LONDON, March 19 (Xinhua) -- Some 250 children in London will carry special backpacks on their journeys to school to monitor air quality exposure, it was announced Tuesday.

Primary school students up to the age of 11 will carry special backpacks fitted with state-of-the-art air quality sensors to help monitor the levels of toxic air young Londoners are exposed to, in a new scheme launched by the capital's Mayor Sadiq Khan.

Weighing just over 1 kg, the sensors fit into lightweight bags and measure particulate matter, PM2.5 and PM10, and nitrogen dioxide (NO2) levels.

The children will use the backpacks like a normal bag as the monitor takes up one pocket, leaving plenty of room for school equipment, allowing the monitors to record pollutant levels on each child's journey to school and throughout the school day, including during their lessons.

The data from this will allow scientists from King's College, London to analyze at which point of their journey to school, or which part of their school day, children are exposed to the most pollution.

They will also be able to compare the exposure of children who have similar journeys but take different routes and travel modes, and then make recommendations of how children can reduce their exposure in future.

The study will involve young students from five London primary schools in Southwark, Richmond, Greenwich, Haringey and Hammersmith and Fulham.

A City Hall spokesperson said: "The wearable sensors are the latest stage of the Breathe London project to create the most comprehensive air quality monitoring network of its kind in the world."

"Breathe London includes more than 100 fixed monitors and the deployment of air quality monitoring cars on the streets of London," added the spokesperson.

Mayor Khan said: "It remains a shameful fact that London's toxic air is harming the lung growth and health of our young children, and we are determined to do everything in our power to protect them."

The mayor said "I hope the success of this scheme will act as a blueprint for cities around the world as they battle their own toxic air emergencies."

Kate Barnes, Head teacher at Haimo Primary School, one of the schools taking part, said: "Haimo children are aware of the dangers of air pollution and how action is needed and have successfully campaigned for Haimo Road to be closed both at the start and end of the school day. Our focus on air quality has developed their understanding of social responsibility, not only for themselves, but for future generations."