Percentage of population resident in urban areas potentially exposed to NO2 concentration levels exceeding the annual limit value, EEA member countries, 1997-2007
The annual mean limit value is 40 µg NO2/m3. Over the years 1997-2007 the total population, for which exposure estimates are made, increased from 54 to 113 million people due to an increasing number of monitoring stations reporting air quality data under the Exchange of Information Decision. Data prior to 1996 with a coverage of less than 50 million people are not representative for the European situation. Year-to-year variations in exposure classes are partly caused by changes in spatial coverage. Only urban and sub-urban background monitoring stations have been included in the calculations. Data for Cyprus, Iceland, Liechtenstein, Luxembourg, Malta, Norway and Turkey are not included due to the geographical coverage of the Urban Audit and/or lack of air quality data.