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Last week, Michael Gove, the former Secretary of State for Environment, Food and Rural Affairs, gave a speech where he revealed his support for the UK adopting the World Health Organisation’s (WHO) recommended legal limit on the annual mean concentration of PM2.5, which is particulate matter measuring less than 2.5 micrometres and is known to have negative effects for health.

The UK currently has different legal limits for different air pollutants. These limits establish the permitted annual mean concentration for different air pollutants on hourly, daily or yearly intervals. Most of these limits are EU-derived, but the WHO limits are more ambitious than any of the UK’s current ones.

However, air pollution cannot be tackled by only focusing on the UK’s legal limits. An equally important tool to reducing the dangers posed by air pollution is communicating the levels of, and health dangers posed by, air pollution to the public.

The public are aware that air pollution is an problem. Surveys show that the public are alert to air pollution being harmful for heath. For example, 71% of UK adults in 2018 were concerned about the impacts of air pollution on the health of themselves and others, as Bright Blue polling showed.

But a survey from earlier this year found that 65% of UK adults don’t know who to turn to for information and advice on air quality, despite the public prominence of air pollution as an issue.

To communicate current and future levels of the most damaging air pollutants, the Department for Environment, Food and Rural Affairs (DEFRA) maintain the ‘Daily Air Quality Index’ (DAQI), which is an area-based scoring system that assigns an area a score of one to ten to communicate the levels of air pollution in real time, as well as recommend actions and health advice based on their levels.

The DAQI provides a health message alongside this score, as shown below in Figure 1.

The DAQI can also be used to see how the danger posed by air pollution to health varies over the year, as the data is readily available online. This is shown in Chart 1 below for 2018, which shows how many times each region in the UK was given a DAQI score in each of the brackets in Figure 1 above. Each region is assigned a score for each day of the year.

Chart 1. The total number of times each DAQI bracket was scored across geographic regions by month, 2018.

Source: UK Air Information Resources, “DAQI regional data”, (2019)

Clearly, air pollution was worse between March and July last year, with the average DAQI score peaking in May at roughly 3.5. This was due to high summer temperatures last year, generating high levels of ozone (O3) and therefore increasing the average regional DAQI score.

This tell us that air quality in the UK, on average, is good enough for the official health advice to be “enjoy your usual outdoor activities” almost all year round. Indeed, only 0.4% of DAQI scores issued for regions in the UK were “high” or “very high” last year, meaning 99.6% of regional DAQI scores were low enough for people to “enjoy their normal outdoor activities”.

However the awareness of where to find information like the DAQI amongst the public is low. The Government is taking action on improving the communication of air pollution, as the recent Clean Air Strategy 2019 reflects through proposing personalised messaging systems during high air pollution episodes.

But more needs to be done. More creative ways of communicating air pollution risks should be considered by Government to tackle this issue, as a recent Public Health England report suggested.

Recent examples include targeted social media campaigns, creative academic studies to make air pollution relevant to people’s lives, and even air pollution art exhibitions.


With Michael Gove announcing his ambition for the WHO limit on PM2.5, post-Brexit air quality limits look to improve.

Yet more needs to be done to arm people with the knowledge of how air pollution can be dangerous and how they can avoid it. Legal limits are important to reduce air pollution, but so is providing people with knowledge of the levels and dangers of air pollution. This allows the public reduce their own exposure to, and therefore harm from, air pollution.

William Nicolle is a Researcher at Bright Blue.