title: California wildfires of 2008: coarse and fine particulate matter toxicity.
abstract: BACKGROUND
  During the last week of June 2008, central and northern California experienced thousands of forest and brush fires, giving rise to a week of severe fire-related particulate air pollution throughout the region. California experienced PM(10-2.5) (particulate matter with mass median aerodynamic diameter > 2.5 mum to < 10 mum; coarse ) and PM(2.5) (particulate matter with mass median aerodynamic diameter < 2.5 mum; fine) concentrations greatly in excess of the air quality standards and among the highest values reported at these stations since data have been collected.
  
  
  OBJECTIVE
  These observations prompt a number of questions about the health impact of exposure to elevated levels of PM(10-2.5) and PM(2.5) and about the specific toxicity of PM arising from wildfires in this region.
  
  
  METHODS
  Toxicity of PM(10-2.5) and PM(2.5) obtained during the time of peak concentrations of smoke in the air was determined with a mouse bioassay and compared with PM samples collected under normal conditions from the region during the month of June 2007.
  
  
  RESULTS
  Concentrations of PM were not only higher during the wildfire episodes, but the PM was much more toxic to the lung on an equal weight basis than was PM collected from normal ambient air in the region. Toxicity was manifested as increased neutrophils and protein in lung lavage and by histologic indicators of increased cell influx and edema in the lung.
  
  
  CONCLUSIONS
  We conclude that the wildfire PM contains chemical components toxic to the lung, especially to alveolar macrophages, and they are more toxic to the lung than equal doses of PM collected from ambient air from the same region during a comparable season.
authors: Department of Pulmonary and Critical Care Medicine, University of California, Davis, California, USA.
authors: Teresa C
authors: TC
authors: Wegesser
authors: Kent E
authors: KE
authors: Pinkerton
authors: Jerold A
authors: JA
authors: Last
mesh_terms: D000393:Air Pollutants / Q000633:toxicity*; D000818:Animals; D002140:California; D005390:Fires; D019570:Inhalation Exposure / Q000009:adverse effects; D008168:Lung / Q000187:drug effects*; D016676:Macrophages, Alveolar / Q000187:drug effects; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D052638:Particulate Matter / Q000633:toxicity*; D015208:Smoke Inhalation Injury / Q000139:chemically induced; D014481:United States
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter