Air Date: Week of January 23, 2004

Living on Earth’s Jennifer Chu reports on how rice could become a key ingredient for cutting down road noise.

Transcript

CURWOOD: Just ahead, find out how you can join me for an adventure on safari in Africa. First, the Note on Emerging Science from Jennifer Chu.

[SCIENCE NOTE THEME]

CHU: When the rubber hits the road, highways can get pretty noisy for residents who live near them. Researchers in Japan are working on a way to cut down on road noise. Their solution: just add rice. Or more specifically, rice bran, the brown layer found between the husk and the grain. This layer, combined with grain, is what we call brown rice. Up until now, the bran has been thrown away, or used as cattle feed. Now there’s another option.

Scientists have found that mixing and heating the rice bran with resin, then adding it to asphalt, makes for some promising pavement. The rice and resin mixture acts as a light and porous material. During tests, scientists discovered these rice-based roads absorb 25 percent more noise than regular asphalt roads. There’s one more advantage: since the rice mixture is porous and flexible, it can filter through and more easily drain away water.

In the long run, this could prevent cracks and potholes from forming. Highway analysts say this method is similar to one employed in the U.S. Instead of rice, states like Arizona, California and Texas use ground-up rubber tires in their asphalt to cut down on road noise. That’s this week’s note on emerging science. I’m Jennifer Chu.

CURWOOD: And you're listening to Living on Earth.

ANNOUNCER: Funding for Living on Earth comes from the World Media Foundation Environmental Information Fund. Major contributors include the Town Creek Foundation and the Wellborn Ecology Fund. Support also comes from NPR member stations and Bob Williams and Meg Caldwell, honoring NPR's coverage of environmental and natural resource issues, and in support of the NPR president's council. And Paul and Marcia Ginsburg, in support of excellence in public radio.

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