Significant reduction in Oxford’s air pollution after cleaner buses introduced – but city still has toxic air in some streets

Published: Monday, 2nd July 2018

Oxford has seen a significant reduction in air pollution levels following the introduction of ultra-low emission buses – but the city still has toxic air in some streets.

New data from the city’s 74 air pollution monitoring locations has shown that levels of toxic nitrogen dioxide (NO2) fell by an average of 22.7% between 2016 and 2017 – the largest ever year-to-year drop.

But four of the city’s air pollution monitoring locations still registered NO2 levels above the legal limit in 2017, and health experts have warned that there is no safe level for NO2.

The reduction is a significant step in the progress towards delivering zero emissions in Oxford city centre – to be underpinned by the Zero Emission Zone. This will ban diesel and petrol vehicles in stages between 2020 and 2035, and will take NO2 to near-background – and therefore considerably safer – levels.

The fall in NO2 between 2016 and 2017 has been attributed to Oxford Bus Company and Stagecoach Oxford introducing ultra-low emission buses (Euro VI standard) into Oxford from 2014, but particularly in 2016 and 2017. About 40% of buses in city centre streets are now ultra-low emission.

Oxford City Council secured £1.7m of Government funding earlier this year to upgrade a further 78 buses to be ultra-low emission over the next 18 months – and convert five of Oxford’s sightseeing buses to become the city’s first fully-electric double-decker buses.

A 2016 report from the Royal College of Physicians and the Royal College of Paediatrics and Child Health found that outside air pollution – of which about 75% comes from road traffic – cuts short 40,000 lives a year in the UK.

The European Union requires national governments to keep annual average NO2 levels in towns and cities across their countries to below 40µg/m3 – a legal limit that was supposed to be met in 2010.

But health experts have warned that there is no safe level for NO2, and the World Health Organisation, which also currently targets 40µg/m3 for NO2, is expected to revise this figure downwards.

The new air pollution data is published in the City Council’s Air Quality Annual Status Report, which provides an overview of annual averages for nitrogen dioxide levels across Oxford’s 74 monitoring locations.

Some of the highlights of the Air Quality Annual Status Report were:

  • NO2 across Oxford was reduced by 22.7% between 2016 and 2017. The largest previous year-to-year reductions were in 2007, when NO2 levels fell by 14.6%; and in 2013 in the lead-up to the introduction of the Low Emission Zone, when levels fell by 12.2%
  • Oxford’s continuous monitoring stations met the legal limit for the first time ever, with NO2 in St Aldate’s dropping from 49µg/m3 in 2016 to 40µg/m3 in 2017 (an 18.4% reduction) and High Street from 47µg/m3 in 2016 to 39µg/m3 in 2017 (a 17% reduction)
  • In 2017 there were four monitoring locations registering a level of NO2 above the legal limit, compared to 17 in 2016 and 21 in 2015
  • Air pollution around Westgate Oxford has fallen back since the rise in 2015 and 2016 during the construction works. The Norfolk Street monitoring location registered an NO2 level of 23µg/m3 in 2014, 30µg/m3 in 2015, 35µg/m3 in 2016 (the highest level around Westgate Oxford in 2016), and 23µg/m3 in 2017
  • Overall, levels of NO2 have fallen by 42.9% across Oxford in the last decade                                                                                                                              

The report found that the top five reductions in NO2 were in:

  • Latimer Road/London Road, where nitrogen dioxide fell by 35.1%, from 37µg/m3 in 2016 to 24µg/m3 in 2017
  • Norfolk Street, where nitrogen dioxide fell by 34.3%, from 35µg/m3 in 2016 to 23µg/m3 in 2017
  • Castle Street, where nitrogen dioxide fell by 33.3%, from 42µg/m3 in 2016 to 28µg/m3 in 2017
  • Bonn Square, where nitrogen dioxide fell by 32.4%, from 37µg/m3 in 2016 to 25µg/m3 in 2017
  • New Road, where nitrogen dioxide fell by 31.4%, from 35µg/m3 in 2016 to 24µg/m3 in 2017

But it found there were still NO2 levels above the legal limit in four locations across Oxford:

  • St Clement’s Street, where the nitrogen dioxide annual mean was 47µg/m3 in 2017 (117.5% of the legal limit) – but this is a 23% reduction from 2016, when it measured 61µg/m3
  • High Street, where the nitrogen dioxide annual mean was 42µg/m3 in 2017 (105% of the legal limit) – but this is a 20.8% reduction from 2016, when it measured 53µg/m3
  • Summers Place, near Cutteslowe Roundabout, where the nitrogen dioxide annual mean was 41µg/m3 in 2017 (102.5% of the legal limit) – an increase of 2.5% on the 2016 level of 40µg/m3
  • BP service station in Woodstock Road, where the annual mean nitrogen dioxide level was 41µg/m3 in 2017 (102.5% of the legal limit). The site was not monitored in 2016

Only the Summers Place monitoring station and Botley Road/Duke Street showed increases in NO2 levels, the latter rising by 13.6% from 22µg/m3 in 2016 to 25µg/m3 in 2017.

