Menus Subscribe Search

Follow us


Blinded by the Light

• October 11, 2009 • 12:00 PM

In every corner of the globe tonight, our nighttime sky shines brighter than it did less than 10 years ago with potentially serious consequences to humans, animals and ecosystem.

Plants, animals and humans developed with an internal clock — the circadian rhythm. It’s a 24-hour cycle that affects physiological, biochemical and behavioral processes in almost all organisms.

Civilization brought with it artificial light to homes in every village, town and city across the world, and as more buildings and factories came online, industrialization increased and the population continued to expand, our nighttime sky looked a lot like the day, changing our deep, dark sleep patterns and altering that 24-hour internal timekeeper.

With that, all living creatures’ lives changed in ways only now becoming clear to us.

Dawns the light
To understand light pollution, it’s important to know there are two different types: First, there is astronomical light pollution that obscures the view of the night sky, and the second kind is ecological light pollution, which alters natural light systems in terrestrial and aquatic ecosystems.

“Light pollution started to be identified in the 1800s when we realized that birds flew into the sides of lighthouses and consequently died,” says Travis Longcore, science director of the Urban Wildlands Group, research associate professor at the USC geography department and a lecturer at the UCLA Institute of the Environment in Los Angeles. (Beginning in the 1940s, radio and television towers become “the spiral of death for birds that regrettably hit the guy-wires,” he added.)

Twenty years later, it was discovered that artificial coastal lighting in Florida was disorienting and disrupting the rhythm of sea turtles that bury their eggs in the sand. When the eggs hatch, the hatchlings must go toward the water and beachside nests for their survival, but the babies were being distracted by the light and diverted from their natural course, often ending up facing dehydration, being eaten by predators or even wandering along the highway.

As more animals encountered night lighting, it became evident that while night light might benefit people, it wasn’t helping wildlife.

Light pollution has had disastrous effects on migrating birds, resulting in millions dying each year, and that figure increases with the combination of outdoor light and fog. Birds use the light at the horizon to migrate at night. When the birds see a brightly lit building, they become confused and fly around and around — in essence becoming trapped in the light — eventually dropping dead from exhaustion.

The term photopollution — artificial light that has adverse effects on wildlife — was coined in a watershed paper by Dutch ecologist F.J. Verheijen in 1985. In the paper, Verheijen says that many nocturnally active animals need a natural light field between sunset and sunrise as a requirement for survival.

“When we think about the night and the extent of light pollution in the last 20 years, it’s growing far faster than the human population and has changed the environment significantly,” explained Longcore.

But light pollution’s harmful effects aren’t restricted to animals.

“Women who work at night, change shifts often or don’t get proper sleep at night suppress their melatonin production and have higher rates of breast cancer,” explained Dr. Mario Motta, president of the Massachusetts Medical Society and associate at the North Shore Cardiovascular Associates. “It’s a fact. The exact cause is speculative, but we think it’s because of the changes in the melatonin production due to disruption of their circadian rhythm.”

Disrupting the circadian rhythm can cause insomnia, depression and increase the risk of cancer and cardiovascular disease.

Fallout from the disruption of your circadian rhythm can be harsh medicine to swallow, but so can simply living in the glare of the night’s lights. Straining to see at night in the face of glare from oncoming traffic or streetlights that shine over the landscape can be irritating and uncomfortable, but it also can be dangerous.

“If I shined a light on your eyes in a dark room you wouldn’t be able to see the rest of the room,” Motta observed. “Every time you pass a bright light on the highway or the street your pupils constrict,” causing decreased nighttime visibility.

Adults between the ages of 40 to 50 start to notice glare more, when the lens of the human eye begins to harden and calcify. Cataracts may develop, which can exacerbate the glare, and require surgery to remove.

Citing energy efficiency and glare reduction, the American Medical Association in June officially approved a resolution advocating light pollution control. Dr. Motto introduced the resolution saying, “This is just what the doctor ordered.”

