Category: Light + Health

LRC: Tailored Lighting Improves Quality of Life for Persons with Alzheimer’s Disease

Lighting tailored to the needs of an individual can improve sleep and reduce depression and agitation in persons with Alzheimer’s disease, according to a recent study led by Dr. Mariana…

Lighting tailored to the needs of an individual can improve sleep and reduce depression and agitation in persons with Alzheimer’s disease, according to a recent study led by Dr. Mariana Figueiro, Light & Health Program Director at the Lighting Research Center (LRC) at Rensselaer Polytechnic Institute in Troy, NY.

The study, published in the April 2016 Lighting Research & Technology journal, is the latest in a series of high-impact papers dating back to 2010, when Figueiro started conducting research funded by her first R01 grant from the National Institute on Aging.

Older adults in long-term care facilities often spend their days and nights in dimly-lit rooms with minimal time spent outdoors. The constant, unvarying dim light found in many long-term care facilities means that older adults are not experiencing the robust daily patterns of light and dark that synchronize the body’s circadian clock to local sunrise and sunset. Disruption of this 24-hour rhythm of light and dark affects human biological systems, from DNA repair in single cells to melatonin production by the pineal gland in the brain. Circadian disruption is most obviously linked with disruption of the sleep-wake cycle—feeling sleepy during the day and experiencing sleep problems such as insomnia at night—but is also linked with increased risk for diabetes, obesity, cardiovascular disease and cancer.

Sleep problems are all too common among older adults, especially those in long-term care facilities, yet sleep could not be more important to their overall health and wellbeing. In fact recent research has shown that poor sleep may directly impact the onset and progression of Alzheimer’s disease, and conversely, healthy sleep may prevent or slow progression of the disease.

lrc1In the new study, LRC researchers focused on a specific challenge: delivering light in a way that was highly effective for individuals with Alzheimer’s disease. To meet this challenge, the LRC developed a self-luminous light table to complement the custom-built overhead and ambient lighting systems used in the previous phase of the study.

The first light table, installed at the Albany County Nursing Home in Albany, New York, has garnered praise from caregivers and residents alike. The study was featured in the January issue of the American Psychological Association’s Monitor on Psychology magazine.

For the most recent phase of the study, now underway and enrolling new participants, the research team installed tailored lighting at several long-term care facilities throughout the U.S., including the MorningView Assisted Living Center in South Bend, Indiana. Staff members at MorningView have already seen improvements from the new lighting.

“Residents are now sleeping through the night. We have also seen a vast improvement in their mood,” said Dr. Suhayl Nasr, Psychiatry Medical Director of Beacon Health System, who introduced the lighting project to MorningView Assisted Living Center.

The tailored light treatment provides cool, high light levels for high circadian stimulation during the daytime, delivering a circadian stimulus (CS) of 0.4. A CS of 0.4 translates to approximately 2000 lux at the cornea of 25,000 K (bluish white) light, similar to a blue sky on a clear day.

Results show that the tailored light treatment significantly improved sleep, significantly reduced depression, and significantly reduced agitation in Alzheimer’s patients. Both depression and agitation scores remained significantly lower after removal of the intervention, suggesting a beneficial carryover effect of the light.

Among the many positive outcomes of this project is the fact that the lighting principles and technologies utilized in these long-term care facilities can be transferred to benefit other populations: newborns in the NICU, students in schools, office workers, and eventually, the general public in their own homes.

“Today, many people think of light as just part of a building,” said Figueiro. “In the future, light will be more personalized and customizable, with the goal of improving human health and wellbeing.”

LRC’s 24-hour lighting scheme demonstration room provides cycled electric lighting with cool, high light levels during the day and warm, low levels in the evening. Construction of the room was made possible by the Light and Health Alliance: Acuity Brands, Cree, GE Lighting, Ketra, OSRAM Sylvania, Philips Lighting, and USAI Lighting.