The 2017 data is a dramatic change from 2016, when the levels of NO2 appeared to be plateauing above the legal limit across Oxford. Between 2011 and 2013, average NO2 levels across the city centre fell by 18.9 per cent. But between 2014 and 2016, average NO2 levels fell by just 3.9 per cent.

Last year, Oxford City Council and Oxfordshire County Council announced proposals to introduce the world’s first Zero Emission Zone in Oxford city centre in stages between 2020 and 2035.

More than 750 residents and businesses took part in the public consultation on the proposals, with between 68% and 71% backing each stage of the Zero Emission Zone.

Further consultation – with stakeholders including disability groups, bus companies, taxi owners and operators, city centre businesses and University of Oxford colleges – has been carried out over recent months to look at how Oxford can transition to zero emissions.

Detailed proposals are now being developed for the Zero Emission Zone, which will be released for public consultation later this year.

Oxford City Council has secured £3.25m of Government funding in recent years to help with the introduction of the Zero Emission Zone, including £1.7m to upgrade buses to be ultra-low emission or fully electric, £800,000 to install electric vehicle charging points for residents with on-street parking, and £500,000 to install charging points for taxi owners and operators. Oxford has also received £474,000 of Government funding to introduce the world’s first pop-up electric vehicle charging points.

This week (4 and 5 July), the city will host the Oxford EV Summit, which will see 300 leaders and key players from the electric vehicle and charging infrastructure industries to explore the opportunities – and barriers – on the road towards zero emissions.

Oxford City Council was named as the number one local authority in the UK for tackling air pollution by Government Business, and ClientEarth named the City Council as one of the best local authorities in the UK for tackling air pollution.

The Government announced plans in July 2017 to ban all new petrol and diesel cars and vans from 2040, but earlier this month (June) Oxford City Council joined the Mayor of London and leaders from a dozen other UK cities to call for this to be brought forward to 2030.

The city leaders also called for the Government to introduce a scrappage scheme to support low-income diesel drivers making the shift, and to provide local authorities with more funding and powers to tackle air pollution.

Oxford City Council has a legal duty to monitor air pollution in Oxford, and has been doing so since 1999. The City Council has 74 monitoring locations at the side of roads with high traffic levels: three are continuous monitoring stations, which produce live data; and 71 are diffusion tubes, which produce annual averages.

The figures in the Air Quality Annual Status Report are subject to approval by the Department for Environment, Food and Rural Affairs (DEFRA).

Councillor Tom Hayes, Executive Board Member for a Safer and Greener Environment, said: “There is no safe level of air pollution. When cities like Oxford slash pollution levels, fewer people suffer and die. But, put very bluntly, air pollution is an invisible killer, and Oxford must accelerate our pollution protection – especially in illegal parts of the city such as St Clement’s – because every day that we don’t, people will live in it, work in it and commute in it.

“Air pollution isn’t just an environmental concern. Nor is it simply a public health crisis. It’s a clear health injustice – everybody breathes the same air, but the poorest in our community and the very vulnerable are hit hardest by toxic pollution. As a council, we’re committed to ending all forms of inequality and all causes of inequality, and that means cleaning up our toxic air to end health inequalities in our city.

“Oxford is determined to eliminate air pollution from our roads once and for all and, with our Zero Emission Zone, accelerate the electric vehicle revolution which can nudge more drivers to trade in polluting cars for cleaner ones.

“We are installing electric vehicle charging points for residents, businesses and taxi operators across Oxford, to make it easier for local drivers to shift to cleaner vehicles. Already nearly 250 local residents own electric cars and we want to see that number grow, as well as more people walking and cycling in the city.

“Next year we will see fully-electric double-decker buses operating in Oxford for the first time. We have a long way to go, but we are delighted to join Oxford Bus Company, Stagecoach Oxfordshire, and local residents and businesses on this road to zero.”

Professor Stephen Holgate, Medical Research Council Clinical Professor of Immunopharmacology and Honorary Consultant Physician within Medicine at the University of Southampton, said: "There is no longer any doubt that air pollution cuts short lives, especially in the vulnerable with on-going heart and lung disease. In children it reduces lung function as well as causing new asthma and making established asthma worse.

