Within Common Information To European Air (CITEAIR) the first European Common Air Quality Index (CAQI) was developed and was used to harmonize the air quality database displayed on a Common Operational Webpage (COW).

The COW provided a platform to compare near-real time air quality information.

The project started in March 2004 and ran until the end of 2007, supporting cities and regions in the development of efficient means to collect, present and compare air quality data across a multitude of sites. CITEAIR I provided an input to the air quality reporting and action planning, supporting European cities and regions in their efforts to meet limit values and improve the air quality for their citizens.

During almost three years of productive work among partners and an exchange with stakeholders including the European Commission (DG Environment) and the European Environment Agency (EEA) a valuable set of products have been developed.

The main developments underpinned by products of CITEAIR are: