Breathe Easier : Smog: In the six months that ended Nov. 1, the Los Angeles Basin had the cleanest air since records began in 1955, air quality officials say.

Clean air is in the eyes--or is it the lungs?--of the beholder.

Air quality officials announced this month that during the six-month smog season that ended Nov. 1, the Los Angeles Basin had the cleanest air they have ever recorded. There were fewer smog alerts in 1990 than in any year since records for Southern California were first kept in 1955.

Many people in the San Gabriel Valley say they can see and feel the improvement. But they also say the San Gabriel Valley is a long way from breathing clean, healthy air. And experts agree.

The San Gabriel Valley still reports more smog alerts at its four air quality stations than any other part of the basin. That makes it the nation’s smoggiest region.

Also, while controls on auto and industrial emissions have helped clean the air, a significant part of the most recent improvement is believed to be caused by favorable weather conditions that may not last, said officials at the South Coast Air Quality Management District.

Researchers suggest that San Gabriel Valley residents continue to lose lung capacity from living in the ozone-laden air. And one city, Glendora, still has to bridle under its designation as “America’s Smoggiest City.”

But first, the good news:

The San Gabriel Valley’s four air monitors--in Azusa, Glendora, Pasadena and Pomona--reported a total of 60 smog alert days during the 1990 “smog season,” compared to 94 in 1989. As recently as 1982, the four monitors recorded 170 smog alert days.

Air quality officials declare first-stage smog alerts when ozone, the area’s principal pollutant, reaches .20 parts per million. Second-stage smog alerts are declared when ozone reaches .35 parts per million.

During the 1990 smog season--for the fourth year in a row--no second-stage alerts were declared in the San Gabriel Valley.

AQMD officials called the improvements “mind-boggling” and “dramatic.”

In the San Gabriel Valley itself, most people judge the smog by looking toward the San Gabriel Mountains. And by this measure, as well, many have seen improvement.

“There is no question I go out from my house more days and say, ‘Aren’t the mountains beautiful!’ ” said Glendora Mayor Bob Kuhn. “I used to go out and say, ‘Where are the mountains?’ ”

The improvement can also be seen on the pages of the Glendora Unified School District’s “Smog Book.” The district has an ozone meter and logs days on which schools are notified to curtail students’ exercise. The book shows 43 such alerts in 1986, compared to nine in 1989 and just two this year.

AQMD officials say the air has improved substantially over the last decade, in large part because of greater controls on car exhausts and industrial emissions. “When you compare it with the past, it’s like night and day,” said Joe Cassmassi, senior meteorologist with the AQMD. “There’s really been a dramatic improvement.”

In this year’s improvement, favorable weather conditions also played an important part, they said.

Ozone forms in the air when hydrocarbons and nitrogen oxides emitted by cars and industry are exposed to sunlight. High pressure holds the pollution close to the ground and prevents it from blowing away.

But more low-pressure systems penetrated the Los Angeles Basin in the last year, cleaning the air, said Joe Cassmassi, AQMD senior meteorologist.

“Most of the days of improvement are based on weather conditions,” Cassmassi said.

Weighing the impact of weather against emission controls is difficult, he said. Researchers have estimated that this year, an average of four smog-alert days were eliminated at each smog station by pollution controls, and the rest by helpful weather, Cassmassi said.

Experts say the elements will not always be so accommodating.

Researchers added that although they are encouraged by the lower ozone levels, residents’ health is still suffering because of air pollution.

There were still 180 days this year when ozone levels at least one reporting station in the Los Angeles area exceeded the state’s more stringent clean air standard of .09 parts per million of ozone, the AQMD reported.

“Certainly it’s good news that we have had fewer alerts and lower levels of pollution,” said Roger Detels, a professor of epidemiology at UCLA’s School of Public Health. “But we should continue to be concerned about levels of air pollution.”

Detels and a UCLA research group will soon publish the latest chapter in a study that has documented the decreased lung function of people who live in polluted areas.

The researchers compared residents of Glendora and Long Beach with Lancaster, a control area with relatively cleaner air.

“Young people tend to have an increase in lung function until the age of about 25,” Detels said. “But in the polluted areas kids did not have as large an increase as in the control area. And after 25 years of age they had a greater decline in lung function.”

