© Terrence Antonio James / Chicago Tribune/Chicago Tribune/TNS The city of Chicago is swapping its sodium vapor streetlights for LED streetlights. The lights on Irving Park Road at Lavergne Avenue are seen on Dec. 5, 2019. The nearest lights are LED and emit a neutral light while the more distant lights are sodium vapor and emit a yellowish light.

For almost two generations of Chicagoans, orange has been the color of night.

High pressure sodium vapor lights, which create a glow reminiscent of a tire fire, have lit Chicago since the 1970s. They have provided the backdrop for crime scenes, romantic encounters and waiting for a bus after a late shift. Chicago, viewed from the air, looked like a year-round Halloween display.

But in 2017, the city started swapping out the sodium vapor lights for energy-efficient LEDs, which create a whiter radiance. When the project is complete in 2021, the city will have replaced 270,000, or 85%, of its streetlights. As of mid-December, 185,000 fixtures had been replaced, said Chicago Department of Transportation spokesman Michael Claffey.

© Terrence Antonio James / Chicago Tribune/Chicago Tribune/TNS Streetlights on Irving Park Road looking west from Lavergne Avenue, shown Dec. 5, 2019, are LED and emit a neutral-colored light.

The new lights are saving the city $100 million over 10 years in electricity costs, Claffey said. They’ve also created better nighttime visibility and made streets safer for drivers, pedestrians, and bike riders, he said.

But the new fixtures use more of the shorter wavelength “blue” portion of the visible light spectrum, and questions have been raised about whether this could be harmful. Studies have shown that exposure to artificial sources of blue light, which is also emitted by personal electronic devices, can disrupt sleep patterns. The sun is the main natural source of blue light.

© Terrence Antonio James / Chicago Tribune/Chicago Tribune/TNS Streetights on Irving Park Road looking east from Lavergne Avenue, shown on Dec. 5, 2019, are sodium vapor and emit a yellowish light.

The new lights also have changed the look of the city. Not everyone thinks it’s for the better.

Ben Gonzales, a photographer and videographer, said that for his profession, the lights are good, and will probably help the television crews working all over town.

“Having brighter light is always going to be more beneficial as far as getting truer colors. The issue becomes that there’s been character that is lost when you switch away from the sodium vapor lights,” said Gonzales, of Humboldt Park, who owns Gopho Collective. "There’s this charm in the deeper amber color.”

Al Yellon, managing editor of the BleedCubbieBlue.com web site, spends a lot of time around Wrigley Field, where the lights were installed last summer. He’s a fan of them. “What a difference driving from an area where the lights light up everything to an area with those awful orange lights," he said.

Yellon said he’s also noticed that the new lights are more focused downward, so they don’t shine in his bedroom window like the old ones did.

Bernadette Libao of Logan Square, said she expected to be more nostalgic for the yellow lights, but isn’t bothered by the LEDs.

“I think they’ve grown on me,” Libao said. “They’re pretty bright."

The downward focus of the new lamps could cut light pollution and help people in Chicago see the stars better, though it’s too soon to know for sure, said Andrew Johnston, vice president of astronomy and collections at the Adler Planetarium.

The Adler plans to send up balloons over the city to see the effects of the new LED lights versus sodium vapor lights, and how much the light goes down instead of up.

The LEDs have been installed in multiple city wards on the South, West and North sides, including the Lakeview, Austin and Englewood neighborhoods, and along many major arterial streets, such as Irving Park Road, 55th Street and Cicero Avenue. Large portions of the Northwest and Southwest Sides, as well as the Loop and areas around the Loop, are still waiting for lights.

They consume 50 to 75% less electricity than the sodium lights, which is equivalent to taking 2,400 cars off the road for a year, according to the city. The new system also gives the city greater ability to respond to service requests, and allows lighting levels to be controlled remotely.

They provide a brightness level of 3000 Kelvin, which is how light’s color temperature is measured. High pressure sodium vapor lights are at around 2200 Kelvin.

Sodium lights first were installed on the Dan Ryan Expressway in 1969, replacing blueish mercury vapor lights, and went up around the city in the mid-1970s. Then-Tribune architecture critic Paul Gapp strongly objected to the sodium lights, comparing their light to the “bizarre paintings of Hieronymus Bosch, the frightening futurism of Stanley Kubrick’s A Clockwork Orange, and other nightmares.”

To replace the sodium vapor lights, the city considered 4000K LED lights during the procurement process, city spokesman Claffey said. The 4000Ks were tried in big cities like New York City and Seattle, where residents complained that they created the ambiance of a prison yard.

In 2016, an AMA report recommended that cities use 3000K or lower lighting. Dr. Mario Motta, a cardiologist and trustee with the American Medical Association, who co-authored a 2016 AMA report on LED lights, commended Chicago for choosing 3000K lighting, which was the best the city could get at the time.

“We wanted to be in compliance with the AMA report,” Claffey said.

Motta said the city “did the right thing."

But Motta said if he were writing the report today, he’d recommend LEDs that produce even less blue light, which have become more widely available.

“Nowadays, we can do better, ” Motta said. “I’d advise them to use the lowest ones they can get.”

Blue light creates more “scatter," which makes it more difficult for drivers over age 40 to see, Motta said. It also suppresses melatonin, the hormone that helps people sleep, and harms insects and other animals, Motta said.

“It’s environmentally toxic... ” Motta said. “The lighting industry was completely oblivious to the harm they’re doing with high blue lighting.”

Audrey Fischer, past president and current board member of the Chicago Astronomical Society, has been passionately vocal about her concerns, contacting city officials about what she sees as the need to swap out the current 3000K lights with LEDs with minimal blue light. Fischer has cited research that more exposure to blue light could increase the risk of cancer, mood disorders and obesity, as well as hurting people’s ability to see the stars.

“If they do the 2200s, we could restore starlight over the city of Chicago,” Fischer said. She said the city also could put “blue blocker” filters on existing lights.

Claffey pointed to research that electronic devices and indoor lights may expose people more to blue light than outdoor lighting.

Lumican, a Canadian company that makes 2200K LED street lights, said it gave the city a half dozen to test. But Claffey said the Lumican 2200K lights do not meet the city’s specifications, which call for 3000K. The Ameresco energy company is handling the contract, and acquires the lights for the city, he said.

Ald. Scott Waguespack, 32nd, said he wondered why the city could not at least try fixtures that produce less blue light in a few locations, to see how well they work.

“I don’t think the city does a good job of reaching out to companies and doing research into what’s quality and what’s not,” Waguespack said.

But Waguespack agreed that the LED lights he has seen so far in his ward are “definitely a lot better” than the orange sodium vapors they replaced.

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