city of some experiences from stockholm bc measurements in

Christer Johansson, Stockholm City & Stockholm university, Sweden

Christer JohanssonDepartment of Environmental Science and Analytical Chemistry, Stockholm University, Stockholm Environment and Health Administration, City of Stockholm, Sweden

Some experiences from BC measurements in Sweden

City ofStockholm

- BC measurements in Sweden – Why and how?

- Relation to other pollutants – NOX, PM10, PM2.5

- Monitoring strategies in Stockholm


Black carbon measurements in Sweden

Gårda (Göteborg)2015-

Vavihill2015-

Dalaplan(Malmö)2015-

Aspvreten(2005-)

Hornsg (Stockholm)2006-

Torkel(Stockholm)(2006-)

V:a Esplanaden

(Umeå) 2015-

Södra länken(2017-)

E18 Mörby(2017-)

1 Road tunnel5 Traffic1 urban background2 rural


Why BC measurements?• Strong associations with adverse health effects

• Indicator of local PM emissions due to combustion• Diesel vehicles

• Biomass burning

• Potentially new limit value in Europe

• Replaces old Black Smoke measurements


AutomaticPM10 low-volumesampling (2.3 m3/h)

16 filters

EC and OC analysisThermal Optical Transmission (TOT)EUSAAR 2 protocol1.5 cm2 punches of loaded filters


Different BC vs EC relations in the cities

Göteborg

Malmö

Umeå


StockholmMAAP, AE33, EC


Standard for EC (=EUSAAR 2)

As a result of the laboratory and field measurementcampaign the EUSAAR 2 transmittance measurementprotocol was chosen as the basis of the standard methodEN 16909:2017.


BC monitoring strategy in Sweden

• Use EC to ”calibrate” BC– Automatic filter sampler– Eusaar 2 protocol

• Use a MAAP instrument as ”field standard”• Keep one MAAP in the lab to check the ”field standard”


BC IN RELATION TO OTHERPOLLUTANTS


BC in relation to NOx, PM10, PM2.5

High correlation with NOxboth from veh exhaust

Low correlation with PM10no non-exhaust

Higher correlation with PM2.5 compared to PM10

LRT BC



Malmö sticks out

BC more correlated withLRT than local vehicleexhaust


Downward time trend in

BC/NOxratio



• Highly beneficial to co-locate BC, NOx, PM10, PM2.5

• Provides insights into– source contributions– relative health impacts


Concentration

Urban background

Local hot-spots

Limit valueRegional background

1

2

3

�A few, but well equipped, measurement stations

�Use emission inventoring & air quality disperson models to get detailed geographic variations and importances of sources

Monitoring strategies in Stockholm


Different aims with the monitoring

• Control of regulated pollutants

• Trends in local emissions

• Estimate emission factors

• Estimate population exposure


• Most polluted areas (hot spots)

– finding highest concentrations of air pollutants

– Street canyons where many people are exposed

• Urban background

• Regional background

– Import of air pollutants from other countries

• All methods are compared to Reference methods acc. the AQ directive

Strategies for monitoring

Street canyons(traffic contribution)

Roof-top(urban background)

Rural site(contribution from non-local sources)


Sonic anemometer

TemperaturesRelative humidityPrecipitation

PM10, PM2.5, BC,Total particle number,NO, NO2, CO, CO2O3

Hornsgatan street:

PM10, PM2.5, PM1, PM0.5Black carbon (BC),Total particle number,Particle number sizeDistribution, NO, NO2, CO, CO2, O3

ROOF-TOP

MeteorologyNumber of Vehicles/hourStreet wetness


PM10, BC, NOx and Particle numberdominated by local traffic contribution

NOx

PM10


ModellingMeasurements

Control of limit valuesTrendsValidation of modelling

Source contributionsConsequence analysesExposureDeposition/processes

Balance betweenmeasurements and modelling

1+1=3!!


City ofStockholmThank you!

[email protected]

city of some experiences from stockholm bc measurements in

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