Eco Halos are ethereal structures that can be used both as public art and as monitors of changing levels of environmental pollution (a supernatural warning against air pollution?). These changes are reflected in the color and intensity of the Eco Halo’s light, using data relayed from existing local air quality monitoring stations. Green stands for good, Blue stands for OK, Red for bad, and Flashing Red for critical (run now!).
In any case, Eco Halos present certain advantages: they are not conventional pollution readers, they are pretty, they can be rapidly installed, they are protected from casual vandalism, and if solar powered panels are used as the energy source, the Eco Halos would involve no running costs.
Here are some inventive applications taken from the Eco Halo site
London Notting Hill Gate (it was granded planning permission, it is unknown if it was realized)