A new study has revealed that children in London are five times more exposed to air pollution when travelling to school than at any other time of the day.

Some 250 primary school pupils took part in the King’s College London study which involved them carrying special backpacks containing Dyson air quality sensors on their journey to and from school for one week.

Data was analysed by scientists at Kings College and revealed:

  • Pupils were exposed to on average five-times-higher concentrations of harmful NO2 pollution on the school run than when they were at school
  • 5­ concentrations were also higher during the journey to school, though the difference was less pronounced
  • For both NO2 and PM2.5 children who walked to school by backstreets were exposed to the lowest levels of pollution
  • The highest concentrations were recorded by children walking along main roads
  • Pollution levels were higher in cars and buses than on back streets
  • Parents who drive to school can contribute to high levels of air pollution on back streets as they tend to use these roads for school runs while leaving their car engines idling

As a result of taking part in the study, 31 percent of children changed the way they commute to and from school in order to reduce their exposure.

Mayor of London, Sadiq Khan, funded the study in partnership with C40 Cities.

“Air pollution is a public health crisis and it is shocking that pupils are exposed to such high levels of harmful air,” he said. “All the schools who took part in this study are using the results to educate pupils and their families on air quality and helping them find the least polluting routes for their journeys.”