In this activity, students quantify and analyze their personal contributions of smog-forming compounds due to driving. The activity builds upon the previous lesson (Ground-Level Ozone). The students will review online materials on vehicle emissions and use an environmental calculator produced by Environmental Defense to examine their individual emissions of ozone-forming compounds. They will enter year, model, and make of vehicle, along with annual mileage, and receive an estimate of output of smog-forming nitrogen oxides and hydrocarbons (VOC's). To conclude the activity, they will review some online resources on the connection between asthma and air pollution.