Studies Raise Concern on Clean Air Standard : New Research Shows Even Low Concentrations of Ozone Can Have Acute Effects on Health

New air pollution studies have concluded that ozone has acute health effects at lower concentrations than previously thought and that the national clean air standard may no longer be adequate to protect even healthy individuals.

Among the human health effects at ozone levels near the current standard were persistent reductions in lung capacity, aggravation of respiratory diseases such as asthma, and increased hospital admissions at times when ozone concentrations are at or near the Clean Air Act standard. In addition, separate animal toxicology studies point to the premature aging of lungs, structural damage to the lungs and a weakened ability to resist respiratory infections.

It has long been known that high levels of ozone--the principal component of smog--are unhealthy for everyone. But, the new studies indicate that low concentrations decrease breathing ability even in well-conditioned athletes, especially when they are involved in heavy exercise.

Health Safety Margin

The findings, reviewed by a panel of scientists advising the U.S. Environmental Protection Agency, have led the EPA’s Office of Air Quality Planning and Standards to conclude that the current ozone standard provides little or no margin of health safety. The studies will be formally submitted to EPA Administrator Lee M. Thomas in the next several weeks.

“All the evidence and information points, if anything, to a greater health effect,” said J. Craig Potter, who heads the EPA Office of Air and Radiation.

Potter said from Washington in a telephone interview that there is little doubt that the study results will increase pressure on the EPA to tighten the existing standard. He said that the EPA will begin a review of the present standard’s adequacy late this year or early next year. Thomas has previously said that the EPA would examine state and local enforcement efforts.

“These new data are especially disturbing when read in the context of recently measured real-world ozone levels,” Thomas told the Air Pollution Control Assn. meeting in Minneapolis this summer.

The EPA chief said that a third of the U.S. population lives in urban areas such as Los Angeles where peak ozone concentrations are often three times that allowed by the current standard.

“Despite recent improvements, Los Angeles continues to suffer from the worst air quality in the nation,” Thomas said. He also pointed to the Texas Gulf Coast, the Northeast and Chicago as other exceptionally smoggy areas.

Morton Lippmann, the chairman of the EPA’s Clean Air Scientific Advisory Committee, said there was no doubt that the data from laboratory and field studies has measured a respiratory response at ozone levels equal to or only slightly greater than the standard. “The question is whether those things we can measure are adverse health effects. That remains a major controversy,” Lippmann said.

Nonetheless, Lippmann, a professor of environmental medicine at New York University Medical Center, said, “The convergence of all the information--the animal data showing biologically significant responses at levels near the current standards and the data on adults and children . . . point to a whole variety of biological responses which collectively give more concern.”

It’s Called Smog

Ozone is formed in the lower atmosphere when emissions of hydrocarbons, such as unburned fuel and paint vapors, react in sunlight with products of combustion known as oxides of nitrogen. The pungent, colorless, toxic gas accounts for 95% of what is commonly called smog.

In 1979, when the current ozone standard was set, officials said it provided the margin of safety required by the federal Clean Air Act. The latest studies, however, strongly suggest that the standard--0.12 parts of ozone per 1 million parts of air for one hour--is inadequate. By comparison, the ozone standard in Canada is 0.08 parts per million (ppm).

Under the Clean Air Act, the 0.12 standard must be met by the end of 1987. But, it is clear that most of the urban areas not now in compliance will be unable to meet that deadline.

The South Coast Air Basin, which includes Los Angeles, Orange, San Bernardino and Riverside counties, is not expected to comply with the current standard until at least the year 2020, and perhaps never, the South Coast Air Quality Management District said.

Indeed, every day since July 29, ozone readings have exceeded the first-stage level--considered unhealthy for everyone--in various locations in the basin. During the last week, there have been first-stage alerts in Azusa, Burbank, Fontana, Glendora, Lake Gregory, Newhall, Pasadena, Redlands, San Bernardino and Upland. Since September of 1982, there have been 13 days of second-stage smog episodes, in which peak ozone levels were at least three times the national standard, the most recent was on June 27 in Glendora.

Relaxation ‘Unlikely’

Thomas has served notice that it is “highly unlikely” that the ozone standard will be relaxed as the EPA prepares to begin its required five-year review of the standard’s adequacy.

Indeed, several environmentalists, including a member of the EPA’s Clean Air Scientific Advisory Committee, said the results cry out for tightening the current standard.

“There is no excuse for delaying any action whatsoever,” said biochemist A. Karim Ahmed, a member of the EPA Clean Air Scientific Advisory Committee.

“Obviously, present levels of ozone are affecting the health of a number of individuals and I think it’s high time to change these standards,” Ahmed said from New York in a telephone interview. He is also research director and senior scientist with the Natural Resources Defense Council, a private environmental organization.

Mark Abramowitz, a Los Angeles environmentalist, called the studies “a clear mandate to Congress and the EPA that we need to be even more aggressive in controlling sources of air pollution.” Last year, Abramowitz won an out-of-court settlement under which the EPA agreed to make stronger efforts to enforce the Clean Air Act.

Credibility Bolstered

Each of the ozone studies have been published in professional journals, attesting to their credibility, and were reviewed by the EPA’s Clean Air Scientific Advisory Committee, as well as the staff at the EPA’s Office of Air Quality Planning and Standards.

One of the key clinical studies was conducted at Los Angeles County’s Rancho Los Amigos Medical Center in Downey by Dr. Jack Hackney, chief of environmental health services, and Edward Avol, director of the center’s Aerosol Chemistry Laboratory.

