title: The effect of sand storms on acute asthma in Riyadh, Saudi Arabia.
abstract: OBJECTIVE
  Major sand storms are frequent in the Middle East. This study aims to investigate the role of air particulate matter (PM) level in acute asthma in children in Riyadh, Saudi Arabia.
  
  
  METHODS
  An aerosol spectrometer was used to evaluate PM < 10μm in diameter (PM10) and PM < 2.5 μm in diameter (PM2.5) concentrations in the air every 30 minutes throughout February and March 2012 in Riyadh. Data on children 2-12 years of age presenting to the emergency department of a major children's hospital with acute asthma during the same period were collected including their acute asthma severity score.
  
  
  RESULTS
  The median with interquartile range (IQR) levels of PM10 and PM2.5 were 454 μg/m(3) (309,864) and 108 μg/m(3) (72,192) respectively. There was no correlation between the average daily PM10 levels and the average number of children presenting with acute asthma per day (r = -0.14, P = 0.45), their daily asthma score (r = 0.014, P = 0.94), or admission rate ( r= -0.08, P = 0.65). This was also true for average daily PM2.5 levels. In addition, there was no difference in these variables between days with PM10 >1000 μg/m(3), representing major sand storms, plus the following 5 days and other days with PM10< 1000 μg/m(3).
  
  
  CONCLUSIONS
  Sand storms, even major ones, had no significant impact on acute asthma exacerbations in children in Riyadh, Saudi Arabia. The very high levels of PM, however, deserve further studying especially of their long-term effects.
authors.affiliation: Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Abdullah A
authors.initials: AA
authors.lastname: Alangari
authors.affiliation: Division of Population Health Sciences and Education, St. George's University of London, London, UK.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Riaz
authors.affiliation: Department of Soil Science, College of Food Science and Agriculture, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Mohamed Osman
authors.initials: MO
authors.lastname: Mahjoub
authors.affiliation: Department of Emergency Medicine, King Saud Medical City, Riyadh, Saudi Arabia.
authors.forename: Nidal
authors.initials: N
authors.lastname: Malhis
authors.affiliation: Department of Emergency Medicine, King Saud Medical City, Riyadh, Saudi Arabia.
authors.forename: Saleh
authors.initials: S
authors.lastname: Al-Tamimi
authors.affiliation: Department of Soil Science, College of Food Science and Agriculture, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Abdullah
authors.initials: A
authors.lastname: Al-Modaihsh
keywords: Saudi Arabia; Status asthmaticus; air particulate matter; environmental health; sand storms