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Modelled background pollution data 

Introduction

Background pollution maps at 1x1 km resolution are modelled each year under Defra's Modelling of Ambient Air Quality (MAAQ) contract. These maps are used to provide policy support for Defra and to fulfil the UK's reporting obligations to Europe. They are also made publicly available for other research applications such as university studies, epidemiology and public health research, nature and conservation studies.

These maps should not be mistaken for the Local Authority-specific maps which are alternative maps based on the same model results as presented here but which provide source-sector splits and projections to future years by Local Authority to aid the Local Air Quality Management process.

Please acknowledge Defra as the source for this data if using the maps for your work.

Modelled estimates of population-weighted annual average PM2.5 concentrations suitable for use in estimating the mortality burden associated with long-term exposure to anthropogenic particulate air pollution at Local Authority level are presented in a later section of this page.

Methodology

The models are continually updated and improved and so the methodology often changes each year. The most recent methodology report is for 2014 and can be found on the UK-AIR website: Report (PDF). Users should be mindful of these year to year changes when comparing model outputs between years.

Updates

The maps are produced over the summer each year and typically the latest updates are checked and approved by the autumn and made available on this website by mid-October.

File formats

The maps are all downloadable as .csv files for each year and each pollutant/metric as shown in the summary table below. Simply choose the output that you are interested in and click on the Download link (CSV) in the table.

Each file will contain some basic summary information about the dataset at the top of the file (the first four rows contain pollutant, year, metric and units). The data begins on row 6 of each file and contains 4 columns:

  • a unique code (ukgridcode) for each 1x1km cell in the map
  • the x coordinates for the centroid of each grid cell
  • the y coordinates for the centroid of each grid cell
  • the values for the metric itself.

The ukgridcode field allows several maps to be joined in a single file using that code as the lookup column.

'MISSING' values

There are some grid squares in each data set that do not have values associated with them and are labelled as ‘MISSING’. These are coastal squares for which the centre of the grid square is not located on the land and therefore the model does not provide a concentration for.

Units

Most of the model outputs are annual means, represented in µg m-3. CO concentrations are represented in mg m-3. Specific units and information about the different metrics is provided in the summary table below.

Additional notes

  • PM data prior to 2004 was modelled in TEOM units. From 2004 onwards these were modelled in genuine gravimetric units.
  • The models are calibrated using monitoring data from the national networks and in 2006 there were issues with the gravimetric PM analysers (Partisols). The monitoring data was subsequently reviewed and corrected and these changes were then incorporated into the modelling process to provide the final corrected grids. See the report Analysis of Trends in Gravimetric Particulate Mass Measurements in the United Kingdom (2.6MB PDF).

Queries

For any queries about these maps, please contact Andrew Kent at andrew.kent@ricardo.com.

Directory of maps

Jump to: PM10, PM2.5, NOx and NO2, CO, SO2, Ozone, Benzene

PM10

Pollutant Year Metric Header label Comments Download link (CSV)
PM10 2001 Annual mean pm102001 TEOM units mappm102001
PM10 2002 Annual mean pm102002 TEOM units mappm102002
PM10 2003 Annual mean pm102003s15a TEOM units mappm102003s15a
PM10 2004 Annual mean pm102004g Gravimetric units mappm102004g
PM10 2005 Annual mean pm1005ac Gravimetric units – corrected to account for updated Partisol monitoring concentrations1 mappm1005ac
PM10 2006 Annual mean pm102006gh Gravimetric units – corrected to account for updated Partisol monitoring concentrations1 mappm102006gh
PM10 2007 Annual mean pm102007g Gravimetric units mappm102007g
PM10 2008 Annual mean pm102008g Gravimetric units mappm102008g
PM10 2009 Annual mean pm102009g Gravimetric units mappm102009g
PM10 2010 Annual mean pm102010g Gravimetric units mappm102010g
PM10 2011 Annual mean pm102011g Gravimetric units mappm102011g
PM10 2012 Annual mean pm102012g Gravimetric units mappm102012g
PM10 2013 Annual mean pm102013g Gravimetric units mappm102013g
PM10 2014 Annual mean pm102014g Gravimetric units mappm102014g
PM10 2015 Annual mean pm102015g Gravimetric units mappm102015g

