The Dirt on Dirt
You might think the old-fashioned dirt road is harmless. But that's not so. Airborne dust from road creation and from wind and traffic compromises vegetation, erodes soil (increasing runoff), increases water sediment loads (degrading aquatic vegetation) and pollutes the air.
Controlling dust creates new problems. For years, petroleum-based coatings, such as emulsified asphalts and motor oil, were used to stop the dust from flying off the roads. More recently, the slightly less damaging calcium chloride has been used to grab moisture out of the air and weigh down the materials on the surface of the road, but its runoff is so environmentally unfriendly that its use may be illegal in some states, according to Grit.com.