LRC’s 24-hour lighting scheme demonstration room provides cycled electric lighting with cool, high light levels during the day and warm, low levels in the evening. Construction of the room was made possible by the Light and Health Alliance: Acuity Brands, Cree, GE Lighting, Ketra, OSRAM Sylvania, Philips Lighting, and USAI Lighting.

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“Going Beyond the Lumen?” by Jim Brodrick

Republication of Postings from the U.S. Department of Energy (DOE) Solid-State Lighting Program by Jim Brodrick, SSL Program Manager, U.S. Department of Energy Light sources are typically evaluated in terms…

Republication of Postings from the U.S. Department of Energy (DOE) Solid-State Lighting Program by Jim Brodrick, SSL Program Manager, U.S. Department of Energy

Light sources are typically evaluated in terms of how much light they produce (in lumens) relative to how much power they draw (in watts). From lighting designers to building owners to consumers, we’re encouraged to choose the most efficacious light sources appropriate for the task at hand — those with the highest lumens per watt (lm/W). The numerator of that expression is a measure of light output, based on human visual sensitivity under standard viewing conditions. That makes sense: we want to know how much light the source is producing that will help humans to see and function in the world.

But what we’re also starting to understand is that light has other impacts — and potentially great benefits — that are unrelated to human visual sensitivity. In fact, these other benefits, such as improving productivity, have been receiving an increasing amount of attention. But many potential benefits, especially those that depend on the ability to tune the spectrum of SSL products, can’t be accurately conveyed solely in terms of lumens — which means that we may end up needing additional metrics in order to do them justice.

That’s because the lumen is a measure of light output, where emitted light of various wavelengths is weighted in accordance with humans’ visual sensitivity to those wavelengths. But as we’re still learning, the effect of light on humans (and other living creatures) extends well beyond enabling us to see. Researchers have discovered that the human eye contains at least five different types of nonvisual photoreceptor cells — that is, cells that detect light but that play no role whatsoever in visual perception. We’re still learning about the various functions of such cells, but we know that one thing they do is help regulate the production of melatonin, a hormone that plays a key role in regulating the sleep-wake cycle and affects our health in many other ways as well.

We also know that the peak sensitivity for melatonin suppression is for light at around 464 nm, which is in the blue range. And because LEDs — far more than other light sources — are highly tunable, they can be carefully tailored to adjust their emission around 464 nm, or in any other portions of the spectrum the manufacturer desires. They can also be made to be tunable by the user, so that the spectral power distribution can change with the turn of a dial or the touch of a keypad, in accordance with whatever effect is desired.

While much more research is needed to understand how this spectral flexibility can best be used, the potential benefits range from normalizing our circadian rhythm, to promoting relaxation, to improving mood and concentration, to speeding convalescence, to promoting the optimal growth of plants and animals. Further, spectrally adjusted light can help protect sensitive wildlife that live in areas where outdoor lighting is used. And all of this is to say nothing about visual value that’s not captured by the photopic lumen — such as tuning the spectrum to emphasize certain colors or provide contrast for retail, inspection, and high-value fine-manual work applications such as surgery.

Given that we now have a type of light source that can be spectrally tailored to suit our needs, wants, and whims — visual and otherwise — and given that our knowledge of the nonvisual functions is growing by leaps and bounds, it stands to reason that we may need to more carefully consider additional metrics to capture the full range of gifts SSL has to offer, and develop new metrics as science advances.

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AMA Issues LED Streetlighting Guidance, Controversy Ensues

Street and area lighting are among the most popular applications for LED sources. It’s estimated that more than 10% of streetlights have been converted to LED technology in the U.S….

Street and area lighting are among the most popular applications for LED sources. It’s estimated that more than 10% of streetlights have been converted to LED technology in the U.S.

Many LED streetlights exhibit characteristics that are very different than traditional high-pressure sodium sources. The popularity of LED streetlighting led the American Medical Association (AMA) to issue community guidance to communities installing it.

