Dirty Road Snow
Snow melt is a great time to visualize the pollution caused by cars. When you see the filthy slush on the sides of the roads, do you ever stop to think, what is all that black stuff? Is it just dirt and sand? Well, the sidewalks don’t ever get so disgusting from the bottoms of shoes, not even close. Seems the filth must be a combination of engine oil and gasoline droplets combined with rubbings from tires maybe mixed portions of the asphalt that are continually breaking up. And what kinds of chemical additives and heavy metals are in all these pollutants?