Wednesday, May 27, 2009

Starry, Starry Nights ...

Awhile back, my friend Argentum Vulgaris, of Tomus Arcanum, published a post on Light Pollution (you can see it HERE). I first heard of light pollution some years ago while camping in the Florida Keys. We were lucky enough to join a group of astronomers who shared their telescopes ... and a great view of the skies ... with us. After a wonderful evening of sharing the sky's treasures, the leader of the group talked about light pollution. He pointed out the glow in the sky and told us how it was created by the lights of Miami ... some 132 miles away. He also pointed out that without that glow, we'd be able to see so much more.

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.

Light Pollution ... just one more area where we can make a difference.

As always ... I would love to hear from you!


  1. Great! if there are more and more people who are not only aware of the environment but who do something about the problems such s pollution, then our planet will be safe.

    Bless you...

  2. Wow... I have always thought of switching off lights to save energy but never thought of it from the pollution point of view and frankly speaking hardly people in India will be aware of this fact...
    Just a stupid question may be but I will still go ahead...
    I am a person who is against people driving cars on high beams in the evening even in places with proper bright street lights... does that add up to the pollution? will driving on low beams help?

  3. As one who has been far out to sea and away from any lights, I know exactly what your group leader was talking about. I have known about light pollution's effects on astronomy for many years. I was unaware of some of the other problems light causes. Thanks for that info.

  4. Hi Mukund,

    Not a stupid question at all. My personal feelings about headlights are that safety, of course, has to come first so ... if one is driving in an isolated area, perhaps the headlights on high are appropriate. Beyond that I would say that yes, any light that shines outward and upward contributes to light pollution. And, driving with the high beams on, all the time, is dangerous to other drivers.

    Thanks for the question!


  5. Wow thanks for writing about this. The best night sky I have every seen was in the winter in the wilds of Canada. There was no light pollution and the sky was clear and cold. As a bonus there was no noise pollution either. Have you ever noticed how ones hearing becomes more acute if there is no noise pollution and only the sounds of nature Thanks...

  6. I had read about light pollution, but I thought our little sururban neighborhood was a relatively mild source until last winter when we ate dinner at a friend's house just thirty minutes north. I was floored by the number and the brightness of the stars. Also I hadn't even thought about the health effects.

  7. What a thought provoking post. My wife and I are getting much, much better about turning off lights. Actually, we hardly use lights at all, only at night when necessary. As others have mentioned, I also haven't thought about it from a pollution standpoint. Thanks for the awareness and hope things are good.

  8. Thank you for sharing this. I always turn off lights to save energy, but I never knew about this light pollution. I will remember this when telling my friends to turn off their lights.

  9. Thanks for bringing this subject up! Most people don't even think about it until they (if they are lucky) they actually get to be somewhere without any light pollution, and then it's hard to ignore.....there's nothing like seeing so many stars. -kate

  10. Hi...

    I thought you were singing 'Starry, starry night'...and drop by. You were instead star pollution? Joking! Always so good to read all your GREEN postings.

  11. For ten years I lived in a small town in Northern Ontario where the skies were alive at night. Since returning to Toronto we seldom ever look up because there is so little to see.

    What a loss for us!

    Lets light the night wisely people. This was a very important post.

  12. Your article reminds me of an evening a few years back. My son and I were driving home to our farmhouse from a meeting in town. It was winter in southern Illinois, and there were no lights; so the night was pitch black and cold.

    Having lived in the Los Angeles area for most of his life, my son had never really seen the stars. All of a sudden, he pointed up at the sky and asked, "Mom, what's that?!"

    I looked up to the north and saw the Aurora Borealis, shimmering in brilliant blues and greens and purples. It was a breathtaking sight! One which the folks in St. Louis, a mere 30 miles away, most certainly missed.