Streetlights Are Mysteriously Turning Purple. Here's Why

Streetlights in Europe are getting bluer – that may be bad for health

To combat the negative effects of light pollution, the Pittsburgh City Council has passed a new Dark Sky Ordinance for all of the city's parks, facilities and streetlights. The Office of Mobility and Infrastructure prepared the ordinance with support from two Carnegie Mellon dark sky experts.

Streetlights, especially super bright LEDs, may harm insect populations

Caterpillar populations decline 50 per cent in areas with streetlights

The Streetlights in an Entire County Were Swapped to LEDs. Light Pollution got Worse