A view of the Valley from Mulholland Drive | Photo by Ilpo's Sojourn via Flickr

A report about San Fernando Valley air quality released yesterday states that overall air quality has improved but the West Valley's ozone levels have risen while some East Valley neighborhoods have seen an increase in particulate matter, according to the Daily News.

"The San Fernando Valley Economic Research Center, at California State University, Northridge, reported overall decreases in carbon monoxide, nitrogen dioxide, sulfur dioxide, sulfate and lead, according to the report," the paper said.

In the West Valley where ozone levels have increased is mass spread out suburbia and little public transit compared to other parts of the city. The Orange Line ends at the Warner Center and a northern extension is being built, but the area is generally car country. By comparison, the East Valley has some more density and transit options, especially in the Southeast part in NoHo Arts District Studio City, Sherman Oaks, etc. The Northeast Valley, where particulate matter levels rose, is home to many auto shops and other heavier industrial businesses.