Lung toxicity of ambient particulate matter from southeastern U.S. sites with different contributing sources: relationships between composition and effects.
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.
Seagrave
JeanClare
J
Lovelace Respiratory Research Institute, Albuquerque, New Mexico, USA. jseagrav@LRRI.org
McDonald
Jacob D
JD
Bedrick
Edward
E
Edgerton
Eric S
ES
Gigliotti
Andrew P
AP
Jansen
John J
JJ
Ke
Lin
L
Naeher
Luke P
LP
Seilkop
Steven K
SK
Zheng
Mei
M
Mauderly
Joe L
JL
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
D000393:Air Pollutants; D009930:Organic Chemicals