Researchers examine oleic acid in atmosphere


Sandhya Gopalakrishnan

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COLUMBUS, Ohio Researchers at Ohio State University are studying how oleic acid a heart-healthy fat touted for lowering cholesterol levels interacts with other molecules once it gets into the atmosphere.

Scientists know that oleic acid can react with other atmospheric compounds, such as ozone, and create byproducts that are hazardous to our health. But they haven't been able to precisely measure the amount of byproducts those particular reactions create.

The process of charbroiling or frying meat releases oleic acid into the air. And urban areas particularly where there are clusters of restaurants can have fairly high levels of atmospheric oleic acid, said Sandhya Gopalakrishnan, the study's lead investigator and a postdoctoral researcher in chemistry at Ohio State.

"It's the byproducts formed by the reactions between fatty acid particles and other atmospheric compounds, such as ozone, that can cause health problems," she said. "These particles are often small enough to inhale, and can irritate eyes and skin as well as cause respiratory problems such as asthma and bronchitis."

In this preliminary study, scientists looked at the structure of individual oleic acid molecules. They wanted to see how these molecules oriented themselves when they came into contact with the surface of water molecules.

Heather Allen

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"Knowing how molecules orient themselves is a big factor in understanding how they react and what byproducts they form," said Gopalakrishnan. "These orientations may play a big role in how compounds change during reactions. We don't know much about how the orientation of molecules affects chemical reactions."

Gopalakrishnan conducted the work with Heather Allen, an assistant professor of chemistry at Ohio State. Gopalakrishnan presented their findings in Columbus on June 25 at the annual Molecular Spectroscopy Symposium.

The researchers looked at the reaction between molecules of oleic acid and water by using a technique called sum-frequency generation spectroscopy. This technique uses laser light, which lets researchers see both molecular structure and orientation at the interface between compounds.

The researchers next want to study what happens on the surface of molecules when oleic acid reacts with ozone, which is a dangerous pollutant at ground level.

Oleic acid and ozone react to form more fatty acids and free radicals in the air, which in high enough concentrations can cause health problems, Gopalakrishnan said.

With their future work they hope to be able to quantify the amount and exact kind of byproducts formed when oleic acid and ozone react.

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Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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