According to the definition provided by the United States Environmental Protection Agency (US EPA), an air quality management cycle includes all the measures taken by a regulatory authority to protect human health and the environment against the harmful effects of air pollution. This cycle is dynamic and comprises inter-related elements.
Meanwhile, emission inventories are considered essential tools for the targeting of regulatory actions in the context of the air quality management cycle. In fact, they provide precise tools for the determination of the main air pollution sources and the quantification of their contributions to air pollution.
The term "emission inventory" refers to a database containing a structured collection (based on spatial and temporal scales) of the emissions originating from a variety of sources. The ultimate objective of an emission inventory is to quantify the pollutants emitted by different sources into the atmosphere, as well as to identify and prioritize all those sources that contribute to air pollution in the area of interest. Moreover, emission inventories are regarded as a prerequisite for the creation of air quality dispersion models and large- or micro-scale photochemical models. In addition, emission inventory systems can be used to conduct impact assessments of air pollution mitigation plans.
Emission inventories represent fundamental components of air quality management plans and the most significant scientific tool for the recognition and mitigation of air pollution. In the lack of emission inventories, planning mitigation strategies would be completely unfeasible. As a matter of fact, emission inventories are able to convert quality objectives into quantitative targets, allowing evaluations of the effectiveness of control measures.
The National Emission Inventory is a web-based, user-friendly platform that targets 10 polluted megacities in Iran (Tehran, Mashhad, Karaj, Isfahan, Tabriz, Shiraz, Arak, Ahvaz, Qom, and Kermanshah) and was launched for the first time in 1398 (2019).
In the National Emission Inventory system is conducted considering the following sources