In the UK, more children suffer from respiratory conditions than anywhere else in Europe.

The UN agency Unicef is calling it a "public health emergency," and in a new report claims that around one in three British children live in areas with unsafe levels of pollution.

As Ella walks her children to school through Bristol city centre, she shares her concerns about how air pollution is affecting her family.

Produced for the BBC News at Six and BBC News at Ten by Rachel Price.

Environment correspondent: Claire Marshall