Since then additional laws and regulations have been added including the 1990 Amendments to the Clean Air Act. In order to make improvements in the air quality, the amount of pollutants in the air must be measured. The Emissions Measurement Center develops standards and evaluates testing methods so that regulations can be developed and enforced. An emission factor is a relationship between the amount of emissions that are released and the activity of the producer. Emission factors are used to predict emission levels fordifferent industries.
Emission inventories are quantities of pollutants measured over time.
Emission inventories can be compared with air pollutant levels in an area to determine if increased emissions decreases the air quality. Once the measurements are made the information must be collected and stored so that it can be used to evaluate the air quality and effects of the regulations. This is the job of the Emission Factor and Inventory Group. Modeling The emissions data that is gathered is also used to create models which can help to predict what air quality will be like in the future and what effect new regulations might have on air quality. Software Computer software programs have been created to help people to evaluate and sort out the pollution data that has been collected.