PM2.5

Pollutant Year Metric Header label Comments Download link (CSV)
PM2.5 2002 Annual mean pm252002   mappm252002
PM2.5 2003 Annual mean pm252003grav   mappm252003grav
PM2.5 2004 Annual mean pm252004g   mappm252004g
PM2.5 2005 Annual mean pm2505ac corrected to account for updated Partisol monitoring concentrations1 mappm2505ac
PM2.5 2006 Annual mean pm252006gh corrected to account for updated Partisol monitoring concentrations1 mappm252006gh
PM2.5 2007 Annual mean pm252007g   mappm252007g
PM2.5 2008 Annual mean pm252008g   mappm252008g
PM2.5 2009 Annual mean pm252009g   mappm252009g
PM2.5 2010 Annual mean pm252010g   mappm252010g
PM2.5 2011 Annual mean pm252011g   mappm252011g
PM2.5 2012 Annual mean pm252012g   mappm252012g
PM2.5 2013 Annual mean pm252013g   mappm252013g
PM2.5 2014 Annual mean pm252014g   mappm252014g
PM2.5 2015 Annual mean pm252015g   mappm252015g

NOx and NO2

Pollutant Year Metric Header label Comments Download link (CSV)
NO2 2001 Annual mean no22001_3   mapno22001_3
NO2 2002 Annual mean no22002_1   mapno22002_1
NO2 2003 Annual mean no22003   mapno22003
NO2 2004 Annual mean no22004   mapno22004
NO2 2005 Annual mean no22005   mapno22005
NO2 2006 Annual mean no22006   mapno22006
NO2 2007 Annual mean no22007   mapno22007
NO2 2008 Annual mean no22008   mapno22008
NO2 2009 Annual mean no22009   mapno22009
NO2 2010 Annual mean no22010   mapno22010
NO2 2011 Annual mean no22011   mapno22011
NO2 2012 Annual mean no22012   mapno22012
NO2 2013 Annual mean no22013   mapno22013
NO2 2014 Annual mean no22014   mapno22014
NO2 2015 Annual mean no22015   mapno22015
NOX 2001 Annual mean nox2001_3 µg m-3 (NOX as NO2) mapnox2001_3
NOX 2002 Annual mean nox2002_1 µg m-3 (NOX as NO2) mapnox2002_1
NOX 2003 Annual mean nox2003 µg m-3 (NOX as NO2) mapnox2003
NOX 2004 Annual mean nox2004 µg m-3 (NOX as NO2) mapnox2004
NOX 2005 Annual mean nox2005 µg m-3 (NOX as NO2) mapnox2005
NOX 2006 Annual mean nox2006 µg m-3 (NOX as NO2) mapnox2006
NOX 2007 Annual mean nox2007 µg m-3 (NOX as NO2) mapnox2007
NOX 2008 Annual mean nox2008 µg m-3 (NOX as NO2) mapnox2008
NOX 2009 Annual mean nox2009 µg m-3 (NOX as NO2) mapnox2009
NOX 2010 Annual mean nox2010 µg m-3 (NOX as NO2) mapnox2010
NOX 2011 Annual mean nox2011 µg m-3 (NOX as NO2) mapnox2011
NOX 2012 Annual mean nox2012 µg m-3 (NOX as NO2) mapnox2012
NOX 2013 Annual mean nox2013 µg m-3 (NOX as NO2) mapnox2013
NOX 2014 Annual mean nox2014 µg m-3 (NOX as NO2) mapnox2014
NOX 2015 Annual mean nox2015 µg m-3 (NOX as NO2) mapnox2015

CO

Pollutant Year Metric Header label Comments Download link (CSV)
CO 2002 Annual mean coamean2002_1 Units are mg m-3 mapcoamean2002_1
CO 2003 Annual mean coamean2003_1 Units are mg m-3 mapcoamean2003_1
CO 2004 Annual mean coamean2004_1 Units are mg m-3 mapcoamean2004_1
CO 2005 Annual mean coamean2005 Units are mg m-3 mapcoamean2005
CO 2006 Annual mean coamean2006 Units are mg m-3 mapcoamean2006
CO 2007 Annual mean coamean2007 Units are mg m-3 mapcoamean2007
CO 2008 Annual mean coamean2008 Units are mg m-3 mapcoamean2008
CO 2009 Annual mean coamean2009 Units are mg m-3 mapcoamean2009
CO 2010 Annual mean coamean2010 Units are mg m-3 mapcoamean2010
CO 2002 Max 8-hr mean co8hr2002_1 Units are mg m-3 mapco8hr2002_1
CO 2003 Max 8-hr mean co8hr2003_1 Units are mg m-3 mapco8hr2003_1
CO 2004 Max 8-hr mean com8hr2004_1 Units are mg m-3 mapcom8hr2004_1
CO 2005 Max 8-hr mean com8hr2005 Units are mg m-3 mapcom8hr2005
CO 2006 Max 8-hr mean com8hr2006 Units are mg m-3 mapcom8hr2006
CO 2007 Max 8-hr mean com8hr2007 Units are mg m-3 mapcom8hr2007
CO 2008 Max 8-hr mean com8hr2008 Units are mg m-3 mapcom8hr2008
CO 2009 Max 8-hr mean com8hr2009 Units are mg m-3 mapcom8hr2009
CO 2010 Max 8-hr mean com8hr2010 Units are mg m-3 mapcom8hr2010