In that study, 50 well-conditioned athletes, most of whom were members of area bicycle clubs, were exposed to various doses of ozone while exercising only half as hard as they were capable of doing. At that level they were breathing in and out 57 liters of air per minute.

(By comparison, athletes in a bicycle race might breathe 100 to 130 liters per minute. Sitting still, an individual usually breathes six to 10 liters per minute. Backyard gardening may require 20 liters per minute.)

By measuring how much air athletes could rapidly inhale and expire, researchers could determine how constricted air passages became when the athletes were subjected to various doses of ozone.

Lung Function Decreases

On the average, Avol said there was a 6.5% decrease in lung function at ozone levels of 0.16 ppm, a 17% decrease at 0.24 ppm, and a 23% decrease at 0.32 ppm. (For comparison, a first-stage smog alert is called when ozone reaches .20 ppm; a second stage alert at .35 ppm.)

Avol said a 6.5% decrease would be noticeable and might affect performance. “You would be aware that you were a little short of breath. It’s not a dramatic effect in the sense that you need medical attention. At 17% decrease, you’d feel poorly. It would be noticed and uncomfortable. You’d have all the classical effects, shortness of breath and a burning feeling in the chest. At 23%, it would be even more dramatic.”

The study also found that it took several hours for the athletes’ pulmonary functions to return to normal after they finished exercising, even though they rested in an ozone-free room.

“There are literally millions and millions of people who go out and run, jog, swim, play basketball and ride bikes who are exposed and have these high ventilation rates and are getting high doses of polluted air--and it turns out that it does affect them,” Avol said.

Avol added, “For people who live in the South Coast Air Basin, just because you’re healthy doesn’t mean you are not at risk if you go out and exercise when it’s smoggy.”

Caution Advised

He said exercise should be avoided during the early afternoon, when temperatures and ozone concentrations are high. People sensitive to air contamination should remain indoors, he advised. Just being indoors with the windows closed cuts ozone concentrations in half, he said.

Nearly 200 studies, some dating to the 1970s, were considered by the EPA staff in drafting its ozone report. But particular attention was paid to about a dozen more recent studies conducted by the EPA as well as by researchers in the United States and Canada. Ahmed said four clinical studies, including Avol’s, were especially noteworthy.

Based on those clinical and epidemiological studies, the EPA staff concluded that:

- There is a statistically significant reduction in respiratory function even in healthy, exercising children exposed to levels of ozone now permitted by the 0.12-ppm air quality standard for two hours, and to heavily exercising, healthy adults and adolescents exposed for one hour to 0.14 ppm to 0.16 ppm.

- Exposure to ozone concentrations as low as 0.02 ppm--a dose six times lower than the standard allows--will decrease lung function by 1.6% during intermittent light exercise, by 2.4% during moderate exercise, by 2.8% during heavy exercise, and by 4.7% during very heavy exercise.

- Some healthy exercising adult males experienced more than a 10% reduction in respiratory function when exposed to 0.12 ppm.

- Epidemiological studies indicate that respiratory impairment by ozone concentrations near the standard may be exacerbated by the presence of other pollutants.

- The relationship between acute (immediate, short-term)and long-term respiratory effects of ozone is not yet established, but preliminary results indicate that repeated acute and chronic exposures to ozone may cause more irreversible adverse health effects than short-term reductions in lung function produced by single one- and two-hour exposures to ozone. In children, impaired lung function has lasted as long as a week after four days of ozone at concentrations between 0.12 ppm and 0.185 ppm.

- Although it may be premature to draw firm conclusions regarding persistent respiratory effects associated with multiple-day or longer-term exposures to ozone, there is reason for concern about respiratory function and possibly structural changes beyond the transient pulmonary function decreases previously reported.

- Respiratory symptoms in adults acutely exposed to ozone in controlled exposure and field studies show a close association with changes in pulmonary function. At ozone levels above 0.12 ppm, there were both respiratory and non-respiratory symptoms, including throat dryness, difficulty or pain in breathing deeply, chest tightness or pain, cough, wheeze, weariness, malaise, headache and nausea. Such symptoms are associated with children at levels as low as 0.10 ppm.

- Lung structure damage has been induced in several animal species by long-term exposures to ozone. Although it is difficult to draw conclusions that apply to humans, the animal study findings should be considered in building in a “margin of safety” in any ozone standard.

- Changes in immune systems have been reported in animals exposed to acute and lower levels of ozone and it is “reasonable to hypothesize” similar effects in humans.

Urges Aggressiveness

David Hawkins, senior attorney with the Natural Resources Defense Council’s Washington office and former chief of the EPA’s air pollution program in the Carter Administration, said, “We think the EPA needs to tighten the air quality standards. We also think the EPA needs to become more aggressive in adopting pollution control rules or get state and local governments to adopt rules to meet today’s ozone standard, let alone tougher ones.”

But, he said, policy makers will find it difficult to adopt a stricter ozone standard knowing that many areas of the United States are unable to meet the current one.

The law allows the EPA to impose economic sanctions against any area that does not attain the standard by Dec. 31, 1987. But the EPA’s Thomas has virtually ruled out such penalties.

Potter, underscoring Thomas’ remarks, told The Times that it is highly unlikely that the EPA will impose economic sanctions, especially against regions and states that have improved air quality but, despite efforts, have failed to meet the standard.

Instead, he and Thomas have said that the EPA will work with individual states such as California to develop a smog-reduction plan fitted to the state’s needs. Thomas called for expanded air quality monitoring and stricter compliance with existing regulations.

In the longer term, however, Thomas has said that the Clean Air Act will have to be amended to take into account the fact that its December, 1987, deadline will not be met by many urban areas.