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Spring Arrives ... with Pollen & Increased Air Pollution


Spring's warm air and sunshine are here at long last, but with them come some unwelcome visitors — pollen and increased air pollution.

"Pollen particles are quite large and when you breathe in they are filtered by your nose and throat," said Carnegie Mellon Professor Neil Donahue, director of the Center for Atmospheric Particle Studies (CAPS). "That's not good news for allergy sufferers, but it's good news for your lungs. Air pollution, on the other hand, deals with much smaller, and much more dangerous, particles."

Research at CAPS focuses on understanding the sources of air pollution and finding effective means to reduce it. Donahue sites the example of some fine particles known as PM2.5, which are 10 times smaller than a human hair. PM2.5 particles can lead to severe health effects, and they are also the cause of haze.

"When you can't see downtown [Pittsburgh] from Schenley Park in the summer, it is because there is lots of PM2.5 in the air," Donahue said, adding that up to 50,000 deaths per year in the United States can be blamed on PM2.5 respiration. "To make matters more interesting, fine particles also serve as the nucleus for each and every cloud droplet formed in the atmosphere," Donahue explained.

"The number of cloud droplets depends on the number of fine particles, which means that particles control how white the clouds are."

About 30 percent of incoming sunlight to the Earth reflects off of clouds, and this "whiteness" effect is a leading source of uncertainty in assessing global warming.

While its focus is complex, CAPS mission is simple: to be world leaders in science, engineering and policy covering the full role of fine particulate matter in the atmosphere. Their goal in research is to educate leaders and actively participate in the evolution of environmental policy related to particulate matter.

Bringing together scientists from all fields, as well as policy analysts, the work of CAPS embodies the interdisciplinary nature of research at Carnegie Mellon and within the Steinbrenner Institute for Environmental Education and Research.

Related Links: Center for Atmospheric Particle Studies  |  SEER  |  Chemistry Dept  |  Chemical Engineering Dept  |  Intergovernmental Panel on Climate Change

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