London children fighting toxic air with school bags
Schoolchildren will carry backpacks with inbuilt air quality sensors to help monitor levels of pollution in London.
Some 250 pupils from five primary schools will wear the bags to and from school for a week.
The inbuilt sensors, which weigh about 1kg, measure particulate matter and nitrogen dioxide (NO2) levels.
London mayor Sadiq Khan said the scheme was the sort of "bold and innovative" action needed to tackle air pollution.