Because a large number of glass or other reflective materials are used, it will cause light pollution and affect people's eyesight, and it will also react with pollutants in the air to cause secondary pollution (it seems that this phenomenon has happened in London and Los Angeles, causing thousands of deaths, but I can't remember the details. If it is wrong, please forgive me! )
There is also noise pollution caused by too many cars, which will affect people's rest and thus affect people's mental state.
And now many people use air conditioners and other similar household appliances, which leads to the decline of people's resistance, and people staying at home for a long time will also turn people into many diseases or mental diseases!
The above is purely my own thinking. Please forgive me if I make a mistake! ! !