Smog over Melbourne.

Smog is a problem in most large cities. It is caused by emissions from industry, motor vehicles, domestic wood combustion and other sources, accumulating under certain meteorological conditions.

The term smog was first used during the 1950s to describe a mixture of smoke and fog. EPA can forecast days when smog will be a problem, and will issue appropriate alerts when necessary.

Page last updated on 20 May 2015