Air pollution is a very big problem in the United States. A large part of air pollution comes from cars. The Environmental Protection Agency says, "The most polluting activity an average person does everyday is drive their car"(1 factsheet OMS-5). Most people probably aren't aware that they are polluting the environment. Maybe if everyone knew how serious this pollution problem is, they would find ways to reduce the pollution. Most pollution that is released by cars comes from the exhaust, mainly in the form of hydrocarbons(1 factsheet, ....