Can the UK meet the World Health Organization PM2.5 interim target of 10 μg m-3 by 2030?

David Dajnak; Nosha Assareh; Nutthida Kitwiroon; Andrew V Beddows; Gregor B Stewart; William Hicks; Sean D Beevers

doi:10.1016/j.envint.2023.108222

Can the UK meet the World Health Organization PM_2.5 interim target of 10 μg m^-3 by 2030?

Environ Int. 2023 Nov:181:108222. doi: 10.1016/j.envint.2023.108222. Epub 2023 Sep 28.

Authors

David Dajnak¹, Nosha Assareh², Nutthida Kitwiroon², Andrew V Beddows², Gregor B Stewart², William Hicks², Sean D Beevers²

Affiliations

¹ Environmental Research Group, School of Public Health, Imperial College London, Sir Michael Uren Biomedical Engineering Hub, White City Campus, 80 Wood Lane, W12 0BZ London, United Kingdom. Electronic address: d.dajnak@imperial.ac.uk.
² Environmental Research Group, School of Public Health, Imperial College London, Sir Michael Uren Biomedical Engineering Hub, White City Campus, 80 Wood Lane, W12 0BZ London, United Kingdom.

PMID: 37948865
DOI: 10.1016/j.envint.2023.108222

Abstract

The recent United Kingdom (UK) Environment Act consultation had the intention of setting two targets for PM_2.5 (particles with an aerodynamic diameter less than 2.5 μm), one related to meeting an annual average concentration and the second to reducing population exposure. As part of the consultation, predictions of PM_2.5 concentrations in 2030 were made by combining European Union (EU) and UK government's emissions forecasts, with the Climate Change Committee's (CCC) Net Zero vehicle forecasts, and in London with the addition of local policies based on the London Environment Strategy (LES). Predictions in 2018 showed 6.4% of the UK's area and 82.6% of London's area had PM_2.5 concentrations above the World Health Organization (WHO) interim target of 10 μg m^-3, but by 2030, over 99% of the UK's area was predicted to be below it. However, kerbside concentrations in London and other major cities were still at risk of exceeding 10 μg m^-3. With local action on PM_2.5 in London, population weighted concentrations showed full compliance with the WHO interim target of 10 μg m^-3 in 2030. However, predicting future PM_2.5 concentrations and interpreting the results will always be difficult and uncertain for many reasons, such as imperfect models and the difficulty in estimating future emissions. To help understand the sensitivity of the model's PM_2.5 predictions in 2030, current uncertainty was quantified using PM_2.5 measurements and showed large areas in the UK that were still at risk of exceeding the WHO interim target despite the model predictions being below 10 μg m^-3. Our results do however point to the benefits that policy at EU, UK and city level can have on achieving the WHO interim target of 10 μg m^-3. These results were submitted to the UK Environment Act consultation. Nevertheless, the issues addressed here could be applicable to other European cities.

Keywords: Air pollution modelling; Airborne Particulate Matter; Electric Vehicles; Net Zero; WHO guidelines.

MeSH terms

Air Pollutants* / analysis
Air Pollution* / analysis
Cities
Environmental Monitoring / methods
Particulate Matter / analysis
United Kingdom

Substances

Air Pollutants
Particulate Matter