Southland Smog Drops to Lowest Level in Decades

The Southern California smog season that ends this week has been the best in decades, and air quality officials say the state’s new cleaner-burning gasoline deserves much of the credit.

Although the fight against dirty air in the four-county region around Los Angeles has made steady progress, the 1996 season stands out as substantially better than even last year, which had the fewest serious smog episodes in more than 40 years of record-keeping.

Stage One alerts, which indicate severe bouts of pollution, were triggered on seven days, half the number reported last year by the South Coast Air Quality Management District. Health advisories--when residents are warned to limit time outdoors--occurred on 52 days, down from 59 in 1995, according to the agency.

The Los Angeles region also lost one of its most dubious distinctions: The nation’s worst smog day this year was in Houston, which hit a peak of 0.26 parts per million of ozone--more than twice the limit deemed healthful under the federal standard and barely edging out May 11 in Crestline in the San Bernardino Mountains.

Despite the good news, there remains plenty of bad. Southern California still exceeded the health standard on 87 days, compared with 13 for Houston. An average of twice a week this year, the inland valleys recorded air foul enough to be linked to serious health effects, especially for children, the elderly or people with respiratory ailments.

“Everything is going in the right direction,” said AQMD senior meteorologist Joe Cassmassi, “but we have a long way to go.”

Within a span of a few years, the worst smog zone has shifted east about 35 miles, moving from the Glendora area in the east San Gabriel Valley to Crestline, north of San Bernardino.

The eastern shift has occurred because emissions have declined, especially from cars driving during morning rush hours in Los Angeles and Orange counties. With fewer overall emissions, it takes longer for the fumes to build up in the air--and the longer it takes, the farther east they are carried by winds before they react to form ozone. The trend also means smog is peaking later in the afternoon than it used to.

Although air pollution can be severe year-round, Southern California’s peak smog season runs from May through October. Strong sunshine, warm temperatures, stagnant airflow and gases from vehicles, industry and other sources combine in a chemical reaction that forms ozone, an invisible pollutant that is the most prevalent component of smog. The smoggiest day of the year was Saturday, May 11, mirroring a recent, unexplained trend of peaks hitting on weekends.

When differences in weather conditions are taken into account, the area’s average smog level this year was 18% better than in 1995 and 1994, the California Environmental Protection Agency said.

Cassmassi said the weather this year was average as far as influencing smog levels, and state and local officials said California’s new reformulated gasoline had the single largest impact on the smog season.

Since June, all California motorists have been using the new gasoline to reduce exhaust, eliminating the equivalent of 3.5 million cars from the state’s roads, the state Air Resources Board says. The new gasoline raised average manufacturing costs an estimated 10 cents per gallon and reduced motorists’ mileage 1% or 2%, the state agency says.

Some drivers have expressed concerns that the new cleaner-burning gas is wearing out rubber fuel system components in older cars and causing potential fuel spills. Such concerns, though, have been refuted by car companies, state officials and many mechanics and fleet managers.

“There have been some leaks in fuel, and it’s probably a very small segment of the market, and a lot of that is just the normal mechanical repairs that are needed for cars,” said Vince Haavisto, president of the California Service Station and Automotive Repair Assn.

The record-breaking year comes as the AQMD is mired in a fierce debate over a new clean air plan. The proposal is less aggressive in cutting emissions than the plan now in place and is based on more optimistic projections of future pollution. The AQMD board is expected to vote next week on whether to adopt the new plan.

Environmentalists and some air quality scientists applauded the good news but remained worried that the agency has gotten too confident and is backing off out of fear of upsetting businesses.

“What we’re not pleased about is the direction that the district is going with the new plan,” said Linda Waade, executive director of the Coalition for Clean Air. “The only reason we’ve gotten to this point is because of the very strict rules and programs we’ve had in this basin.”

Unfortunately, visibility in the region has not been improving as much as the lung irritant ozone. People can see mountain and valley vistas more clearly than a few years ago, but a thick brown haze still often obscures the view, and it is difficult for air quality scientists to quantify the improvement.

The haze is caused by another pollutant--particulates, which have been declining, too, but not at the same pace as ozone. Particulates are a complex mix of diesel soot, road dust, smoke, auto and industrial emissions, sulfates and other compounds that are harder to control.

Severe smog began to cast a pall over the Los Angeles area during World War II, when people didn’t know whether to call it smoke or fog and thus dubbed it “smog.”

Since then, air quality regulators, by imposing controls on vehicles and industries, have managed to shave off many of the extreme peaks in pollution that occurred so often in the 1960s and 1970s, especially in the San Gabriel Valley.

In 1976, the region had 102 days of smog alerts because of ozone. It was not unusual for people to endure smarting eyes and tightness in the chest throughout most of the summer. As new pollution rules take effect and people turn in their older cars for newer ones, the AQMD predicts that Stage One alerts will cease to exist by 2000.

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Breathing Easier

This year was a landmark one for smog. There were far fewer Stage 1 alerts and a decline in health advisories, even compared to 1995, which was a record-breaking year.

Smog alters* through Oct. 29

‘76: 121

‘96: 7