text: Air pollution is probably one of the main disadvantages that come with cars. The gas that your car burns, releases harmful chemicals that can cause environmental problems, like smog for example. That's not good, especially for people who have health problems, such as ahsma. I know from personal experience that my little sister has bad ahsma, and sometimes she finds it hard to breathe if she walks into a room where someone has smoked in even hours before. Image how the smog would affect other people like that. Paris enforced a partial driving ban to clear the air a bit. The smog cleared quite a bit just within a few days with the ban. They even recorded that due to the ban, there was a 60 percent congestion drop.