outdoors

Our disappearing dark skies

Light pollution hides stars, affects health

— Remember when you were a child, full of curiosity, and you looked up with wonder at the Milky Way? If you were lucky, your sky was dark, your eyesight was sharp, and an adult explained that those billions of stars were like our suns, many with their own planets and moons, located an incomprehensible number of light years away.

I remember many summer evenings when we young cousins and childhood friends lay in the grass staring upward, feeling so insignificant and awed by those distant mysteries of the night.

Chances are, if we returned to those yards of yesteryear, we wouldn’t see the same sky. Dark skies have disappeared because of dense populations, development and poor choices of artificial light. Some children have never seen the Milky Way because of light pollution.

Most of us don’t give much thought to light pollution, especially here in north-central Arkansas where there are fewer lights. Yet darkness is disappearing.

To promote awareness of this issue, the Little Red River Audubon Society in Fairfield Bay invited Jim Fisher, Arkansas chapter leader of the International Dark-Sky Association, to present a program on “Protecting the Night Environment.” Fisher is also president of the Central Arkansas Astronomical Society.

“It’s hard to find a good dark sky,” Fisher said. “There’s always a sky glow around populated areas. Even if you can’t see the light source, the sky is lit by activities, traffic and development.”

These Arkansas astronomers set up their telescopes in rural areas and host star parties open to the public. Three upcoming star parties, all on Saturdays, are on the Arkansas State Park schedule: 9-11 p.m. July 23 on Pinnacle Mountain, where there is a backup indoor astronomical program in event of rain or cloudy skies; dusk on July 30 at Woolly Hollow State Park in Greenbrier and 8:30-11 p.m. Oct. 29, which will be a Halloween Trick or Celestial Treats Star Party complete with costumes and candy.

Besides being able to view the night sky, improved health is another benefit of reducing light pollution, Fisher said.

“Darkness is vital to human health,” Fisher said. “The American Medical Association in June 2009 came out with a strong policy statement addressing the need to curtail too much light at night, which suppresses melatonin production and disrupts circadian rhythms.”

Melatonin, a hormone secreted by the pineal gland in the brain, has been linked with the prevention of breast and prostate cancer, depression, high blood pressure and diabetes. A person’s circadian rhythm is an internal biological clock that regulates a variety of biological processes in an approximate 24-hour period, including sleep patterns. When it’s dark, the body produces more melatonin; with bright lights, melatonin production drops.

“Lights at night are a serious threat to nocturnal wildlife,” Fisher added. “Too much light affects mammals, frogs, salamanders, other amphibians, reptiles, insects, fish and, in fact, entire ecosystems.

“When sea turtles hatch, for instance, they are drawn to the sea by its natural reflective glow and turn away from dark grassy beach areas. However, with so many development lights, they often become confused and go in the wrong direction, only to get run over on the road.”

Birds are also affected by light. The Fatal Light Awareness Program estimates that in North America, at least 100 million birds collide with manmade structures. Migratory birds often fly at night, depending on light from the stars and moon; they are confused by lights emanating like thousands of moons from cities and towns.

Lighting is considered important for human safety.

“Where you need lights, choose the right type,” Fisher said. “Some lights create so much glare that they actually decrease visibility. They’re inefficient and costly.”

Looking outside at the parking lot of the Indian Hills Country Club, Fisher commended its lighting choices.

“All the lights are shielded, projecting the light downward, right where you need the light to be, except for that one really glaring light near the door. What’s up with that ?”

Fisher recommended placing lights for homes or businesses under porches or eaves. Shield all outdoor lights so that glare doesn’t project upward, where it’s wasted, or trespass onto your neighbor’s property. Turn lights off when they’re not needed; consider motion detectors for porch or garage lights. Don’t get the brightest light available, but instead use as low a candlepower as necessary.

“All these measures also save energy and expense,” he said, recommending the web site www.darksky.org for guidelines to help choose responsible lighting.

One of the best ways to prevent light pollution and save money is to incorporate curfews: For example, turn lights off automatically after a certain hour when businesses close or traffic is minimal. Wasted light is found frequently at malls, parking lots, sports facilities and auto sales lots, and on billboards. A light curfew is an easy and fast way to initiate dark-sky practices and is especially important during bird-migratory periods.

Many communities have approved outdoor-lighting ordinances, using the International Dark-Sky Association’s recommendations. Ordinance adoption improves nighttime visibility, security and safety; eliminates harsh glare and “light trespass” between properties; and reduces wasted light shining upward into the nighttime sky.

“Raising awareness is very important,” Fisher said.

There has been some good publicity, including in the National Geographic, which in November 2008 featured “The End of Night: Why We Need Darkness” on its cover.

The article, by Verlyn Klinkenborg, states, “In the end, humans are no less trapped by light pollution than the frogs in a pond near a brightly lit highway.” But, he adds, “Of all the pollutions we face, light pollution is perhaps the most easily remedied.”

One well-known leader who has encouraged the darksky mission is Arizona Congresswoman Gabrielle Giffords, who has been so much in the news and hearts of U.S. citizens after she was shot in January while at a public event. She received the Astronomical League’s 2010 Presidential Award for her outstanding efforts. The international movement to preserve darkness is headquartered at International Dark Sky in Tucson.

Tough decisions need to be made about artificial lights in a world where we love our televisions, brightly lit cities, celebrations like the Fourth of July and our ability to work and read after the sun sets. It’s a tall order to rethink our relationship with light, but in the interests of our own health, along with that of other ecosystems, we need to grapple with this quality-of-life issue.

If we make the right choices, dark skies and circadian rhythms can be reclaimed. Then even those who live in cities can once again show their children and grandchildren nocturnal creatures, planets, stars and our own galaxy, the awesome Milky Way.

Tri-Lakes, Pages 126 on 06/26/2011

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