Panel Toughens Standard on Smog Alerts

On a day when Southern California was reeling from its worst smog of the season, the state Air Resources Board in Sacramento lowered the threshold at which smog alerts are called.

The board’s decision Thursday is expected to dramatically increase the number of smog alerts and is aimed at providing earlier warnings of climbing air pollution levels to sensitive individuals, including young children and adults who exercise heavily.

“The increased number of health warnings does not mean smog is getting worse, but that it causes health problems for some people at levels lower than we previously believed,” ARB Chairwoman Jananne Sharpless said. “Those people will benefit from an earlier warning.”

The board’s action coincides with the worst smog siege of the season in the South Coast Air Basin. A yellow-brown pall hung over large portions of the four-county basin Thursday, obscuring the San Gabriel Mountains and office towers in downtown Los Angeles.

A sergeant at the Los Angeles Police Academy, located in Elysian Park overlooking downtown, said he was unable to spot buildings only a few miles away.

“It’s pretty damn bad, and smells bad,” Sgt. Sam Barber said.

Had the new threshold been in effect Thursday, first-stage alerts--called when the air is considered “very unhealthful”--would have been triggered throughout Los Angeles, Orange, Riverside and San Bernardino counties.

As it was, the alerts were limited to two areas in portions of the Riverside-San Bernardino area.

Had the lower threshold been in effect during the last three years, the ARB estimates, an average of 127 health warnings a year would have been called in Los Angeles County instead of 67, 29 instead of 7 in Orange County, 83 instead of 20 in Riverside, 119 instead of 51 in San Bernardino and 19 instead of 1 in San Diego. For the first time, alerts also would have been called in Ventura County and southern Santa Barbara County.

Smog alerts are issued when pollution levels exceed federal health standards. A first-stage alert, while serious, is the least severe of three health advisories on smog and is the only one affected by the ARB revision. According to the new standards, a first-stage smog alert will be called when ozone concentrations hit 0.15 parts per million parts of air over a one-hour period. Currently, a first-stage alert is called when concentrations reach 0.20 p.p.m.

Regional air pollution districts throughout the state have until next summer to implement the new guidelines.

Meanwhile, despite the recent onslaught of heavy smog, officials of the South Coast Air Quality Management District were unrepentant about their prediction last month that the 1990 smog season would be among the mildest on record.

“It’s probably among the worst days of the year, but this has been such a good year that Thursday’s pollution is like a little peak in the valley,” AQMD spokesman Tom Eichhorn said.

AQMD officials took pains to point out that the cloud of pollutants so visible this week was not ozone, which is invisible and considered the most threatening to human health, but microscopic particles.

While these particles also are a health concern, they are primarily bothersome because of their ability to absorb light and obscure visibility.