Locations of Bristol City Council operated air quality monitoring sites, which defines the areas of poor air quality in Bristol.Data displayed is annual nitrogen dioxide (NO2) concentrations measured using diffusion tubes. Green dots indicate concentrations, for the latest year of data available, below the national annual objective for this pollutant of 40 ug//m3. Yellow indicate concentrations between 40 ug//m3 and 60 ug//m3 and exceed the annual objective for this pollutant. Red dots show those locations with concentrations greater than 60 ug//m3.Data are bias adjusted and annualised where required. Full details of air quality monitoring results are reported to Defra on an annual basis. The most recent reports on air quality in Bristol are available for download at: https:////www.bristol.gov.uk//pests-pollution-noise-food//air-quality