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
Christer Johansson, Stockholm City & Stockholm university, Sweden
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
Christer Johansson, Stockholm City & Stockholm university, Sweden
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
Christer Johansson, Stockholm City & Stockholm university, Sweden
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
Christer Johansson, Stockholm City & Stockholm university, Sweden
Different BC vs EC relations in the cities
Göteborg
Malmö
Umeå
Christer Johansson, Stockholm City & Stockholm university, Sweden
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.
Christer Johansson, Stockholm City & Stockholm university, Sweden
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”
Christer Johansson, Stockholm City & Stockholm university, Sweden
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
Christer Johansson, Stockholm City & Stockholm university, Sweden
BC in relation to NOx, PM10, PM2.5
Malmö sticks out
BC more correlated withLRT than local vehicleexhaust
Christer Johansson, Stockholm City & Stockholm university, Sweden
Downward time trend in
BC/NOxratio
Christer Johansson, Stockholm City & Stockholm university, Sweden
BC in relation to NOx, PM10, PM2.5
• Highly beneficial to co-locate BC, NOx, PM10, PM2.5
• Provides insights into– source contributions– relative health impacts
Christer Johansson, Stockholm City & Stockholm university, Sweden
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
Christer Johansson, Stockholm City & Stockholm university, Sweden
Different aims with the monitoring
• Control of regulated pollutants
• Trends in local emissions
• Estimate emission factors
• Estimate population exposure
Christer Johansson, Stockholm City & Stockholm university, Sweden
• 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)
Christer Johansson, Stockholm City & Stockholm university, Sweden
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
Christer Johansson, Stockholm City & Stockholm university, Sweden
PM10, BC, NOx and Particle numberdominated by local traffic contribution
NOx
PM10
Christer Johansson, Stockholm City & Stockholm university, Sweden
ModellingMeasurements
Control of limit valuesTrendsValidation of modelling
Source contributionsConsequence analysesExposureDeposition/processes
Balance betweenmeasurements and modelling
1+1=3!!
Christer Johansson, Stockholm City & Stockholm university, Sweden
City ofStockholmThank you!