The following charts show how the average 12-monthly concentrations of nitrogen dioxidxe (NO2) and particulate matter (PM10 and PM2.5) have changed since 2010 at sites measured for regulatory purposes in the City of Manchester and neighbouring areas as reported by Air Quality England. 

The following charts illustrate trends in nitrogen dioxide concentrations measured using diffusion tubes for Manchester City Council.  The concentrations are not adjusted for bias and include estimates where the monthly raw source data is either missing or anaomalous.  Source:  Air Quality Annual Status Reports (various years) Greater Manchester Combined Authority