Nearly 50,000 primary school children in London are being exposed to dangerous pollution, a study has revealed.

In areas of the capital including Lambeth, Southwark, Wandsworth and Tower Hamlets, one in five primary schools are by major roads.

Campaigners from Mums for Lungs are calling on London’s mayoral candidates to take action on poisonous emission from traffic.

These parents demand an overhaul of Red Route roads and guarantees to safeguard the expansion of the ULEZ congestion zone.

Tens of thousands of youngsters are breathing in toxic air because their schools are located next to Red Routes, a study from the Environmental Defence Fund Europe (EDF Europe) has found.

Mums for Lungs campaign poster, Putney

Mum's for Lungs campaign poster, Putney

The Red Route road continues to breach legal limits for NO2 air pollution and also borders the planned expansion of the Ultra-Low Emission Zone in October this year.

Mums for Lungs was started in Brixton but has since expanded across the capital.

Campaigners have installed a poster near Upper Richmond Road, Putney, which shows the impact air pollution has on lungs.

The lung starts off white and changes colour as it becomes more polluted.

Spokesperson and Putney father David Nicholson, 55, said: “Every day I smell the diesel from the road, the exhaust fumes and it smells horrible. Putney is one of the most polluted parts of the country and my family are being exposed to it every day.

“It’s like if you went to the cinema and someone started lighting up cigarettes next to you. In ten years time we will be amazed that people were allowed to drive dirty polluting cars on the road. It should not be acceptable.”

“Air pollution damages every cell in human body including shrinking children’s lungs. Our children may not notice now but when they are older they will feel the impact significantly. We must take action now."

Founder of Mums for Lungs Jemima Hartshorn, 38, Herne Hill, said: “We really need more awareness of the impact air pollution is having on our health and our children’s health.

“So many trips in London are short and could be walked or cycled. If people knew the damage it was doing they would take more proactive steps. This poster is all about raising awareness.

“The lungs of young children are being damaged; it is casing and triggering asthma. I’m so worried about my children and other people’s children.

Mums for Lungs campaign poster, Putney

Mum's for Lungs campaign poster, Putney

Mums for Lungs is supported by scientists at international charity EDF Europe.

Oliver Lord, Head of Policy and Campaigns at EDF Europe, said: “Kids in London have been breathing illegal levels of air pollution far too long, and not just in the city centre.

“Exposure to air pollution at a young age can irreversibly stunt children’s lungs and create health problems for the rest of their lives.”