While acknowledging the benefits of LED streetlighting, AMA cautioned against possible health and safety impacts, notably resulting from poorly designed “high intensity,” blue-rich lighting.

“Despite the energy efficiency benefits, some LED lights are harmful when used as streetlighting,” says AMA Board Member Maya A. Babu, MD, MBA. “The new AMA guidance encourages proper attention to optimal design and engineering features when converting to LED lighting that minimize detrimental health and environmental effects.”

AMA advised communities to:

* Use LED lighting that minimizes blue spectral content
* Use sources that are 3000K CCT or lower
* Use luminaires that are properly shielded to prevent glare
* Consider dimming during off-peak operating times

Click here to download the AMA guidance (registration required).

Some AMA statements resulted in instant controversy.

The Illuminating Engineering Society issued a statement that said: “Of primary concern to the IES is the potential for this report and its ensuing press to misinform the public with incomplete or inaccurate claims and improper interpretations. We intend to respond to this through a proper analysis.”

IES added it hopes to work with AMA to ensure any lighting recommendations involve discussion with the IES.

Click here to read the IES response.

The Lighting Research Center issued a statement that included these key points:

* InGaN LED sources have greater potential than HPS to suppress melatonin (the hormone that regulates sleep-wake cycles)
* However, the amount and duration of exposure must be known before saying InGaN LED sources affect melatonin at night
* CCT alone is not enough to characterize the effect of a light source, in fact it’s misleading as it’s not really designed as a light and health metric
* Glare is mainly determined by amount and distribution of light entering eye, not light’s spectral content

Click here to download the LRC response.

The U.S. Department of Energy responded by stating there is nothing inherently dangerous about LED streetlighting. LED sources, in fact, offer advantages such as precise optical control, tailored spectral content and relative ease of dimming.

“Some media coverage can give the impression that LEDs are the enemy when in fact they’re a critical part of the solution, which the AMA acknowledges,” says Jim Brodrick, SSL Program Manager, DOE. “The key takeaway from the AMA’s guidance is the importance of properly matching lighting products with the given application, no matter what technology is used. More than another technology, LEDs offer the capability to provide, for each application, the right amount of light, with the right spectrum, where you need, when you need it.”

Click here to read the DOE response.

NEMA also responded:

* AMA guidance aligns with industry recommendations for lighting controls, proper source shielding, and minimizing light levels and energy necessary for the task
* AMA recommendations for spectral content is problematic–it is one factor, and a single solution is not effective for all applications

“The AMA recommendation encouraging the use of 3000K correlated color temperature (CCT) or lower may compromise the ability of the lighting system to meet all critical design criteria for each unique application,” NEMA stated. “As indicated by the U.S. Department of Energy (DOE) in its June 21, 2016, statement, CCT does not explicitly characterize the potential for nonvisual effects, which also depend on quantity and duration of exposure to light. The DOE further clarifies than an LED light source with the same CCT as a non-LED source has about the same amount of blue spectral content. The AMA recommendation for 3000K or lower is not an appropriate solution for all applications, nor is it is supported by the current body of research. NEMA will issue additional technical guidance specific to the issues and tradeoffs related to the spectral content of lighting solutions.”

Click here to read the NEMA response.

My take:

It appears the AMA is well-intentioned here and raising some legitimate concerns, though their conclusions are questionable based on the research, and their solution may be oversimplified. They should consult the lighting industry on any lighting guidelines. IES has said it will contact AMA and seek to represent the lighting industry on lighting-related guidelines, which is very positive. As the lighting industry has been talking about light and health for some time, I’m surprised that link doesn’t already exist.

But even that would not have solved one of the biggest problems here, which is media ignorance about lighting and constant need to quickly and simply convey a story, which results in misleading instead of informing. In my opinion, IES needs to go even further to ensure that if the AMA sends a press release, that release not only promulgates guidelines IES endorses but also puts forward one or more lighting experts who can talk to the media and represent the lighting industry. These experts would get some type of media training.

