{"id":9737,"date":"2025-07-20T06:07:17","date_gmt":"2025-07-20T06:07:17","guid":{"rendered":"https:\/\/www.newsbeep.com\/uk\/9737\/"},"modified":"2025-07-20T06:07:17","modified_gmt":"2025-07-20T06:07:17","slug":"uk-air-quality-is-improving-but-pollution-targets-are-still-being-breached-new-study","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/uk\/9737\/","title":{"rendered":"UK air quality is improving but pollution targets are still being breached \u2013 new study"},"content":{"rendered":"

An estimated<\/a> 4.2 million deaths can be attributed to poor air quality each year. Poor air quality is the largest fixable environmental public health risk<\/a> in the world. <\/p>\n

Our new study<\/a> presents analysis of the UK-wide trends for three major pollutants \u2013 nitrogen dioxide (NO\u2082), ozone (O\u2083) and tiny particulate matter known as PM\u2082.\u2085 \u2013 between 2015 and 2024 to calculate how often air quality targets<\/a> were breached. <\/p>\n

Both nitrogen dioxide and PM\u2082.\u2085 showed robust decreases over the period 2015-2024, declining on average by 35% and 30% respectively. In 2015-2016, the average Defra monitoring site exceeded the nitrogen dioxide target on 136 days per year. By 2023-2024, this had dropped to 40 days per year. <\/p>\n

For PM\u2082.\u2085, the number of days the average Defra site breached the target went from 40 to 22 days per year. While this is an improvement, the World Health Organization advises that these targets should not be breached on more than four days per year.<\/p>\n

\"\"<\/p>\n

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To examine the sources of pollution, we studied how pollutants were influenced by factors including time of day, day of week, wind direction and origin, location of monitoring station and even interactions between pollutant. Nitrogen dioxide concentrations are highest at monitoring sites located next to busy urban roads, lower at urban background sites (which are located at sites further from traffic such as parks) and much lower in rural sites. <\/p>\n

Profiles over 24-hour periods show strong nitrogen dioxide peaks coinciding with the morning and evening rush hours and clear decreases at weekends. This all points to local traffic emissions being the major source. While PM\u2082.\u2085 is also higher in urban than rural locations, it exhibits more muted rush hour peaks and is more consistent between the week and weekend, suggesting traffic plays a smaller role.<\/p>\n

We explored how wind direction and origin influenced nitrogen dioxide and PM\u2082.\u2085 by running a weather forecast model<\/a> backwards for three UK locations: Reading, Sheffield and Glasgow. While nitrogen dioxide showed only a weak correlation with wind origin, PM\u2082.\u2085 was much more dependent. <\/p>\n

For example, the probability of PM\u2082.\u2085 breaching air quality targets on a given day exceeded 15% only when the air had come from continental Europe and, for Sheffield and Glasgow, passed over much of the UK too. <\/p>\n

\"\"<\/a><\/p>\n

NO\u2082 and PM\u2082.\u2085 pollution reduced over the last decade but remains too high while O\u2083 pollution has worsened.
\n James Weber, CC BY<\/a><\/p>\n

While nitrogen dioxide and PM\u2082.\u2085 showed clear improvements, ozone exhibited a less positive picture. Ozone increased in 115 of the 121 sites considered, growing by 17% on average. A similar trend was observed across much of northern Europe. The average number of days ozone exceeded the World Health Organization target<\/a> doubled from seven to 14 per year.<\/p>\n

This may seem modest at present, but several factors are conspiring to drive ozone higher. In much of the UK, the relatively high levels of nitrogen dioxide effectively suppress ozone: as a result, ozone is higher in rural rather than urban areas and, as nitrogen dioxide decreases, ozone will increase further. <\/p>\n

Unless, that is, we also target nitrogen dioxide\u2019s partner in crime, volatile organic compounds (VOCs). VOCs are critical to the production of ozone and are emitted from human sources such as traffic and industry, plus certain types of vegetation like oak trees. While emissions of nitrogen dioxide fell by 20% between 2015-2024, human-driven VOC emissions declined by only 1%. <\/p>\n

Ozone also increases in periods of hot weather due to elevated VOC emissions from vegetation and greater mixing of air from higher up in the atmosphere into the layer closest to the surface. Incidents of hot weather are only going to become more frequent<\/a> in the UK, making it even more critical to crack down on human-driven VOC emissions to limit ozone pollution. <\/p>\n

Up in the air<\/p>\n

In the UK, considerable efforts have been made to improve air quality. Its importance has been enshrined in law<\/a> for nearly 70 years. An extensive network of air quality monitoring sites<\/a> is maintained by the UK government\u2019s Department for Environment, Food and Rural Affairs (Defra) plus devolved and local authorities. <\/p>\n

Local authorities are required to monitor air quality and develop air quality management areas in places where targets are unlikely to be met. Clean air<\/a> or low emission zones<\/a> have been introduced as a result. <\/p>\n

However, air quality policy must be designed to reflect the complex nature of each pollutants\u2019 drivers. Nitrogen dioxide is dominated by local sources, PM\u2082.\u2085 by transport from further afield and ozone by a combination of both.<\/p>\n

\"big<\/a><\/p>\n

An air quality monitoring station.
\n Chemival\/Shutterstock<\/a><\/p>\n

Local and national policies that cut traffic emissions by incentivising the replacement of older cars with newer, cleaner vehicles, retrofitting buses and restricting entry of the most polluting vehicles into towns and cities will probably reduce nitrogen dioxide further. <\/p>\n

But, if nitrogen dioxide decreases are not accompanied by reductions to VOC emissions, locally and internationally, ozone will continue to rise, especially with more frequent hot weather.<\/p>\n

By contrast, most PM\u2082.\u2085 comes from sources further afield, including industry and agriculture<\/a> from other parts of the UK and beyond, so reductions hinge on stronger national and global policies that target emissions at source rather than just local efforts. <\/p>\n

Air pollution doesn\u2019t respect borders and while the technologies to facilitate continued improvements exist, they must be deployed in joined-up, international efforts. <\/p>\n

\"Imagine<\/p>\n

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Get a weekly roundup in your inbox instead.<\/a> Every Wednesday, The Conversation\u2019s environment editor writes Imagine, a short email that goes a little deeper into just one climate issue. Join the 45,000+ readers who\u2019ve subscribed so far.<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"An estimated 4.2 million deaths can be attributed to poor air quality each year. Poor air quality is…\n","protected":false},"author":2,"featured_media":9738,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[22],"tags":[1397,90,56,54,55],"class_list":["post-9737","post","type-post","status-publish","format-standard","has-post-thumbnail","category-environment","tag-environment","tag-science","tag-uk","tag-united-kingdom","tag-unitedkingdom"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/posts\/9737","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/comments?post=9737"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/posts\/9737\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/media\/9738"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/media?parent=9737"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/categories?post=9737"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/tags?post=9737"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}