Air filters will be installed in London’s most polluted schools as part of a pilot scheme, Sadiq Khan has said.
The Mayor of London said PM2.5 filters would be fitted in 200 schools later this year.
If deemed a success, the filters could be installed in every classroom in London, City Hall said.
Mr Khan said: “I want every single child to breathe clean air in and around their school.”
He added: “In those vital early years, the difference to young people’s health and well-being can be life-changing.”
The pilot is expected to cost £2.7m and forms part of the mayor’s 2024/25 budget, which will be voted on by the London Assembly on Thursday.
The funding will pay for the filters and their maintenance, school engagement, educational materials and monitoring the impact of the programme, City Hall said.
Daniel Kebede, general secretary of the National Education Union, said the pilot would be a “massive benefit to pupils and staff in London schools”.
He called for the scheme to be “taken up more widely across the country”.
Andrea Carneveli, founder of Chiswick Oasis said: “In June 2019, we had the honour of giving Sadiq Khan a tour of our school, St Mary’s Catholic School in Chiswick, showcasing the remarkable impact of our newly installed air purifiers, which successfully reduced pollution levels by approximately 94%.
“To see now how 200 schools will be able to follow in our footsteps and provide children with cleaner air to breathe brings immense joy as a parent and fills me with renewed optimism for our future.”
City Hall said the schools chosen for the pilot would be spread across London and selected based on pollution levels, as well as those in more deprived areas.
Source BBC London news – all rights acknowledged. Read the article on BBC website here
About PM2.5 and HEPA Filters
PM2.5 and HEPA filters are used in air purification systems, as HEPA filters are among the most effective technologies for capturing PM2.5 particles and improving indoor air quality.
Understanding PM2.5
PM2.5 particles, at 2.5 micrometers or less in diameter, are small enough to stay suspended in the air and penetrate deep into the lungs when inhaled. Due to their health risks, reducing PM2.5 in indoor air is essential, particularly in high-pollution areas or during events like wildfires.
How HEPA Filters Work
HEPA, or High-Efficiency Particulate Air filters, are designed to capture very small particles, making them particularly effective for filtering PM2.5. For a filter to be certified as HEPA, it must remove at least 99.97% of airborne particles that are 0.3 micrometers in diameter. Although PM2.5 particles are smaller than 0.3 micrometers, HEPA filters still capture them effectively due to their specialized filtration mechanisms, which include:
Diffusion
Smaller particles like PM2.5 follow a random, zigzag motion (called Brownian motion) and collide with fibers in the HEPA filter, where they get trapped.
Interception
Particles following the airstream are intercepted by filter fibers, trapping them in place.
Impaction
Larger particles collide with the filter fibres and stick to them.
Benefits of HEPA Filters for PM2.5 removal.
High Filtration Efficiency: HEPA filters capture nearly all PM2.5 particles in the air, improving indoor air quality substantially.
Reducing Health Risks: By removing these fine particles, HEPA filters can lower the risk of respiratory and cardiovascular issues, especially for sensitive groups like children and people with asthma.
Improving Indoor Air Quality in high-pollution areas, HEPA filters can ensure that indoor air remains cleaner than outdoor air, especially during pollution spikes.
Where HEPA Filters Are Used
HEPA filters are used in various settings where air quality is critical, including:
Schools and offices: To create cleaner air environments, especially in high-pollution zones.
Homes: In air purifiers and HVAC systems.
Hospitals: To reduce airborne pathogens as well as particulate pollution.
Maintenance Required: To remain effective, HEPA filters need regular replacement, as accumulated particles can reduce airflow and filtration efficiency.
In summary, HEPA filters are one of the most reliable ways to capture PM2.5 particles and provide cleaner, healthier indoor air, making them an essential component in environments where air quality control is critical.