Air pollution map of Bristol

This map shows the data collected by Bristol City Council in 2018. Red and black dots are bad news. You can also open the full map or click on the dots to find out more information.

What do the colours mean?

Red and black dots are bad news.

Red and black dots mean that the pollution at that site is breaking the national and EU limits for air pollution – specifically, for the annual average measurement of nitrogen dioxide. Green means the site is below the limit, but the locations are at risk of breaking the rule and so should be monitored. Overall, more than five deaths a week in Bristol are linked to air pollution. This number would decrease if our air pollution levels were lower.

The council also monitors other pollutants and has hourly emissions monitoring to check for extreme pollution events. The annual (mean) average of nitrogen dioxide is the only legal limit that Bristol is breaking.

Why is it worse in some places than others?

Air pollution is caused by a combination of factors. The first is how much air pollution is being emitted: how busy is the road or are there other sources nearby. However, the level of air pollution also depends on how much the air is circulated or where the wind takes polluted air. So higher, windier places will tend to have less pollution, but low-lying places like Bedminster, or valleys may have worse pollution.

What is causing the pollution?

The main cause of air pollution in Bristol – and most urban areas in the UK – is traffic, especially diesel engines. In recent research on Bristol specifically (see p.105 of this document) it was found that 40% of Bristol’s nitrogen dioxide emissions in the centre are from diesel cars. Buses and coaches cause 23% of emissions. Diesel LGV (light goods vehicles like delivery vans) cause 22% and HGV (big lorries) cause 11%. Even though bigger vehicles may use more fuel, their engines are required to meet tougher standards and there are fewer of them on our roads.

Who chooses where to monitor/why aren’t they monitoring my street?

The council decides where to locate the monitors. They are not evenly spread across the city or region because it is more efficienty to concentrate them where two conditions apply: areas where they know we risk breaking the nitrogen dioxide limits; and near to where people are living. This means the sites are targeted at main roads and busy central areas, or where there have been concerns about hotspots.

In 2018, the council installed extra monitors at 59 schools in central Bristol to check their air. Almost all were below the annual mean limit value, but Colston Girls’ School and Summerhill Infants playground monitoring were above the legal limit, and monitors on the road in front of Parson Street School were also above the limit. Read our blog to find out more about how schools in different places are dealing with air pollution.

What is important about nitrogen dioxide?

Anywhere with a red or black dot on the map is a location that is failing to meet the national and EU standards for air pollution. The rule we are breaking is the “annual mean of nitrogen dioxide,” which is 40 µg/m3 (40 micrograms per cubic metre). The problem you can see is a chronic level of air pollution that is too high overall, rather than specific short-term incidents that might make it bad for a few days or hours, but then fine the rest of the year. Air pollution is linked to heart attacks, strokes and other conditions affecting thousands of people in our city.

What does air pollution do to our health?