“With imaginative and bold steps, Oxford is leading the way for toxic pollution reduction measures suitable for cities outside London. They also recognise that there is no safe level of air pollution and, therefore, there is still more to do, but what a great start."

Professor Holgate chaired the UK Government Committee on the Medical Effects of Air Pollutants, the Expert Panel on Air Quality Standards, the Hazardous Substances Advisory Committee, and was a member of the Royal Commission on Environmental Pollution.

Dr Timothy Hinks, Senior Research Fellow at the University of Oxford and Honorary Consultant in Respiratory Medicine at the John Radcliffe Hospital, said: “Air pollution is an invisible killer. A large body of research is now revealing the full extent of the damaged caused. Some people are particularly at risk of its effects: those with lung disease and the very young. Asthma affects 1:12 adults in UK, and we know poor air quality increases their symptoms and the risk of asthma attacks. Effects can last for several days. The people we care for in Oxfordshire with severe asthma often struggle to make it through a day despite the medications they take. Air pollution worsens their lung function, increases admissions to A&E and forces people to take time off work. Asthma alone claims the lives of three people each day and costs the UK £1.1 billion each year, so anything we can do here in Oxfordshire to help would be an important step forward.

“Air pollution doesn’t just affect people with asthma: we now know it accelerates decline in lung function, increases type II diabetes, heart attacks, strokes, cancer and even the cognitive decline in later life. So living near a major road increases the risk of dementia. The most vulnerable group are young children. As their lungs and immune systems develop they’re very susceptible to damage. So we see children living in highly polluted areas are four times more likely to have poor lung. But what is particularly worrying is evidence that the effects last life-long. A study this year from Southampton showed that even after 60 years children exposed to air pollution in childhood have 25% more lung disease, 14% more heart disease and 7% more cancers. So we need to act now to make changes which will have benefits for the rest of the century.

“The more we study air quality, the clearer it is becoming that there is no lower limit below which pollution is safe. So a recent, massive study of 60 million people in the United States found that even below the legal safe limits for particulates or for ozone, there were still significant adverse impacts on health, and increases in death rates particularly amongst disadvantaged people groups. So whilst it’s great to see Oxford reducing pollution levels nearer to legal limits, that’s really only a start. The lower we can get levels of NO2 and PM2.5s the better.

“We need to be ambitious. This is costing UK £20 billion each year. In the 1950s we successfully tackled coal smoke in towns, in the 1980s we tackled lead pollution and carbon monoxide, in the 1990s it was CFCs, now as road traffic has increased, and we’ve switched to diesel, we have to tackle the NO2 and PM2.5s. Now we know the consequences, and we have the tools – in the shape of electric cars and bicycles – there’s no excuse not to act.”

Phil Southall, Managing Director of Oxford Bus Company, said: “The findings are extremely encouraging, and we believe further improvements will be achieved as we continue to invest in upgrading our fleet. We pride ourselves as being at the forefront of environmental technology innovation and introduced our first hybrid buses to the city in 2011.                    

“The improvements announced today follow our £11.5 million investment in ultra-low emission Euro VI buses, which started in 2014 and continued in 2016 and 2017 ahead of the Westgate opening.

“We now have 67 ultra-low emission buses and coaches in our fleet, and we have plans to increase this further both through upgrading more than 65 of our existing fleet, and investing in further new vehicles. While there is still a lot to do to continue to improve air quality in Oxford this report demonstrates buses are a key part of the solution.”

Martin Sutton, Managing Director of Stagecoach in Oxfordshire, said: "Diesel cars are the single biggest contributor to poor air quality, responsible for 41% of all NOx emissions from road transport, while every double decker bus can take up to 75 cars off the road.

“We are delighted to be helping deliver better air quality in Oxford by driving improvements in our own fleet. Nearly 80% of Stagecoach services in the City will shortly either meet the latest Euro 6 emissions standard or offer Euro 5 electric hybrid buses. It follows our £10 million investment in nearly 50 greener buses in the past two years and a further 17 buses being converted to the latest low-emissions standards with the backing of money secured by Oxford City Council from the Government's Clean Bus Technology Fund.

“Switching from the car to the bus is the best way to deliver less congested roads and healthier communities and we look forward to continuing to work closely with Oxford City Council in delivering further air quality improvements in the future.”

Fiona Tavner, Coordinator of Oxford Friends of the Earth, said: “We welcome the findings that toxic levels have reduced in areas of Oxford. However, serious air pollution hot spots remain and there is still a lot of work to be done to bring air pollution levels down to safe levels across the city, and the county.”

To read the full Air Quality Annual Status Report, visit: