Fight Light Pollution!

Outdoor lighting exists to illuminate our surroundings on the ground, yet every year in our nation billions of dollars are (literally) thrown up into the sky as wasted light.  By using light fixtures that direct the light so that none of it is sent up into the sky, we can use lower wattage lights to get the same amount of ground illumination that we now get with obsolete higher wattage light sources.  We’re talking cost savings ranging from 30 percent to 50 percent over traditional outdoor lighting!  Maybe we need more power plants, but even if that is the case, why should we continue to waste more money through the use of inefficient lighting?  If the U.S. as a whole someday finds itself strapped for electricity in manner similar to California in recent times, the power we save with more efficient lighting could be the difference between uninterrupted electrical service and rolling brown-outs or black-outs. 

It was the wasting of tax money along with health and safety issues that has prompted several states and many municipalities to outlaw the use of sky polluting light. 

Every nighttime motorist knows that he cannot see the road well when another car is approaching him with its lights set to high beam.  Good viewing is impossible because a part of the light goes in a straight line from the oncoming car’s headlights directly to his eye, keeping him from seeing the part of the light he really needs to see – that latter part being the light that is reflected off of objects in the road.  It is the bad direct light that we perceive as glare.  When oncoming lights are set to low beam, less light is coming directly from the opposing car and more is reflected off of objects in and around the road.  Just as with the high beam headlights, unshielded streetlights put more light directly in the eye of the motorist and pedestrian.  Alternatively, streetlights with properly designed reflective hoods put most of their light into illuminating sidewalks and streets, thereby relieving our eyes of blinding glare.  Furthermore, reflection off of the inner surface of the fixture may also partially polarize the light, in turn, lessening eyestrain. 

If the security light in your front yard is not shielded to reduce glare you may not be able to determine whether or not a person standing in your yard at night is someone you don’t want there. 

There are other public safety issues, but for brevity’s sake let me proceed to the subject of health problems associated with excessive nocturnal light. 

The human body requires periods of deep darkness during sleep in order to produce the hormone melatonin.  Even small amounts of light entering around blinds or through thin curtains can disrupt production of this important hormone.  Melatonin is one of the body’s defenses in preventing breast cancer in women and preventing prostate cancer in men. 

In the Newsletter #61 of the organization known as Breast Cancer Action, there is mention of a study where the high incidence of breast cancer was plotted on a map.  High incidence rates fell into areas known for excessive light pollution levels with mind-boggling frequency.  A coincidence?  Read on. 

In a study by the National Cancer Institute, women living with significant amounts of nocturnal light were compared to a control group of women who got more “dark time” at night (see study J. Natl. Cancer Inst. 2001;93:1557-62).  The former group’s breast cancer contraction rate was estimated to be 60 percent higher than the control group.  Perhaps light pollution is at least part of the reason that breast cancer is much more prevalent in developed countries (such as the U.S. and European nations) than in less developed areas of the world. 

Until recently, my only concern about light pollution was that it was gradually obliterating our view of the stars and the Milky Way.  You see, I am an amateur astronomer and that’s what started me looking at the light pollution problem.  Not even suspecting they existed, I stumbled upon the above-mentioned side effects.  My concern has gone from mere worry about the future of my hobby, to alarm about the adverse impact on my pocket book, to our society and to the environment. 

But now that I have come to it, let’s talk about the natural treasure we are loosing: the night sky.  Following is a sad commentary. Not a long time ago, there was an SUV commercial on TV showing a father and daughter who are far enough out in the country to where the little girl is awed by how numerous and beautiful the stars are.  She asks, “Why don’t we have stars back home?”  Her father answers, “We have stars at home.  You just can’t see them.”   The implication being that you should buy an expensive recreational vehicle so that you can travel to inconvenient locations for what until recently was your birthright as a human being

The night sky used to be a glorious wonder that you could see just by stepping out your back door.  At far-removed places where there are no local rural residences with inefficient lighting, often the glow from an urban area fifty miles away can obliterate the stars near the horizon.  Even the unshielded dusk-to-dawn light one-half mile a way can greatly limit what you can see.  Eventually the most remote wilderness may show only small numbers of severely dimmed stars and there will not be a place where you can truly see their grandeur – even in an SUV. 

How can we definitely say that we need new power plants when we are squandering so much power already?  Shouldn’t we try to see how much power we can save first by using our common sense?  Light pollution is just one way we’re wasting power.  Inefficient heating and cooling systems, and power-wasting domestic and industrial appliances are just two more of the many energy leaks that we have in the system.  We don’t have to lower our standard of living to keep all of the conveniences that we have now.  Several years ago, my wife and I switched from electric baseboard heating and multiple window air conditioning units to a modern high-efficiency electrical heating and cooling system.  We are now comfortably warm in the winter, pleasantly cool in the summer, and our power bills have been cut drastically!  I would say that taking this step has raised our standard of living, not lowered it.  Better yet, my quality of life during retirement will be even more improved because I am currently putting aside the money I was wasting in higher power bills. 

But let’s go back to the light pollution issue.  Is there anything that an individual can do about that particular aspect of the power problem?  There is if an unshielded light mounted on a power utility pole is in or near your yard.  Seek to have it replaced or to have a reflecting hood put over it so that its light is reflected downward.  Putting a hood on an existing light will not improve its energy efficiency; however, the light that was being sent into space will be directed downward making what you need to see be more brightly lit. 

Two of the worst light polluters are the traditional unshielded green mercury dusk-to-dawn light and the unshielded yellow high-pressure sodium dusk-to-dawn light.  These fixtures are sometimes referred to as “light bombs” because they send light out indiscriminately in all directions similar to the way that an explosion radiates its destructive pressure waves.  They are cheap to manufacture, but use much more electricity than properly designed lights and are thus much more expensive to run.  Though better low-wattage reflective fixtures may cost a utility company more money upfront (typically around $60 per fixture as compared to about $30), within the first year that extra cost is usually cancelled out by power savings.   You can find a detailed illustration of this fact and the simple calculations to prove it in Information Sheet #3 of the International Dark Sky Association (  The power company can actually make more money while keeping the leasing rate for the lights the same because the lights would be far cheaper for them to operate.  The probable reason that most power companies don’t install more efficient lighting by default is that light pollution issues haven’t been brought to their attention, given that it is still a relatively new concept.  After all, companies usually don’t knowingly throw away money!  Even so, there have been a few instances where power companies resist merely through bureaucratic inertia.  In other words, “We’ve always done it this way.  Why should we change?”  A display of determination to correct this problem by a concerned customer base is the ultimate cure for this malady. 

Some people would say that the obtrusive and ugly over-kill lighting with which we now live is the necessary price we pay for progress.   The truth is, you can actually see your terrestrial surroundings better with the proper light fixtures, do so more economically and leave future generations with the heritage that is the night sky. 

There is an excuse that I have heard that some city or county councils use to keep from changing the status quo.  These people say that it is important to have all of this visually blaring glare to impress upon prospective incoming companies that the city is modern, thriving, and thus a great place to do business.  Many cities now look at this situation differently.  One of their ploys to obtain more business is to say, “Look at our downtown lighting.  Notice how much better you can see.  But the best part is, we won’t be charging you higher taxes for wasted electricity via light pollution!”   Business people think with their pocket books.  Which argument do you think would impress them more?


copyright 2003 Singularity Scientific