Smog in Much of Basin Down 50%, Study Says

Providing proof that the fight against smog is working, air pollution has dropped by 50% in much of Southern California over the last 10 years and the dangerous peak levels have declined by more than 25%, according to a state report made public Monday.

“Southern California has almost a dual distinction of having the worst smog problems in the nation but also of being one of the few places where we are making genuine progress,” said Bill Sessa, a spokesman for the California Air Resources Board, which conducted the study.

The air pollution improvements in Los Angeles, Orange, Riverside and San Bernardino counties were spread across the basin, from the desert to the coast. Officials credited the smog reductions to strict state emission controls on motor vehicles and regional pollution standards for factories.

The study found that the average top hourly smog readings declined from 0.33 parts smog per million parts air to 0.25 p.p.m. from 1981 to 1991, a reduction of more than 25%. Though encouraging, the lower level still considerably exceeds the state health standard of 0.09 p.p.m. Above that standard, people may experience a loss of lung function in the long term and a burning throat, watery eyes and shortness of breath in the short run.

“The biggest health threat is at the peak levels, when individuals with respiratory and heart ailments are most vulnerable to breathing problems,” Sessa said.

The state air pollution board’s examination of monitoring data also showed that coastal cities now experience 200 to 400 hours of smog each year exceeding the health standard, about half of what those cities suffered a decade ago.

Similarly, inland cities now are besieged by hazardous air pollution 600 to 800 hours a year, down 50% over the last 10 years.

Other parts of California also made improvements in air pollution, but not as dramatic as those in Southern California. Hazardous peak levels declined by 15% in the San Francisco Bay Area, with overall smog there down about 50%.

In San Diego County, peak levels dropped by 12% but overall smog declined less than 5%. In Sacramento and the San Joaquin Valley, smog remained about the same.

The lack of dramatic improvements in those areas reflects rapid population growth, Sessa said. “The fact that the ozone levels did not go up in those areas is a significant accomplishment in light of the growth,” he added.

Sessa and other state officials credited much of the gains to the state’s air pollution standards for motor vehicles, the toughest in the world. “It now takes roughly 10 new cars to match the pollution output of a single car built 15 years ago,” Sessa said. “And standards we have adopted through the model year 2003 will make those cars 50% to 80% less polluting than today’s cars.”

State officials said the gains in Southern California outpaced those of other metropolitan centers across the nation. A recent National Research Council report, for instance, found that Houston has seen virtually no improvement in air quality over the last decade, and Fairfield, Conn., representing the trend in Northeastern cities, saw a decline in overall smog of about 30% to 35%.

“There tends to be a much bigger drop-off in urban smog in Southern California,” Sessa said. “Part of that is because the problem was so large to start with, but part of it is the technical approach we have taken.”

James M. Lents, executive officer of the South Coast Air Quality Management District, said he was pleased by the “significant” declines but warned that “there is a lot of work to be done over the next 15 or 18 years to get us to where we are breathing reasonably clean air.”

He attributed 90% of the reductions to state and regional air pollution requirements, the rest to possible declines in emissions by factories producing less because of the recession and changes in the mixture of industries within the region.

“We enjoyed the three cleanest records during the last three years, and we’re on our way this year to number four,” Lents said. “I think people in Southern California should notice a difference.”

However, Lents said gains made over the last decade were the easiest to achieve and that reaching similar reductions in the future will require innovation and renewed effort.

The AQMD is about to launch a new, market-based system to reduce air pollution. Under the system, polluters that reduce their emissions beyond required levels any way they choose can sell right-to-pollute credits to other companies. The idea is to allow individual companies that buy credits to exceed certain pollution requirements as long as the overall air quality goal for the region is met.

Under the old system, the smog agency mandated that factories install certain kinds of equipment and materials to reduce pollution.

Tim Little, executive director of the Los Angeles-based Coalition for Clean Air, cited the reductions as evidence that the current rules and regulations to fight smog work.

“We should think twice before we embark into a wholesale departure from those rules” for a pollution-trading system, he said.

But Rick Zbur, an attorney who represents a group of about 20 Southern California businesses that are subject to AQMD smog rules, said the encouraging air quality improvements of the last decade do not mean the old rules are best.

“The cheapest and easiest control means have already been put into district rules,” he said. “The only way the basin is going to achieve attainment (with state and federal standards) is if the regulatory approach moves to provide incentives for new technology.”