Area’s Smog Year Almost as Clean as Record 1993

In Glendora, the nation’s smog capital, the quality of the air depends on your perspective.

An average of once every 18 days since May, the town at the foot of the San Gabriel Mountains has been smothered by air deemed so unsafe to breathe that even healthy people were warned to stay indoors. But as bleak as that seems, 1994 has been a breath of fresh air for Glendora and other Southland cities compared to the foul 1970s and much of the 1980s, when smog alerts and summer afternoons went hand in hand.

Embracing the good news/bad news philosophy of a longtime sufferer, the four-county Southland ended its May-through-October smog season Monday closely mirroring 1993, which was the cleanest year in more than 40 years of record-keeping.

By a slim margin, this year set a record low for ozone-based smog alerts in the basin that comprises Los Angeles, Orange, San Bernardino and Riverside counties, according to measurements by the South Coast Air Quality Management District. Stage 1 alerts occurred on 23 days compared to 24 days in 1993, 41 in 1992 and 121 days in 1977.

On the other hand, health advisories, which mean the pollution poses a serious threat but not enough for a full-scale alert, were recorded on 96 days, up slightly from 92 days in 1993 and much better than 1992’s 109.

The trend toward milder smog seasons is promising to local and state air quality officials, who believe their regulations have set the Los Angeles Basin on a permanent path toward meeting the elusive goal of blue skies.

The peak concentration of ozone--a colorless, lung-scarring oxidizing gas that is the Southland’s most pervasive pollutant--has dropped 33% in 15 years, largely because of emissions controls on cars and industrial plants, according to AQMD data.

AQMD senior meteorologist Joseph Cassmassi said even with stagnant air and other weather conditions that foster ozone, he does not expect the Southland to return to the severe levels of the past. Annual smog alerts for ozone, he said, will probably never top 35 days--as they did in 1992--and could soon dip below 20.

“We expect with pretty adverse weather conditions we would see 30 to 35 episodes. Keep in mind, 10 years ago, it would have been 100 episodes under those same conditions,” he said.

Much of the time, however, the air remains unhealthful. An average of once every two to three days, or 118 days this year, the national health standard for ozone was violated in at least one part of the basin. This year’s worst ozone concentration--0.3 parts per million recorded in Glendora on Aug. 5--exceeded the standard 2 1/2 times.

Even more distressing, AQMD officials say the Southland will keep violating the health limit at least through 2010--even if every element of its controversial anti-smog plan, which will cost at least $5 billion a year, is enacted. Next week, the California Air Resources Board meets in Sacramento to decide whether to adopt a far-reaching 20-year clean air plan for the state.

Dr. Henry Gong, a USC medical professor who has performed numerous studies on urban air pollution, said 1994’s concentrations of ozone remained severe enough to gradually deplete the lung function of even healthy adults.

“The bad news is we still have the nation’s worst ozone concentrations and the concern is not so much acute health effects, but chronic health effects,” he said.

Medical research shows lungs seem to age prematurely from the ozone in the Los Angeles Basin’s air. Glendora residents suffered twice as much loss of lung function every year than residents of Tucson, which does not have an ozone pollution problem, according to studies by UCLA scientists.

“It’s an insidious type of thing. You don’t have to be symptomatic. When you breathe ozone it causes changes in your airways that you don’t realize,” Gong said. “It’s like hypertension, sort of a silent killer. Ozone decreases your breathing reserve, and perhaps other reserves in your body. It also makes you more susceptible to lung infections.”

During smog alerts, the air is deemed unsafe for everyone within the affected area, and even healthy people are advised to avoid the outdoors or risk symptoms of acute smog sickness, such as chest pain, shortness of breath and stinging eyes, as well as long-term lung damage.

Even highly trained, healthy athletes can suffer. In Gong’s 1984 studies, Olympic cyclists exposed to Stage 1 levels of ozone in a smog chamber had substantially worsened lung function and exercise performance and symptoms such as shortness of breath. Their cycling performance also worsened at a much lower concentration, one that frequently occurs throughout the Los Angeles Basin.

Asthmatics and people with other lung diseases also say they can notice the difference between a good smog year and a bad one.

“Anecdotally, my clinical impression is the cleaner the air the better the lung health of my patients,” said Gong, who treats respiratory patients as chief of environmental health service at Rancho Los Amigos Medical School in Downey.

Although anti-smog rules deserve credit for the long-term decline in ozone, when it comes to year-to-year fluctuations, weather is the key factor.

Ozone, or photochemical smog, is formed when hydrocarbons and nitrogen oxides released by motor vehicles, industries and other sources react with strong sunlight and are trapped near the ground by inversion layers. Cloudy skies and ocean breezes prevent its formation.

Cassmassi said 1994 turned out much milder than expected because of strong sea breezes in late August and September, which usually is one of the smoggiest periods.

No alerts have been recorded for almost three months. A low-pressure area hovered off the coast, drawing southerly winds through the atmosphere and weakening the inversion layer.

“It has been an extraordinarily clean two-month period,” Cassmassi said.

An early hot, smoggy streak in June and cool late-summer breezes canceled each other out, bringing average weather conditions for the year that neither fostered nor deterred heavy ozone buildup.

Because the pollutants that create ozone are emitted mostly near the coast but move toward the mountains before reacting, ozone is most severe in the San Gabriel, Santa Clarita and San Bernardino valleys.

Glendora, Crestline, Fontana, San Bernardino, Redlands, Upland and Santa Clarita suffered the worst smog in the four counties this year.

While maintaining its stigma as the U.S. smog capital, Glendora, in the eastern San Gabriel Valley, suffered dramatically fewer days of severe smog this year than last. Glendora’s 10 smog alerts compared to 19 in 1993, and Azusa, with two alert days this year and 11 last year, vastly improved. Pasadena and Pomona also had good years.

Downtown Los Angeles--which many people wrongly perceive as a symbol of smog--has experienced no alerts for two years in a row, compared to eight a decade ago. Riverside fared almost as well, with two alert days, better than 1993’s five.

On the other hand, Orange County’s air worsened a bit, with two alert days in La Habra and one in Anaheim, while there were none in 1993. Air quality also declined in San Bernardino (eight alert days), Santa Clarita (six alert days), Crestline (nine alert days) and Fontana (nine alert days).

Cassmassi said those areas probably worsened because of temporary, local wind patterns, not increases in emissions there.

Ventura County has a much less severe ozone problem than the Los Angeles Basin, but the county still violated the federal health standard 15 days this year, an increase of two days from last year but much fewer than in the 1980s. The county had no smog alerts.

Although the ozone season has ended, the Southland’s other pollution problems have just begun.

Carbon monoxide, which can endanger heart patients, and nitrogen-based pollution that causes a whiskey-brown haze, peak in winter weather conditions. Although those pollutants can reach levels severe enough to trigger health alerts, they too, have been steadily declining.