There are a lot of disadvantages of living in a big city, air pollution is among the most serious problems. Firstly, air pollution comes from the factories in the city. Big cities attract a lot of both inside and outside investments, so the number of factories is increasing quickly. This makes the air extremely polluted by smoke from factories. Secondly, that there are too many transportation means also makes this problem worse. Exhaust from cars, motorbike is one of the factors that make the air polluted. To conclude, air pollution, which contributes to making more and more people get many serious diseases, such as lung cancer, tuberculosis and so on, is a big drawback of city life.