"Each year a large number of Lake County homeowners get their driveways seal-coated to maintain a smooth, clean look while also protecting the asphalt beneath from winter snow, ice and salt.

Government officials often do the same with public parking lots.

But recent studies show that the coal tar used in the seal-coating process could be negatively impacting the health of humans and the environment, said Barbara Mahler, a researcher and hydrologist with the U.S. Geological Survey."

Sheryl DeVore reports for the Lake County News-Sun/Chicago Tribune October 16, 2015. [2]