On Tuesday, Mayor Rahm Emanuel announced the city has now installed more than 100,000 new LED streetlights across all 50 wards.

The $160 million dollar program to swap energy efficient LED lights for the city’s orange-hued lights is projected to save taxpayers more than $100 million over 10 years, the city said.

But research by health, wildlife and safety experts suggest that these bright white lights (with high blue spectrum levels) could impact health, animals and even crime rates.

The research has led the American Medical Association and activists across the nation to ask municipalities to consider lights with the lowest levels of blue spectrum light possible. The AMA further recommends that cities use fully shielded fixtures that can prevent light from traveling past its target.

Health and wildlife advocates have recommended 2200 kelvin streetlights, but the city continues to install 3000 kelvin lights. The city also hasn’t adopted the fully shielded fixtures, but said it could install them on individual fixtures if it got complaints.

Chicago Department of Transportation spokesman Mike Claffey said on Tuesday that the city looked last year at a 2200 kelvin light manufactured in Canada. But, he said, the samples “did not meet the specs in terms of light output. They are sending a new batch and we will test them also.”

Professor Martin Aube, a Canadian physicist and light pollution researcher says the current 3000 kelvin lights could improve night sky viewing slightly over the old orange lights, but that switching to 2200 kelvin lights could reduce light pollution by “as much as 50 percent in Chicago.”

Beverly resident Audrey Fischer, a former board member of the International Dark Skies Association, has been appealing to the city to consider 2200 kelvin lights with a lower blue spectrum for more than a year. She said she is familiar with the Canadian lights the city has so far rejected.

“I’m heartbroken because I think those 2200 kelvin lights are outstanding,” she said.

Last year, WBEZ’s Curious City received a question about the effects of the lights from Chicago seventh grader and astronomy buff JJ Nnawuchi. He was worried about the environment, human health, crime and light pollution. WBEZ researched the latest science on the issue and found that Nnawuchi’s fears had some merit.

Light pollution is excessive artificial light that travels into the night sky (or people’s windows as they are try to sleep), and Chicago is one of the most light polluted cities in the nation. Activists say they want lower kelvin lights, in part, to improve viewing of the night sky in Chicago.

But the story isn’t over. Claffey said the city is leaving open the possibility of adopting newer lights as they become available.

“It’s a four year program,” he said in an email, “and in each year we look at the market to take advantage of lower prices and improved technology.”

Monica Eng is a WBEZ reporter. Follow her on Twitter at @monicaeng or write to her at meng@wbez.org