Transforming the Night
“The one thing most responsible for our nighttime sky looking like the middle of the day is there’s an unwarranted volume of streetlights that aren’t necessary for our safety,” said Leo Smith, the northeast regional director of the International Dark-Sky Association, a nonprofit focused on preserving the night sky through smarter outdoor lighting. “In many cases, we don’t need streetlights, but streetlight manufacturers are pushing their products.”

“In Connecticut,” said Smith, a member of the Illuminating Engineering Society of North America and a roadway lighting committee member in Suffield, “we have sections where the road is 30 miles long and is continually illuminated. There’s a tremendous amount of energy loss from unneeded streetlights and ones that don’t need to be on when there’s no traffic.”

In comparison, Interstate 20 in Atlanta has no overhead roadway lights outside the beltway, with five lanes of traffic in each direction, but it does have is a 4-foot median barrier that blocks the glare from oncoming headlights.

When it comes to dusk-to-dawn outdoor lighting, one solution that’s been offered is to light streets only until 10 p.m. After that time, programmable photocell lights would turn off. Also, it is suggested that private residences use only fully shielded lighting fixtures for porches or driveways.

Smith also pointed to a solution that helps those migrating birds: “Eventually, we will have motion-sensor controls, so when you’re in the building and using it, lights will be on and when the building isn’t in use, the lights will be off.”

He estimates that more than 100 cities in the United States have ordinances on the books regarding outdoor lighting. One such a town is Stowe, Vt.

The Stowe City Council passed standards for outdoor lighting in 1998. The regulations require outdoor lighting be cutoff fixtures, as they direct light downward where it is needed, not sideways or upward. “We do have height restrictions of 16 feet for parking lot lighting,” said Stowe Zoning Director Rich Baker, “and we don’t allow sodium vapor lights or internally illuminated signage.

“This is a tourist area. People come here for outdoor recreation and for the aesthetics. We needed to cut down bright outside lighting.”

New on the energy horizon and ready to take the bite out of squandered light is the federal government’s new planned matrix for Energy Star qualification or fitted target efficiency. The old Energy Star qualification system factored how much energy would you get out of a light bulb. Soon, it will factor how much energy is going to the target, reducing squandered light energy.

The Dark-Sky Association estimates that wasted light squanders the equivalent of 32 million barrels of oil or 9 million tons of coal each year in the United States alone. Some other industrialized nations might point the way toward improvement: Longcore said much of Europe is ahead of the U.S. on confronting this issue, particularly the Czech Republic, which has a nationwide light pollution law on the books.

“Lighting the night is a purely manmade condition,” Motta says. “We can’t do anything about the sun, but we can do something about the nighttime lighting situation.”

Of all the complex environmental problems that so desperately need our attention and a solution, light pollution is the most easily remedied.

Sign up for our free e-newsletter.

Are you on Facebook? Become our fan.

Follow us on Twitter.

Add our news to your site.

Judith Stock
Judith Stock is a Los Angeles based environmental journalist. Her articles have appeared in USA Weekend, National Wildlife, Cooking Light, HGTV and Preservation Online. Her usual beat is green building, design and the environment. And, to mix it up a bit, she also writes about dogs, cats and health topics. When she's not writing, she's out playing catch with her two Labradors, Maddie and Holly.

More From Judith Stock

A weekly roundup of the best of Pacific Standard and PSmag.com, delivered straight to your inbox.

Recent Posts

November 26 • 4:00 PM

Turmoil at JPMorgan

Examiners are reportedly blocked from doing their job as “London Whale” trades blow up.


November 26 • 2:00 PM

Rich Kids Are More Likely to Be Working for Dad

Nepotism is alive and well, especially for the well-off.


November 26 • 12:00 PM

How Do You Make a Living, Taxidermist?

Taxidermist Katie Innamorato talks to Noah Davis about learning her craft, seeing it become trendy, and the going-rate for a “Moss Fox.”


November 26 • 10:28 AM

Attitudes About Race Affect Actions, Even When They Don’t

Tiny effects of attitudes on individuals’ actions pile up quickly.


November 26 • 10:13 AM

Honeybees Touring America


November 26 • 10:00 AM

Understanding Money

In How to Speak Money, John Lanchester explains how the monied people talk about their mountains of cash.


