A3: Concentrations of fine particulate matter (PM2.5) in the air

Short Description

This indicator is a measure of the level of long-term exposure of people to harmful airborne fine particulate matter (PM2.5). Long-term exposure to particulate matter contributes to the risk of developing diseases such as cardiovascular disease and lung cancer. The main sources of PM2.5 pollution are industrial processes, combustion in residential, public, commercial, and agricultural sectors and road transport.

This indicator is an assessment of clean air (reporting the condition of the atmosphere as an asset). Exposure to PM2.5 can also be considered as a pressure on human health. The indicator is determined by calculating the annual population-weighted mean concentration of PM2.5 in the air, assessed as background concentrations per 1 km square. Background concentrations are estimated based on a combination of monitored and modelled data. The population-weighted mean concentration is used as a measure of the impact of PM2.5 on the health of the total population. Greater weighting is given to concentrations of PM2.5 in urban areas to reflect the higher population density as those concentrations will affect a greater number of people. In addition, people living in urban areas are generally exposed to greater levels of PM2.5 than those living in rural areas.

Readiness and links to data

Data on fine particulate matter (PM2.5) are published annually at UK Air Information Resource, Modelled background pollution data.

Indicator components

Figure A3: Concentrations of fine particulate matter (PM2.5) in England, 2011 to 2021

Table A3: Concentrations of fine particulate matter (PM2.5) in England, 2011 to 2021

Year Value
2011 12.09
2012 11.11
2013 11.52
2014 11.17
2015 9.42
2016 9.99
2017 9.41
2018 9.52
2019 9.57
2020 7.54
2021 7.35

Trend description for A3

Population-weighted annual mean concentrations of PM2.5 in England have fallen from 12.1 μg per m3 in 2011 to 7.4 μg per m3 in 2021, a decrease of 39% over the latest 10 years for which data are available.

Assessment of change

Concentrations of PM2.5 have shown a decrease (improvement) over the short-term assessment period. The time series is not yet long enough to make a trend assessment over the medium and long-term time periods. This assessment does not consider whether improvement is on a sufficient scale for meeting any targets. Assessment of progress towards the Environment Act PM2.5 targets is based on measured data only and information on this can be found on the UK-Air website.

Change since 2018 has also been assessed. A decrease (improvement) in concentrations of fine particulate matter was also observed since 2018. However, this result is based on only 4 data points so should be considered as indicative and not evidence of a clear trend. Some variance is also expected from year to year as concentrations of PM2.5 can be affected by weather conditions and a range of other variables.

Further information on this assessment, along with details on the methodology, is provided in the Assessment background page. Summaries by 25 Year Environment Plan goal and information on indicator links are presented in the Assessment results pages.

Table A3: Assessment of change

Component Subcomponent Period Date range Percentage change Smoothing function Assessment of change
A3 None Short term 2015 to 2020 -19.19 Loess Improvement
A3 None Medium term N/A N/A N/A Not assessed
A3 None Long term N/A N/A N/A Not assessed

Note that assessment categories were assigned based on smoothed Loess, so percentage change figures in Table A3 may differ from unsmoothed values quoted elsewhere. Percentage change refers to the difference seen from the first to last year in the specified date range.

Indicator Metadata