The Year’s Dirtiest Air : Despite Pollution Alerts This Week, Smog Season in the Southland Looks to Be Mildest in Decades

The foulest air of the year blanketed the Southland’s valleys Thursday and Friday, marring a mild smog season that still may shape up to be the best in decades.

Stagnant air flow, powerful sunshine and a persistent, strong inversion layer combined to shroud the region with the year’s worst concentrations of ozone--the potent, lung-scarring gas that makes Southern California’s air the unhealthiest in the nation.

First-stage smog alerts were issued in the San Gabriel Valley, San Bernardino Valley and Riverside on Friday. Most other inland areas of Los Angeles, Orange, San Bernardino and Riverside counties also suffered unhealthful air but barely skirted the hazard warnings.

“Thursday was the worst day we’ve experienced so far this year and today (Friday) isn’t much better,” said Joseph Cassmassi, senior meteorologist for the South Coast Air Quality Management District. “It’s been a very, very persistent stagnant air mass sitting over us.”

Some unsafe conditions will linger in the valleys today, but air quality meteorologists predict that the worst is over--at least for a few days.

“This episode should be fairly short-lived,” Cassmassi said, “but it will be the worst we’ve had all year.”

For many people in the smoggiest areas, eyes teared, chests tightened and the slightest outdoors exertion caused breathing problems. Adding to the misery, temperatures soared Friday to 106 degrees in Riverside, 94 in Burbank and the mid-80s in Downtown Los Angeles and coastal cities.

Michael DeLeo, 21, of Moreno Valley was playing golf at Fairmount Park in Riverside on his day off Friday, but he only made it through eight holes before giving up.

“I started not feeling good. I was chewing air and I started wheezing, so I stopped playing,” DeLeo said with a noticeable wheeze.

Even seasoned meteorologists could think of no better adjective to describe Friday’s air than “gunky.” In addition to ozone, nitrogen dioxide--the whiskey-brown pollutant that obliterates skylines--was severe.

“It looked really bad out there yesterday, as it has today,” Cassmassi said Friday. “It’s air pollution, it’s Los Angeles and it’s summer--finally. This has been a phenomenally clean summer and that’s directly a result of the weather.”

Smog has been relatively mild all year, even when compared to the past few years, which also featured notably cleaner skies. For much of the summer, an upper-level low-pressure layer has hovered over the Southwest, bringing good wind flow, cloud cover, cooler than usual upper-atmosphere temperatures and a weak inversion layer--conditions that are not friendly to smog.

So far in 1993, smog alerts were issued on 22 days, compared to about 30 days by this time last year and the year before, Cassmassi said.

Coincidentally, the year’s two worst smog days came as the AQMD board held hearings on a controversial new strategy to combat industrial air pollution. On Thursday and Friday, the agency was debating whether to adopt a new plan, called RECLAIM, which would allow Southland businesses to choose their own methods of smog control and trade pollution credits to reach a goal of slashing emissions 75%. The board will convene a final hearing Oct. 15.

Ozone, a colorless gas that forms when hydrocarbons and nitrogen oxides bake under the sun, can permanently impair respiratory function and prematurely age lungs, pulmonologists say.

For longtime residents, the heavy smog was a reminder of the old days. Less than a decade ago, bouts occurred much more frequently, often lasting most of the summer. In the 1970s, pollution often peaked at concentrations twice as bad as Friday’s.

This week’s worst air, as usual, was in Glendora, the nation’s smog capital, where ozone concentrations peaked Friday at .25 parts per million--more than twice the concentration that health officials deem safe to breathe.