Air quality

Toxic air is one of the biggest threats to our health. Air pollution damages healthy lungs and makes problems worse for people living with a lung condition.

Air pollution is linked to up to 36,000 deaths in England every year and costs society more than £20 billion. Two of the most dangerous pollutants are nitrogen dioxide (NO2) from vehicles and particulate matter (PM2.5) from vehicles, wood burning, industry and farming. 

PM2.5 air pollution

This page gives evidence and information on particulate matter (PM2.5) levels across England and in local areas. It checks progress against the Taskforce recommendation to:

  • Place new restrictions on particulate matter (PM2.5) emissions from all sources  

With the following measure of success:

  • No-one in England lives in an area with an annual average level of PM2.5 which exceeds the WHO recommended limit, as measured by Defra.

What is PM2.5?

Different emitters of PM2.5: Vehicles, industry, power generation and domestic heating

The air that you breathe contains a mixture of solids and liquids, including carbon, chemicals, sulphates, nitrates, mineral dust, and water. This is known as particulate matter.

Some particles are more dangerous than others. Particles such as dust, soot, dirt or smoke, are large or dark enough to be visible. But the most damaging particles are minuscule particles, known as PM10 and PM2.5. PM2.5 particles are invisible to the naked eye and small enough to pass through the lungs, into the bloodstream, and into your organs. Generally, they come from the combustion of solid and liquid fuels, through power generation, domestic heating and in-vehicle engines.

Particulate matter is measured as μg/m3, which is the concentration of an air pollutant, and stands for “micrograms per cubic meter of air”.

Exposure to PM2.5 can cause illnesses like asthma, COPD, coronary heart disease, stroke, and lung cancer. There is also evidence that links PM2.5 to low birth weight, diabetes and diseases such as Alzheimer’s and Parkinson's.

What's the story so far?

We need a far more ambitious legal limit for PM2.5 to protect public health 

We need a far more ambitious legal limit for PM2.5 to protect public health 

The current legal limit for PM2.5 in the UK is currently set at 20 μg/m3. Until 2021, the World Health Organisation (WHO) limit was set at 10 μg/m3. This has now been updated to 5 μg/m3.

The WHO limit was reduced in part because of research from systematic reviews which suggests that there is a potential increased risk of mortality even in areas where PM2.5 is below the previous WHO limit of 10μg/m3.

This means that now, the current UK limit is four times more than the updated level recommended by the WHO.

Colour scale bar showing EU and WHO limits

The target of 2040 is not ambitious, and the timeframe should be shortened

After going out to consultation, clean air targets, including the target of 10 μg/m3 for PM2.5 by 2040, were announced by the UK government in December 2022.

This new limit is still twice the updated WHO limit, and its timeframe is not ambitious. Research by Imperial College London in 2022 shows that a target of 10 μg/m3 for PM2.5 levels could be achieved by 2030 across most of the UK and this is supported by the latest air pollution data.

While it is positive that PM2.5 has been decreasing over the years, this needs to be happening faster.

There’s no safe level of air pollution. Even the WHO’s recommended limit does not guarantee you suffer no harm.

Before the pandemic, in 2019, over 33% of all local authorities had unsafe background levels of PM2.5 above 10 μg/m3

In 2019, 106 out of 317 local authorities (33%) had unsafe levels of PM2.5 that were over the limit recommended by the WHO, 10μg/m3.

What’s more, 75% of local authorities with modelled roadside levels of PM2.5 had at least one road over 10 μg/m3.

YearTotal LAsBreached LAs% Breached

% of local authorities who have breached legal limits per year

The pandemic had a significant impact on the levels of PM2.5 across the country, with no local authorities estimated to have a background pollution above 10μg/m3 in 2021.

This likely still doesn’t reflect normal travel patterns due to the impact of lockdowns for COVID-19. We will have to wait to see if the pollution in these areas increases again above the old limit as travel patterns return to normal, or if the reduced pollution is maintained.

The reduction in air pollution may have been partly due to reduction in travel when lockdowns were in effect.

