Pollutant levels fall by half at a site previously identified as having air quality issues
Published 19 January 2026
Two locations in South Oxfordshire which had previously been identified as having air quality issues, have recently seen major improvements with pollutant levels reducing by more than half at one site and just under a third at the other.
While the majority of the district has very good local air quality, historically there have been a small number of specific spots (called Air Quality Management Areas – AQMAs) that needed targeted action as nitrogen dioxide pollutant levels were higher than the national target. The specific sites were Henley, Wallingford and Watlington. The council’s Air Quality Action Plan aimed to improve air quality across the district and focussed on the AQMAs.
At a meeting of the South Oxfordshire District Council Licensing Committee on Thursday 15 January, councillors heard that officers have assessed air quality in the districts and found that over five years the AQMAs have seen a consistent reduction in nitrogen dioxide, a key pollutant primarily linked to emissions from combustion engine vehicles.
Watlington had seen a reduction of approximately 54 per cent since it was declared an AQMA in March 2009, while Henley had seen a reduction of approximately 31 per cent since it was declared an AQMA in January 2003.
The Department for Environmental, Food and Rural Affairs (Defra) advise that revocation of an AQMA should be considered following three consecutive years of compliance with the relevant objective, as evidenced through monitoring. Where there have been no exceedances for a period of five consecutive years, local authorities must revoke the AQMA.
Since the air quality in Wallingford had met these criteria previously, its AQMA was revoked in December 2024. Both Henley and Watlington have now also achieved levels of nitrogen dioxide below the national air quality objective and their AQMAs will also be revoked to comply with government guidance.
Cllr Sue Cooper, South Oxfordshire District Council cabinet member for the environment, said: “The improvement in nitrogen dioxide levels can be attributed to many factors including more electric vehicles on the road and technological improvements in combustion engines – both of which have reduced emissions.
“While current legislation directs us to monitor nitrogen dioxide levels, it is not the only pollutant in our air from traffic. So we will continue to promote measures such as walking and cycling for short journeys, the increased use of public transport where possible and the take up of low or no emission vehicles. The council will remain vigilant and continue to monitor air quality to ensure the pollutant levels are not left unchecked.”
Air quality throughout the districts will continue to be monitored by the council’s Environmental Protection Team through the existing diffusion tubes and analysers and the results will be available on the Oxfordshire-wide air quality website oxonair.uk
Notes to Editors
The matter was discussed at South Oxfordshire District Council Licensing Committee on 15 January 2026
Cabinet report on the revocation of the Watlington and Henley Air Quality Management Areas
Air pollution levels (nitrogen dioxide) have significantly reduced in the Watlington AQMA since its declaration on 31 March 2009 (level of 51.3 µg/m3), with the national objectives for nitrogen dioxide being met in Watlington AQMA since 2020 (see cabinet report).
Air pollution levels have significantly reduced in the Henley AQMA since its declaration on 1 January 2003 (level 45.1 µg/m3), with the national objectives for nitrogen dioxide being met in Henley AQMA since 2020 (see cabinet report).
