More than half the Central Valley residents polled in an ongoing survey say air pollution is a big problem. Last year, the study showed 42% residents saw it as a big problem.

The poll from the Public Policy Institute of California is being released today. The nonprofit institute, based in San Francisco, has done several similar polls, dating back to 2000.

The poll looks at public opinion on a lot of other air quality and environmental issues.
It shows people in the combined San Joaquin and Sacramento valleys are still tuned into air quality.

One other interesting issue in the poll was air regulation. Almost 80% of Californians favor stricter restrictions on commercial and industrial activities or diesel-fueled vehicles, such as trucks or buses.