Polypropylene flock exposure and respiratory outcomes among manufacturing workers

Occupational exposure to polypropylene flock may increase the risk of respiratory symptoms and disease. A cross-sectional study evaluated respiratory effects of polypropylene flock among workers at a large manufacturing facility. Participants completed a questionnaire and spirometry testing; those with abnormal findings received a physical examination. Exposure was based on work history in polypropylene production rooms. Fifty-five workers (39 exposed; 16 unexposed) participated. Exposed workers (59%) more frequently reported phlegm in the past 12 mo compared with unexposed workers (25%) (P = 0.04); other respiratory symptoms did not differ significantly. There were no differences in FEV1% predicted, FVC% predicted, and FEV1/FVC% results between the groups. Nasal cavity erythema (7 exposed; 0 unexposed) was the most prevalent finding on examination. Overall, results showed limited evidence of upper airway irritation from polypropylene flock exposure and no evidence of lower airway disease, including interstitial lung disease. Due to the small sample and the potential for healthy-worker effect bias, results should be interpreted with caution. A longitudinal medical surveillance program to monitor workers with polypropylene fiber exposure above the working occupational exposure limit was recommended.