Air Pollution’s Link to Asthma

Vol. 19 •Issue 5 • Page 10
Air Pollution’s Link to Asthma

Long-Term Study Looks at Health Effects While States Aggressively Clean their Air

In the royal family of U.S. cities with poor air quality, Los Angeles long has been the indisputable king. Thanks to the city’s geography and climate, the wheels of smog turn continuously above the city skyline like a vicious cycle: fumes from automobiles, diesel trucks and manufacturers emit into the air; emissions mix with sunlight to produce ozone; and all the pollutants stay trapped in the air between the Los Angeles Basin and the San Fernando Valley.

The measly 15 inches of annual rainfall in L.A. fail to clear the smog; and pollutants continue hanging, condensing and posing a health threat to residents.

Poor air quality in the L.A. area is not the stuff of breaking news, of course. For decades, scientists have been identifying which noxious gases are most prevalent in which areas of the city, and environmentalists have been lobbying state lawmakers in Sacramento and members of Congress for stricter air-quality legislation. Meanwhile, medical investigators have been studying the effects that breathing outside air has on L.A.’s youngest residents.

At the forefront of those health studies is the University of Southern California Preventive Medicine Department. Before starting its Children’s Health Study (CHS) in 1991, USC and other research facilities already had established that pollutants caused acute and sub-acute respiratory effects, led to a decline in pulmonary function and increased respiratory symptoms and inflammation. But USC researchers wanted to know whether breathing polluted ambient air actually caused chronic respiratory disease. Their finding? Yes, it can.

Finding Pilot Group

For the study, USC enrolled 6,000 children ages 5 to 6 years living in 12 southern California communities. Study designers wanted to focus strictly on children for several reasons. Kids spend more time outside. They exercise more than adults. Young kids don’t smoke. They don’t work hazardous jobs. And they are less likely to have lived elsewhere, meaning their young lungs were accustomed to breathing the southern California air.

The team followed the kids for 13 years, giving annual PFTs, analyzing answers to questionnaires about respiratory symptoms and monitoring school absences, amount of time spent outside and participation in sports. At the same time, the investigators measured particulate matter, ozone, nitrogen dioxide and acid vapor in each L.A.-area community. Air pollution and kids’ health do not mix well, they found.

In a 2004 brief prepared for the California Air Resources Board and the state Environmental Protection Agency, John M. Peters, MD, ScD, principal investigator at USC, outlined major findings of the study. They included:

• Lung function consistently is linked with a pack of highly correlated pollutants including particulates, nitrogen dioxide (NO2) and acids, but not ozone. However, ozone was found to be linked to new cases of asthma.

• Vehicle-related pollution is likely to have life-long adverse health effects.

• Air pollution in southern California is associated with several serious health effects that are costly to the state’s budget.

Outdoor Play Impact

Furthermore, they found that kids living within 82 yards of a major highway are 50 percent more likely to have asthma symptoms than kids who live far from a freeway. CHS Investigator Rob McConnell, MD, associate professor of Preventive Medicine at USC, presented this information to an audience at the American Thoracic Society meeting in 2005 in San Diego.

“If we establish that children’s asthma is linked with heavy traffic, then it’s likely to be a long-term and expensive proposition to begin to design cities to separate transportation corridors from where children live, go to school and engage in outdoor exercise,” he said in a statement.

After the highway-asthma connection came to light, California enacted a law that prohibits building a new school within 500 feet of a freeway or busy highway.

Staying away from areas near highways may just be the start of zoning laws to stall the rapidly growing asthma rate among kids. Areas with high incidence of NO2, particulate matter, acid vapors, and ozone might be off-limits too. CHS investigators discovered high asthma rates among kids who frequently played outside in high ozone areas. Lungs developed and grew more slowly among kids living in communities with higher concentrations of NO2, particulate matter and acid vapor.

Interestingly, the asthma-air pollution connection was not found among kids who moved away from the study communities during the 13 years. Moving to areas that had lower particulate pollution increased lung development in some kids, while decreased lung development was recorded in kids who moved to more polluted areas.

California’s Fight to Clean Air

To protect kids’ respiratory health, California has remained proactive throughout the years to reduce air pollution. In fact, the state has adopted the most aggressive clean-air measures in the world.

Even before the federal government enacted the Clean Air Act of 1970, California had its own version of the law, in part to reduce vehicle emissions. When the federal act passed, California was allowed to keep its own laws which are stricter than the national version; but both aim for the same goal: limiting vehicles’ tailpipes from exhausting hydrocarbons, nitrogen oxides, carbon monoxide, particulate matter and formaldehyde.

Where they differ is that California’s law calls for manufacturers to ensure vehicles emit almost no pollutants, encouraging car makers, among other things, to produce hybrid vehicles.

The Clean Air Act also allowed other states, beginning in 1990, to either go with the federal program standards or go with California’s Low Emission Vehicle standards (CLEV). Currently, 10 states and the District of Columbia have adopted the California standards.

Reducing Vehicle Emissions in PA

Among them, the Commonwealth of Pennsylvania currently is trying to extend its Clean Vehicle Program, passed in 1998, which applies the CLEV regulations on car models through 2006. The Pennsylvania Department of Environmental Protection wants to tweak the language of the program to include models made through 2008, but the department is facing a battle with some state lawmakers and lobbyists who want to do away with California’s rules for automakers altogether.

