title: Estimation of the residential radon levels and the annual effective dose in dwellings of Shiraz, Iran, in 2015.
abstract: BACKGROUND
  Radon is the second most important cause of lung cancer after smoking. Thus, the determination of indoor radon concentrations in dwellings and workplaces is an important public health concern. The purpose of this research was to measure the concentration of radon gas in residential homes and public places in the city of Shiraz and its relationship with the type and age of the buildings as well as the type of materials used to construct the building (brick, block). We also determined the radon dosages that occupants of the building would receive.
  
  
  METHODS
  The present study is a descriptive-analytical and cross-sectional research that was conducted on the building's indoor air in the city of Shiraz in 2015. Using geographic information system (GIS) software and a spatial sampling cell with an area of 25 square kilometers, 200 points were selected. In this study, we used passive diffusive samplers as Solid State Nuclear Track Detector (SSNTD) CR-39 polycarbonate films for three months in the winter. Sampling was conducted in accordance with the U.S. Environmental Protection Agency's protocol. We determined the concentrations of radon gas at the time of sampling, and calibration factors were determined. The data were analyzed by IBM-SPSS, version 20, descriptive statistics, Kruskal-Wallis, and Mann-Whitney tests.
  
  
  RESULTS
  This study showed that the average radon concentration was 57.6 ± 33.06 Bq/m(3) in residential dwellings. The average effective dose was 1.45 mSv/y. The concentration of radon in 5.4% of the houses was found to be greater than 100 Bq/m(3), which is above the level allowed by the World Health Organization (WHO).
  
  
  CONCLUSIONS
  Since radon is the second leading cause of lung cancer, it seems necessary to increase the public's awareness of this issue and to take action to reduce radon in homes when the concentrations are above the WHO's guideline.
authors: Environmental and Occupational Health Center, Ministry of Health and Medical Education, Tehran, Iran.
authors: Maryam
authors: M
authors: Yarahmadi
authors: Environmental and Occupational Hazards Control Research Center, Shahid Beheshti University of Medical Science, Tehran, Iran; Ph.D., Assistant Professor, Department of Environmental Health Engineering, School of Public Health, Shahid Beheshti University of Medical Science, Tehran, Iran.
authors: Abbas
authors: A
authors: Shahsavani
authors: Research Center for Environmental Pollutants, Qom University of Medical Sciences, Qom, Iran.
authors: Mohammad Hassan
authors: MH
authors: Mahmoudian
authors: Department of Environmental Health Engineering, School of Health, Student Research Committee, Shiraz University of Medical Sciences, Shiraz, Iran.
authors: Narges
authors: N
authors: Shamsedini
authors: Center for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran.
authors: Noushin
authors: N
authors: Rastkari
authors: Department of Environmental Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran.
authors: Majid
authors: M
authors: Kermani
keywords: CR-39; ICRP; Indoor radon; Lung cancer; Shiraz