During the pandemic, most areas were still above the updated WHO limit

Although air pollution decreased across the country during the pandemic, when compared to the updated recommended WHO limit, 98% of local authorities were still above 5μg/m3.

It is positive that air pollution decreased, but this shows that even with a reduction in travel due to the pandemic, the majority of people throughout the country were exposed to dangerous levels of PM2.5.

This shows how important it is for the Government to update the legal limits as soon as possible and take action to reduce pollution.

Even during the pandemic, there were still unsafe levels of air pollution

What does this mean?

The reduction in air pollution in the past few years shows us that it is possible to reduce it, but there is still a long way to go. It also makes it clear that the current UK limit for PM2.5 must be updated far sooner than 2040.

Even if levels of air pollution have reduced, this does not minimise the need for action such as the introduction of clean air zones in order to reduce unnecessary harm to people.

An average of 1 in 18 deaths are linked to PM2.5 each year

Almost 6% of adult deaths are linked by PM2.5 each year

Although pollution may be moving in the right direction, there is no safe level of PM2.5, and this pollution impacts people’s health and can contribute to deaths across the country.

According to figures published by the Office of Health Improvement and Disparities (OHID), in 2020 around 5.6% of deaths in those aged over 30 could be attributed to PM2.5 air pollution. That's around 1 in every 18 deaths.

Some local areas across the country are estimated to be even higher than this, with parts of London almost as high as 8%, around 1 in 13 deaths.

A detailed analysis

Background concentrations of PM2.5 vary greatly across the country

Background concentrations of PM2.5 are affected by the amount and scale of emitters in an area. Based on modelled background pollution data the lowest background concentration of PM2.5 across the country in 2021 was estimated to be 4.2 μg/m3, in Allerdale.

The highest concentration was in the city of London, with a background level of 9.8μg/m3, just below the old WHO limit and far higher than the updated limit of 5 μg/m3. Levels this high present a considerable health risk as showcased by the proportion of deaths linked to PM2.5, but even the lowest concentration poses a risk to people’s health.

Bar titleIcon filenameValueRange-minRange-maxTargetLeft is goodLine of peopleScale-minScale-maxUnitRange-min-labelRange-max-label
The range in background level of PM2.5 across the country (2021)4.29.8515μg/m3AllerdaleCity of London

The impact air pollution has on human life depends on where you live. The proportion of deaths linked to the pollutant ranges from 3.0% to 7.8% of deaths.

The impact on human life depends on the population of an area and how close people live to dangerous concentrations of PM2.5. More remote areas like Allerdale have an estimated 3% of deaths linked to PM2.5 air pollution. This is still too many deaths. However, areas of London, including Newham, have up to an estimated 7.8% of deaths linked to PM2.5, a shockingly high proportion.

Bar titleIcon filenameValueRange-minRange-maxTargetLeft is goodLine of peopleScale-minScale-maxUnitRange-min-labelRange-max-label
The range in the % of deaths linked to PM2.5 across the country (2020)3.07.812%AllerdaleNewham

The problem is far worse in the south and near cities, towns and major roads

Toxic levels of pollution can be found across the UK, but towns and cities are affected more than rural areas. The south east of England is the worst affected region outside of London in terms of the estimated impact on mortality. This is likely to be because PM2.5 is influenced by weather patterns and the south of England is also affected by pollution from mainland Europe.

Towns, roads and cities are the worst affected areas, especially in the south of England

Our asks

There is no safe level of air pollution and everyone deserves the right to breathe clean air. To change the toxic levels of pollution in the UK:

•    We need better monitoring across the country
•    We need better information and data on air pollution so that everyone has clear advice on how to protect themselves and breathe cleaner air
•    We need the government to strengthen the national clean air strategy.
•    We need a specific plan to protect the most vulnerable, including children and people with a lung condition, from the effects of toxic air
•    We need greater government support for local authorities so they can put the right solutions in place, including clean air zones

Help and more information

If you would like more information on air pollution and how best to protect yourself please visit the Asthma+ Lung UK website.

Data sources

All data sources can be found on our data sources page.

The modelled background pollution data methodology was updated in 2020 and can be found here.