Evaluation of Pulmonary Function Among a Pharmaceutical Occupational Cohort in Islamabad, Pakistan

Abstract

Occupational exposure to active pharmaceutical ingredient (API) dust, excipient powders, solvent vapors and antibiotic aerosols is a chronic exposure in the pharmaceutical manufacturing industry, which has not been extensively studied for its occupational respiratory health effects in Pakistan. The present study is a cross-sectional study aimed to assess pulmonary function and health related quality of life (HRQoL) among a pharmaceutical occupational cohort in Islamabad. A total of 78 workers from a pharmaceutical manufacturing plant in Humak Industrial Sector, Islamabad were recruited. Standardized measurements of pre- and postbronchodilator spirometry were made according to ATS/ERS 2019 guidelines: Forced Vital Capacity (FVC), Forced Expiratory Volume in 1 second (FEV₁), FEV₁/FVC ratio and Peak Expiratory Flow (PEF). The ventilatory patterns were determined according to the accepted diagnostic criteria, and the obstructive cases were further divided by GOLD criteria and bronchodilator reversibility. The validated St. George's Respiratory Questionnaire (SGRQ) was used to measure HRQoL. Pearson correlation (α = 0.05) was used to explore associations between work duration, smoking status, BMI and spirometric outcomes. The cohort had a mean age of 31.6 ± 11.2 years (56.4% female), mean BMI of 21.7 ± 4.2 kg/m², and mean occupational tenure of 5.1 ± 4.1 years. In total, 62.8% showed ventilatory impairment: obstructive (33.3 %), restrictive (23.1 %) and mixed (6.4 %). Of those who were obstructive, 65.4% fulfilled GOLD criteria for COPD and 34.6% had reversible asthma-like obstruction. Mean SGRQ Activity domain score (28.6 ± 14.0) exceeded Symptoms (22.5 ± 14.2) and Impacts (14.5 ± 14.2) scores. Spirometric parameters were positively correlated with smoking (confounded by sex). Within the relatively short tenure studied no significant correlation was found between occupational duration and lung function. There is a significant level of ventilatory impairment among this pharmaceutical manufacturing workforce that is much higher than that reported among other comparable occupational groups in Pakistan. This indicates that there are multiple pathophysiological mechanisms at play, as there is a higher proportion of obstructive rather than restrictive4 patterns and both fixed COPD-pattern and reversible asthma-type obstruction were identified. The present results support the notion of the implementation of compulsory, periodic spirometric surveillance in pharmaceutical manufacturing industry and highlight the importance of further occupational respiratory health studies in this industry in Pakistan.