Other
Clean Air Revival: Burning Issues: Constituents of Wood Smoke
Site has several articles on particles from wood smoke and its health effects.
NASA
Nasa Earth Observatory: What Are Aerosols? Fact Sheet
This article discusses tiny particles in the air called aerosols. There are naturally occurring aerosols from volcanic ash, sea spray, grassland fires, and other sources. Learn how scientists believe that aerosols have effects on the...