Air pollution in Oxford sees 29% decrease during 2020

The 29% reduction in air pollution levels is equivalent to the level of reduction achieved during the ten-year period between 2009-2019.

The new data, published in the City Council’s latest Air Quality Annual Status Report shows the average air pollution levels across 71 air pollution monitoring locations in the city, during 2020.

Now, as Oxford starts to emerge from the pandemic, the Council is exploring how it can learn from the changes that happened during the lockdowns to ensure Oxford moves forward to the cleanest air possible. This is as Oxford gets ready to launch Britain’s first Zero Emission Zone this August.

Some of the highlights of the latest Air Quality Annual Status Report are:

• For the first time since air quality monitoring started in Oxford, all 71 monitoring stations across the city were fully compliant within the national legal limit of 40µg/m3 
• The average reduction of NO2 levels across 2020 in the entire city was of 29%. This reduction is consistent with the 20-30% reductions in NO2 levels which was observed across the country.
• Particulate Matter show an average 19% reduction of PM10 levels, and a 22% reduction of PM2.5 levels.
• During the first lockdown, Oxford saw reductions of up to 60% in NO2 levels, the main pollutant of concern, primarily from a significant reduction in fossil fuel traffic – this is the lowest level recorded in the city since Oxford’s air quality was first monitored in 1996.
• According to data from Oxfordshire County Council, between 23rd March to 31st December 2020, traffic levels reduced by 35% in Oxford’s city centre.  
• The biggest NO2 reductions were seen on George Street during the periods of lockdown and pedestrianisation, where the two monitoring stations recorded decreases of 45% and 40% in air pollution levels.
• The lowest reductions in air pollution were seen at Cowley Road/Union St and Sunderland Avenue, which saw a 14% and 15% reduction in NO2 levels.
• Traditionally Oxford’s most air polluted road, St Clement’s Street saw a large improvement in air quality compared with the previous year. This location was nonetheless the one with the highest annual mean for NO2 in 2020 (St. Clements Street/The Plain) with a value of 36 μgm-3 although it saw a 32% decrease in NO2 levels when compared with data from the previous year (53 μgm-3).
• Air pollution around Westgate Oxford saw a 30% overall decrease in NO2 levels.

The full air pollution report is available to view here.

Air pollution

The European Union has set a legal limit for the average limit of toxic nitrogen dioxide (NO2) levels in towns and cities of 40µg/m3 or below– however, recent studies seem to indicate that there is no safe limit for NO2.

There have been several studies produced over the years that have tried to estimate the true health impacts of air pollution in Oxford.

In April 2014, a report issued by Public Health England presented estimates of local mortality burdens associated with particulate air pollution. The report shows that long term exposure to anthropogenic particulate air pollution in Oxford could be responsible for 6% of all deaths of people aged 25 and over.

In January 2021, the City Council’s Cabinet approved the adoption of a new Air Quality Action Plan (AQAP) for the city, replacing the old plan which expired in December 2020.

Under the new Action Plan, the Council set its own voluntary target for 30 µg/m3 of NO2 to be achieved, by 2025 at the latest—going far beyond the current national legal target set out by the UK Government of 40 μgm-3.

The NO2 target of 30 µg/m3 is both stretching and realistically achievable by 2025 – however, without the introduction of key schemes such as the Oxford Zero Emission Zone and Connecting Oxford, it is unlikely that Oxford will meet this local target.

Over the past few years, air pollution levels in the city have plateaued following a period of significant improvements in air quality, with the need for stronger measures being highlighted in order to ensure a further reduction in air pollution levels.

In 2019, before the pandemic, the city was experiencing NO2 levels that were above the annual mean legal limit at six locations in the city (High Street, Long Wall Street, St Clements (on two monitoring stations), George Street, St Aldate's).

According to Oxford’s most recent source apportionment study, the transport sector is the largest contributor of NOX emissions in the city, accounting for 68% emissions.  This is followed by domestic combustion (19%), combustion from industry and services (12%) and others: waste, agriculture, solvents, nature (<1%).

Since 2013, the contribution of buses to total road NOx emissions have reduced by 50%. This shows how effective measures such as the introduction of the city’s Euro V Low emission Zone for buses in 2014 and the retrofitting of a significant amount of buses to Euro VI standard have been in reducing air pollution from this vehicle type. On the other hand, the data also reveals that the contribution from cars to total road NOx emissions have increased by 22% - from 15% to 37%.

“The air that you breathe, the air that your loved ones breathe, is the cleanest that it has been in modern times. Nobody would want to repeat the lockdowns which reduced air pollution levels by 29%, but they have provided concrete proof that getting people out of polluting cars cleans up our air and protects your lungs.

The city has taken action to meet a public health crisis in the last year, we should be willing to do so for that other invisible public health crisis—air pollution—which hurts the poorest and marginalised in our city the most. We need to back the bus, go on boosting the biking boom we’ve started, electrify a lot more transport, and make a success of Britain’s first Zero Emission Zone piloting this year.”

Councillor Tom Hayes, Deputy Leader and Cabinet Member for Green Transport and Zero Carbon at Oxford City Council