Air Date: Week of June 13, 2008

Bee populations are collapsing, and new research shows pollution may have something to do with it. As Margaret Rossano reports, air pollution diminishes the scent of flowers and pollinators can’t always locate their food source.

Transcript

[MUSIC: "Track 70 - Bee Swarm" from 'The Ultimate Digital-Stereo Sound Effects Library, Nature and Animals' ]

There's been a lot of buzz in the news lately about bees. That's because U.S. bee populations both honeybee and wild—have plummeted.

[THEME MUSIC]

Honeybee colonies have declined by almost half in the past 60 years. Scientists aren't sure exactly what's causing so-called Colony Collapse Disorder, but a recent study by a research team at the University of Virginia suggests that air pollution may have something to do with it.

Emissions from vehicles and industry contribute to the formation of air pollutants like ozone. The scent molecules produced by flowers - which help pollinators find them - are extremely volatile, and bond easily with these pollutants.

The UVA researchers created a mathematical model that shows how far scent molecules travel at different levels of pollution, from very low, pre-industrial revolution levels to current levels found in areas downwind of large cities.

The team found that air pollution destroys flowers' aroma by as much as 90 percent. Scent molecules that once traveled three quarters of a mile may now migrate less than one quarter of a mile.

Because scent molecules cover only a short distance before they are chemically altered, it's much more difficult for pollinators to find them. Bees struggle to find food, and flowering plants suffer because they're not pollinated.

It looks like bees may be yet another reason why we need to curb air pollution.

That's this week's note on emerging science. I'm Margaret Rossano.