Did policies to abate atmospheric emissions from traffic have a positive effect in London?
A large number of policy initiatives are being taken at the European level, across the United Kingdom and in London to improve air quality and reduce population exposure to harmful pollutants from traffic emissions. Trends in roadside increments of nitrogen oxides (NOX), nitrogen dioxide (NO2), particulate matter (PM), black carbon (CBLK) and carbon dioxide (CO2) were examined at 65 London monitoring sites for two periods of time: 2005–2009 and 2010–2014. Between 2005 and 2009 there was an overall increase in NO2 reflecting the growing evidence of real world emissions from diesel vehicles. Conversely, NO2 decreased by 10%·year−1 from 2010 onwards along with PM2.5 (−28%·year−1) and black carbon (−11%·year−1).