CIE Position Statement on Obtrusive Light and Light Pollution, 1st Edition

DOI

10.25039/PS.5dqvhsty

The purpose of lighting at night is to improve visual amenity and safety. However, in the design and setting-up of lighting installations one should avoid disproportionate unwanted effects.

Key take-away points from this Position Statement are described below:

• There are benefits of light at night, such as:
  • reduction in the risk of road accidents at night;
  • increase in reassurance that it is safe to walk through or be in a space;
  • lighting can make a space more inviting, encouraging the use of and social interactions within an area and thereby reducing social exclusion.
• However, there are also drawbacks to use of light at night, such as:
  • adverse health effects including disruption to sleep and circadian rhythms;
  • disruption of breeding patterns, migration routes and pollination cycles in plants and animals;
  • increased sky glow causing reduced ability to see the night sky and affecting astronomical observations.
• The lighting industry offers solutions that can mitigate obtrusive light, mostly based around:
  • good lighting design;
  • understanding of the needs of a space through local knowledge and planning;
  • adaptability of lighting solutions to different demands at different times.
• Further research is needed to better understand the effects of anthropogenic light at night on species and ecosystems as well as development of better measurement methods for obtrusive light and sky glow.

The CIE Position Statement can be downloaded here.