ASSESSMENT OF PULMONARY FUNCTION PARAMETERS IN LONG-TERM SMOKERS VERSUS PASSIVE SMOKERS. A COMPARATIVE STUDY
DOI:
https://doi.org/10.53350/Annalspakmed.1.8.12Keywords:
pulmonary function, long-term smokers, passive smokers, spirometry, secondhand smoke, FEV1, FEV1/FVC ratio, airway obstruction.Abstract
Background: Tobacco smoke exposure, whether through active smoking or passive inhalation, remains a major contributor to respiratory morbidity. Long-term smokers experience direct toxic insult to the airways, while passive smokers are involuntarily exposed to similar harmful constituents, often resulting in subclinical pulmonary dysfunction. Understanding the comparative impact of these exposures is essential for guiding public health interventions.
Objective: To compare pulmonary function parameters between long-term smokers and passive smokers using standardized spirometry.
Methods: A comparative cross-sectional study was conducted from January 2024 to May 2025 at tertiary care hospitals in Punjab, Pakistan. A total of 100 participants were included, consisting of 50 long-term smokers and 50 passive smokers. Demographic information and exposure history were documented, and pulmonary function testing was performed according to ATS/ERS guidelines. Spirometric parameters including FEV1, FVC, FEV1/FVC ratio, PEFR, and FEF25–75% were analyzed using independent sample t-tests.
Results: Long-term smokers exhibited significantly impaired pulmonary function compared with passive smokers. Mean FEV1 and FVC were markedly reduced in long-term smokers, along with a substantially lower FEV1/FVC ratio indicative of obstructive airway changes. PEFR and FEF25–75% were also considerably decreased, demonstrating both large and small airway compromise. Passive smokers, while demonstrating comparatively better lung function, also showed reduced mid-expiratory flow values, suggesting early small-airway involvement related to chronic secondhand smoke exposure.
Conclusion: Long-term smoking causes pronounced deterioration across all major pulmonary function parameters. Passive smokers also demonstrate measurable impairment, highlighting that involuntary exposure to tobacco smoke is not harmless. Strengthening smoke-free policies and implementing targeted awareness programs are essential to reducing smoke-related respiratory burden.
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