A rendering in the city's bid document for the citywide lighting framework plan. View Full Caption City of Chicago

STREETERVILLE — Mayor Rahm Emanuel and the city recently put out a call for design proposals to turn Chicago into North America's "City of Lights," a plan that would illuminate five Downtown landmarks in hopes of giving tourism numbers a boost.

But Audrey Fischer, head of the Chicago Astronomical Society, worries it could be harmful to Chicagoans' health, based on research done on the effects of light pollution.

Light pollution "is incredibly linked to breast cancer, prostate cancer, Type 2 diabetes, mood disorders, sleep disorders, aggression," Fischer said in remarks to commissioners at a Park District board meeting last week.

"It even affects the birds: Every single living creature on the planet" is affected by bright, densely concentrated lights as seen in Chicago's Loop, she said.

Audrey Fischer pleads with Park District commissioners, including Supt. Mike Kelly (r.), to lobby against Mayor Emanuel's "City of Lights" plan. View Full Caption DNAinfo/Lizzie Schiffman

Lizzie Schiffman dug up some research on how the mayor's plan to make Chicago a "City of Lights" could be harmful to your health:

A 2010 study at the University of Connecticut concluded that exposure to artificial light at night increases cancer risk, "especially for cancers [such as breast and prostate cancers] that require hormones to grow."

Another test comparing incidences of breast cancer to the levels of light pollution at night across 164 countries found a 30 percent to 50 percent increased risk of breast cancer in the brightly lit countries.

The exact connection between light pollution and increased cancer risk has yet to be identified, but a prevailing theory is that melatonin, a hormone produced in nighttime darkness, is partially to blame, according to the 2010 study.

In other cancer studies, the infusion of melatonin-rich human blood collected at night slowed the growth of human breast cancers in rats, whereas tumors injected with melatonin-poor blood treated with nighttime light exposure were unchanged.

But Emanuel's office said that adding more light to the night sky isn't the City of Lights project's goal.

"Lighting design is not about creating more light, but using light more efficiently to enhance various parts of the city," Eve Rodriguez, a spokeswoman for the mayor's office, said Friday.

Rodriguez also emphasized that the plan is still in its infancy.

"The purpose of the lighting design competition is to generate ideas," she said.

"Any final design must be energy-efficient and respect migratory bird patterns, which is why the review team will include representatives from the environmental and birding communities."

If the plan goes through, Kristen Knutson, an assistant professor of medicine at the University of Chicago who studies the effects of sleep interruption, said that Loop residents living near newly illuminated landmarks may need to take measures to protect themselves.

"If somebody lives near some place that's going to be more brightly lit as a result of this plan, I would suggest that they take steps to reduce the amount of light in their bedrooms — whether by hanging blackout curtains, blinds, or with something as simple and inexpensive as a sleeping mask," she said.

"Being exposed to artificial light at night can have consequences."

There was no item related to the mayor's proposal on the Park District meeting's agenda, and Park District commissioners did not address Fischer's comments during the meeting.

Fischer said she wanted to testify in front of as many public bodies as possible to get her message across.

While addressing the board, Fischer presented an image she says a friend took of the night's sky somewhere outside of the city's boundaries, beyond where light pollution can dim the visibility of stars and planets.

"This is the natural night sky," she said. "We've gone so far away from it. That's the Milky Way that's over our Chicago skies, and we never see it."

Fischer, who heads the Chicago Astronomical Society, offered to connect the Park District "with the top researchers in the world" and pleaded with board members to "do anything" to stop the mayor's plan.

If the plan does move forward, Fischer said she hoped to see risk-reducing measures in place, like avoiding blue-white lights and aiming light beams downward instead of toward the sky.

"We can have our street lights, all the necessary lights we want, we can even have decorative lighting," she said. "As long as they don't go up into the sky. Keep them out of people's bedroom windows, keep them out of the bright blue spectrum."

Earlier this month, Jason Epperson, executive director and lighting designer of the Greenhouse Theater Center in Lincoln Park, published a scathing blog post criticizing the plan to further illuminate Downtown.

In his post titled "Dear Chicago, please don't bathe our city in pink and purple light," Epperson argues that the best type of lighting often goes unnoticed, unlike the renderings released that place more emphasis on neon lights glowing under the city's bridges than the bridges themselves.

"Has anyone ever looked down the classic view of the river at night and said 'this needs fixing'?" Epperson wrote. "Or upon our skyline and said 'this would be a much better view if we picked out a couple buildings and made them look like neon popsicles'?"

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