Smog Implicated as Cause of Asthma

Vol. 15 •Issue 5 • Page 12
Air Quality

Smog Implicated as Cause of Asthma

New Asthma Study Empowers Environmental Activists to Push for Pollution Reduction

Conventional wisdom says we should encourage children to get outside and run around, maybe shoot some hoops, rather than stay inside roosting on the couch watching TV. A recent study in a major scientific journal, however, gives one pause.

Researchers tracked 3,535 Southern California children with no previous history of asthma for five years. They found children living in smoggy areas who played three or more outdoor sports were 3.3 times more likely to develop asthma than those who tended to stay indoors.

Scientists have long held that air pollution exacerbates but does not cause asthma. This study, published in the February issue of The Lancet, is the first ever to implicate smog as causing the disease.

“Our study provides evidence that ozone is involved in the development of new-onset asthma in children who exercise heavily,” lead author Robert McConnell, MD, told the Philadelphia Inquirer.

Of course, children should still play outdoors, McConnell, associate professor of preventive medicine at the University of Southern California, was quick to add. But he recommended limiting outdoor exercise when smog reaches unhealthy levels.

His study rings sweetly in the ears of environmental activists. It comes at a time when the U.S. is pumping out more carbon dioxide emissions than it has in a decade, according to the Energy Department, and when rumors of imminent Bush Administration rollbacks to the Clean Air Act are rampant.

“We’re very excited about (the asthma study),” environmental activist Martha Dina Arguello, told ADVANCE. “This is one more peer-reviewed study from a reputable medical institution that tells us we really should be concerned about the public health effects of air pollution.”

A Niagara Falls’ worth of research flows regularly from epidemiologists to confirm the deleterious effects of dust, soot, nitrogen dioxide and other materials released into the air. Some recent examples:

• Diabetics with heart disease are twice as likely to be hospitalized as patients without diabetes when particulate levels are high, according to research appearing in the September issue of the American Journal of Respiratory and Critical Care Medicine.

• In 2000, epidemiologists studied health records during a temporary closure of a steel mill in Utah in the 1980s. They documented a decrease in elementary school absences, bronchitis and asthma admissions for pre-school-age children, as well as declines in hospital admissions for pneumonia, pleurisy, bronchitis, asthma, pulmonary function abnormalities, mortality and age-adjusted death rates for malignant and nonmalignant respiratory disease. This study appeared in the August issue of the same journal.

• Global warming may be raising levels of allergy-causing ragweed pollen in the air, according to a recent U.S. Dept. of Agriculture report. Pollen counts have doubled since 1900, the USDA contends.

The new USC study impresses not only activists but also officials at EPA, which partially funded it. In the past, the EPA has linked fine particulates, largely the byproduct of combustion at power plants and in car engines, to persistent coughs, phlegm production, wheezing and physical discomfort.

“Outside of occupational exposure studies, this is the first relatively convincing evidence, although preliminary, that air pollution may contribute to asthma,”declared John Bachmann, associate director for science policy at EPA. “It’s a qualitative piece of knowledge we didn’t have. We’ve been saying air pollution is not responsible for the significant and troubling increase in asthma, but the population aggravated by air pollution insults is growing. This study adds to our concern that it may, in some small populations, actually contribute to causing it.”

Most funding for the USC study came from the California Air Resources Board (CARB), the state’s pollution agency, as part of a broader $18 million initiative to examine how air pollution affects children’s health. Since 1993, CARB-funded researchers have tracked more than 6,000 children in a dozen Southern California communities.

“We’re finding indications of lung function growth retardation in children in the most polluted areas in California,” said Dane Westerdahl, a health advisor for CARB. “It implicates ozone as the primary factor associated with the new asthma. Other common air pollutants recorded included nitrogen dioxide, acidity and other particulate matter.”

Ozone affects the airways acutely, Westerdahl continued, especially when children inhale it deeply as they become winded playing sports. “Ozone, on a daily or hourly basis, is a very reactive chemical that can damage lung tissue. It sets into effect biochemical regulatory processes that are potent in the lung. It causes redness in the airways and increased production of mucus.”

