Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 50 2 2012 02 15 122 126 EN Hossein Kakooei Department of Occupational Health, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Abdollah Gholami Department of Occupational Health, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Mehdi Ghasemkhani Department of Occupational Health, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Mostapha Hosseini Department of Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Davoud Panahi Department of Occupational Health, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Golamreza Pouryaghoub Center for Research on Occupational Diseases, Tehran University of Medical Sciences, Tehran, Iran. 2015 09 28 Dust can be produced by almost all production processes in Portland cement factory. Dust exposure potentially can affect respiratory function. But evidence for respiratory effect of cement dust exposure has not been conclusive. In this study we assessed effect of cement dust exposure on respiratory function in a cement production factory. A respiratory symptoms questionnaire was completed and pulmonary function tests were carried out on 94 exposed and 54 non exposed workers at a cement factory in the east of Iran. Additionally, respirable dust level was determined by the gravimetric method. X-ray fluorescence (XRF) technique was performed to determine the silica phases and the SiO2 contents of the bulk samples. The arithmetic means (AM) of personal respirable dust were 30.18 mg/m3 in the crushing, 27 mg/m3 in the packing, 5.4 mg/m3 in the cement mill, 5.9 mg/m3 in the kiln and 5.48 mg/m3 in the maintenance that were higher than threshold limit value (TLV) of the American Conference of Governmental Industrial Hygienists (ACGIH) which is 5 mg/m3 . This value in the unexposed group was 0.93 mg/m3 . In this study cough, sputum, wheezing and dyspnea were more prevalent among exposed subjects. Exposed workers compared to the unexposed group showed significant reduction in Forced Expiratory Volume in one second (FEV1), Forced Vital Capacity (FVC), and Forced Expiratory Flow between 25% and 75% of the FVC (FEF25-75%) (P<0.05). It can be concluded that in our study there was close and direct association between cement dust exposure and functional impairment among the cement factory workers. https://acta.tums.ac.ir/index.php/acta/article/view/3870 https://acta.tums.ac.ir/index.php/acta/article/download/3870/3845