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Report: Light pollution has impact on health, environment

18th December 2017   ·   0 Comments

By Della Hasselle
Contributing Writer

Louisiana is getting brighter. According to scientists, that’s not a good thing.

A light pollution map created in part by data from the Earth Observation Group and the National Oceanic and Atmospheric Administration shows parts of the state, especially around New Orleans and Baton Rouge, illuminating more at night between 2014 and 2017.

The Baton Rouge Astronomical Society has been aware of the problem for years, and has even dedicated a team of star-watchers to measure the level of sky glow and gather evidence to show it’s growing.

Louisiana isn’t alone. According to the World Atlas of Artificial Night Sky Brightness, 80 percent of the world’s population now lives under such glow.New-Orleans-skyline-121817

The phenomenon is caused by light pollution, defined by the International Dark Sky Association as any adverse effect of artificial light. That can include glare, light clutter, decreased visibility at night and energy waste.

Light pollution is problematic, scientists say, because it interferes with people’s internal clocks.

Throughout history, scientists say, people have evolved to the rhythms of the natural light-dark cycle of day and night. But now, the spread of artificial lighting means most people can’t experience truly dark nights.

Research suggests that this adjustment at night can negatively affect human health by increasing risks for obesity, depression, sleep disorders, diabetes, breast cancer and more.

According to Ken Wright, an associate professor of integrated physiology at the University of Colorado in Boulder, the internal clock is measured by a hormone called melatonin.

Melatonin levels are low during the day time, and they tend to rise about two hours before sleep at night.

It helps people because it has antioxidant properties, induces sleep, boosts the immune system, lowers cholesterol and helps the functioning of the thyroid, pancreas, ovaries, testes and adrenal glands.

“The internal clock is important, as it coordinates much of our physiology and behavior,” Wright said, “including the time of day when we eat, when we perform at our best, as well as when we sleep.”

Nighttime exposure to artificial light suppresses melatonin production.

Studies show that most light pollution in the United States comes from poorly executed lighting systems that are put up outside of homes or offices.

In general, 13 percent of residential electricity use throughout the United States is for outdoor lighting, according to the International Dark-Sky Association.

In the average house, outdoor lighting wastes 0.5 kilowatt-hours of energy per house, per night, or enough energy to power a 50-inch plasma television for one hour, according to the association.

Researchers found that causes roughly 15 million tons of carbon monoxide to be emitted each year, which is the same emission rate as three million passenger cars being driven on the road.

Ultimately, it amounts to 40,000 tons of CO2 being put into the atmosphere every day. About 600 million trees would have to be planted to offset that kind of emission rate.

That’s equal to about $3 billion per year worth of energy lost to the skyglow, according to the association.

Nor does it look like light pollution will decrease any time soon, according to a recent study published in the November issue of Science Advances.

In the article, “Artificially lit surface of Earth at night increasing in radiance and extent,” the authors said their use of the first-ever calibrated satellite radiometer designed for night lights shows an upward trend in artificially lit outdoor areas.

Specifically, from 2012 to 2016, Earth’s artificially lit outdoor area grew by 2.2 percent per year, with a total radiance growth of 1.8 percent per year, the study showed.

“In the near term, it appears that artificial light emission into the environment will continue to increase, further eroding Earth’s remaining land area that experiences natural day-night light cycles,” the study reads. “This is concerning, because artificial light is an environmental pollutant.”

In addition to affecting human health, the authors say the outdoor light will also threaten the 30 percent of vertebrates and more than 60 percent of invertebrates that are nocturnal, as well as plants and microorganisms.

The study showed that most of the growth in light pollution came from developing nations, rather than in countries like America. Previous research had shown trends relating light pollution to growth in a country’s Gross Domestic Product.

However, the authors argue that the situation might not be permanent, as people will eventually crave darkness again.

“In the longer term, perhaps the demand for dark skies and unlit bedrooms will begin to outweigh the demand for light in wealthy countries, leading to an “environmental Kuznets curve” for outdoor light,” the authors wrote.

At least 18 states, the District of Columbia and Puerto Rico have recognized the dangers of light pollution and have put in place laws to reduce it. Those states have enacted so-called “dark skies” legislation to promote energy conservation, public safety, aesthetic interests and allow for better astronomical research.

Louisiana is not one of them.

In the meantime, however, the International Dark-Sky Association has recommendations for how municipalities and individual homeowners can conserve energy and reducing light pollution.

Mainly, the organization recommends installing “quality” outdoor lighting. Those include LEDs and compact fluorescents with warm-white bulbs. The organization also recommends the use of dimmers, motion sensors and timers to reduce illumination levels.

Doing so could cut energy use by 60 to 70 percent, researchers note.

The organization also suggests shielding outdoor lighting and directing light down where it is needed, rather than into the sky.

Fully shielded fixtures can also save energy and cost, as can turning of unnecessary indoor lighting, particularly empty office buildings at night, the organization says.

For residents in Louisiana, participating in a local energy savings program “is the best way to gain energy savings and reduce kWh use and cost,” according to Jamie Wine, executive director of Energy Wise Alliance – a local non-profit that works to deliver cost-conscious energy efficiency solutions to Louisianians to help them save money and maintain the environment.

Wine says that additional, behavioral elements such as “reducing AC and heating use when not at home, closing drapes on sunny days and setting the water heater at 120 degrees are all free ways to save energy and money.”

The Energy Smart program, and other programs like it, works to help residents find solutions to home energy overuse. Residents can set up appointments for free home energy assessments during which they receive advice and recommendations about how to make their homes more energy efficient. Rebates are also available for Energy Smart appliances and LEDs that consumers can take advantage of at local retailers, says Wine.

Energy Smart is the efficiency program available to residents in Orleans Parish; Entergy Solutions and Cleco Home Solutions are available to residents of other parishes.

To learn more about Energy Smart in Orleans Parish, call 504)-229-6868 or visit

This article originally published in the December 18, 2017 print edition of The Louisiana Weekly newspaper.

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