Chlorofluorocarbons deplete the ozone layer , which absorbs UV radiation. This may weaken immune systems and increase the chances of skin cancer and eye diseases. The United States EPA, Environmental Protection Agency, banned CFC's in aerosol sprays in 1978. Smog was a mix of smoke and fog. Now, it also includes pollutants such as ozone, sulfur dioxide, and nitrogen oxides.
Smog aggravates respiratory ailments.