November 26 • 8:00 AM

The Exponential Benefits of Eating Less

Eating less food—whole food and junk food, meat and plants, organic and conventional, GMO and non-GMO—would do a lot more than just better our personal health.


November 26 • 6:00 AM

The Incorruptible Bodies of Saints

Their figures were helped along by embalming, but, somehow, everyone forgot that part.


November 26 • 4:00 AM

The Geography of Real Estate Markets Is Shifting Under Our Feet

Policies aimed at unleashing supply in order to make housing more affordable are relying on outdated models.



November 25 • 4:00 PM

Is the Federal Reserve Bank of New York Doing Enough to Monitor Wall Street?

Bank President William Dudley says supervision is stronger than ever, but Democratic senators are unconvinced: “You need to fix it, Mr. Dudley, or we need to get someone who will.”


November 25 • 3:30 PM

Cultural Activities Help Seniors Retain Health Literacy

New research finds a link between the ability to process health-related information and regular attendance at movies, plays, and concerts.


November 25 • 12:00 PM

Why Did Doctors Stop Giving Women Orgasms?

You can thank the rise of the vibrator for that, according to technology historian Rachel Maines.


November 25 • 10:08 AM

Geography, Race, and LOLs

The online lexicon spreads through racial and ethnic groups as much as it does through geography and other traditional linguistic measures.


November 25 • 10:00 AM

If It’s Yellow, Seriously, Let It Mellow

If you actually care about water and the future of the species, you’ll think twice about flushing.


November 25 • 8:00 AM

Sometimes You Should Just Say No to Surgery

The introduction of national thyroid cancer screening in South Korea led to a 15-fold increase in diagnoses and a corresponding explosion of operations—but no difference in mortality rates. This is a prime example of over-diagnosis that’s contributing to bloated health care costs.



November 25 • 6:00 AM

The Long War Between Highbrow and Lowbrow

Despise The Avengers? Loathe the snobs who despise The Avengers? You’re not the first.


November 25 • 4:00 AM

Are Women More Open to Sex Than They Admit?

New research questions the conventional wisdom that men overestimate women’s level of sexual interest in them.


November 25 • 2:00 AM

The Geography of Innovation, or, Why Almost All Japanese People Hate Root Beer

Innovation is not a product of population density, but of something else entirely.


November 24 • 4:00 PM

Federal Reserve Announces Sweeping Review of Its Big Bank Oversight

The Federal Reserve Board wants to look at whether the views of examiners are being heard by higher-ups.



November 24 • 2:00 PM

That Catcalling Video Is a Reminder of Why Research Methods Are So Important

If your methods aren’t sound then neither are your findings.


November 24 • 12:00 PM

Yes, Republicans Can Still Win the White House

If the economy in 2016 is where it was in 2012 or better, Democrats will likely retain the White House. If not, well….


November 24 • 11:36 AM

Feeling—Not Being—Wealthy Cuts Support for Economic Redistribution

A new study suggests it’s relative wealth that leads people to oppose taxing the rich and giving to the poor.


Follow us


Attitudes About Race Affect Actions, Even When They Don’t

Tiny effects of attitudes on individuals' actions pile up quickly.

Geography, Race, and LOLs

The online lexicon spreads through racial and ethnic groups as much as it does through geography and other traditional linguistic measures.

Feeling—Not Being—Wealthy Cuts Support for Economic Redistribution

A new study suggests it's relative wealth that leads people to oppose taxing the rich and giving to the poor.

Sufferers of Social Anxiety Disorder, Your Friends Like You

The first study of friends' perceptions suggest they know something's off with their pals but like them just the same.

Standing Up for My Group by Kicking Yours

Members of a minority ethnic group are less likely to express support for gay equality if they believe their own group suffers from discrimination.

The Big One

One in two United States senators and two in five House members who left office between 1998 and 2004 became lobbyists. November/December 2014

Copyright © 2014 by Pacific Standard and The Miller-McCune Center for Research, Media, and Public Policy. All Rights Reserved.