London art installation measures toxic air

The interactive Pollution Pavilion art installation in London has buttons which passers-by can press to compare data on annual air quality data gathered at five monitoring stations. The balloons change colour from light blue for the cleanest areas to deepening pink for readings above legal limits for toxic nitrogen dioxide. Photo: Handout

Londoners will be able to see how dirty the British capital’s air is through a public art installation launched recently, as pressure mounts to tackle the hidden killer.

Large air balloons, which change colour to show how much harmful nitrogen dioxide has been measured in the air at sites across the capital, have been installed in central London for the project led by environmental charity Hubbub.