Mayor invests £2.7m in air quality filters for schools to clean up air in classrooms

·        Mayor delivers on manifesto pledge with £2.7m investment into indoor air quality filters for hundreds of schools across London. 

·        City Hall research published today reveals levels of the key pollutant PM_2.5 were up to 68 per cent lower in classrooms with the filters compared to classrooms without.

·        Programme will benefit tens of thousands of children and be focused in areas of poorer air quality and higher levels of deprivation.  

The Mayor of London, Sadiq Khan, has today launched a new £2.7 million programme to deliver indoor air quality filters to hundreds of schools across the capital, bringing cleaner air to tens of thousands of children in their classrooms. 

Filters play a vital role in reducing air pollution by helping remove particulates that are generated indoors or enter the classroom from nearby sources, like roads. The School Filters Programme fulfils a manifesto pledge from Sadiq as part of his wider work to tackle London’s air pollution. 

At least 200 schools across London will receive HEPA (High Efficiency Particulate) filters, which have been proven to be effective at reducing levels of the key pollutant PM_2.5, benefiting the health of pupils and staff. Research commissioned by City Hall found that PM_2.5 levels in classrooms with HEPA filters were between 27 and 68 per cent lower compared to those without (1), and similar levels of improvement have been found in external research (2).  

The programme, delivered by WSP, SmartAir and the Walk Wheel Cycle Trust (formally Sustrans), will bring cleaner air to tens of thousands of pupils in their classrooms, which is associated with lower rates of respiratory infection, better attendance and potentially improved academic outcomes (3).  Participating schools will receive one filter per classroom where possible, with the roll-out focused in areas of poorer air quality and higher levels of deprivation. The Mayor believes access to clean air is a social justice issue, with poor air quality disproportionately affecting more deprived areas.   

The Mayor’s funding will also provide a support programme for the schools and indoor air quality monitors to understand the impact of the filters, as well as lessons and assemblies on air quality to raise awareness of the impact of air pollution amongst staff and pupils. The filters are energy efficient and automatically switch off outside of school hours to keep energy costs low.  

Sadiq and his Deputy Mayor for Environment and Energy, Mete Coban, today visited St Mary’s RC Primary School in Battersea to be part of an assembly on air quality and meet pupils and staff. The school is benefitting from the indoor air quality filters and has taken significant steps to invest in protecting pupils from air pollution, including air quality monitors and a living green wall.   

The Mayor of London, Sadiq Khan, said: “I’ve made tackling air pollution a top priority as Mayor and along with parents and teachers, I want every single child to breathe clean air in and around their school. In those vital early years, the difference this can make to young people’s health and wellbeing can be lifechanging. These filters have been proven to significantly lower levels of pollution, PM2.5.

“This new £2.7 million City Hall initiative – one of my manifesto pledges - will provide indoor air quality filters to at least 200 schools across all London boroughs, benefitting tens of thousands of children, who we know are one of the most vulnerable groups to the impacts of pollution. Access to clean air is a social justice issue, and the roll-out will be focused in areas of poorer air quality and higher levels of deprivation. 

“Our world leading policies to tackle air pollution are having a big impact, with London recently reaching legal limits for toxic NO2 pollution for the first time, almost 200 years earlier than predicted. I'll continue to work with the Government, London boroughs and partners to continue building a healthier, greener, fairer London for everyone.”

Rosamund Adoo-Kissi-Debrah CBE, founder of the Ella Roberta Foundation and a WHO BreatheLife Ambassador, said: “I am delighted the first phase of the school filtration project is under way. I first approached the Mayor about the issue of indoor air quality in schools after noting the scarily high school absence rates of children and young people after the COVID pandemic.

“I realised then that the quality of the air inside schools was a huge issue and we needed to address the filtration process now, in order to help those suffering with conditions such as asthma, but also to help the health of all students and staff who are breathing in dirty, polluted air inside our schools.  I am grateful the Mayor has committed to this filtration scheme in all London schools and hope it will go some way to improve the health of our city’s children."

Catherine Sutton, CEO of Airborne Allergy Action CIC, said: “This is an important step towards protecting children and teachers suffering from asthma, allergies and anaphylaxis by improving indoor air pollution. Children and adults with a range of health conditions can be triggered or exacerbated by allergenic and non allergenic particles in the air such as dust mites, mould, tree/grass pollen, animal dander, pollutants and viruses. Cleaning up the air in classrooms will only help improve health for all.”

Jared Brading, Executive Headteacher at St Mary’s RC Primary School in Battersea, said: “We’re thrilled to welcome the Mayor of London to St Mary’s RC Primary School to see the real impact his School Filters Programme has had on our children’s lives. These new air filters are the culmination of a journey that began back in 2017, when the school was involved in the Mayor’s School Audit programme due to being in a busy central London location.

“Since then, we’ve worked closely with the Mayor’s Office, Wandsworth Council and our local community to do what we can to mitigate the impact of poor air quality— from installing a green screen to help reduce pollution in the playground, installing air quality monitors and campaigning against motorists engines idling outside school. Successive groups of children have worked to keep the school a safe healthy environment in which to learn. Today, every classroom benefits from cleaner, safer air, and that’s something our whole school community can be proud of.”

In London, around 4,000 premature deaths per year were previously attributed to toxic air (4) and a recent report from the Royal College of Physicians estimates that air pollution costs the UK more than £27 billion per year (5). Air pollution increases the risk of developing asthma, lung cancer, heart disease and stroke, and there is growing evidence that air pollution exposure increases the risk of developing dementia. The programme forms part of a wider series of policies and measures the Mayor is delivering to tackle air quality, including the London-wide ULEZ, which aim to reduce emissions of air pollutants as a priority. 

The Mayor is also delivering the Greener Schools Programme, providing Breathe London air quality sensors for over 50 schools and supporting borough-led projects through his Air Quality Fund, as well as supporting over 800 School Streets. In addition, he is working on electrifying all of London’s bus fleet, expanding London’s Electric Vehicle charging network and tackling emissions from the construction industry, as part of his commitment to making London the healthiest city in the world to grow up in. 

Since the Mayor took office in 2016, following the implementation of his ambitious policies, such as ULEZ, levels of toxic NO2 at roadsides has nearly halved. In 2024 London met the legal limits for toxic NO2 pollution for the first time (6) - almost 200 years earlier than predicted (7) – and the capital is leading by example when it comes to air quality, with many other major cities with far smaller populations and fewer vehicles – including Manchester, Liverpool and Birmingham – still exceeding the legal limits.