high-pressure sodium lights/LED 2,700-kelvin lights

Ahwatukee resident John Broussal took these photos on Ranch Circle North Drive last November. The photo on the left shows the way old high-pressure sodium lights illuminated the roadway and the much brighter illumination provided by the new LED 2,700-kelvin lights that the Streets Transportation Department installed there and throughout Phoenix. Among Broussal’s concerns is light pollution in Ahwatukee. He’s asked city officials to no avail to retrofit the new lights with amber lenses to reduce the glare.

If you’ve noticed the streets in Ahwatukee seem a little brighter at night, don’t worry: it’s not your eyesight.

New LED lights have been installed not only along all of Ahwatukee’s streets but on most throughout Phoenix.

And while the project began less than two years ago, Streets Transportation Department spokeswoman Monica Hernandez said the city has replaced about 86,000 of  its 100,000 high-pressure sodium lights with 2,700-kelvin LED lights. Kelvin is a unit of temperature, and scientists say the higher the number, the more dangerous the lights.

Ahwatukee’s lights have all been converted, according to an interactive map showing the progress of the project on the Phoenix government website at http://files.evari.io/PhoenixStreetlightViewer.

And that doesn’t make at least one resident too happy.

John Broussal, who lives near Ranch Circle North Drive, said he worries about the impact of the new lights not only on nocturnal wildlife but on residents as well.

Last November he wrote interim Mayor Thelda Williams and Councilman Sal DiCiccio, complaining about the “obtrusive glow more associated with that of a lit-up football stadium” and expressed concern that “the piercing glare of the 2,700 kelvin lamp is extremely uncomfortable to the human eye, and is a safety factor to drivers.”

Andrea Gaston, a staffer for Williams, sent a reply stating, “The Mayor appreciates your input and the amount of research you have done on the topic. Your engagement in the process is welcomed and your comments have been noted. As you are probably aware, a contact number and email address have been created for those seeking additional information, or wishing to relay concerns, regarding the LED Street Lights. Thank you again.”

Merissa Harrison, a staffer in DiCiccio’s office, replied with an email that stated, “Thank you for your input. I believe that the lights have already been purchased by the City. The new lights saved the City $80M in the first year. I will note your preference for when the time comes to change the lighting once again.”

Frustrated, Broussal replied back to Gaston, noting he had “specifically asked for the Mayor’s active support in looking into a solution regarding the problems associated with the new LED lamps, but your response offers no involvement or support on the Mayor’s behalf.

“Can you please clarify if the Mayor is willing, or not willing to assist in working on a solution to the problems associated with the LED lamp project?”

He received no reply.

The streets department in 2013 adopted the LED technology after what it called “many years of testing,” saying it would cut its electrical costs in half and save about $22 million cumulatively by 2030.

In adopting that standard, it joined innumerable cities worldwide which had opted for LED on grounds they not only saved money but better illuminated streets, making them safer not only for motorists but for pedestrians who might otherwise fall prey to muggers.

“At full implementation, the city will save more than $1 million a year in maintenance costs and more than $2.8 million a year in energy costs,” the department said. “This move significantly advances the city’s sustainability efforts, while saving taxpayers tens of millions of dollars.

“The LED fixtures that are being installed have been designed to provide an improved distribution of light. The LEDs shed light along the roadway, increasing visibility in dark spots between street light poles, rather than solely dumping light directly below street light fixtures as high-pressure sodium lights do,” it added.

In 2015, Phoenix City Council approved going out for bid on LED lights, asking for prices on four different categories of kelvin measurements with 2,700 the lowest.

A firestorm followed council’s decision to go with 4,000 kelvin lights – a level that has been condemned by a variety of groups ranging from the American Medical Association to the International Dark Skies Association.

So, the city went back to the drawing board, finally opting for 2,700-kelvin lights.

“We’ve set big sustainability goals for the city and converting to LED street lights brings us one step closer to meeting them,” said then-Mayor Greg Stanton. “Saving taxpayer dollars and cutting energy costs in our city makes us a more attractive place to live and do business.”

