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Hot Asphalt May Increase Air Pollution in Urban Areas

Research shows that road asphalt exposed to heat and sunlight may eventually become a significant emissions source.
September 21, 2020, 9am PDT | Camille Fink
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Washington State Dept of Transportation

A new study reports that asphalt emits significant amounts of pollutants in hot conditions. "[Researchers] observed that asphalt emissions doubled when the temperature increased from 40C to 60C — levels the material often reaches in summer," reports Rhi Storer.

When road asphalt was exposed to both solar radiation and heat, to mimic outdoor summer conditions, the researchers found a 300 percent increase in emissions. The release of secondary organic aerosols has been shown to have public health impacts, notes Storer.

While most traffic-related pollution comes from vehicle sources, the impact of cars and trucks may decrease as gross polluters are phased out. As a result, asphalt emissions may contribute more to air pollution as urban areas grow—45 percent of the surface area in the United States is paved—and temperatures rise due to climate change.

Full Story:
Published on Wednesday, September 2, 2020 in The Guardian
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