Percentage of urban population resident in areas where pollutant concentrations are higher than selected limit/target values, EEA member countries, 1997-2006
Targets * A limit value for PM10 of 50 microgram/m3 (24 hour average, i.e. daily), not to be exceeded more than 35 times a calendar year. * An annual mean limit value for nitrogen dioxide of 40 microgram NO2/m3. * A target value for ozone of 120 microgram O3/m3 as daily maximum of 8 hour mean, not to be exceeded more than 25 days per calendar year, averaged over three years. * A limit value for sulphur dioxide of 125 microgram SO2/m3 as an daily average, not to be exceeded more than three times a calendar year.