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Can the Impact of Human-centric Lighting be Measured?

Light and health, light and productivity–can it be measured? This LUX webinar explores whether the impact of human-centric lighting can be measured, and how. Check it out here.

Light and health, light and productivity–can it be measured?

This LUX webinar explores whether the impact of human-centric lighting can be measured, and how.

Check it out here.

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Circadian Health Could be Transformational for Lighting Industry

Lighting is on the cusp of major change, say three lighting experts while discussing the subject of lighting and circadian health at the annual lighting colloquy sponsored by the National…

Lighting is on the cusp of major change, say three lighting experts while discussing the subject of lighting and circadian health at the annual lighting colloquy sponsored by the National Lighting Bureau.

The three panelists were Mariana G. Figueiro, Ph.D., professor and Light & Health Program director, Lighting Research Center, Rensselaer Polytechnic Institute; Kevin Kampschroer, director, Office of Federal High-Performance Green Buildings, U.S. General Services Administration; and Mary Beth Gotti, LC, manager, GE Lighting Institute, GE Lighting. The discussion was moderated by EdisonReport.net’s Randy Reid.

Dr. Figueiro explained that morning light synchronizes people to the local time on Earth. When synchronization is disrupted, circadian rhythm is disrupted. Research shows that circadian-rhythm disruption can have a negative effect on human health and well-being, and that long-term circadian-rhythm disruption has been associated with diabetes, obesity, and cancer. All light stimulates the human brain, she said, and can also exert an acute alerting effect on people. Blue light helps maintain synchronization and increase alertness, but saturated red light can also maintain alertness; e.g., red light after lunch or in the middle of the night helps people feel more alert and less sleepy. Historically, lighting has been thought of in terms of color and light level, she said. Now, timing has become important, too. As such, lighting controls will soon not only adjust lighting levels; they will also change lighting’s color at certain times or in response to certain stimuli.

Mr. Kampschroer commented that, historically, lighting systems were designed to do no harm to building occupants. Now, he said, we have lighting that can improve the well-being and performance of building occupants and enhance their ability to sleep at night. Insofar as lighting-energy conservation is concerned, he noted that, when people have the ability to adjust lighting on their own, they generally optimize their visual comfort by selecting settings that also happen to reduce energy consumption. He was particularly enthused about using more daylighting in buildings. He noted that, in hospitals, individuals who had undergone major surgery healed faster when their rooms were illuminated by daylighting. He commented that the value derived from shorter hospital stays would more than pay for the lighting systems required to achieve it.

Ms. Gotti said that the new roles lighting can fulfill give manufacturers significant opportunities and incentives to take lighting quality to a whole new dimension. She foresees opportunities not only in office buildings, but in educational and health-care facilities as well.

Check it out here:

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Juno’s Scott Roos on Tunable-White Lighting

I recently had the pleasure of interviewing Scott Roos, VP of Product Design, Juno Lighting Group, on the topic of tunable-white lighting. I’m happy to share his responses with you…

I recently had the pleasure of interviewing Scott Roos, VP of Product Design, Juno Lighting Group, on the topic of tunable-white lighting. I’m happy to share his responses with you here. The interview informed an article I wrote for the May 2016 issue of tED.

DiLouie: Looking at LED sources and controls, what are the different technological methods used to produce tunable-white light in commercial luminaires?

Roos: RGB color mixing is a long-standing method, but this model has poor color rendering and many technical and performance limitations, so it is seldom used outside of creating theatrical, colored lighting effects. There are multi-channel drivers that allow varying the intensity of two to three different color temperature, phosphor-converted white LEDs. And then there are hybrid multi-channel systems that combine nominally white phosphor-converted LEDs with one or more monochromatic colors to achieve a higher quality and greater range of tunable white lighting effects.

