A summary of the criteria pollutant inventory is published annually.
Point sources are fixed pollution sources such as electric power plants and refineries.
There are also about 135 aggregated point source categories. An area-wide source category is made up of sources of pollution mainly linked to the activity of people. The principal agencies contributing data to the stationary and area-wide source inventory are the ARB and the California air pollution control and air quality management districts. The information represented in the California emission inventory is a snap-shot of a variety of dynamic and variable processes. As such, the emission inventory can only represent an estimate of what is actually occurring.