New data released today by Oxford City Council shows that whilst emissions from public transport continue to fall, the city’s levels of nitrogen oxide still breach UK air quality limits.

The report, compiled by Ricardo Energy and Environment and available on the council’s website, assesses air pollution data from a number of sites across the city taken in December 2019, and will be used to inform the City Council’s new Air Quality Action Plan which is expected to be published later in 2020.

The report’s main findings are that the city’s levels of particulate matter PM10 and PM2.5 are within both the legal limits as well as the WHO’s advisory limits. However, levels of the pollutant NOx (nitrogen oxides) breach legal limits in key areas of the city, such as the High Street, George Street and St. Clement’s. The levels of NOx emissions from road traffic, which can contribute to and exacerbate serious respiratory diseases, would need to be reduced by 22.9% in order to fall below the legal limit on the High Street, and a drop of 16.9% and 9.5% respectively for George Street and St. Clement’s.

The transport sector was deemed to be by far the greatest source of emissions, contributing 68% of the city’s total; domestic sources, primarily heating, contributed 19% of NOx emissions, whilst industry and service sources accounted for another 12%.

Despite representing Oxford’s most significant source of harmful emissions, the introduction of higher-standard Euro VI buses, as well as the retrofitting of existing fleets, has resulted in the contribution of buses to total transport NOx emissions falling from 64% to 32% since 2013. Meanwhile, contributions to this total from cars, predominantly with diesel engines, has risen from 22% to 37% in the same time, largely due to the decrease in emissions from buses.

The report comes as the City Council’s plans to introduce the Oxford Zero Emission Zone have been postponed by six months, from late 2020 until summer 2021, as a result of the disruption caused by the Covid-19 pandemic.

News that the High Street and George Street are sites of notably high NOx pollutants will be of particular concern for students, with Exam Schools and popular bars and restaurants located in the most polluted areas of the city. 

Commenting on the report’s findings, Councillor Tom Hayes, Deputy Leader and Cabinet Member for Green Transport and Zero Carbon Oxford, said, “Oxford is breathing cleaner air, perhaps the cleanest ever. Our clean air measures have led to a big reduction in harmful emissions from transport in recent years, but the council has more to do to ensure everyone is breathing the very cleanest air.”

Hayes added, “Oxford’s Low Emission Zone has significantly reduced emissions from buses and our Zero Emission Zone will be the real game-changer to ensure citizens are not choking on toxic air. In particular, the operation of cleaner buses will ensure that air quality on St Clement’s Street becomes legally compliant with very significant reductions.”

The Managing Director of Stagecoach Oxfordshire, Chris Coleman, commented, “We continue to be fully supportive of Oxford City Council’s measures to improve air quality in the city and will further invest in our fleet of vehicles to reduce emissions and improve air quality.”

In addition, Coleman said, “Covid-19 has given us a window on what could be a positive future world – one with dramatically fewer cars on our roads, safer streets, cleaner air and less damage to our environment. Buses will continue to play a crucial role in supporting the renewal of cities like Oxford as we look to emerge from the pandemic.”

In January 2019, the UK Goverment launched its Clean Air Strategy, which aims to reduce the annual cost of air pollution to society by £5.3 billion by 2030.

Layla Moran, the Liberal Democrat MP for Oxford West and Abingdon has been contacted for comment.

Max Spokes

Max (he/him) was formerly Environment News Editor and Climate Columnist at The Blue. He is in his final year studying History and Politics at Balliol.