There are many control protocols that can be used with tunable white lighting, but each system is designed to be compatible with a specific one. At one extreme, there exists the conventional, economical and easy-to-commission phase and 0-10V dimming. At the other extreme, DMX and DALI systems provide more capabilities but are more costly and require a greater degree of commissioning. And then there is the emerging field of using smart devices to wirelessly commission and control fixtures using protocols that include Bluetooth and Wi-Fi.

DiLouie: What are the different effects that can be created, such as color stability/consistency, dim-to-warm, CCT selection?

Roos: Warm-to-dim is the easiest effect to employ and understand. What’s required is simply connecting the luminaire to a compatible dimmer and it behaves like an incandescent or halogen lamp to create warmth and intimacy in settings such as homes, restaurants, hotel rooms, bars, etc. where this shift in ambiance is expected and appreciated.

CCT selection allows the color temperature to be changed post-installation independent of dimming. This can be a static selection to set the CCT to exactly complement a given interior décor, or it can be dynamic where scenes are set or automatic color temperature changes are programmed into a lighting control system. Dynamic tunable white systems enable users to change the appearance of the space from warm to cool depending on time of day or activity.

More sophisticated multi-channel hybrid LED systems with phosphor-converted white plus color settings allow spectral tuning of the luminaire beyond CCT. The multiple color channels can fill in missing or deficient spectrum of the phosphor-converted white LED to create exceptionally high color rendering and color fidelity. The color point can be moved off the Planckian locus – the reference for what humans perceive to be natural white light – to enhance interior finishes, art and store merchandise. Additionally, the spectrum can be optimally tuned to support circadian health and productivity. And these more sophisticated systems typically employ thermal and optical sensing and feedback systems to help tightly manage out-of-box color consistency and color stability over the service life of the luminaire.

DiLouie: What markets and applications do different tunable-white lighting effects serve? What’s the low-hanging fruit?

Roos: Applications for warm-to-dim in residential and hospitality settings are the low-hanging fruit, as they are essentially replicating the expected and appreciated effects of long-standing incandescent and halogen technology. The technology can be relatively inexpensive and requires no additional design or commissioning time or expense, so there are really no barriers to widespread adoption.

Tunable white lighting, on the other hand, is opening up an entirely new frontier in lighting design and human health and productivity. For aesthetic-driven applications, there are many low-hanging fruit opportunities – with the limiting factors being education, willingness for an end user to pay for the incremental cost of the luminaires, controls and commissioning. High-end retail, hospitality, art and museum lighting stand out as examples of early adopter applications that can realize the most compelling benefits from this technology.

Tunable white lighting for human health and productivity is on the cusp of pioneering applications coming online in healthcare, education, performance sports and 24/7 work environments. As with any new frontier, a few end users have jumped right in to install beta sites or small scale applications because the benefits of improved quality of life and/or increased performance hold so much promise. Others are taking a ‘wait and see’ attitude, sitting on the sidelines until well documented case studies that quantitatively substantiate claims and IES recommended practices are published; at such time, they will have the confidence to move forward and avoid potential liability.

DiLouie: How would you characterize demand for tunable-white lighting?

Roos: It is in the very early adopter stage with tremendous opportunity for growth. Even the most basic warm-to-dim technology is at the early stages of what is sure to be exponentially growing demand.

DiLouie: Color temperature has been linked to circadian lighting. What is the link, what research supports it, and how should distributors be selling it?

Roos: It is not actually color temperature, per se, but the spectral content of the light that is linked to our circadian response. Exposure to short wave blue light centering on 480 nanometers has been shown to suppress melatonin and stimulate the production of neurochemicals that promote alertness and health during the day and cause sleep disruption and negative health effects at night. While there is a correlation between color temperature and spectral content, it is important to understand that traditional lighting metrics developed around the human visual response system such as CCT, lumens and footcandles are not accurate predictors of a circadian response. New metrics, such as melanopic lux, are being developed and proposed to support the design and application of circadian lighting.

