Stage 1 Smog Alert Declared in County

San Diego County air-quality officials issued the first Stage 1 smog alert of 1990 late Thursday, warning south county residents in particular to forgo after-work exercise and activity and take refuge indoors.

The alert, which indicates that ozone levels exceeded federal ozone standards for “very unhealthful air,” was called for just two hours--from 5 to 7 p.m. But officials said a stubborn inversion layer might continue to trap smog overhead today and possibly Saturday. They urged San Diegans to schedule any necessary strenuous activity in the cooler morning hours and said people with respiratory problems should remain indoors.

“This is the late part of the smog season, and we were kind of hoping we’d get through it (without a problem), but we didn’t,” said Bob Goggin, a spokesman for the San Diego County Air Pollution Control District. “Basically, the weather pattern is stagnant, so we could be in trouble Saturday as well. It depends on what the wind does.”

Wally Cegiel, a forecaster for the National Weather Service, agreed. Skies will remain mostly clear through the weekend, but fog and clouds will increase along the coast today and Saturday, he said. By Sunday, the clouds and fog may reach as far inland as La Mesa. But that won’t necessarily mean relief from the smog.

“We’re going to have an onshore flow carrying in air pollution” that has been gathering over the ocean, Cegiel said. “And we’ll continue to have an inversion all weekend, which will enhance the smog problem.”

Goggin laid the blame for San Diego’s poor air quality on its northern neighbor, explaining that recent Santa Ana conditions have pushed Los Angeles’ pollution out over the ocean and then sucked that “transport smog” south and inland. Particularly from May to October, he said, such traveling smog becomes trapped over San Diego County by a layer of warm desert air that prevents pollution from rising.

The current inversion layer is sitting very low, at about 1,000 feet, Goggin said, so San Diegans probably will suffer more than usual.

Each year in 1988 and 1989, San Diego air quality officials called two smog alerts when ozone concentrations reached 200 or above on the Pollutant Standard Index. Thursday’s alert was issued after monitors registered 200 in Kearny Mesa.

The smog alert was declared from the coast to 15 miles inland for the southern two-thirds of the county--from Del Mar south. It prohibited all open burning and requested that the public not drive or use gasoline-fueled appliances.

For information on health effects, call the Air Pollution Control District at 694-3332. For hourly air quality levels during a smog alert, call 565-6626.

Times staff writer Jeannette Avent contributed to this report.