Air quality indicators: concentrations

Sector Air quality
Description Concentrations of nitrogen dioxide (NO2), particulate matter (PM) and ozone (O3) evaluated as averages or percentiles
to be comparable with WHO guidelines and EU limit values.
Emissions data describing the historical time-period have been obtained from EMEP, national and regional authorities. The emission data
used for future scenarios is based on IASA projections.
End User Environmental authorities, air quality consultants, urban planners
Calculation method ID Title Period Statistical processing Unit Threshold Comment
cEUNO2hourly 99.8th percentile of
hourly NO2
yearly 99.8th percentile of hourly
averages during a year
(same as 18 exceedances per
µg m-3 200 µg
EU limit value
cEUNO2yearly Yearly average NO2
yearly Average µg m-3 40 EU limit value
cEUPM2.5yearly Yearly average PM2.5
yearly Average µg m-3 25 EU limit value
cEUPM10yearly Yearly average PM10
yearly Average µg m-3 40 EU limit value
cEUPM10daily 90th percentile of
daily average PM10
  90th percentile of daily
averages during a year (same
as 35 exceedances per year)
µg m-3 50 EU limit value
cEUO3daily 93.15th percentile of
daily max of 8-hour
running averages of
ozone concentration
yearly 93.15th percentile of max of 8-
hour running averages
(same as 25 exceedances per
µg m-3 120 EU target value
cO3SOMO35 SOMO35 yearly Sum of excess of max daily 8-
hour averages over
35 ppb (= 70 µg m-3)
calculated for all days in a
year; SOMO35 (Sum
Of Means Over 35 ppb)
days*µg m-3 35 ppb WHO indicator
Provenance These indicators are based on output from the MATCH model
Validation The downscaling made by MATCH in Urban SIS has been validated against observations in Urban SIS deliverable 5.2, where an overview is given in Table 4.
Calculation caveats Spatial representation: S2
Other caveats: O5
Could be compared to:
Could be used with:
Motivation EU air quality limit/target values are an essential legal instrument for air quality management in Europe.  The ozone indicator SOMO35 defined by WHO is an exposure metric used as a basis for health impact assessments. The presented exposure estimates are used as a basis for the air quality health impact indicators.
A large part of the population is exposed to the urban background concentration of air pollutants. The urban background concentration is used for indicators related to population exposure and health impact due to air pollution. The concentration indicators provide an overview of the concentrations and can for example be used to identify areas with air pollution exceeding or getting close to the air quality limits or guidelines.
Experience user  

Directive 2008/50/EC of the European Parliament and of the Council of 21 May 2008 summarized at

WHO 2005: Air quality guidelines. Global update 2005. Particulate matter, ozone, nitrogen dioxide and sulfur dioxide. ISBN 92 890 2192 6.