Emissions from asphalt are a significant source of air pollutants in cities, especially in hot weather, a study shows.
Researchers found that when asphalt was exposed to hot summer conditions it resulted in a 300% increase in emissions of secondary organic aerosols (SOA), an air pollutant known to have significant impacts on public health.
Asphalt emissions doubled when the temperature increased from 40C to 60C — levels the material often reaches in summer.
A main finding is that asphalt-related products emit substantial and diverse mixtures of organic compounds into the air, with a strong dependence on temperature and other environmental conditions.
Although the impact of emissions from asphalt on ozone formation was minimal compared with motor vehicles in urban areas, research into road asphalt is an important part of tackling the climate emergency.