Cook County Comm. Maggie Trevor (D-9) is pictured during County Board President Toni Preckwinkle's budget address in October. [Don Vincent/The Daily Line]

The Cook County Board of Commissioners on Thursday approved a measure outlawing the retail sale and commercial application of coal tar sealant on asphalt pavement, a move which advocates say will mitigate further introduction of toxic pollutants into the environment.