Light pollution is a big deal to amateur astronomers, who wish to explore the constellations, as well as to large observatories where our universe is studied. It also represents, as Argentum pointed out, huge amounts of energy usage and waste. But did you know that light pollution also affects nature and our health?
In the human body, excessive light exposure can result in adverse health effects such as headaches, fatigue, stress and anxiety. It has been shown to elevate blood pressure and is considered a factor in some forms of cancer due to the suppression of the normal nocturnal production of melatonin. Simply put ... we need darkness. It helps set our circadian rhythms which determine our sleeping patterns. Our core body temperature, brain wave activity, hormone production, cell regeneration, as well as many other biological activities are all linked to sleep ... and darkness.
Light pollution is also affecting nature. All life exists with natural patterns of light and dark. Interfere with those patterns and many aspects of animal behavior change. For example, light pollution confuses animal navigation. The U.S. Fish and Wildlife Services estimate that 4-5 million migrating birds per year are killed when they become disoriented by the lights on tall structures. Moths and other nocturnal insects, being drawn to artificial lights, affect night blooming flowers that depend on these nighttime creatures for pollination. Lights around lakes prevent zooplankton from eating surface algae, causing algal blooms which kill off aquatic plants and destroy water quality.
One of the most well-known casualties of light pollution are the sea turtles. Hatchlings emerge from their nests and find the ocean by moving away from the darkness of the dunes. When the dunes are artificially lit by street lights or residential outdoor lighting, the hatchlings become disoriented and fatally head inland instead of toward the ocean.
Light pollution ... as with all forms of pollution ... has a negative impact on the environment and our lives. How can be help? Here are a few ideas:
- Whenever a light is not in use, turn it off. This applies inside and out. For outdoor lighting, use a timer or motion sensor. No need to light up a yard if no one is out there, right?
- For lighting, especially outdoor lighting, make sure that the lamp only illuminates the area necessary (use full cutoff light fixtures or lamp shades). For example, if you need to light a deck or patio, make sure that the sky, or a neighbor's yard, isn't also lit.
- Choose low wattage illumination. For example, deck lighting doesn't necessarily have to be as bright as a kitchen. Low wattage can actually create a very pleasant atmosphere for outside, evening activities. And don't forget to use efficient bulbs (CFLs or LEDs).
- Try not to use a light at all. Whenever possible, allow your eyes to adjust to the dark ... and leave the lights off.
- At work, suggest that lights be turned off ... point out the energy & monetary savings that will be realized. If you own a company ... implement policies to turn out lights when not in use.
- Get educated on the subject. For two good resources, check out the International Dark-Sky Association and Starry Night Lights.
Light Pollution ... just one more area where we can make a difference.
As always ... I would love to hear from you!