Improving air quality

We are committed to achieving and maintaining compliance with national air quality objectives, but it is also our ambition to continue to reduce emissions under the Air Quality Action Plan as we recognise that any improvements have the opportunity to improve public health.

Where does air pollution come from?

Key outdoor air pollutants in the city are mainly emitted from traffic. Diesel cars are responsible for most of these emissions, but buses and lorries also contribute a large amount. Shipping and industrial sources also add to high levels of pollutants in the city.

Domestic wood burning in stoves and open fires is one of the largest sources of particulates in certain neighbourhoods, especially during the winter.

Idling, which contributes to toxic emissions in the air we breathe, is when your vehicle’s engine is running when you're stationary for a period of longer than 30 seconds. If you're parked, waiting for someone or stuck in traffic, switch off your engine. Idling wastes fuel and rereleases harmful pollution into the air which harm public health.

What are we doing to improve air quality?

Local authorities are required to monitor local air quality to identify where ‘national air quality objectives’ are not being met. Southampton meets all air quality objectives other than that for yearly average levels of nitrogen dioxide in certain areas. Most of our measures focus on reducing emissions of this pollutant by tackling its main source: road transport. As a result of these measures, levels of this pollutant have been improving steadily.

We have tackled engine idling by:

  • Working with schools to produce no-idling banners, leaflets and information to parents
  • No-idling signs have been put up around the city and in particular areas known to be hotspots for idling

1. Air Quality Action Plan SHOW


2. Clean Air Strategy 2019-25 SHOW


3. The Local NO2 Plan SHOW


4. The Green City Charter and Plan SHOW