Asphalt adds to air pollution, especially on hot, sunny days

Asphalt is a near-ubiquitous substance - it's found in roads, on roofs and in driveways - but its chemical emissions rarely figure into urban air quality management plans. A new study finds that asphalt is a significant source of air pollutants in urban areas, especially on hot and sunny days. Yale researchers observed that common road and roofing asphalts produced complex mixtures of organic compounds, including hazardous pollutants, in a range of typical temperature and solar conditions. The results of their work, from the lab of Drew Gentner , associate professor of chemical & environmental engineering,  appear Sept. Advances. Decades of research about and regulations of emissions from motor vehicles andother combustion-related sources have resulted in improved urban air quality. But recent studies show that as those efforts succeeded, numerous non-combustion-related sources have become important contributors of organic compounds.