TRAFFIC RELATED AIR POLLUTION: total mass PM10 or Black Carbon (BC) as indicator?

Transcription

1 TRAFFIC RELATED AIR POLLUTION: total mass PM10 or Black Carbon (BC) as indicator? Frans Fierens Olivier Brasseur Elke Trimpeneers IRCEL-CELINE / VMM IRCEL-CELINE / IBGE-BIM IRCEL-CELINE / VMM

2 IRCEL-CELINE Belgian Interregional Environment Agency Flanders Brussels The Walloon Region spw.wallonie.be

3 Road transport emissions? PM10 concentrations

4 CHEMKAR Chemical composition of PM10 (period september 2006 september 2007) 40 Urban / traffic??? Small difference total mass Rural bodemstof dust Mineral nss SO4 µg/m Houtem Zelzate Mechelen Borgerhout Aarschot Hasselt alle stations NH4 NO3 Sea zeezout salt OM EC SIA = 41% Large difference for specific components : +/- 4 times more EC (Elementary Carbon, dieselsoot) Most efficient way to reduce total mass PM = reduction of SIA Source: CHEMKAR report - Vlaamse Milieumaatschappij (2009),

5 PM10 Flanders REF2007 PM10 andere bronnen (buiten Europa+natuurl.) 32% Vlaamse antropogene bronnen 23% niet Vlaamse bronnen (gekende Europese emissies + int. Scheepvaart) 45% PM10 Flanders on average +/- 25 % can be attributed to Flemish anthropogenic emissions +/- 50% = emissions of agriculture (NH3)

6 Contribution of Flemish emissions in PM10 and EC Urban area (Antwerp) Contribution of Flemish Emissions (%) Bijdrage van antr. Vlaamse emissies [%] PM10 (average ~ 35 %) EC (average ~ 75 %) 80 Borgerhout Borgerhout - winter PM10 concentratie [µg/m 3 ] Source : BelEUROS model Bijdrage van antr. Vlaamse emissies [%] 100 Borgerhout Borgerhout - EC EC10 concentratie [µg/m 3 ] Important contribution of local sources to EC

7 Reduction of PM10 : which (local) measures? Ammonia (NH3) reductions in agriculture: Largest impact on the reduction of total mass PM relevant for compliance with limit values But (small?) impact on health effects? Traffic measures: Significant reduction of Black Carbon (and NOx) Probably more effective to reduce impact on health But (very) small impact on the reduction of total mass PM less relevant for compliance with limit values

8 Local traffic emission reductions? Impact on PM10, PM2.5 and BC

9 Car Free Sunday, Brussels - 20 September 2009 Source : Vanderstraeten et al., J.Env.Prot Car Free period Black Carbon PM Black Carbon (ng/m³) PM10 (µg/m³) :30 4:00 5:30 7:00 8:30 10:00 11:30 13:00 14:30 16:00 17:30 19:00 20:30 22:00 23:30 1:00 PM10 : high secundary fraction -> precursors yesterday/outside BRUSSELS BC : local (traffic ) emissions much more important : immediate effect!

10 Impact of speed limits on highways during PM smog episodes Difference (%) in PM10 concentrations during the SMOG episode in December 2007 PM Source : Lefebvre et al. (2009) Difference for total mass PM10 and PM2.5 is rather small (only a few %), but...

11 Impact of speed limits on highways during PM smog episodes Difference (%) in EC concentrations during the SMOG episode in December 2007 EC Source : Lefebvre et al. (2009) EC (Elementary Carbon, diesel soot): reductions up till 30 %!!

12 Black Carbon? Traffic related pollutants

13 Location of PM10 / BC monitoring sites in Brussels 41R001 dense traffic + habitation + industrial activities PM10 stations BC stations 41WOL1 dense traffic open surrounding 41R002 dense traffic canyon street 41R012 urban background residential (soon available)

14 Correlation between BC and other pollutants Traffic related pollutants Source : Vanderstraeten et al., J.Env.Prot Pollutant Correlation coeff. Half hourly Daily avg. Black Smoke ~ 0.96 NOx ~ 0.85 ~ 0.92 NO, NO 2 ~ 0.76 ~ 0.86 CO ~ 0.70 ~ 0.75 PM10, PM2.5 ~ 0.48 ~ 0.65 Part. number Ø < 1 µm ~ 0.45 ~ 0.58 SO 2 ~ 0.38 Part. number Ø > 1 µm ~ 0.05 BC = high correlation with traffic related pollutants (BS, NOx, CO)

15 Correlation between BC and NOx Molenbeek-St-Jean (41R001) - Daily concentrations - Period: July 2010 to June Black Carbon (µg/m³) y = 0,0311x + 0,7899 R 2 = 0,8438 Daily BC-NOx: R = NOx (µg/m³)

16 Correlation between BC and Black Smoke Measured since 1968! Molenbeek-St-Jean (41R001) - Daily concentrations - Period: 7 July to 15 December 2010 Black carbon (µg/m³) y = 0,1824x + 0,4724 R 2 = 0,9287 Daily BC-BS: R = 0.96! Black smoke (µg/m³) Source :

17 Long time series of Black Carbon? Molenbeek-St-Jean (41R001) - Daily concentrations - Period: July 2010 to June Black Carbon (µg/m³) y = 0,0311x + 0,7899 R 2 = 0,8438 NOx measured since 1981 (half hourly) NOx (µg/m³) Molenbeek-St-Jean (41R001) - Daily concentrations - Period: 7 July to 15 December Possible to reconstruct time series of Black Carbon over the last 10 years 9 8 y = 0,1824x + 0,4724 R 2 = 0,9287 Black carbon (µg/m³) Black Smoke measured since 1968 (daily) Black smoke (µg/m³)

18 Findings on health impacts of air pollution in European cities Source Aphekom project Living near busy roads responsible for some 15-30% of: All new cases astma in children COPD adults 65+ Coronary heart disease % of the population of the 10 EU cities studied lives near busy roads

19 Conclusions (Local) primary traffic emission reductions : Small impact on total mass PM Important to reduce impact on health Total mass PM = not the best indicator for traffic related air pollution Support for measures that have only little effects on the current PM indicators = not easy Black Carbon : Probably one of the most toxic components(?) but not regulated (yet?) High correlation with traffic related pollutants Direct effect of local (traffic) measures Needs more attention

20 Thank you for your attention! twitter.com/smog_be