analyses provide an overview of the air toxics program and build on the power
of a large data set to find the central tendencies in the data.
|Knowledge is needed
of the nearby sources, operating schedules, facility upsets and closures, new
emission sources, types of emissions, types of controls and scheduled
implementation, data reporting and quality issues, changes in sampling and
methodology, local meteorology, and other details to fully understand changes
in ambient pollutant concentrations.