I realize I'm treading on hallowed ground in the following suggestions, but I don't feel I'm out of line.
Eliminate or significantly reduce ag-burning days to once or twice a year. I know ag is big business and a powerful lobby in our Valley, but it should be held to task also. There are chippers and shredders that can handle logs up to diameters of 6 inches to 8 inches. Shredding the brush to mulch and spreading it over the fields seems to be an excellent recycling method that would be much favored over burning.
Speaking of big business; the trucking and busing industries need significant regulation of the fume-spewing diesels that operate in our Valley, everything from those large tractor-trailer rigs that deliver goods to our stores and distribution centers to the commercial and city buses that operate one-third-full most of the time.
Eliminating or greatly reducing those significant amounts of pollutants they produce as well as that horrendous ag burning could go a long way to significantly clear our air. Going after the fireplace burners who are simply trying to save some money on those inflated Pacific Gas and Electric bills smacks of a government replete with big business influence.