Above Clean-Air Level : Hold Your Breath! Smog Fouls Air This Weekend

The smog level in San Diego County exceeded the clean-air standard Friday, and officials say the cloud of polluted air will remain through next week, making breathing difficult for thousands of San Diegans--including those planning to run in the eighth annual America’s Finest City Half-Marathon on Sunday.

The ozone layer blanketing the area can irritate even the healthiest person’s throat and lungs when the smog level exceeds the clean-air standard, pollution control officials said.

For this reason, officials advise people with heart or respiratory problems to avoid strenuous activity and stay indoors during the late afternoon’s peak smog periods this weekend.

Sunday’s half-marathon is scheduled for 7 a.m., when the smog is at its lowest level. Nonetheless, marathon directors expect this year’s running times to be slower than in previous years because of the smog and muggy weather.

“An athlete’s ability is significantly reduced during heavy smog days, especially if that runner suffers from any respiratory problems,” said Dr. Tom Mosher, medical director for the half-marathon.

“I suspect that some runners may voluntarily drop out of the race all together,” Mosher said.

Pollution control officials blame a high-pressure front for the county’s smog. The front pushed a massive cloud of automotive exhaust down from Los Angeles and Orange counties Thursday night.

The bad air settled over the San Diego Bay until Friday afternoon’s coastal breezes blew the smog inland. There, the mixture of coastal and desert air caused an effect similar to lowering a ceiling, trapping high concentrations of the polluted air over the county, said Hal Brown, a meteorologist with the Air Pollution Control District.

Friday was the first time in more than a month that San Diego’s smog level exceeded the clean air standard, Brown said. “We’ve had a month of clean air, which is pretty remarkable for a summer in Southern California,” he said.

“Normally, we are over the standard 10 days or so each month,” he added.

Officials detected the highest pollution levels at Oceanside and Del Mar Friday afternoon.

Pollution control officials expect today’s levels to peak in Alpine at almost 38 points above the clean-air standard of 100.

“The weekend peak should not exceed 50 points above the standard,” Brown said.

If smog reaches the 200 mark, the APCD issues a smog alert advising everyone, healthy or otherwise, to stay indoors.

San Diego pollution control officials have issued two smog alerts so far this year.