Indicator 3.9.1 Mortality rate attributed to household and ambient air pollution

Fraction of all-cause adult mortality attributable to ambient particulate air pollution (measured as fine particulate matter, PM2.5)

Mortality burden associated with long-term exposure to particulate air pollution at current levels, expressed as the percentage of annual deaths from all causes in those aged 30+.

In the old method only anthropogenic particulate air pollution is measured. In the new method total particulate air pollution is measured.

Old and new methods also use different concentration-response function (CRF) coefficients, which represents the relationship between a pollutant and an adverse effect on health. For the old method a CRF of 1.06 was used. For the new method a CRF of 1.08 was used. Data in the two series are therefore not directly comparable.

England

Percentage (%)

PM2.5 - Also known as fine particulate matter. PM2.5 is the mass (in micrograms) per cubic metre of air of individual particles with an aerodynamic diameter generally less than 2.5 micrometers.

Local Authority – Lower tier local authority. Consists of Unitary Authorities and Districts. (pre Apr 2019)

No calculations were performed on the source data.

See the Indicator Definitions and Supporting Information for the old method and the new method for more information.

The methodology is described in PHE (2014) Estimating local mortality burdens associated with particulate air pollution.

Caution is needed when considering apparent trends over time. Trend data should not be over-interpreted for a number of reasons - Concentrations of PM2.5 vary from year to year due to the weather. This variation due to weather is generally greater than the year-to-year variation from changes in emissions; The methods and data inputs for the pollution modelling are continually updated and improved.

2020 data includes the period from March 2020 onwards, so the mortality data used in its calculation will reflect effects of the COVID-19 pandemic. Values for 2020 should therefore be interpreted with caution.

There is no accepted way of fully quantifying the uncertainty associated with modelled concentrations of PM2.5. The modelling used in calculating the indicator meets the requirements of the EU's Directive 2008/50/EC on Ambient Air Quality that the uncertainty in modelled annual average PM2.5 concentrations should be no more than 50% in the region of the Limit Value (25 micrograms per cubic metre).

Modelled background PM2.5 data are published on a 1km x 1km grid square basis by Defra. Background annual average PM2.5 concentrations for the year of interest are modelled on a 1km x 1km grid using an air dispersion model, and calibrated using measured concentrations taken from background sites in Defra’s Automatic Urban and Rural Network . 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). Concentrations of total PM2.5 are used for estimating the mortality burden attributable to particulate air pollution (COMEAP, 2022).

This indicator is being used as an approximation of the UN SDG Indicator. Where possible, we will work to identify or develop UK data to meet the global indicator specification. This indicator has been identified in collaboration with topic experts.