Two bills introduced in October, one in the state Senate and one in the House, aim to make the switch to the federal standards. This isn’t a good idea for the health of Pennsylvanians, the state’s economy, and the environment, said Kurt Knaus, press secretary for DEP.

The DEP predicts that by 2025 the CLVE statute will rid the air of more volatile compounds and nitrogen oxides than would the federal standards, by 12 percent and 9 percent respectively. Applying the findings of the USC team, fewer pollutants in the air could ease the number of new asthma cases reported in Pennsylvania, where asthma already is widespread.

For example, on the Asthma and Allergy Foundation of America’s 2006 Asthma Capitals™ list released earlier this month, Scranton, Pa., was ranked No. 1 in the nation, followed by Philadelphia at No. 3.

What’s more, the CLEV rule is an instrumental part of Pennsylvania’s compliance with the EPA’s Air Pollution Control Act. If Pennsylvania lawmakers pass a law that would change to the federal emissions rule, DEP would have to reorganize and reduce emissions elsewhere, most possibly targeting the already-heavily regulated manufacturers in the state, Knaus told ADVANCE.

Tricky Emissions Control

“If we’re not able to meet the federal requirements with looser vehicle emissions, it would immediately make stricter air-quality laws for manufacturers,” he said. “EPA doesn’t know where we can control any more emissions. We are a heavily regulated state in terms of controlling air pollution from smokestacks and point sources. If we’re not able to achieve these emission reductions on mobile sources, we would be hard-pressed to find other places to improve air quality.”

The Pennsylvania General Assembly has not voted on the matter yet, and the state DEP’s Environmental Quality Board will hold meetings throughout the state in March to gather public comment on any change.

• More information on the USC Children’s Health Study can be found at the California Air Resources Board Web site at Find additional information about the efforts to improve air quality in the L.A. area at the South Coast Air Quality Management District’s Web site at

• To find out some of the latest updates on asthma treatment, the Ohio Asthma Coalition and other organizations are sponsoring a conference, “What’s Up with Asthma? An In-the-Trenches Approach,” on March 10 at the Ohio State University Fawcett Center. Contact Pamela El-Din or Barbara Hickcox at (614) 466-1390 to register.

You can reach Stacey Miller at [email protected]

Thousands Expected to Seek Free Asthma Screening in May

In May, people who have experienced shortness of breath, coughing and wheezing are invited to attend one of hundreds of free asthma screenings taking place throughout the U.S. to find out whether asthma is to blame.

More than 300 cities will host the free screenings as part of the American College of Allergy, Asthma and Immunology’s 10th Annual Nationwide Asthma Screening Program held throughout May, otherwise known as National Asthma and Allergy Awareness Month.

At the screenings—to be held in malls, civic centers, health fairs and other accessible places—suspected asthmatics are given basic spirometry tests and answer various questions about their lung health.

If test and questionnaire results reveal a lung obstruction, those patients are advised to get a further professional evaluation. Of the 10,000 people expected to show up for this year’s screenings, about half are likely to get such a referral, said John Winder, MD, FACAAI, chair of the Nationwide Asthma Screening Program.

“Our goal for the day is certainly to raise awareness of asthma and to detect people who may have asthma and not realize it,” he told ADVANCE. “This provides a convenient way for a lot of people to meet with a physician to determine whether they should seek a thorough examination. It is also a good opportunity for those who already know they have asthma to talk with a specialist about their disease and efforts to keep symptoms under control.”

For the questionnaire portion of the exam, adults answer a Life Quality (LQ) Test, which asks “yes” or “no” points about their breathing (i.e. I have trouble breathing or I cough when I walk or perform simple chores). Children ages 8 through 14 take a special LQ test called the “Kids’ Asthma Check,” which enables older children to answer questions themselves about their breathing problem.

Tracking Young Asthmatics

Children with breathing problems are especially encouraged to take advantage of the free screening, Winder said.

“A big thing about asthma is early detection,” he said. “There has been research that has shown the earlier individuals catch their asthma and start taking anti-inflammatory medicines and other medications, the less likely they are to have long-term consequences of the disease.”

Furthermore, organizers of the screenings attempt to reach out to children at risk. For instance, studies have shown asthma is more prevalent among Hispanic children than other ethnicities; therefore, allergists target Hispanic communities, ensuring information is given to these residents in Spanish and English.

Aside from information on how to treat asthma, allergists give attendees at the screenings literature on how to control allergens that may exacerbate their symptoms.

Winder said: “If through the evaluation they find someone is sensitive to mold, the allergists will go over the things they can do to control mold or dust in their home. Or they might be advised to do away with indoor pets–whatever the trigger might be for them.”

For some asthmatics sensitive to indoor allergens, the solution to control their symptoms lies in ensuring the indoor air is neither too moist nor too dry.

“In the winter, indoor humidity should be 30 to 50 percent,” Winder said. “Below that, the indoor air can irritate the respiratory tract; but above that, it supports mold growth and dust mite growth, which also can irritate the lungs of people sensitive to those allergens.”

As far as using air purifiers, asthmatics can find a wide range of brands on the market, but Winder advises patients need to ensure the purifier does not generate ozone, which does more harm to the lungs than good.

By the end of March, the ACAAI will list the locations of the free screenings on its Web site at under the Public Education section. In the meantime, respiratory therapists interested in participating in a screening program in their area can call the program Help Line at (312) 558-1175 or e-mail [email protected] for more information.

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