SO2

Pollutant Year Metric Header label Comments Download link (CSV)
SO2 2002 Annual mean so202annd   mapso202annd
SO2 2003 Annual mean so203ann   mapso203ann
SO2 2004 Annual mean so204ann   mapso204ann
SO2 2005 Annual mean so205ann   mapso205ann
SO2 2006 Annual mean so206ann   mapso206ann
SO2 2007 Annual mean so207ann   mapso207ann
SO2 2008 Annual mean so208ann   mapso208ann
SO2 2009 Annual mean so209ann   mapso209ann
SO2 2010 Annual mean so210ann   mapso210ann
SO2 2011 Annual mean so211ann   mapso211ann
SO2 2012 Annual mean so212ann   mapso212ann
SO2 2013 Annual mean so213ann   mapso213ann
SO2 2014 Annual mean so214ann   mapso214ann
SO2 2015 Annual mean so215ann   mapso22015

Ozone

Pollutant Year Metric Header label Comments Download link (CSV)
Ozone 2003 DGT120 daysgt12003_2 metric is number of days on which the daily max 8-hr concentration is greater than 120 µg m-3 mapdaysgt12003_2
Ozone 2004 DGT120 dgt12004 metric is number of days on which the daily max 8-hr concentration is greater than 120 µg m-3 mapdgt12004
Ozone 2005 DGT120 dgt120_2005r metric is number of days on which the daily max 8-hr concentration is greater than 120 µg m-3 mapdgt120_2005r
Ozone 2006 DGT120 dgt120_06 metric is number of days on which the daily max 8-hr concentration is greater than 120 µg m-3 mapdgt120_06
Ozone 2007 DGT120 dgt120_07 metric is number of days on which the daily max 8-hr concentration is greater than 120 µg m-3 mapdgt120_07
Ozone 2008 DGT120 dgt120_08 metric is number of days on which the daily max 8-hr concentration is greater than 120 µg m-3 mapdgt120_08
Ozone 2009 DGT120 dgt120_09 metric is number of days on which the daily max 8-hr concentration is greater than 120 µg m-3 mapdgt120_09
Ozone 2010 DGT120 dgt120_10 metric is number of days on which the daily max 8-hr concentration is greater than 120 µg m-3 mapdgt120_10
Ozone 2011 DGT120 dgt120_11 metric is number of days on which the daily max 8-hr concentration is greater than 120 µg m-3 mapdgt120_11
Ozone 2012 DGT120 dgt120_12 metric is number of days on which the daily max 8-hr concentration is greater than 120 µg m-3 mapdgt120_12
Ozone 2013 DGT120 dgt120_13 metric is number of days on which the daily max 8-hr concentration is greater than 120 µg m-3 mapdgt120_13
Ozone 2014 DGT120 dgt120_14 metric is number of days on which the daily max 8-hr concentration is greater than 120 µg m-3 mapdgt120_14
Ozone 2015 DGT120 dgt120_15 metric is number of days on which the daily max 8-hr concentration is greater than 120 µg m-3 mapdgt120_15

Benzene

Pollutant Year Metric Header label Comments Download link (CSV)
Benzene 2003 Annual mean bz2003   mapbz2003
Benzene 2004 Annual mean bz2004   mapbz2004
Benzene 2005 Annual mean bz2005   mapbz2005
Benzene 2006 Annual mean bz2006   mapbz2006
Benzene 2007 Annual mean bz2007   mapbz2007
Benzene 2008 Annual mean bz2008   mapbz2008
Benzene 2009 Annual mean bz2009   mapbz2009
Benzene 2010 Annual mean bz2010   mapbz2010
Benzene 2011 Annual mean bz2011   mapbz2011
Benzene 2012 Annual mean bz2012   mapbz2012
Benzene 2013 Annual mean bz2013   mapbz2013
Benzene 2014 Annual mean bz2014   mapbz2014
Benzene 2015 Annual mean bz2015   mapbz2015

Population-weighted annual mean PM2.5 data

These data are population-weighted annual mean concentrations (µg m-3) for each Local Authority. These data are suitable for use in estimating the burden of mortality attributable to long-term exposure to particulate air pollution using methods such as those recommended by COMEAP in its statement "Estimating the mortality burden of particulate air pollution at the local level" and used in calculating the Public Health Outcomes Framework indicator "Fraction of Mortality Attributable to Particulate Air Pollution".

