Research News
4:06 am
Mon March 18, 2013

Scientists Catalog Individual Dust Particles

Originally published on Mon March 18, 2013 12:38 pm

Transcript

STEVE INSKEEP, HOST:

Now, even if you do not suffer from asthma, it may still be a good idea to reduce your exposure to dust. Invisible tiny particles are constantly swirling around in the air we breathe.

And as reporter Gretchen Cuda Kroen reports, depending on what's in those particles, they may be affecting our health.

GRETCHEN CUDA KROEN, BYLINE: Take a deep breath.

(SOUNDBITE OF INHALATION)

KROEN: Chances are you just inhaled millions of dust particles. The average person breathes in around 50 billion dust particles an hour. And the tiniest particles make their way deep into our lungs, where they can get into the bloodstream and trigger allergies, asthmas, and possibly other diseases.

James Coe is a chemist who studies the composition of individual dust particles at Ohio State University.

JAMES COE: Pretty much all the material in our universe was dust at one point.

KROEN: Most researchers study big globs of dust and look for harmful chemicals. But they don't know how those chemicals are distributed. Coe and his team have managed to trap individual dust particles, and then analyze their unique chemical makeup. He's using the results of his analysis to generate what he refers to as a dust particle library - basically an electronic catalogue of the dust particles in his own lab.

COE: Here is an individual dust particle.

GRETCHEN CUDA-KROEN, BYLINE: One's of Coe's graduate students points to a graph with a bunch of peaks. He explains that the location of the peaks tell him what's in the dust.

UNIDENTIFIED MAN: So like here is calcite, here is dolomite, here is gypsum.

CUDA-KROEN: Dust particles are kind of like snowflakes - no two are exactly alike. But they all share a base of common materials: minerals like calcite, gypsum or quartz, and organic materials from stuff that is, or used to be, living. The organic stuff is what they are most interested in - because it's the organic components in the dust we breathe that are thought to have the biggest impact on human health. Coe wants to compare the dust particles from clean air environments like his lab, to the dust in places where the air is maybe not so nice.

COE: Like in a parking garage and so there's a lot of automobile exhaust, or in a bar where there's a lot of smoking

CUDA-KROEN: By getting an accurate picture of the dust in various environments, researchers may be able to draw conclusions about how air quality affects human health.

And that's just what Laura Fonken is trying to do in a neuroscience lab across campus. Fonken wanted to know whether normal air pollution would affect the brain. So she collected dust from the air around Columbus Ohio, and then exposed a group of mice to the airborne particles. After a year - the majority of a mouse's life - she compared their memory, behavior - and the brains of those mice, to mice who had only been exposed to clean, filtered air.

LAURA FONKEN: So basically, we found that the mice that were housed with polluted air showed more depressive like responses, they had a harder time remembering where they are in the maze, they had a more difficult time finding that escape box. And we found the mice that were exposed to polluted air had less connections between the neurons compared to the mice that were housed with filtered air.

CUDA-KROEN: In other words, the brain cells of the mice that were exposed to the air of Columbus, Ohio made fewer connections, and the mice had a harder time remembering things and acted depressed.

Now Fonken readily admits her experiments can't say anything definitive about how air pollution affects the brains of human beings, but she says, it does get people thinking about how the dust around us can have harmful effects.

And that's important because the health impacts of dust are underappreciated says Tim Buckley.

TIM BUCKLEY: I think we have discovered that dust can be anything but harmless.

CUDA-KROEN: And Buckley says the dangers of dust aren't just in polluted air - but in our homes. The house dust that accumulates on our carpets and floors can be a reservoir for toxic chemicals like pesticides, and flame retardants. And that's a problem because children often pick up food or toys from the floor and a lot of that dust ends up in children's mouths.

BUCKLEY: You can accumulate a lot of house dust on a hot dog or slice of cheese.

CUDA-KROEN: A better understanding of the chemicals that make up the dust particles on that cheese is a first step in understanding, not only how they might harm us - but how we might control them. And that's just what Buckley hopes James Coe's library of dust particles will eventually do.

In the meantime, he says, a certain amount of dust is unavoidable. We simply have to remove it the best we can.

(SOUNDBITE OF VACUUM CLEANER)

CUDA-KROEN: For NPR News, I'm Gretchen Cuda-Kroen. Transcript provided by NPR, Copyright NPR.