Diffusion Tube Monitoring

The map below shows all the diffusion tube monitoring sites within the Borough. You can search the map by postcode, town, or just zoom in to your local area, however please bear in mind that unless you live very close to a diffusion tube site, the levels at your house may vary significantly from those shown. 

The Air Quality Objective for Nitrogen Dioxide is 40 µg/m­­³ (Annual Mean)

Key to map symbols:

Symbol	Site Type	Description
	Urban background	Urban residential areas away from sources of pollution
	Kerbside	Within 5 metres of the kerb
	Roadside	Typically 5 to 15 metres from the kerb
	Suburban	Residential areas on the outskirts of towns (>15m from major roads)
	Industrial	Used to monitor industrial emissions
	Rural	Open countryside away from roads, industry or populated areas
	Other	Specific emission sources such as car parks, motorways or other monitoring categories.

All levels are shown as Bias Adjusted Annual Means.