The substances that come out of a car's tailpipe, such as carbon monoxide, sulfur oxide, nitrogen oxide, hydrocarbons and carbon dioxide, are harmful to our health and to the environment. Carbon monoxide affects the blood supply and can cause heart disease; sulfur dioxide causes acid rain; nitrogen oxide causes the haze over populated cities; carbon dioxide gases produce the greenhouse effect; and hydrocarbons cause cancer. The federal government set up regulations to limit car emissions, ensuring a safer, healthier environment.
