Google Street View cars have driven 100,000 miles in 4,000 hours to collect data on how levels of pollution differ from street to street in parts of California.

Now the company is releasing that data in hopes that scientists and others can use it to better understand and combat the causes of poor air quality.

The cars, equipped with air quality sensors developed by Aclima, generated data to build street-level maps of pollution in Los Angeles, San Francisco, and Central Valley.

"The measurements indicate that traffic-choked freeways, traffic on local streets, and weather patterns that blow pollution inland all influence the patterns of air pollution," Karin Tuxen-Bettman, a program manager at Google Earth Outreach, wrote in a blog post announcing the data release.

Google has set up a separate page where scientists and academics can request access to its air quality data.

"At this early stage of our experimental project, our goal is to make this data as accessible as possible to help the scientific and academic communities," the page states. "However, we may use some discretion as to its wide distribution in order to safeguard against misinterpretation of data analysis and interpretation."

Google asks anyone who fills out a request for the data to give their name and organization, and describe what they'll do with the data.