title: Lung toxicity of ambient particulate matter from southeastern U.S. sites with different contributing sources: relationships between composition and effects.
abstract: BACKGROUND
  Exposure to air pollution and, more specifically, particulate matter (PM) is associated with adverse health effects. However, the specific PM characteristics responsible for biological effects have not been defined.
  
  
  OBJECTIVE
  In this project we examined the composition, sources, and relative toxicity of samples of PM with aerodynamic diameter </= 2.5 microm (PM2.5) collected from sites within the Southeastern Aerosol Research and Characterization (SEARCH) air monitoring network during two seasons. These sites represent four areas with differing sources of PM2.5, including local urban versus regional sources, urban areas with different contributions of transportation and industrial sources, and a site influenced by Gulf of Mexico weather patterns.
  
  
  METHODS
  We collected samples from each site during the winter and summer of 2004 for toxicity testing and for chemical analysis and chemical mass balance-based source apportionment. We also collected PM2.5 downwind of a series of prescribed forest burns. We assessed the toxicity of the samples by instillation into rat lungs and assessed general toxicity, acute cytotoxicity, and inflammation. Statistical dose-response modeling techniques were used to rank the relative toxicity and compare the seasonal differences at each site. Projection-to-latent-surfaces (PLS) techniques examined the relationships among sources, chemical composition, and toxicologic end points.
  
  
  CONCLUSIONS
  Urban sites with high contributions from vehicles and industry were most toxic.
authors.affiliation: Lovelace Respiratory Research Institute, Albuquerque, New Mexico, USA. jseagrav@LRRI.org
authors.forename: JeanClare
authors.initials: J
authors.lastname: Seagrave
authors.forename: Jacob D
authors.initials: JD
authors.lastname: McDonald
authors.forename: Edward
authors.initials: E
authors.lastname: Bedrick
authors.forename: Eric S
authors.initials: ES
authors.lastname: Edgerton
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Gigliotti
authors.forename: John J
authors.initials: JJ
authors.lastname: Jansen
authors.forename: Lin
authors.initials: L
authors.lastname: Ke
authors.forename: Luke P
authors.initials: LP
authors.lastname: Naeher
authors.forename: Steven K
authors.initials: SK
authors.lastname: Seilkop
authors.forename: Mei
authors.initials: M
authors.lastname: Zheng
authors.forename: Joe L
authors.initials: JL
authors.lastname: Mauderly
mesh_terms: D000392:Air Movements; D000393:Air Pollutants / Q000032:analysis / Q000633:toxicity*; D002947:Cities; D004784:Environmental Monitoring; D006801:Humans; D008168:Lung / Q000187:drug effects* / Q000473:pathology; D009930:Organic Chemicals / Q000032:analysis / Q000633:toxicity*; D010316:Particle Size; D025341:Principal Component Analysis; D011634:Public Health; D012621:Seasons; D015144:Southeastern United States; D014835:Volatilization
chemical_list: D000393:Air Pollutants; D009930:Organic Chemicals