respiratory system is the most vulnerable system in the cement industry. is study was conducted to determine the e ects of occupational exposure to cement dust on the respiratory system more thoroughly. Material and Methods: In this cross sectional study an interviewer-administered questionnaire on socio-demographic characteristics and respiratory symptoms was com- pleted and pulmonary function tests were carried out on 100 exposed and 120 non-exposed workers at the cement factory in Mashhad, Iran. e data was statistically analyzed by SPSS 16. Results: e mean of age and work duration in the exposed group was 37.5±6.3 and 10.7±5.4 years compared with the non-exposed group that was 36.1±7.1 and 10.1±5.7 years, respectively. Levels of exposure to inhalable cement dust in the exposed group were 23.13 mg/m3 (higher than national occupational exposure limits for such particles). Among the exposed group, respiratory symptoms as cough (6% vs. 0.8% of the non-exposed) and sputum (7% vs. 0.8% of the non- exposed) were signi cantly more prevalent (p < 0.05). Forced expiratory ow 25–75% (FEF25–75%) was signi cantly lower in the ex- posed workers compared with non-exposed ones (p < 0.05). Also forced expiratory volume in 1 s / forced vital capacity (FEV1/FVC) and FEF25–75% had a reverse correlation with the length of employment (p = 0.000 and p = 0.003, respectively). Conclusions: e nd- ings of this study showed that occupational exposure to cement dust could be a signi cant factor of respiratory system dysfunction. Strict implementation of a respiratory protection program is recommended in cement industries. Med Pr 2015;66(4):471–477
Key words: occupational exposure, respiratory symptoms, pulmonary function test, Portland cement dust, Iran, occupational diseases