Blue Light and the Night Sky

A hearing last week on revisions to East Hampton Town’s 2006 “smart-lighting” law, designed to reduce nighttime sky glare, centered on the Kelvin level of outdoor lighting, a measure of the light color spectrum of a particular bulb.

Blue light, speakers agreed, creates more glare, interrupts night vision, and is less desirable. Speakers disagreed, however, on where the line should be drawn: a provision in the legislation sets a “goal” of lights at no more than 3,000 Kelvin, but would allow the planning board to approve Kelvin levels up to 3,500.

“The East End of Long Island is one of the last places where the Milky Way is visible in the northeast corridor, and it is worth preserving,” said Susan Harder of Springs, a lighting consultant, dark-sky advocate, and the New York section leader of the International Dark Sky Association.

Allowing more blue light into the atmosphere, she said, would “erode our view of the night sky” by creating “more glare, more skyglow, and adaptation problems at night.”

Ms. Harder, who submitted a detailed memo to the board, said the primary problem with the blue light produced at higher Kelvin levels is the impairment of night vision and increased glare.

Blue wavelengths entering the eye may not only hasten age-related macular degeneration, according to Ms. Harder’s memo, but also reduce melatonin levels in the body, which are tied to healing processes.

Ms. Harder pointed out that the lighting engineer consulted by the town in drafting the 2006 code had recommended prohibiting outdoor light sources rated more than 3,000 Kelvin. The difference between the 3,000 and 3,500 rating is “significant,” she said. Most outdoor lighting in the town, she said, falls between 2,000 and 2,800 Kelvin.

Margaret Turner, executive director of the East Hampton Business Alliance, argued that levels of blue light are not an issue until they reach the 4,000 Kelvin range. She submitted information sheets created by lighting industry experts, making that assertion.

Lights at higher Kelvin levels are more energy-efficient, she said, and that should be a consideration, given the town’s recently adopted goal of achieving 100-percent renewable energy use.

Ms. Turner was a member of a committee appointed by former Town Councilwoman Theresa Quigley that met for two years to rework the lighting law based on the concerns of business owners and others who felt the regulations were difficult to understand and comply with. The current proposal, which Councilwoman Sylvia Overby worked with town staff to develop, hews close to the original law but seeks to incorporate the committee’s suggestions and address the issues raised.

“We wanted a new law, which we didn’t get,” Ms. Turner said. “We wanted the same law for businesses and homeowners, which we didn’t get. We wanted a grandfathering clause, which we didn’t get.” The committee’s proposal would have allowed businesses, in some cases, to continue to use lights that did not comply with the smart-lighting law.

“Nine years of a grace period is enough,” Jim MacMillan of Amagansett told the board.

 “We’ve got to protect it; it’s so unique,” said Alexander Peters of Amagansett, speaking of the night sky view.

“I’m here to support the notion of dark skies,” said Janet Van Sickle. Night lighting can have a negative impact on migrating and resident birds, she said, and “Blue light is very unpleasant.” It is hard to regain night vision after encountering blue light, she argued.

Dava Sobel, a Springs resident and science writer whose books include “Galileo’s Daughter” and “The Planets,” said she had come to the meeting expecting to feel like the “lunatic fringe” while speaking against excessive night lighting and skyglow. She said she was happy to hear so many people address the importance of “our great natural resource of the night sky.

Ms. Harder submitted a packet containing fact sheets and research paper abstracts. She also submitted a letter to the board from Leo Smith, the International Dark Sky Association’s Northeast regional director, who recommended a 3,000 Kelvin limit. Increasing the rating to 3,500 Kelvin, he said, “would open the door to problems associated with increased glare, skyglow, misuse of energy, and unintended consequences to human health and the environment.”

Also submitted to the board was a letter from the Montauk Observatory board of directors, which echoed that recommendation. The East End, wrote Terry Bienstock, president of the board, has “a unique resource within the Eastern Seaboard, a view of the night sky relatively free of ‘light pollution.’”  East Hampton’s 2006 code, he wrote, set an example that was followed by other Long Island towns.

“Every single town in Suffolk County — there are 10 of them — and now Suffolk County, is adopting 3,000 Kelvin,” said Debra Foster, a former town councilwoman who was on the board when the 2006 smart lighting law was adopted.

Allowing the planning board the discretion to permit variances from lighting standards could be a “slippery slope,” she warned, noting that grant­ing variances is normally the job of the zoning board of appeals. 

Others also said that the language allowing lights of more than 3,000 Kelvin should be removed from the law before its adoption. “There is a substantial difference between 3,000 and 3,500 Kelvin,” said John Broderick of Amagansett, a lighting and production designer for large musical acts.

Ms. Harder recommended that the board establish a lighting advisory committee with members qualified and experienced in dark sky lighting technology. Public education and information on how to choose appropriate light fixtures is key, she said. “I think we should acknowledge that a standard has been set in our region.”

“I don’t think anyone has made a compelling case that we need to exceed that standard,” said Jeremy Samuelson, executive director of Concerned Citizens of Montauk. He called the proposal under discussion “a compromise,” but said that the Kelvin limit should be adjusted to the lower limit.

 Ed Geus agreed, telling the board that the town should not allow light levels, as measured in Kelvin, more than what the county allows.

“Blue lighting,” Stuart Vorpahl said, “is first cousin to the light of welding arc . . . totally contrary to how our eyes, over eons and eons, evolved. Because they were developed to the orange light of a wood fire.”

The town board took no action on the proposed law following the hearing.