Which neighbourhoods have the worst air pollution?

Air pollution poses a serious threat to lives and livelihoods. Find out which neighbourhoods in England and Wales have the highest levels of air pollution and how the impacts of dirty air are unfairly distributed across society.

01 Apr 2025

*** This article was first published in 2022. We’ve since analysed new data to update the map and statistics presented below, including the local authority data analysis. We’ll aim to update this article further when new data becomes available in autumn 2025, subject to time constraints. ***

Air pollution costs thousands of lives and billions of pounds every year. It’s one of the UK's biggest killers and is seriously detrimental to our health, from causing lung cancer and worsening asthma symptoms to triggering heart attacks and strokes. Dirty air also creates a massive burden on health services and business – the costs of illness and lost workdays are estimated to add up to £20 billion a year.

Friends of the Earth has used government data to identify those neighbourhoods across England and Wales that are exposed to the worst levels of air pollution – those where background air pollution has double the levels of key pollutants than the World Health Organization (WHO) recommends. We’ve identified how many schools are in these neighbourhoods, as children are particularly susceptible to dirty air, as well as the unfair and disproportionate impact on people of colour and people on low incomes. We’ve also outlined some actions the government and local authorities must take to ensure clean air for all.

The analysis uses 2021-2023 data – the latest available – using a 3-year average to account for annual variations. The modelling calculates averages across neighbourhoods, which means there may be locations within some neighbourhoods where pollutant levels are higher, such as by busy roads.

Since we first conducted this analysis in 2022, data suggests that levels of air pollutants have reduced slightly in 2023, partially due to improvements in car efficiency, as well as the implementation or expansion of congestion or low emissions zones in towns and cities. However, the annual data is also subject to annual variations due to weather, particularly unusual wind patterns. For these reasons, we’ve decided in this update to move to a 3-year moving average using the latest 3 years of data (2021-2023). Further details on the methodology and data sources can be found at the bottom of this article.

What causes air pollution and what harm does it do?

Our research looked at the 2 most damaging pollutants from a human health perspective – particulate matter (PM_2.5) and the toxic gas nitrogen dioxide (NO₂). Wood burning, industrial processes and road traffic, including non-exhaust emissions, are the major sources of particulates. Road transport is the primary source of NO₂, particularly diesel cars.

Particulates – which are tiny particles measuring 10 μm or less (PM₁₀), or even smaller particles measuring 2.5 μm or less (PM_2.5) – are known to reduce life expectancy, most likely due to cardiovascular and respiratory diseases. Particulates also cause lung cancer and may have wider impacts such as dementia. PM_2.5 emissions are of particular concern because these particles can enter the bloodstream and be transported around the body, lodging in critical organs. This can seriously impact health, especially in vulnerable groups such as the young, the elderly and those with respiratory problems.

NO₂ is a respiratory irritant that can cause inflammation of the airways and lead to coughs, mucus and shortness of breath. Studies have shown that NO₂ is associated with reduced lung growth and respiratory infections in early childhood, and affects lung functioning in adulthood.

Air pollution is currently the biggest environmental threat to health in the UK, with up to 43,000 premature deaths attributed to long-term exposure each year.

Where is air pollution the worst?

Using the latest government data from 2021-2023 on background air pollution, Friends of the Earth has identified the average annual level of these 2 air pollutants (PM_2.5 and NO₂) in every neighbourhood across England and Wales. From this, we’ve determined the number and location of neighbourhoods that breach WHO guidelines.

We’ve also identified which areas have “very high air pollution” – those with double the level recommended by WHO for at least one of NO₂ and PM_2.5.

“Neighbourhoods” in this context are Lower Layer Super Output Areas (LSOAs). These are small areas identified by the Office of National Statistics and have an average population of 1,700 people.

Consult our interactive map to see how air pollution fares in your area.

Table 1 below identifies the number of neighbourhoods with very high air pollution grouped by local authority area. Over 90% of these neighbourhoods are in London. This doesn’t mean that other areas don’t have an air pollution problem – 96% of neighbourhoods in England and Wales are above WHO guidelines for PM_2.5, and 53% are above guidelines for NO₂. Instead, we’re simply highlighting the 2,336 neighbourhoods where air pollution is the worst.

In 7 of London’s local authority areas, all neighbourhoods have very high air pollution. Our research also found that 127 neighbourhoods in London have twice the recommended level of both NO₂ and PM_2.5.

Table 1 – Number and proportion of very high air pollution neighbourhoods grouped by local authority area

See the complete spreadsheet for data on all local authorities.

