Poor air quality is the largest environmental risk to public health in the UK, associated with short and longer term respiratory and cardiovascular problems. Approximately 40,000 premature deaths in England, or 300 in Bristol, can be attributed to NO2 and fine particulate matter pollution every year . Additionally, the most vulnerable members of society are often hit more by pollution creating and worsening health inequalities. Legally, concentrations of nitrogen dioxide (NO2) must not be more than 40 μg/m3 (microgrammes per metre cubed) as an annual mean (i.e. measured over a year). Yet across the UK there are many places that exceed these limits, including in Bristol.