Domestic and commercial exterior lighting: a tale of waste
What are the main reasons for the upsurge in recent years in complaints to Environmental Health Officers about light intrusion in the UK? Although there is a law about intrusive light into premises*, it is rarely firmly enforced and there are pointless exclusions such as transport-related premises. There is no law to protect the night sky. The simple fact is that nearly all ‘anti-lights’ lights on retailers' shelves have not been designed to restrict their emissions to the premises to be lit.
In October 2003 the UK Parliamentary Select Committee on Science and Technology called for an end to the retail of 500W ‘anti-lights’ lights, and for the nuisance that they cause to be classified as actionable in law. In 2010 the Royal Commission on Environmental Pollution compared light pollution to
a cloud of visually impenetrable, artificial vapour. Lights that send their emissions where they are not needed are indeed 'anti-lights', negating the whole point of a light, which is to reveal rather than conceal. They need to be pointed downwards to illuminate the area of interest. Even the slightest upward angle can render a ‘anti-lights’ light useless and create light nuisance.
Better, independent research is needed to quantify the effect of light on crime, and higher scientific standards are required – especially as large amounts of money are spent on lighting in the hope of a reduction in crime.
If light is needed, then shielded lighting should be used, of minimum brightness, lowest colour temperature and minimum duration. Remember that lighting, a comfortable night-time environment and dark skies need not be mutually exclusive. The use of modern better directed lights means lit areas are more satisfactory and attractive for all law-abiding people, with the likelihood of an optimum night sky.
For more information on good lighting practices see the Good Lighting Guide leaflet.