Concentrations of anthropogenic, rather than total, PM2.5 are used as the basis for this indicator, as burden estimates based on total PM2.5 might give a misleading impression of the scale of the potential influence of policy interventions (COMEAP, 2012).  However, modelled concentrations of anthropogenic PM2.5 are more uncertain than those of total PM2.5 because of the uncertainty associated with the assignment to anthropogenic and non-anthropogenic sources.

Background annual average PM2.5 concentrations for the year of interest are modelled on a 1km x 1km grid using an air dispersion model (Pollution Climate Mapping), and calibrated using measured concentrations taken from background sites in Defra's Automatic Urban and Rural Network.  Data on primary emissions from different sources from the National Atmospheric Emissions Inventory and a combination of measurement data for secondary inorganic aerosol and models for sources not included in the emission inventory (including re-suspension of dusts) are used to estimate the anthropogenic (human-made) component of these concentrations.  By approximating LA boundaries to the 1km by 1km grid, and using census population data, population weighted background PM2.5 concentrations for each lower tier LA are calculated.  This work is completed under contract to Defra, as a small extension of its obligations under the Ambient Air Quality Directive (2008/50/EC). 

The data are available from the download links in the table below on an annual basis. Estimated concentrations are population-weighted annual mean PM2.5 in µg m-3. For 2010 the data are provided for UK by Local Authority only. For 2011 onwards, the data are provided for UK by Local Authority and by country. Data are also provided for England by region and upper tier Local Authority. Each data file includes the fields below.

  • Code (LA code/Region code/Country code– an identifier for each local authority (follows the established UWE code)
  • 'PM2.5 [YEAR] (total)' – total estimated PM2.5 concentration
  • 'PM2.5 [YEAR] (non-anthropogenic)' – estimated non-anthropogenic PM2.5 concentration
  • 'PM2.5 [YEAR] (anthropogenic)' – estimated anthropogenic PM2.5 concentration
  • Name (Local authority name/Region name/Country name)
Pollutant Year Metric Download link (CSV)
PM2.5 2010 Population-weighted annual mean (by local authority) popwmpm252010byUKlocalauthority.csv
PM2.5 2011 Population-weighted annual mean (by local authority) popwmpm252011byUKlocalauthority.csv
PM2.5 2011 Population-weighted annual mean (by region) popwmpm252011byEnglandregionanduppertierlocalauthority.csv
PM2.5 2011 Population-weighted annual mean (by country) popwmpm252011byUKcountry.csv
PM2.5 2012 Population-weighted annual mean (by local authority) popwmpm252012byUKlocalauthority.csv
PM2.5 2012 Population-weighted annual mean (by region) popwmpm252012byEnglandregionanduppertierlocalauthority.csv
PM2.5 2012 Population-weighted annual mean (by country) popwmpm252012byUKcountry.csv
PM2.5 2013 Population-weighted annual mean (by local authority) popwmpm252013byUKlocalauthority.csv
PM2.5 2013 Population-weighted annual mean (by region) popwmpm252013byEnglandregionanduppertierlocalauthority.csv
PM2.5 2013 Population-weighted annual mean (by country) popwmpm252013byUKcountry.csv
PM2.5 2014 Population-weighted annual mean (by local authority) popwmpm252014byUKlocalauthority.csv
PM2.5 2014 Population-weighted annual mean (by region) popwmpm252014byEnglandregionanduppertierlocalauthority.csv
PM2.5 2014 Population-weighted annual mean (by country) popwmpm252014byUKcountry.csv
PM2.5 2015 Population-weighted annual mean (by local authority) popwmpm252015byUKlocalauthority.csv
PM2.5 2015 Population-weighted annual mean (by region) popwmpm252015byEnglandregionanduppertierlocalauthority.csv
PM2.5 2015 Population-weighted annual mean (by country) popwmpm252015byUKcountry.csv

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