Smog affects lots of things, for starters, it pollutes the air so (if there is enough of it) the air is unsafe to breathe. It also holds hot air inside Earth's atmosphere so it cannot escape into...
smog is smoke+fog. its illeffects are:
1 it causes respiratory diseases such as bronchitis or asthma
2 it causes air pollution
3 it causes driving problems
4 it blackens the buildings