Answer the following question given this paragraph: 

The ozone in smog is also harmful to human health. The image below shows the levels of ozone to watch out for ( Figure below ). Some people are especially sensitive to ozone. They can be harmed by levels of ozone that would not affect most other people. These people include those with lung or heart problems.


Q: What harmful light does ozone reduce in the upper atmospheres?


A:
ultraviolet light