Air pollution limits

The UK previously derived its air pollution limits from the European Union (EU) – these were transposed into UK law and still apply. In the past, the government has been found guilty in the courts for failing to comply with the current legal limit – measured as an annual average – for NO₂ (40 µg/m³). According to the latest government compliance report, the UK is still failing to meet this limit in 9 of the 43 areas it’s divided into for air quality assessments (UK Air Quality Zones), when all areas should have met this since 2010.

Now we’ve left the EU, the government has set new legal limits, although only for PM_2.5 where it’s proposed an improved limit of 10 µg/m³ by 2040. It’s maintained the legal limit for NO₂ at 40 µg/m³. However, WHO’s guidelines are more stringent – since September 2021 it’s recommended an annual average of 5 µg/m³ for PM_2.5 and 10 µg/m³ for NO₂.

Although we view neighbourhoods with double WHO’s guidelines for at least one of these pollutants as having very high air pollution, UK limits are so lax that levels of even more than double WHO’s guidelines wouldn't breach UK law.

Who fares the worst?

Our analysis shows that air pollution disproportionately impacts lower income and more deprived areas, and particularly affects neighbourhoods with higher ethnic minority populations. Half of neighbourhoods (48%) that have very high air pollution are in the bottom 30% of the most income-deprived neighbourhoods. And nearly half (45%) of the population in neighbourhoods with very high air pollution are people of colour, meaning that people of colour are over 3 times more likely to live in a very highly polluted area than white people. In contrast, across neighbourhoods in which both pollutants are below WHO guidelines, only 2% of the population are people of colour and only 10% are income deprived.

There’s also a disparity between those producing pollution and those most impacted by it. For example, households in neighbourhoods with very high air pollution are over 3 times less likely to own a car than those in the least polluted areas.

Approximately 1 million children, of which two-thirds are under 12, live in areas where NO₂ or PM_2.5 (or both) is double WHO guidelines. There are 1,460 schools in these neighbourhoods, listed in this spreadsheet.

See Table 2 below for more details.

Table 2 – Neighbourhoods with different levels of air pollution grouped by demographic indicators

We’ve identified how demographic indicators map across neighbourhoods with different average annual concentrations of either NO₂ or PM_2.5 (or both), including how these relate to WHO guidelines.

What are the solutions?

Action is needed from every tier of government to tackle the sources of all key pollutants – not just to comply with current UK requirements on air pollution, but also to achieve WHO guidelines as soon as possible.

More must be done on transport, including setting targets to cut vehicle use. Academic research calls for car traffic to be cut by at least 20% by 2030, both to tackle climate emissions and to significantly reduce air pollution. Research for Friends of the Earth outlines how to cut car use significantly.
To date, the government has largely been relying on electric vehicles to improve air quality and reduce carbon emissions, but these still produce particulate air pollution from brake, tyre and road wear. Reducing traffic and encouraging cycling and walking need much stronger emphasis and funding if air pollution goals are to be met.
The government must also halt the massive road building plans it inherited from the previous government, as new roads generate more traffic and more air pollution.
In Wales, the government has introduced a new Clean Air Act, which requires ministers to set a target for PM_2.5 by January 2027 and enables them, but doesn’t require them, to set a target for NO₂.
In England, local authorities have an important role, for example through setting up Clean Air Zones to restrict the dirtiest vehicles in areas of high air pollution, constraining traffic near schools, and providing alternatives to car use such as better buses and segregated cycleways. However, councils are also constrained by poor levels of funding and expertise gaps. Friends of the Earth is campaigning alongside organisations within the Blueprint Coalition for councils to be given more powers and resources.
Other sources of air pollution must also be tackled, for example via measures that constrain domestic wood burning.

Given its serious health and societal ramifications, tackling air pollution must be a priority for the government and local authorities. The unfair and disproportionate impacts of air pollution need to be urgently addressed, and all neighbourhoods should enjoy the benefits of clean and healthy air.

Methodology and data sources

The modelling of air pollution by neighbourhoods (LSOAs) used Defra’s modelled background pollution data published at 1x1 km resolution. This was aggregated to neighbourhoods on an area-weighted basis using LSOA 2011 boundaries. (We’ve used 2011 because schools and income deprivation data isn’t yet available for 2021 LSOAs.)

Pollution concentrations for PM_2.5 and NO₂ were compared with WHO guidelines, and neighbourhoods were categorised based on the extent to which air pollution levels exceeded these guidelines.

Additional socio-economic and demographic data available at the neighbourhood level on schools, child population, ethnic minority (people of colour) population, income deprivation and car ownership were appended to the data set. This was used to derive national, regional and local authority summaries.