Bath & North East Somerset passes Government air quality assessment

Air quality in Bath improved following the launch of the Clean Air Zone in 2021, according to the latest monitoring report from the Government.
Official air quality data from 2021 was submitted to the Government’s Joint Air Quality Unit (JAQU) for review which has now officially declared that the Bath & North East Somerset Council has passed its ‘State 2’ assessment.

State 2 is a checkpoint in determining if the Clean Air Zone is achieving success by improving air quality. The report confirms nitrogen dioxide (NO2) concentrations have decreased.

Its analysis of our 2021 data from 121 air quality assessment sites, both within and outside the CAZ, reveals an average reduction of 22% in NO2 concentration between 2019 and 2021, with the largest decrease of 16.4 µg/m3 recorded at Anglo Terrace. It says during 2021, there were no breaches of the annual mean NO2  limit of 40 µg/m3 which corroborates the earlier publication by the local authority of its 2021 CAZ annual report.

However, the report by JAQU cautions the improvements may in part be attributed to a reduction in traffic during the early part of the year due to Covid restrictions and the closure of Bath’s Cleveland Bridge in October 2021, affecting routing in and around the city, reducing traffic on certain routes and potentially suppressing roadside NO2 concentrations.

Whilst the report warns of a high risk of breaching NO2  limits in subsequent years, the very latest data from the council for 2022 indicates that air quality is continuing to improve with a 26% average NO2 reduction inside the zone compared with 2019.

Councillor Sarah Warren, deputy Leader and cabinet member for Climate Emergency and Sustainable Travel, said: “It is pleasing to see the improvement in air quality in and this is great news for the health of residents and visitors. Whilst the report from government recognises data from 2021, the council’s latest CAZ annual report assessing data from 2022 shows a continuing reduction in pollution levels and improvements in air quality. During 2022, annual mean NO2 concentrations within the CAZ dropped by a further 7% compared with 2021, and a further 6% reduction is indicated across the wider B&NES area.  

“We’ve worked hard to reduce pollution both inside and outside the CAZ and this data indicates the measures we’ve taken are working. I’m particularly pleased to see a huge increase in compliant vehicles since we launched the CAZ with a 71% reduction in the number of higher polluting vehicles driving through our city, it’s having a big impact and I applaud those drivers and businesses who’ve made the switch to a cleaner, greener vehicle. Clearly, though, there’s no room for complacency and we will continue to work to improve people’s health by driving down pollution levels.”

Data collected from 2022 has now been forwarded to JAQU for its progressive ‘State 3’ assessment which will determine if the CAZ has continued to maintain improvements to air quality. 

Bath's CAZ, the first outside London, was launched on 15 March 2021. Its aim is to urgently tackle harmful levels of air pollution caused by the most polluting taxis, vans, buses and larger commercial vehicles driving in the city. Anyone driving a chargeable higher emission vehicle pays £9 or £100 to drive in the zone. The charge does not apply to private cars or motorcycles.

The levy is designed to deter higher polluting vehicles from entering the zone, while also speeding up the natural replacement rate of polluting vehicles in exchange for cleaner ones. Any revenue over the operating cost of the scheme is spent on supporting sustainable transport projects or schemes which contribute towards improvements to air quality.

Find out more about Bath’s Clean Air Zone and JAQU’s assessment criteria here.