Air pollution at street level in European cities

1. Air pollution at street level in European cities Nicolas Moussiopoulos, Zissis Samaras, Liana Kalognomou, Myrto Giannouli, Sofia Eleftheriadou, Giorgos Mellios, ETC/ACC - Aristotle University Thessaloniki, Greece EEA project manager, Jaroslav Fiala EEA technical report sent for country review

2. Background • Traffic-related air pollution is one of the most pressing problems in urban areas. Evidence of the adverse health effects of fine particulate matter is continuously emerging. Most of the traffic-related emissions are in the fine particulates range (<PM2.5) • Human exposure to increased pollutant concentrations in densely populated urban areas is high. LV are in case of NO2, PM10 currently frequently exceeded namely at urban/traffic hotspots • Thereport deals with the air pollution levels at traffic hotspot areas in 20 European cities, compared to the urban background concentrations for NO2, (NOx), PM10 and PM2.5 • Base on the request of DG Env the current situation (reference year 2000) and two scenarios aimed at 2030 (Current Legislation, CLE, and Maximum Feasible Reductions, MFR) were considered to analyse and project air quality

3. Methodology outline • The methodology was developed in the ETC/ACC ‘Street Emission Ceiling (SEC)’ project aiming to determine which local emission reductions are needed in streets in order to reach certain air quality thresholds • Application of the urban scale OFIS model with EMEP model results to obtain the urban background • Application of the local(streetcanyon) OSPM model with OFIS model results to estimate hotspot air pollution levels • Urban emission inventories (2000) were provided by for each city (MERLIN project) • Urban emission projections (2030) predicted according to the emission control scenario CLE • For local emissions (2000) vehicle fleets from TREMOVE and TRENDS were used for calculating emissions with COPERT • Street level concentrations were calculated for three hypothetical street canyon configurations (wide, square and narrow) representing types existing across Europe • The hypothetical street canyons were defined from the ‘Typology Methodology’ representing an attempt to categorise street types

4. Urban and air qualityAnnual NO2 urban background concentrations Range of OFIS model results for the reference year 2000 comparedwith the range of observations and average value of all stations.

5. Urban and air qualityAnnual PM10 urban background concentrations To account for natural primary and secondary PM a constant value of 17μg/m3 has been assumed in all cities. This value was estimated as an average across all data available for the annual mean PM10 concentration measured at the EMEP Range of OFIS model results for the reference year 2000 compared with the range of observations and average value of all stations

6. Urban and air qualityAnnual PM2.5 urban background concentrations Range of OFIS model results for the reference year 2000 compared with the range of observations and average value of all stations

7. Local air quality - street increments 1/3 Air quality at street level calculated using the OSPM for three hypothetical street canyons • Narrow case (h=15 m, w=10 m), average traffic 20 000 veh/day • Square canyon (h=15 m, w=15 m), average traffic 30 000 veh/day • Wide canyon (h=15 m, w=40 m), average traffic 60 000 veh/day • Typology methodology used for HDV%, vehicle speed and street canyon geometry • TREMOVE/TRENDS results used to classify each city into each category (7% or 15% HDV) considered according to typology methodology Differences between the street increments for the three canyon geometries are generally small. In most cases the largest increments are observed for the wide canyon due to the increased number of vehicles. However applicability of the OSPM model is doubtful in case of wide canyon.

8. Local air quality - street increments 2/3 Mean annual NO2 street increments (μg/m3) for the reference year 2000 in 20 European cities: model results for the narrow canyon case compared with observations

9. Local air quality - street increments 3/3 Mean annual PM10 street increments (μg/m3) for the reference year 2000 in 20 European cities: model results for the narrow canyon case compared with observations

10. Scenarios - NO2 Annual mean air quality at regional (EMEP), urban (OFIS) and street scale (OSPM) for selected cities in the reference year (2000) and the CLE and MFR scenarios

11. Scenarios – PM10 Annual mean air quality at regional (EMEP), urban (OFIS) and street scale (OSPM) for selected cities in the reference year (2000) and the CLE and MFR scenarios To account for natural primary and secondary PM a constant value of 17μg/m3 has been assumed in all cities

12. Conclusions • OFIS and OSPM model results were analysed to discuss air quality limit value exceedances in the 20 European cities considered • The exceedance days calculated for PM10 in 2000 are higher than allowed in almost all cities in the narrow canyon, in 14 cities in the square canyon and in half the cities in the wide canyon case • In the year 2030, the model results imply that at street level for a narrow canyon, the annual limit value for NO2 will be met in only very few cases in the CLE scenario and in most cases in the MFR scenario, whereas the indicative limit value for PM10 is not expected to be met even in the MFR scenario • The allowed number of exceedances according to the 2010 limit value is expected to be met for NO2 in all cities for the narrow canyon case even in the CLE scenario, though exceedances of the PM10 indicative limit value are observed in certain cases even for the MFR scenario • For PM2.5 the reduction is in line with the significant reductions in the urban and in street scale PM emissions attributed to the introduction of EURO 5 and EURO 6 compliant vehicles. • Particular unfavourable cases observed in certain cities with exceptionally high concentrations are difficult to model unless the specific street characteristics are known in detail • Detailed local traffic data combined with air quality measurements and data on the specific street are required in order to evaluate the overall methodology of this report as well as to determine the appropriateness of the selection of the particular street canyon configurations • The urban background concentrations with the available top-down emission inventories should be compared against up-to-date, bottom-up local emission inventories upon which local city development scenarios can also be evaluated. Finally, reliable vehicle fleets for new and non EU Member States according to the latest version of TREMOVE are required to obtain accurate street level air quality projections for these cities also.