Narrator: This is Science Today. There are clear health effects associated with levels of what's called fine particle pollution in urban areas. Because of this, environmental health scientist, Thomas McKone of the University of California, Berkeley and the Lawrence Berkeley National Laboratory, is working to better understand this association.
McKone: We have a center here that supports the EPA's effort to better understand the relationship between sources being automobiles, power plants, people burning wood smoke, all these things come together to form this collection of fine particles in the atmosphere in the urban areas.
Narrator: The big issue is, who's going to cut back on this pollution?
McKone: It gets complicated because what we want to look at is not the level you measure in the air, but what's in the level where people actually breathe? And those are quite different. So, what we're trying to do is establish a relationship between what a person sees and the number of sources that could be accounting for the level of pollution - in this case, particulate matter.
Narrator: For Science Today, I'm Larissa Branin.