Pollution isn't only a detriment to our environment and a nuisance to the senses, but it has negative effects on the body. It wears us down internally, causing lung and cardiovascular problems, has been speculated to cause types of cancer, and irritates the eyes, nose and throat on contact. It can also damage our skin and hair, giving us a dingier appearance. If you live in a big city, there is almost no escaping the smog. There are, however, steps you can take to reduce the effects of pollution on your body.
If you can, avoid driving in the smoggier parts of town, near factories and plants that put out large amounts of waste. If you find yourself driving through a cloud of smog, roll up your windows for the duration of the time you are there. It's not going to provide a complete barrier, but your exposure to the toxins will be minimized.