Say your child’s lungs grow at 6 percent a year in a healthy environment, then you move to Los Angeles, Jerry Martin, press officer for CARB, postulated. Not only is it possible your child’s lungs will grow at only half their previous rate, but if you subsequently move elsewhere, what your child lost in L.A. can’t be recouped.

“We think we know that whatever lung development was lost was lost,” Martin explained.

“We were estimating that a child growing up in L.A. loses, say, 5 percent of lung function. That’s possibly an underestimate. Let’s say your kid is a star running back in high school, drafted to the University of Nebraska, a running back school. He’s there with others with similar abilities. We don’t know if it would cost him the starting job. Will the other backs competing for the top slot have less fatigue, more tolerance for exercise?

“At least these individuals would have trainers and sports doctors monitoring their health,” he added. “It would be much harder to keep track of factory workers or other more anonymous individuals.”

How will this deficit affect people later in life? What happens to these children when they hit 60, an age when everyone starts losing lung volume naturally?

Finding out would require a Herculean effort to follow these thousands of children into adulthood. But McConnell and his fellow researchers have applied for an NIH grant to do just that. “You’re obviously talking millions of dollars to track people over long periods of time,” Martin said.

“We’ve followed children as young as 8 or 9 through high school. The bulk of the kids are chosen from families that represent stable communities and tend not to move very much. We did a study in the 1970s that looked at Seventh Day Adventists. They don’t smoke. They tend not to migrate. We followed them for 10 years and looked at lung function, progression of pulmonary disease and other studies. That research focused on people who as a group don’t move around a whole lot. With this group, there’s no way to know what they will do once they turn 18 and leave home.

“It’s difficult to follow them, but we are pursuing funding for it. Perhaps no other group of people on earth has this much medical monitoring to follow their health over time, living as they do in the L.A. basin and exposed to fairly high levels of ambient air pollution.”

In the meantime, environmental activists want action, not more studies.

“We work with different communities,” said Arguello, environmental health coordinator for the group Physicians for Social Responsibility. “We’re aware from stationary and mobile sources that residents living near refineries and power plants bear a heavier burden. Huntington Park residents call where they live ‘asthma town.’ People move in, get sick, move out and recover.”

The government errs by not quantifying the health care costs of air pollution, Arguello argued. “To lower health care costs, we should look at the role air quality is playing,” she said. “We should be looking at how to make large scale polluters pay for the costs of what they are putting into the environment.”

Arguello also expressed disappointment with the performance thus far of Christine Todd Whitman as EPA chief. “When still governor of New Jersey, Whitman was quoted as saying we need to develop a more precautionary environmental policy. We must act before the science is in,” she said. “But she’s not living up to her words. She has shown an unwillingness to be creative and to ally herself with industry.”

At press time, the Bush Administration proposed cutting U.S. power plant emissions of three of the worst air pollutants—sulfur dioxide, nitrogen dioxide and mercury—to reduce acid rain, smog and general pollution.

The plan would cut emissions of these three, but not carbon dioxide, by setting emission target limits, by assigning permits for each ton of pollution, and by allowing firms to trade them in what one administration official called a “cap and trade system,” Reuters reported.

“Cap and trade tells the person who wants to invest now that they can get a financial incentive to reduce emissions that creates a credit they can either use in the future or they can sell to somebody else,” a senior White House official told Reuters. “Unlike the current Clean Air Act, where you don’t get compliance until the date gets…imposed, this one is going to bring the numbers down.”

Under Bush’s plan, emissions of sulfur dioxide, which causes acid rain, would fall from its current level of 11 million tons a year to 4.5 million tons in 2010 and 3 million tons in 2018, the White House said. Nitrogen dioxide emissions, a smog agent, would be reduced to 2.1 million tons in 2008 and 1.7 million tons in 2018, down from their current levels of 5 million tons. Mercury emissions, currently at 48 tons, would drop to 26 tons by 2010.

You can reach Michael Gibbons at [email protected].