For us lighting nerds, a terrific webinar hosted by the US DOE discussing the state of the actual scientific research on street lighting and sky-glow sources, versus the extreme scare-mongering of recent “scientific” publications:
Bruce Kinzey of Pacific Northwest National Laboratory examined key issues underlying concerns raised by the American Medical Association community guidance on street lighting, and their applicability to LED street lighting. The presentation also provided essential background context related to exposure to light at night and reviewed activities currently being supported by the DOE SSL Program to fill in existing knowledge gaps.
To me, the highlight of this presentation is this terrific slide showing the blue-light “melanopic content” of most major light sources (below).
It is a gross misrepresentation of facts to proclaim that LED’s produce more blue light – for instance, compare 4000K white LED (2.35-3.40) to incandescent (2.73) or moonlight (4.56). I don’t hear any AMA recommendations that moonlight and incandescent lighting are bad for your circadian sleep cycles…that wouldn’t play very well in the media, now would it????
It is similar nonsense as to what we encountered a few years ago with museum lighting, where a sensationalist press release claimed that LEDs destroy Van Gogh paintings. The claims were easily rebutted but unfortunately the perception damage was done.