title: Particle mapping in stables at an American Thoroughbred racetrack.
abstract: BACKGROUND
  Airway inflammation and mucus in the trachea are common in racehorses. Fine airborne particles can initiate and coarse particles can worsen airway inflammation in man and in animal models of airway disease. The regional and seasonal distribution of particles of different sizes has never been investigated in American racing stables.
  
  
  OBJECTIVE
  To determine the regional and seasonal concentration and number of airborne particles of different sizes in racing stables.
  
  
  METHODS
  Direct reading instruments were used to determine the mass concentration and numbers of particles 3 times daily (early morning, midday and late afternoon) in July, September and November, in 3 different racing stables.
  
  
  RESULTS
  Average particle concentrations were lowest in July and highest in September and November. Early morning concentrations were significantly higher than those measured throughout the rest of the day. The completely enclosed stable with little natural ventilation, had significantly higher particulate concentrations than the open-sided stable. With regard to numbers of particles, those 2-5 µm were greatest in July and least in November; those 0.5-1.0 µm were greatest in September and least in November. Location of stall within stable also affected concentrations and numbers.
  
  
  CONCLUSIONS
  The concentration and number of particles in sizes known to reach the lower airways varies with stable design/management, time of day, season of year and location of the stall within the stable.
  
  
  CONCLUSIONS
  Particle mapping is a useful tool in the identification of stables, season, and location of stalls within stables where horses may be at greater risk of exposure to offending particulates.
authors.affiliation: Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA. milleric@msu.edu
authors.forename: M L
authors.initials: ML
authors.lastname: Millerick-May
authors.forename: W
authors.initials: W
authors.lastname: Karmaus
authors.forename: F J
authors.initials: FJ
authors.lastname: Derksen
authors.forename: B
authors.initials: B
authors.lastname: Berthold
authors.forename: S J
authors.initials: SJ
authors.lastname: Holcombe
authors.forename: N E
authors.initials: NE
authors.lastname: Robinson
mesh_terms: D000392:Air Movements; D016902:Air Pollution, Indoor; D000818:Animals; D006736:Horses; D006799:Housing, Animal; D052638:Particulate Matter; D012621:Seasons; D013997:Time Factors; D014887:Weather
chemical_list: D052638:Particulate Matter