SOURCE APPORTIONMENT of PARTICULATE MATTER Imperial College 23 rd April 2010 APRIL:Air Pollution Research in London

Which Sources? Emissions? What chemical composition? SO4,NO3,NH4, C, Fe etc Concentration Exposure Where from? nearest road other UK sources outside UK?

SOURCE APPORTIONMENT of PM in INTEGRATED ASSESSMENT MODELLING at IMPERIAL COLLEGE Tim Oxley, Helen ApSimon, Ayman Elshkaki Imperial College London

1.PM modelling in UK IAM: uses data and work from several other modellers: aimed at predicting future concentrations and exposure 2.Emissions 3.Primary PM concentrations 4.Secondary SIA (SO4, NO3 and NH4) concentrations 5.Other contributions to PM 10 & PM Trends 2010 to 2020

UK integrated assessment model, UKIAM Aim: Assess future scenarios and abatement measures in relation to setting of national emissions ceilings for 2020-> UK air quality, ecosystem protection and GHG emissions Pollutants: SO2, NOx, NH3, PM10, PM2.5, CO2, N2O, CH4 Detailed sub-model BRUTAL for road transport -> roadside concentrations + 1x1 km background concentrations Emissions UK sources based on NAEI (point or 1x1 km) Contributions imported from other countries and shipping

shallow canyons suburbs deep street canyons dense pop. city centre Open roads rural Road-side increment NOx, primary PM Emissions each UK road link NOx,PM,CO2,N2O (iMOVE) Traffic flow, ave speed, vehicle mix+ data base emission factors Superimpose on background concentration NOx, primary PM from UK sources Grid 1x1 km emissions road transport Other UK emissions PPM model Add long-range secondary PM: & primary NOx and PM contributions imported (including shipping) and from other sources Calculate NO2 concentrations from total NOx allowing for  frac. BRUTAL (UKIAM)-> modelling of urban air quality

EMISSIONS PRIMARY PM (UEP32 scenario) (ktonnes) PM10 PM2.5 PM10 PM2.5 Power Dom Industry Road Trans Off-road Agric/Nat ______________________________________________________________ Total UK EU 27 (inc UK) NB IIASA total PM2.5 agrees very well but sources covered differ ? Are there missing sources of PM e.g. from cooking

PRIMARY PM CONCENTRATIONS (PPM model) Small contributions imported and from shipping PM 2.5 in 2010 Sources (kt) UEP32 scenario Power 3.0 Domestic 9.9 Industry 24.6 Roads 20.1 Off-road 7.4 Agri/nat. 6.7 Total UK 71.7

PRECURSOR EMISSIONS Secondary Inorganic Aerosol kt UEP32 scenario SO2 NOx SO2 NOx Power Domestic Industry Roads Off-road ___________________________________________________ Total UK EU UK NH3 307kt in both 2010 and 2020 (IPPC not included) EU27 NH kt in 2010 and 4124 in 2020

UKIAM : use of pre-calculated source-receptor footprints each source->rapid scenario assessment Take reference case and estimate effect of reducing emissions from a source by specified amount on concentrations/deposition-> multiply effect for bigger/smaller changes in emission More complicated for secondary PM with interacting pollutants- e.g. need to allow for effect of NH3 on NO3 concentrations. CONCENTRATIONS OF SIA= SO4+NO3+NH4 FRAME and EMEP models-

SIA components in 2020; based on FRAME/EMEP models Frame NH4 SO4 NO3 total PWM 0.74  g/m fine (PM2.5) all (PM 10) EMEP implies larger proportion imported than FRAME-> total SIA 4.5  g/m3

OTHER CONTRIBUTIONS PWC PM10 PM2.5 Ca dust * Fe (inc re-* Suspension) Sea salt * SOA (HARM Model) Water _____________________________ Total * based on maps from AEA (JS)

Total PM 10 in 2010Total PM 2.5 in 2010

Source Apportionment PM 10 in 2010 (UEP32 scenario) NB popn. weighted 1x1 km background concentrations

Source Apportionment Scenario UEP32 PM 10 (2010) PM 10 (2020) NO 2 (2020)

Local road 0ther roads Non-road primary Euro SIA UK SIA Ship PM Import PM Other 30.1  g/m  g/m  g/m  g/m3 M. Road Southampton 2010 ROADSIDE SITES 2020

Roads “at risk” of exceeding AQ limit value (ann. ave. PM 10 > 31.5  g/m3) km UK London NB background higher over east UK (high Ca dust) -> exceedance outside London

Some comments Modelled primary PM reduces with exhaust fraction becoming negligible, and road transport small (tyres and brakes) but are there sources missing from inventory? SIA- also reduces with up to half imported from Europe and dependent on other countries reductions but uncertainties Other components SOA, dust etc add up to as much or more than primary and SIA for PM10, and are also a significant addition to PM2.5-> more work needed on these. In future: Move towards a speciated PM inventory re toxic components, black C etc