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Dec 21, 2023

LED streetlights are energy efficient, but are they environmentally friendly? It's complicated

Rick Newman's backyard in east Boca Raton has that Old Florida vibe: A swimming

Rick Newman's backyard in east Boca Raton has that Old Florida vibe: A swimming pool is surrounded by live oaks and palms.

For years, the trees' lush canopy has kept the area shaded against the sun, as well as the soft, orange-yellow light from a nearby street lamp.

"I’ve been working to create a natural oasis in the middle of the city, and I’ve been very successful," said Newman, a biologist and chair of Boca Raton's Environmental Advisory Board. "Then they come and shine a spotlight in the middle of it. It has an impact."

The "spotlight" he's referring to is a new LED streetlight, which appears much brighter than the traditional high-pressure sodium lamp that was there before. High pressure sodium streetlights emit a warm, amber colored light.

"These LEDs are inappropriate," Newman said. "They’re way too bright."

Since last summer, nearly all of the old lamps on Boca Raton's streets have been replaced with LEDs, or light-emitting diodes. LEDs are whiter and brighter than the traditional high pressure sodium lights and appear brighter to the human eye.

It's a transition that's happening in municipalities throughout South Florida and across the state, the country and the world.

LEDs use significantly less energy, so they're seen as a tool in the fight against climate change. And it costs local governments less money to power and maintain them. But medical experts and scientists warn that, if not used correctly, LEDs can have harmful effects on people, wildlife and the environment.

Satellite images show that LED lighting is increasing light pollution. Skyglow is increasing by 10% a year–far worse than the 2% per year before LEDs. Artificial light at night poses a serious threat to our ecosystem.

Brighter streets mean brighter skies. And more light at night takes its toll on all living things. Researchers in England found LED streetlights kill off nocturnal moth caterpillar populations by fifty percent. Billions of migrating birds aren't able to find their way in our brightening skies. Insect mating is reduced. It affects pollinators. And scientists are worried that light pollution is altering our planet.

LEDs emit blue light, which disrupts circadian rhythms and suppresses melatonin, and lost sleep can lead to health problems like cancer, diabetes, heart disease and obesity, according to a 2016 report from the American Medical Association.

"Amoeba in the ocean are affected. Algae are affected. And all the higher animals are affected," said Dr. Mario Motta, a Boston-area cardiologist who served on the AMA's board of trustees at the time the report was released. "Melatonin is a very primitive hormone that's basically in every animal studied."

Newman argued the transition to LEDs in Boca Raton was the right move, but it was not handled the right way. He wishes the environmental advisory board he chairs had been consulted. Without mitigation measures, he said the switch to LEDs could undermine the board's goals of reducing artificial light pollution, or "skyglow," which can harm sea turtles.

"We’re working on things like skyglow, which is the next step in protecting not just sea turtles but other wildlife. I mean, birds and insects, you name it," he said, "and that doesn't even mention what this kind of lighting does to people."

The decision to transition to LED streetlights wasn't entirely up to city officials. High-pressure sodium lights are no longer readily available from

manufacturers or utility companies.

But, Boca Raton city officials could take steps to mitigate the harm of LEDs, though: Dimmers can turn down brightness. Shields can point the light downward, preventing skyglow. And amber LEDs limit exposure to harmful blue light.

But compared to standard white LEDs, these alternatives can be more expensive.

How LEDs became the new streetlight standard

Federal and state agencies that oversee roads have been pushing the switch to LED streetlights for years, as have utility companies that install and maintain the lights.

In 2016, the Florida Department of Transportation adopted new rules for road and bridge construction that prohibit the use of high-pressure sodium lights from being installed in new state projects.

One explanation from state officials is that brighter intersections are safer for pedestrians at night.

"In general, LED street lighting is considered to significantly increase nighttime safety on roadways," FDOT communications officer Grace Ducanis wrote in an email.

The Federal Highway Administration has highlighted Florida's use of LED streetlights to prevent pedestrian fatalities at night in intersections that previously did not have any streetlights or had only one.

"Florida has a unique approach, particularly in focusing on pedestrian crosswalks," said Richard Stepp, an FDOT engineer, in a December 2021 video from the federal agency. "While the results of that are still preliminary — LEDs are very new — the early results look very promising."

