Our local air board should be very concerned about recent San Joaquin Valley trends in ozone levels.
Without question there has been improvement in valley air quality over the past twenty years. Our air is 20-25% cleaner than before the days of smog controls on cars. No doubt similar state rules currently being implemented for diesel powered vehicles will bring us similar gains.
But, as this chart clearly shows, why has the improvement stopped over the last several years? August and September always have the highest health damaging ozone levels. Comparing the average 8-hour daily readings for those months over the past 6 years is disturbing, to say the least.Since the state seems to be doing its part in regulating mobile sources of pollution our air board needs to decide if it is really doing what is necessary to improve public health. They certainly need to take a hard look at our large stationary sources in agriculture and the oil industry plus all the indirect damage coming from local facilities which require massive amounts of goods movement.
Improvement in the health of valley residents will definitely require some costs to those who are polluting the air. But, it is hard to argue that a healthy population is less important than large profits for a relatively few businesses.