Asthma and Allergies Linked to Climate Change

As pollen counts reach record highs across the United States this allergy season, more patients are likely to visit pharmacists for relief from asthma and allergies. Recent studies suggest global warming may be a contributing factor.

Patients struggling with itchy eyes and red noses may be reluctant to acknowledge Earth Day this year, in light of the human misery caused by one of nature’s most vital—and vexing—processes: pollination.

Some observance of the holiday—taking simple steps to reduce carbon emissions, for example—may actually help reduce allergies and asthma in the long term. Experts say rising pollen counts are influenced by increasing levels of carbon dioxide, or CO₂

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a greenhouse gas produced from the burning of fossil fuels. CO₂ is crucial to photosynthesis, and increased levels prompt plants to produce more pollen—a possible reason why Atlanta, Georgia, recently recorded its second highest pollen count ever of 5733 grains per cubic meter.

David Rosenstreich, MD, director of the division of allergy and immunology at Montefiore Medical Center in the Bronx, agrees that “pollen seasons are lengthening a bit” due to global warming, according to a report by HealthDay. Research also shows that ragweed grows much faster and produces more pollen when planted in cities, where temperatures tend to be warmer and CO₂ levels higher than in rural areas.

Asthma in children is also exacerbated by pollutants, especially in warmer weather. Matthew Strickland, PhD, MPH, of the Department of Environmental Health at Emory University, just completed a study linking concentrations of ozone and motor vehicle exhaust directly to increased emergency department visits for treatment of pediatric asthma.

The findings appear in current online issue of the American Journal of Respiratory and Critical Care Medicine (AJRCCM), and underscore the need for more stringent air quality standards, Dr. Strickland said.

Another recent AJRCCM study found that children who live within 165 feet of a major road had a 50% chance of developing allergies. The same children were also at a higher risk for other atopic diseases, including asthma, hay fever, and eczema.

Still, the exact relationship between asthma or allergies and changes in the environment is not precisely known. In the meantime, patients may need to be reminded of simple, proactive steps they can take to reduce their carbon footprint and cope with seasonal symptoms.

Resources

The American College of Allergy, Asthma, and Immunology publishes numerous patient education brochures and other resources, which are available on the organization’s Web site. For a list of OTC products pharmacists recommend for allergy and asthma, visit the 2009 edition of the Pharmacy Times OTC Guide online at www.OTCguide.net.

For tips on reducing carbon emissions, as well as a handy carbon footprint calculator, visit the Nature Conservancy’s climate change resource center.

For other articles in this issue, see:

• Next-Generation Pharmacist: Shining the Spotlight on Pharmacists
• Can Frequent Indoor Tanning Lead to Addiction?
• Computer-Translated Prescriptions Put Patients at Risk