title: Assessment of Occupational Exposure to Dust and Crystalline Silica in Foundries.
abstract: BACKGROUND
  The term "crystalline silica" refers to crystallized form of SiO2 and quartz, as the most abundant compound on the earth's crust; it is capable of causing silicosis and lung cancer upon inhaling large doses in the course of occupational exposure. The aim of this study was to assess occupational exposure to dust and crystalline silica in foundries in Pakdasht, Iran.
  
  
  METHODS
  In this study, airborne dust samples were collected on PVC filters (37 mm diameter, 0.8 mm pore size), by using a sampling pump and open face cyclone at a flow rate of 2.2 l/min for a maximum volume of 800 liters. For determining crystalline silica spectrometry was used according to the National Institute of Occupational Safety and Health (NIOSH) method No. 7601 for analysis of samples.
  
  
  RESULTS
  Results showed that crystalline silica concentration was higher than NIOSH and the American Conference of Government Industrial Hygienist (ACGIH) allowed extent (0.025 mg/m(3)). Concentration of crystalline silica was 0.02-0.1 mg/m(3). Total dust concentration average was higher than the allowed extent by Permissible Exposure Limit (PEL) of the Occupational Safety and Health Administration (OSHA).
  
  
  CONCLUSIONS
  It is essential to take necessary measures to control crystalline silica dust regarding the fact that 50% of workers are exposed to higher than the allowed extent.
authors: Department of Occupational Health, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors: Ali
authors: A
authors: Omidianidost
authors: Department of Occupational Health, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors: Mehdi
authors: M
authors: Ghasemkhani
authors: Department of Occupational Health, School of Public Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors: Mansour R
authors: MR
authors: Azari
authors: Department of Occupational Health, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors: Farideh
authors: F
authors: Golbabaei
keywords: Crystalline silica, Dust; Exposure; Occupational