In his letter to Williams, Broussal called the 2,700-kelvin lights “only marginally under” the kelvin level that the AMA considers minimally safe for humans, that environmentalists consider less hazardous to an array of animals and other creatures and that the Dark Skies Association considers less of a source of light pollution.

He urged Williams to explore other options to the 2,700-kelvin lights that would still save energy costs but be safer to humans and other creatures.

Those better options available, which would also be in line with the City Council’s goals of providing lower cost street lamp operations, and said at a minimum the city should retrofit all the lights with amber-colored lenses.

Broussal wrote to the mayor when only one light had been installed along Ranch Circle North.

Now that all the lights have been replaced, he said he feels even more passionate about the need for the city to address the problem he sees created by the new fixtures.

“The light pollution is just horrific,” he told AFN. “It’s like going into a high school football stadium. I gather no one in the city did a light pollution study.”

He said he understands the city’s desire to save money, but added, “I think they went too far without considering the quality of life. A compromise can be made to protect quality of life as well as reduce costs.”

The AMA in June 2016 said LED lights “have five times greater impact on circadian sleep rhythms than conventional street lamps” because of the wavelength of the blue light they put off. The higher the kelvin, the bluer the light emission.

The association said longer blue light wavelengths can damage the retina and create a host of maladies, including “reduced sleep times, dissatisfaction with sleep quality, excessive sleepiness, impaired daytime functioning and obesity.”

But its report came under fire by some lighting industry experts, who called the report poorly researched and offered to help the AMA conduct further studies.

The U.S. Department of Energy has acknowledged the AMA’s concerns, but has stated more research is needed. It also has extolled the LED street lights as a significant energy-saving advance.

Last April, the Spanish Consortium for Biomedical Research in Epidemiology & Public Health released a study of 4,000 people linking high exposure to blue light to increased risk of breast and prostate cancer.

Boussal said he has called the city’s hotline for the street lighting project (602-889-0777) to at least get a shield on a street lamp that throws light into his second-floor bedroom

So far, he said, nothing has been done.

Asked if many complaints have come into the hotline about the new LED lights, Hernandez said, “We’ve received complaints and compliments.”

“We have received complaints and we’re addressing them,” she said. “We want to be responsive.”

She said some residents have complained that their neighborhood is now too bright while, on the other hand, people elsewhere in the city have praised the new lights as a solution to areas in their neighborhood that had been dangerously too dark.

She also urged anyone with a complaint to call the hotline and that so far only 665 complaints have been logged.

As for Broussal’s suggestion for amber shields on the lights, Hernandez said she was unaware the streets department is considering such a move.

Globally, the debate over LED street lights appears to be rekindled every time a new city undertakes a project like Phoenix did.

When the debate broke out in Montreal in 2016 as city officials began replacing sodium lights with 4,000-kelvin LEDs, concern was expressed by James D. Lowenthal, professor at the astronomy department of Smith College in Northampton, Massachusetts, who had worked at McGill Space Institute.

As an astronomer, Lowenthal has championed dark skies and advises residents how to make sure their local government is taking a cautious approach to LED conversion.

“It is so important to get it right,” he was quoted as saying. “Cities changing their outdoor lights for white LED ones are conducting an experiment on humans and on wildlife without considering the consequences.”

(2) comments


I have no issue with the fact that they're LED's, but I've never seen so many streetlights flashing. Not sure if a supplier or installation issue, but as an example there are 2 or 3 flashing right at the Ray/Chandler loop intersection. Very distracting. Throw in a DJ and some bass and get your dance party on!

Chad Stevens

i noticed this right away on the light a few houses away. WAY too bright. i feel sorry for the people who live under the lights because they are not necessary. if you're walking your eyes will adapt to the dark. if you're driving you have headlights. light pollution is a thing, and the fact that nothing was publicized prior means the politicians knew they'd get push back, and they did it anyway.

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