1990 Smog Season Had Cleanest Air on Record

From the foothills of San Bernardino County to the coast of Orange County and the valleys of Los Angeles, Southern Californians breathed the cleanest air on record in the 1990 smog season that officially ended Wednesday, records show.

Officials said regulations lowering emissions from cars and industry deserve much of the credit for the dramatic improvement in air quality, but favorable weather also contributed.

“This is mind-boggling,” said Joseph Cassmassi, senior meteorologist with the South Coast Air Quality Management District who has analyzed smog data for nine years. “When you compare it with the past, it’s like night and day. There’s really been a dramatic improvement.”

Days of smog alerts in the basin--which includes Los Angeles, Orange, San Bernardino and Riverside counties--declined by 24% this smog season compared with 1989, which also was considered a light year. The season, which runs May 1-Oct. 31, is believed to be the best in more than 40 years of record keeping in Southern California.

From May through October, alerts for ozone, the prevalent pollutant in the region, were called in at least one city on 41 days, AQMD data show.

That compares with 54 days in 1989 and 77 in 1988. Back in 1977, they occurred nearly three times more frequently, with 121 days. The alerts are triggered when pollutants reach concentrations so high that health warnings must be issued under law.

The nation’s smoggiest city--Glendora, nestled at the foot of the San Gabriel Mountains--had a much lighter season, with 28 days compared to 37 last year and 71 in 1986.

Visibility, however, has not necessarily improved. Much of the haziness comes from a mix of moisture and soot. “We can get ozone to zero and the public might not even notice it because they gauge air quality by visibility,” said AQMD Chairman Norton Younglove.

Ozone, created when a mix of pollutants from cars, businesses and consumer products bake under the sun, is a powerful irritant of the lungs. It especially harms children, people with respiratory disorders, the elderly and people who exercise outdoors. There also is increasing evidence from national researchers that the pollutant causes premature aging and permanent damage that could trigger chronic lung disease in healthy people.

Dr. Robert Phalen, director of the Air Pollution Health Effects Laboratory at UC Irvine, said the air quality improvements recorded this year are significant enough to benefit the health of everyone living in the basin.

“People with lung disorders would notice that this was an easier year for them,” Phalen said. “And those of us who don’t have a lung disorder are benefiting even though we don’t notice it because smog episodes slowly erode lungs.”

Despite the improvements, the basin remains the smog capital of the nation with air quality that is three times worse than any other area. On an average of every four or five days since May, residents in at least one city within the region breathed concentrations of pollution that officials consider unhealthful.

“We’re encouraged, but it’s still flat out awful,” said Tim Little, executive director of the Coalition for Clean Air, a Santa Monica-based environmental group. “It doesn’t show enough of a decline to even put us in the same league with the rest of the country.”

The AQMD has vowed to eliminate smog alerts by the year 2000 and comply with all federal health standards by 2007 with its 20-year plan.

A Stage 1 alert is called when ozone reaches 0.20 parts per million. A Stage 2 is above 0.35 p.p.m. The air is considered unhealthful when it exceeds the federal standard of 0.12 p.p.m.

This year showed a 60% decline in the number of hours that the region exceeded the Stage 1 level, Cassmassi said. That means not only is the problem shrinking in size, but also duration. Smog bouts are lasting shorter periods of time, the data shows.

Ozone peaks from May through October because of strong sunshine and stagnant air, which traps pollutants close to the ground. Most of the pollution builds up from cars and industry in Los Angeles and Orange counties, then moves inland and east toward the mountains.

One of the trends that delighted officials most was the improved air in Riverside and San Bernardino counties, especially in Norco, Upland and San Bernardino. Those areas typically have been the recipient of poor air blown in from Los Angeles and Orange counties.

Cassmassi said 75% of the recorded improvement in air quality should be attributed to reductions in emissions. He said there were no unusual weather patterns this year, so weather accounts for only a quarter of the reduction.

State air-quality officials have analyzed only the first half of the smog season, but they suspect weather is the main reason for dramatic year-to-year declines.

“We would credit the weather with this decline more than the (AQMD) is,” said Bill Sessa, spokesman for the state Air Resources Board. “The weather is a dominating factor in any dramatic change in smog. Improvements from (smog-control) programs are more slow and steady.”

The biggest emission drops traditionally have come from turnover of automobiles. Two million new cars are purchased each year in California. New cars must meet very strict emission standards that reduce pollutants by 90% compared to 15 years ago.

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SMOG SEASON

The 1990 smog season, which started May 1 and ended Wednesday, was the cleanest on record in the Los Angeles Basin, which includes Orange, Los Angeles, San Bernardino and Riverside counties. Air is measured daily in 37 cities. This chart reports the number of smog alert days in selected cities. Officials say recent rules forcing cutbacks in emissions from industry and autos get most of the credit for the 24% basinwide improvement compared with 1989. SMOG ALERT DAYS

City 1990 1989 1988 1987 1986 1985 1984 Glendora 28 37 54 51 70 68 67 Azusa 13 30 33 26 45 48 55 Pasadena 7 17 18 15 33 41 49 Upland 11 19 25 23 38 39 41 San Bernardino 7 22 31 27 41 30 36 Redlands 10 17 25 26 22 31 26 Norco 0 3 7 9 12 20 19 La Habra 4 5 2 6 8 13 14 Downtown L.A. 2 1 2 2 8 9 8 Reseda 0 5 4 2 5 9 6 West L.A. 0 1 2 1 1 4 5 Anaheim 0 4 1 3 1 11 5 El Toro 0 2 2 0 1 7 3 Costa Mesa 0 0 0 0 0 1 1 Long Beach 0 0 0 0 0 1 1 Los Alamitos 0 0 1 0 0 0 0 Total in basin*: 41 54 77 66 79 83 97

*The basin total is the number of days when at least one monitoring station within the four counties reached the smog-alert limit for ozone, which is .20 parts per million.

Source: South Coast Air Quality Management District