The findings support research at USC, which showed that second-graders in the Los Angeles Unified School District had 10% to 15% less lung capacity than a comparable group of children in Houston. And their lung capacity did not increase as much between the second and fifth grades as the Houston children’s, said Kaye Kilburn, the USC professor of medicine who directed the study.

Another USC study showed notable lung abnormalities in 80% of 100 youths who died in homicides or accidents.

“I think essentially what we have accomplished is to stay in the same place over the last decade,” Kilburn said. “We have absorbed more people and more automobiles and we have managed to not let the air pollution situation get worse.”

In the San Gabriel Valley, there is a feeling of impotence in fighting the pollution that blows in from the west and settles against the foothills.

Glendora has recorded the most smog alerts in the South Coast Air Basin, and thus the nation, every year since 1982. But city officials are quick to point out that they are bearing the brunt of a region-wide problem.

“It’s not our smog,” said Glendora Mayor Pro Tem Larry Glenn. “It blows in here and it has nowhere else to go.”

City leaders have also been disgruntled about the location of a smog-monitoring station in their city. They say Glendora’s air quality is no worse than in surrounding areas, but that the city’s reputation has suffered because the Glendora station is near the base of the mountains, where air is the most stagnant.

AQMD officials disagree that the Glendora station is unfairly located, saying the monitor on Leadora Avenue records about the same levels of ozone that have been recorded during spot checks in the rest of the community.

But AQMD officials agreed that Glendora’s air is not necessarily much worse than the rest of the San Gabriel Valley’s.

The Azusa station, for example, reported fewer than half the smog alerts that Glendora did this year. But the Azusa monitor has more auto traffic nearby than Glendora’s, so it registers higher levels of pollutants that come directly from car tailpipes, such as nitrogen dioxide.

These “primary” pollutants tend to force out ozone, which is the most prevalent and most often cited measure of pollution, said AQMD spokeswoman Claudia Keith.

Glendora officials said most people do not pay attention to such subtle distinctions.

The officials were so upset three years ago by the city’s high pollution readings that they asked AQMD officials if they could move the smog station elsewhere, said City Manager Art Cook. The AQMD, however, said it needed the same station to consistently report air quality trends.

“We more or less agreed they could keep it here,” Cook said.

But boosters in a city that calls itself “The Pride of the Foothills” still don’t like the bad publicity that comes with the high ozone readings.

“Unfortunately, we have another agency that is trying to deter our pride or tarnish our image,” Cook said. “The thing that frustrates me is the lack of comparable monitoring stations throughout the foothill communities.

“We are kind of being pegged as the bad boy of the San Gabriel Valley,” he said. “I think we are being made a scapegoat, in a certain sense.”

Most people in Glendora say they have adapted to the bad air with small lifestyle changes--exercising in the mornings and evenings when ozone levels are lowest and staying inside on the worst days.

Among shoppers who streamed in and out of a local supermarket recently, the majority said the city’s low crime rate, highly rated schools and small-town feel more than compensate for the brown curtain that usually shrouds the San Gabriels.

A little humor doesn’t hurt, either.

“I have lived in Glendora since 1961,” says Mayor Kuhn. “Fortunately, I have never smoked, so I’m probably about (as healthy as) a guy out in the desert who has smoked all his life.”

SMOG ALERT DAYS

The 1990 smog season, which started May 1 and ended Nov. 1, was the cleanest on record in the Los Angeles Basin. The following chart shows the number of first stage/second stage smog alert days for ozone throughout the past decade at each of the San Gabriel Valley’s four reporting stations. Ozone is an invisible pollutant that is created when sunlight hits contaminants released by cars and industry. First stage alerts (the first number listed) are reported when ozone reaches .20 parts per million of ozone, while second-stage alerts are called at .35 ppm and above.

City 1980 1982 1984 1986 1988 1990 Azusa 74/7 40/1 55/0 45/0 33/0 13/0 Glendora 30/5* 62/2 67/0 70/1 54/0 28/0 Pasadena 56/3 33/1 49/0 33/0 10/0 7/0 Pomona 49/1 31/0 30/0 24/0 16/0 12/0

*Less than 12 full months of data.