Putney High Street in Wandsworth, South London, looks to have become the capital’s second area to breach the hourly mean limit for nitrogen dioxide in 2018, data from the London Air Quality Network suggests.
UK objectives and EU limits stipulate the maximum nitrogen dioxide concentration – 200 µgm/m3 – that must not be exceeded at a single monitoring site for more than 18 hours over the whole year. These limits came into force in 2010.
Brixton Road recorded the first breach of the 200 µgm/m3 hourly mean limit in late January (see airqualitynews.com story) and has gone on to clock up around 43 exceedances of the legal limit at the time of writing.
Putney High Street has recorded its 19 and 20th exceedances today this week (22 March), meaning that the site has now breached the legal limit.
However, despite the limit value breaches coming early in the year this still represents a significant improvement in the performance of the two locations, and London more generally compared to previous years.
Last year Brixton Road was the first location to exceed the nitrogen dioxide limit value in just six days, whilst Putney High Street hit the 19-hour threshold in just eight days in 2016, recording a total of 1,000 hours above the hourly limit across the year.
Improvements in NO2 pollution levels at the two sites have been in part attributed to the introduction of Low Emission Bus Zones, whereby only buses meeting the Euro VI standard are able to operate in order to reduce emissions.
Currently two Low Emission Bus Zones have been set up, one in Brixton and another at Putney High Street, with plans for a further ten such areas to be established in coming months.
Initial results from the Putney Low Emission Bus Zone have also suggested that pollution on Putney High Street has fallen dramatically as a result of the measure, according to Wandsworth council.
The London Air Quality Network is the most comprehensive urban monitoring network in Europe with detailed information on London’s pollution going back for more than two decades.
In total 24 sites across London and the wider LAQN network exceeded the legal 200 µgm/m3 hourly limit on 19 or more occasions in 2016, latest data suggests, while 50 sites met the target.
London Air Quality Network