a longer time to high levels of cotton dust. It is due to fibrotic lung tissue alterations that reduce FVC but maintain or even increase FEV₁/FVC ratios.¹⁴ Obstructive and restrictive mixed lung disease was noted for exposures longer than 10 years.¹⁵

The prevalence of obstructive impairment (53%) in the current study concurs with previous studies that the majority of cotton workers develop obstructive lung patterns, while restrictive impairments are noted in fewer workers.¹⁶ This highlights the importance of early intervention, regular pulmonary function testing and improved workplace protective habits to decrease respiratory impairment.¹⁷ Preventative measures such as personal protective gear (PPE), improved ventilation and frequent health monitoring are vital in arresting lung function loss.¹⁸ Spirometry screening routinely performed can prevent early detection and intervention.¹⁹

This research highlights the destructive impact of inhaling cotton dust on lung function. An evident drop in spirometry values was observed, particularly in workers with longer exposure. Workplace adjustment and frequent health checks are needed as preventive measures to safeguard worker’s lung functions. Long-term intervention and policy changes need to be explored in future research in order to reinforce occupational health standards

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