Rev Environ Health 2017; 32(4): 333–341 Review Somayeh Rahimi Moghadam, Siavosh Abedi, Mahdi Afshari, Ehsan Abedini and Mahmood Moosazadeh* Decline in lung function among cement production workers: a meta-analysis https://doi.org/10.1515/reveh-2017-0017 Received May 26, 2017; accepted August 16, 2017; previously published online October 10, 2017 Abstract Background: Several studies with different results have been performed regarding cement dust exposure and its pathogenic outcomes during the previous years. This study aims to combine these results to obtain a reliable estimate of the effect of exposure to cement dust. Methods: PubMed and other data banks were searched to identify required electronic articles. The search was extended interviewing with relevant experts and research centers. Point and pooled estimates of outcome with 95% confidence intervals were estimated. Results: Participants were 5371 exposed and 2650 unex- posed persons. Total mean differences (95% confidence intervals) were estimated as of −0.48 (−0.71 to −0.25) L for forced vital capacity (FVC), −0.7 (−0.92 to −0.47) L for forced expiratory volume in the first second (FEV1), −0.43 (−0.68 to −0.19) L for FEV1/FVC%, −0.73 (−1.15 to −0.30) L/ min for PEFR and −0.36 (−0.51 to −0.21) L/s for FEF25-75. Conclusion: Our meta-analysis showed that cement dust has significant impact on lung function and reduces the indicators of FVC, FEV1, FEV1/FVC, PEFR and FEF25-75. Keywords: cement dust; pulmonary function; spirometry. Introduction Cement is one of the most important materials for devel- oping infrastructures and a key factor for economic growth. The demand for cement is directly associated with growth and development of building activities in the world. Cement industry has a main role in improving life standards through direct job creation and other economic benefits. Despite these benefits and popularities, there are many challenges against cement industry due to environ- mental concerns such as stability and compatibility (1). Cement is a fine grey powder sized between 0.05 and 5 μm (2). Cement is derived from hydrated calcium silicate, iron, magnesium and aluminum oxides, calcium sulfate and clay. This mixture then is being grounded and combined with gypsum and purred in high-temperature ovens (3). Cement is not only a pollutant in the industries but also an environmental contaminant especially near the cement manufactures due to inappropriate technology (ineffective air purification and dust collecting systems, low knowledge of the environmental health issues and inadequate legal requirements). Results of a study showed that pregnant women living close to the cement manufac- tures (less than 2 km) had higher risk of preterm delivery compared with those living within 2–4 km of these manu- factures (4). Various complications have been reported follow- ing cement exposure such as allergic dermatitis, rhinitis, pharyngitis, respiratory problems and abnormal pulmo- nary function tests (PFT). Based on the international work institute reports, silicosis and pneumoconiosis following exposure with silica and other components of the cement dust are the most important occupational hazards for cement industry workers (5). However, there are disagree- ments among scientists regarding the definite association between cement dust exposure and respiratory disorders (6–8). Several studies indicated that the incidence of res- piratory symptoms and complications of obstructive pul- monary disorders are higher among workers with cement exposure as compared with those without (2, 3, 9, 10). *Corresponding author: Mahmood Moosazadeh, Health Science Research Center, Addiction Institute, Mazandaran University of Medical Sciences, Sari, Iran. Tel.: +98-911-3555367, E-mail: mmoosazadeh1351@gmail.com Somayeh Rahimi Moghadam and Ehsan Abedini: Student Research Committee, Health Sciences Research Centre, Mazandaran University of Medical Sciences, Sari, Iran Siavosh Abedi: Department of Internal Medicine, Mazandaran University of Medical Sciences, Sari, Iran Mahdi Afshari: Department of Community Medicine, Zabol University of Medical Sciences, Zabol, Iran