Mayor of London to trial indoor air filtration systems in nurseries

The Mayor of London Sadiq Khan has launched a programme of air quality audits to help clean up air at nurseries in some of the most polluted parts of London.

The audits will target sources of indoor and outdoor pollution, with five of the 20 nurseries trialling new air filtration systems to test their effectiveness at reducing indoor pollution. They will focus on reducing NO2, PM10 and PM 2.5 as research shows children exposed to these smaller pollution particles and gases are more likely to grow up with lung problems and to develop asthma.

A study by University College London and the University of Cambridge found that indoor air pollution was significantly higher inside classrooms, due to a range of factors including the age of buildings, ventilation, positioning of windows, and wall-to-wall carpeting.   

The findings suggested that the protection offered by the building increased the further away it was from the busiest roads and that airtight buildings may offer greater protection against pollution. The report also found that, in most classrooms, annual exposure to small particles was higher than recommended World Health Organization guidelines, and that this was caused by a combination of indoor and outdoor sources.    

The audits will also review a range of methods to reduce pollution outside nurseries, including restricting road access outside entrances at drop off and collection times, moving playgrounds away from congested roads, installing green ‘pollution barrier’ hedges, tackling engine idling and promoting cycling and walking.  

The £250,000 programme is funded as part of the Mayor’s Air Quality Fund and audits will be conducted by global engineering consultancy WSP, who will spend the next few weeks in the nurseries, assessing indoor and outdoor air pollution sources, looking at how children travel to the nurseries, and reviewing local walking routes including traffic crossings. These will be the first City Hall trials of indoor filtration, beginning in spring 2019, with results expected later in the year, alongside a toolkit that can be given to all non-participating nurseries so they can conduct their own audits.

Built into the programme is a ring-fenced starter grant of £4,500 for the 20 nurseries to help kick-start recommendations on completion of the audits.