Mention light pollution to most people and the response you get is a universally quizzical look. Light pollution? How can light pollute? The fact of the matter is, it can.
Light pollution is the effect created by humans when we artificially and unintentionally light the sky. Unshielded and poorly aimed lights such as street lights and security lights “leak” an enormous amount of wasted energy illuminating areas all around us. Light pollution produces a variety of adverse effects upon human health and animal behavior, many that we are still discovering.
A big issue is also cost. Money is wasted lighting space and the sky and not lighting intended objects or things.
There are several main components to light pollution that can occur in varying degrees depending upon where man-made (artificial) illumination is present:
Sky glow is the general brightening of the sky created by such things as the collective illumination caused by city lights. Sky glow robs us of the beauty of the night sky.
Light which is the unnecessary or unintentional illumination caused by exterior lighting sources such as house and street lights, parking lot and stadium lighting, and security illumination systems.
Glare is created by such sources as automotive headlights, advertising signs, and reflective surfaces. Glare can be not only physically uncomfortable, it can be dangerous, causing confusion, and traffic accidents.
How can you limit light pollution and save money? Here are a few tips:
- Use shielded, full cut off, light fixtures that direct light only where it’s needed
- Use automatic controls, such as, time clocks and photo cells to control lighting.
- Energy codes have a big say in how this should be done for interior environments.
Use LED dimming fixtures and controls. Have an engineer perform a lighting design and photometric analysis, to determine the proper lighting for the site and reduce or eliminate light pollution.