Tehran University of Medical Sciences Journal of Air Pollution and Health 2476-3071 5 2 2020 06 29 97 106 Majid Kermani Research Center of Environmental Health Technology, Iran University of Medical Sciences, Tehran, Iran AND Department of Environmental Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran Ahmad Jonidi Jafari Research Center of Environmental Health Technology, Iran University of Medical Sciences, Tehran, Iran AND Department of Environmental Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran Mitra Gholami Research Center of Environmental Health Technology, Iran University of Medical Sciences, Tehran, Iran AND Department of Environmental Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran Mahdi Farzadkia Research Center of Environmental Health Technology, Iran University of Medical Sciences, Tehran, Iran AND Department of Environmental Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran Hossein Arfaeinia Systems Environmental Health and Energy Research Center, The Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr, Iran AND Department of Environmental Health Engineering, Faculty of Health and Nutrition, Bushehr University of Medical Sciences, Bushehr, Iran Abbas Shahsavani Environmental and Occupational Hazards Control Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran AND Department of Environmental Health Engineering, School of Public Health and Safety, Shahid Beheshti University of Medical Sciences, Tehran, Iran Abbas Norouzian Department of Environmental Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran Mohsen Dowlati Department of Environmental Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran Farzad Fanaei Student Research Committee, school of public health, Iran university of Medical Sciences, Tehran, Iran 2020 06 04 2020 08 16 Introduction: Estimating air pollution levels in areas with no measurements is a major concern in health-related studies. Therefore, the aim of this study was to investigate the amount of exposure to particulate matter below 2.5 µ (PM2.5) in the metropolis of Tehran. Materials and methods: The hourly concentrations of PM2.5 during 2017- 2018 period were acquired from the Department of Environment (DOE) and Air Quality Control Company of Tehran (AQCC). The hourly concentrations were validated and 24-h concentrations were calculated. Inverse distance weighting (IDW), Universal Kriging, and Ordinary Kriging were used to spatially model the PM2.5 over Tehran metropolis area. Root Mean Square Error (RMSE) and Mean Error (ME) were used to measure and control for the accuracy of the methods. Results: The results of this study showed that RMSE and MENA values in Kriging method was less than the IDW, which indicates that the Kriging was the best method to estimate PM2.5 concentrations. According to the final map, the highest annual concentrations of PM2.5 were observed in the southern and southwestern areas of Tehran (districts 10, 15, 16, 17, and 18). The lowest exposure to PM2.5 was found to be in districts 1, 2, 3, 6, and 8. Conclusion: It can be concluded that Kriging method can predict spatial variations of PM2.5 more accurately than IDW method. https://japh.tums.ac.ir/index.php/japh/article/view/239 https://japh.tums.ac.ir/index.php/japh/article/download/239/243