FDOT also says the old high-pressure sodium streetlights are no longer easy to replace or repair. They are "not considered an industry standard" and "not readily available from light fixture manufacturers," according to Ducanis.

Further, the state agency highlights the energy efficiency of LEDs.

"When compared with previous technologies, LED fixtures have fewer maintenance needs, an improved usage life, and consume less energy, making LEDs more cost-efficient and environmentally friendly," Ducanis wrote.

Florida Power & Light, whose parent company is one of the largest power utilities in the U.S., has also been instrumental in converting streetlights to LEDs throughout South Florida. Public records show that in FPL's presentations to local governments promoting the transition to LEDs, the company highlights "advantages" such as "energy savings up to 50%+."

The presentation — which can be found on page 30 of a Lantana Town Council meeting's minutes — offers no warnings about the downsides of LEDs. One of the sources FPL cites illustrating the "benefits" of LEDs is a company that sells them.

Representatives from FPL, which is headquartered in Palm Beach County, declined to be interviewed for this story. A spokesperson pointed to a phone number listed on the FPL website for a "lighting expert," but when a WLRN reporter called the number, the person who answered said it was the wrong department and provided an email address to contact. WLRN sent a message to the email address and received no response.

There are nearly 5,500 streetlight fixtures throughout Boca Raton, and more than 90% of them have been changed to LEDs since the transition began. Boca Raton's new LED streetlights will use up to 40 percent less energy than high-pressure sodium lamps, according to a city spokesperson.

FPL estimates that's equivalent to taking 234 cars off the road, records show.

Why medical experts, scientists are concerned

The 2016 report from the American Medical Association warned about the health risks posed by the widespread transition to LED streetlights.

"We came out with a paper that basically said, that's a bad idea," said Motta, the former AMA board member. "Because it affects human health and affects the environment in a bad way."

Among the group's major concerns is the disruption of sleep patterns for humans as well as turtles, birds, fish and insects. According to the report, white LEDs have five times greater impact on circadian sleep rhythms than conventional streetlights.

"This is an entirely preventable problem," he continued. "If the lights are shielded, so it doesn't go directly in your eyes, and if you eliminate the blue, the amount of glare goes down dramatically."

Eric Vandernoot, an astronomer who has been operating the Florida Atlantic University Observatory in Boca Raton for nearly a dozen years, works to raise awareness about the dangers associated with brighter night skies.

"If it's not properly dark at nighttime, our cells don't undergo necessary cleanup and repair jobs," he said. "Imagine your house: If you never repair it, or you never take out the trash, what's going to happen after a while? It's going to cease to function."

Kirt Rusenko, a marine conservationist who recently retired after 25 years with the Gumbo Limbo Nature Center in Boca Raton, serves on a committee of lighting specialists for the International Dark-Sky Association, or IDA. The nonprofit based in Tucson, Ariz., is a global leader in combating light pollution.

"Most LED retrofits are overpowered and emit way more light than necessary," Rusenko said.

South Florida also sits on a major migratory bird flyway, traveled by billions of birds annually to southern to wintering grounds. Brighter lights are more likely to throw the birds off course, attracting them to dangerous urban environments and wasting valuable energy trying to navigate back on course.

In that 2016 report, the AMA recommended capping LED streetlights at 3,000 kelvin. Kelvin is a unit of measuring light color and temperature, and the scale ranges from 1000 to 10,000, with 1,000 as the warmest, least amount of light, and 10,000 as the most light and the coolest.

Today, Motta said he would recommend an even lower cap of 2,700 kelvin, especially for residential areas.

The IDA recommends 2,200 kelvin or lower.

Ducanis, the spokesperson for FDOT, wrote in an email that LED lighting in new state projects is capped at 3,000 kelvin, in accordance with the AMA's recommendations.

That rule doesn't apply to municipalities, though. Boca Raton's new inland streetlights range from 3,000 to 4,000 kelvin, according to records provided by the city.

At least 19 states, the District of Columbia and Puerto Rico have laws that aim to reduce light pollution, according to the National Conference of State Legislatures. That includes Florida.

But while laws in many other states include provisions that require shielding or limit brightness, Florida's law is much more narrow, focusing only on lighting in coastal areas where sea turtles nest. The statute leaves it to local governments to decide whether to implement ordinances protecting hatchlings. Many municipalities throughout the state have adopted these local rules.

