To save the planet, better change what’s beneath a car’s wheels (and your feet) than the car itself.
Prepare to get your mind blown. A new study in the journal Science Advances has found that cars may not be the main culprit when it comes to air pollution in the big cities; a bigger evil is lurking around. One that’s easily overlooked by most of us day after day.
Asphalt. The material that city roads are made from is more harmful to our environment than the pollutants released by gasoline and diesel vehicles: “In total, the annual potential [air pollution] production from asphalt related sources in the SoCAB is greater than that of gasoline and diesel on-road motor vehicles combined.”
Scientists came to this conclusion after analyzing chemical compounds released by asphalt in different weather conditions, including high temperatures. These are the VOCs (volatile organic compounds) and I/SVOCs (intermediate/semivolatile organic compounds) we normally notice during fossil fuel combustion.
Turns out, once you put a high-res, mass spectrometer to the work, you will realize the asphalt’s reaction to heat is to emit harmful particles in the air on a shocking scale. The parameters change when the asphalt is heated to 140°C (284°F) – which happens when it is used to pave new roads – in comparison to 60°C (140°F).
So, when asphalt is exposed to solar radiation, 300 times more of these compounds are released, turning the ground we stand on a silent enemy.