There is no fresh air and pure water. The environment is polluted with dust, smoke, garbage and dioxide gases from factories. Most of the people who live in the city are corrupted. So there are lots of crimes in the city. Many thefts and murders often take place in the city. The city is always busy and noisy. There are a lot of vehicles and people in the road.
Apart from that , if you do x ray of people's lungs, all of them will be dark since the air we breathe is not pure, i just go in nature every few months to refresh my lungs and overhaul my system.