There are safer LED options — but they cost more

LED streetlights don't have to be a nuisance.

Dimming the lights can reduce light pollution that affects nesting sea turtles, migrating birds, coral reefs, insects and plants. Shields ease glare in drivers' or pedestrians' eyes, and because they direct light downward, they prevent unnecessarily lighting of the sky at night. Amber-colored bulbs are friendlier not just for sea turtles but for all wildlife when compared with white LEDs, which emit a large amount of blue light.

While energy efficiency is a clear environmental benefit of LEDs, research shows that they are worsening light pollution, a clear detriment.

In fact, Boca Raton has taken steps to protect baby sea turtles, which get confused by artificial lighting. Because hatchlings use the moon and the stars to navigate, illumination from streetlights and buildings can disrupt their ability to find their way to the ocean. Sometimes they’ll travel toward the city, mistaking what's called skyglow for moonlight.

Boca Raton was one of the first municipalities in Florida to adopt an ordinance to safeguard sea turtles, back in 1986. It appears that the city has installed amber-colored LEDs along a roughly one-mile stretch of A1A nearby where sea turtles nest, although those lights are not listed in records provided by the city. For that stretch of beach–all streetlights from 2401 North Ocean Boulevard north to the Highland Beach border are turned off March through October, according to the Gumbo Limbo Nature Center.

"Turtle friendly" LED lighting fixtures can be up to three times more expensive. For example, while fixtures with white LEDs cost about $5 to $9 a month, the special turtle friendly ones range from about $12 to $15 a month.

Diana Umpierre is an environmental advocate and chair of the International Dark-Sky Association's Florida chapter, and she helped plan the Miami and Everglades Dark Sky Week, an annual event raising awareness about astronomy and light pollution.

She said FPL and FDOT should do more to educate their customers on LED lighting.

"Out of the different types of pollution that we have to deal with, this is probably the easiest to fix, the easiest to address," she said. "But it's also I think the one that is most misunderstood."

For example, one common misunderstanding is that light bulbs with the same wattage will appear similarly bright.

But it's not as simple as just switching out the old lights for new ones with the same wattage. Lower-wattage LED bulbs need to be used to achieve the desired level of brightness.

For example, an old 60 watt high-pressure sodium streetlight might need to be replaced with only a 20 watt LED, according to Motta, who worked on the AMA report.

"Unfortunately many lighting companies simply put up the same wattage, … and if unshielded, [that's] very awful to look at," he said.

Rusenko, the retired scientist from Gumbo Limbo, recommends shields for LED streetlights as well as dimmers and motion detectors that lower or turn off the lights when no one is nearby, like in grocery store freezer aisles.

A similar strategy is being tried on some college campuses, said Nancy Clanton, who owns a Colorado-based sustainable lighting design firm that works with cities on appropriate LED lighting.

During times when classes are scheduled, lights on campuses can be set to 3,000 kelvin, she said, "and then when the students sleep, go way down to maybe 1,200 kelvin, to reduce the impact of blue light at night."

While testing different types of lighting in several communities, Clanton found that dimmer LEDs provided better visibility over traditional streetlights. When LEDs were dimmed to 25 percent of their full intensity, visibility increased, and residents were happier, she said.

"Better light, better sight — that's not true," she said. "It's better contrast, less glare."

Bulb brightness varies depending on the manufacturer.

"It's like with any product, there are good quality lights and poor quality lights," Clanton added. "With quality LED lighting, we have the opportunity to reduce sky glow and environmental harm."

Palm Beach County residents are fighting to lower brightness

Boca Raton isn't the first municipality in Palm Beach County to transition to LED streetlights.

In 2017, Lake Worth Beach resident Richard Stowe, a member of the International Dark-Sky Association, helped convince the city commission to limit its new LEDs to a brightness of 2,700 kelvin.

Although the lights meet standards set by the AMA, Stowe said they still appear too bright.

"We were happy that we got the 2,700 kelvin, but we were just pretty down about the intensity of the light," Stowe said.

Two years later, the Lantana Town Council voted to allow FPL to replace the standard high-pressure sodium lamps with 4,000 kelvin LED streetlights.

When longtime resident Media Beverly heard about this, she and her neighbors convinced town leaders to go down to 3,000 kelvin, "after we inundated them with tons and tons and tons of research."