4. Technical operation

The main aim of publishing the regulatory texts cited in this article was to formalize and reframe the air quality monitoring systems that the associations had already set up in the past, in order to gain knowledge of pollution in different types of area: urban background and automobile proximity, suburban, industrial and rural. The main difficulty encountered was choosing measurement sites that were representative of each typology, and ensuring that the choices made were realistic. ADEME has therefore published a guide to the classification of measurement stations [7] , details of which are given below.