More than half of the population of the world live in cties. Because of this liviing in a city has many down points like:
1.- City life can make us crazy. If you live in a city you have more probability to develop a mental disorder, 21% increased risk to develop anxiaty disorder, 39% increased risk to develop a mood disorder.
2.- The constant light don't let us sleep.
3.- The air is polluted. It increases the probabilty to develop asthma.
4.- The noise is terrible.
5.- Rush hours are very common.
6.- There are uncaring crowds.
7.- All of these things affect our inmune system.