By George Moffatt • Programs Support Facilitator
Neil deGrasse Tyson was embarrassed. In discussing how exterior lighting is the bane of astronomers, the director of the Hayden Planetarium admitted to once being rebuked by the International Dark-Sky Association (IDA) because floodlights at his newly reconstructed planetarium pointed skyward.
In his book “Death by Black Hole”, while discussing the problems artificial light creates for astronomers throughout the world, he explained why upward-directed lighting is a “no-no.”
Tyson wrote that light pollution is created by a mixture of water vapor, dust, and pollutants in our lower atmosphere that reflects much of this light back to Earth, “leaving the sky aglow with the signature of a city’s nightlife.” This glow prevents one-third of Earth’s population (including 60% of Europeans and 80% of North Americans) from enjoying the grand spectacle of the Milky Way.
Nighttime romance and aesthetics aside, light pollution shouldn’t be—dare I say?—taken lightly. It affects our health in numerous ways.
Harvard University research shows our circadian rhythm—our night-day or sleep-wake cycle developed over the millions of years—can be affected, as well as our production of melatonin, whose antioxidant properties induce sleep, boost the immune system, lower cholesterol, and help our thyroid, pancreas, ovaries, testes, and adrenal glands to function.
The American Medical Association has warned the short- or blue-spectrum wavelengths emitted by filament and light-emitting-diode (LED) lights could have “potential harmful human health and environmental effects” by increasing the risk of cardiovascular disease, depression, sleep disorders, obesity, diabetes, and breast cancer.
And the Stanford Sleep Epidemiology Research Center also has demonstrated that street lighting can delay our sleep cycles, reducing the quality of our sleep.
Even our homes and offices aren’t safe havens. Many filament lights emit short or blue wavelengths of light, ranging from 415 to 455 nanometers, while LED’s emit light ranging from 400 to 490 nanometers. Both ranges can cause blurry vision, dry eye strain, macular degeneration, and cataracts, as well as sleep problems.
But to be fair to blue wavelengths, during daylight hours they boost our attention, reaction times, and mood. It’s a flip of the coin.
Birds rely on the moon and starlight to navigate when migrating and are profoundly impacted by light pollution. Artificial lighting confuses their “celestial compasses,” luring them from their traditional mating and foraging destinations and into brightly illuminated urban and suburban areas. Streetlights also play havoc with birds’ circadian rhythms. Millions of them die each year.
And the birds’ plight extends to us. University of South Florida researchers found that birds exposed to artificial light incubate West Nile Virus (WNV) for longer than other birds. Mosquitos feed off the infected birds, potentially increasing WNV spread and that of other transmittable diseases in heavily populated areas.
Unfortunately, light pollution’s myriad problems include a contribution to climate change. Unnecessary light in the United States adds up to about 21 million tons of carbon dioxide each year, or about $3.3 billion in energy expense, according to the IDA. Given this, every citizen should be moved to strongly protest our wasteful lighting.
Here’s how we all can save money, conserve energy, reduce carbon pollution, and illuminate more efficiently.
• Choose light fixtures with shielding or light covers that
• Aim lighting downward to specific targeted areas;
• Shield light bulbs from being visible from a distance; and
• Don’t aim light upward for any reason—drama, aesthetics, and corporate hubris be darned.
• Use LEDs, not filament bulbs.
• Turn off office and home lighting when not in use.
• Use varied-timed lights for outside security.
• Visit darksky.org for additional useful information.
Epilogue: The floodlight problem at the Hayden Planetarium was pointed out 20 years ago. A publicist for the planetarium declined to state for this article whether the problem has been fixed.
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