SMOG WATCH : Breath Tests

Strictly speaking, the state decision to declare first stage smog alerts earlier than they now do is no more a policy change than setting an alarm clock for 6 o’clock instead of 7.

But it says a lot about what pollution science taught us and how policy-making has matured in the 30 or more years since smog first appeared on the horizon.

The South Coast Air Quality Management District will not have to change its 20-year plan for making Southern California’s air clean enough to breathe without worrying about keeling over. There’s virtually no cost involved.

What makes the action by the state Air Resources Board important is that years of experimenting have made it clear that it takes less smog to affect people who are physically least able to tolerate dirty air than science knew just a decade ago.

What else makes it important? Smog districts will give earlier warnings. Young children can be gathered into the house earlier; older people can postpone walks until the smog lifts.

The new rule will make everyone more aware of smog--as if in times like these we needed that. First alerts are called when ozone reaches 0.20 parts per million parts of air and stays that way for an hour. Starting next summer, the threshold will drop to 0.15 parts per million. That will mean twice as many alerts in Los Angeles and San Bernardino counties, about four times as many in Orange and Riverside counties and 19 times the number in San Diego. Heightened smog awareness might lend urgency to the need to clean up the air.