In regards to selling circadian lighting, distributors should stick to educating customers on the basic facts without making specific health claims and take extra care to do no harm. For example, warm-to-dim LEDs used at home will certainly support better circadian health than static white LEDs, and a cooler 5000K or 6500K CCT luminaire for 100 percent daytime application will likely promote improved alertness, productivity and mood. When looking at applying more sophisticated spectrally tuned luminaires and controls to optimize the lighting for a hospital, extended care facility, school or 24/7 work environment, for example, distributors and end-users need to work with a professional who has done their homework and has access to the research and researchers that can be found in organizations such as the Human Centric Lighting Committee or the Light and Health Alliance at the Lighting Research Institute. Informed members of these groups can help guide their efforts to ensure the desired results and provide safeguards such that the spectrally tunable lighting system cannot be misapplied and cause harm.

DiLouie: If you could tell the entire electrical industry just one thing about LED tunable-white lighting, what would it be?

Roos: While I can’t predict how quickly tunable white technology will see wider adoption, I can confidently state it is only a matter of time until it does. This is a unique opportunity for industry professionals to invest in education on this topic to position themselves as the experts who will be the ones to advance this emerging field in lighting. It holds great promise to improve the quality of our interior environments and positively impact human health, well-being and productivity.

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ELECTRICAL CONTRACTOR Publishes Article on Light and Health

Light doesn’t only serve as the basis of vision. It can influence behavior and how people feel. Further, light plays an important role in human health. As researchers gain insight…

healthLight doesn’t only serve as the basis of vision. It can influence behavior and how people feel. Further, light plays an important role in human health. As researchers gain insight into the relationship between light and health, the lighting industry is beginning to consider health effects in product and lighting design best practices.

Click here to read a feature article I wrote on this topic for the December 2015 issue of ELECTRICAL CONTRACTOR. The article is largely based on research by the Lighting Research Center.

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Sales Increase with Limbic Lighting

I contributed this short article to the February 2016 issue of tED Magazine, published by the National Association of Electrical Distributors (NAED). Reprinted with permission. Manufacturer Zumtobel recently concluded a…

I contributed this short article to the February 2016 issue of tED Magazine, published by the National Association of Electrical Distributors (NAED). Reprinted with permission.

Manufacturer Zumtobel recently concluded a field study with Gerry Weber that showed an increase in sales based on a lighting solution optimized based on the personality type of the fashion retailer’s target market.

The study, conducted in 2014, follows laboratory research during the previous year by Zumtobel Research and consultancy Gruppe Nymphenburg, which had developed the “Limbic® Model,” a tool for analyzing the complex emotional personality structures of consumers.

Eighty percent of buying decisions made at the point of sale are made unconsciously, mainly depending on influences addressing people’s emotions. Zumtobel wanted to know how influential lighting is in those decisions.

In the lab study, subjects were assigned to seven different personality or Limbic types using a questionnaire. These included Bon Vivants, Hedonists, Adventurists, Performers, Disciplinarians, Traditionalists and Harmonizers. These subjects then looked at 20 different lighting scenarios while their unconscious physical reactions, including brain waves and cardiac activity, were measured. The researchers were then able to identify which lighting scenarios triggered positive or negative emotions, stimulation or relaxation among the different Limbic groups.

While all Limbic groups did not respond positively to a single lighting scenario, there were individual lighting scenarios that multiple groups responded positively to. This allowed the Limbic types to be combined into three main groups:

• Balance (Harmonizers, Traditionalist and Bon Vivants), which responded particularly positively to moderate accent lighting.
• Stimulance (Hedonists, Adventurers), which responded most positively to lighting scenarios with relatively strong contrasts, created by accent lighting and a variety of different spot lights.
• Dominance (Performers, Disciplinarians), which responded negatively to extreme contrasts and responded most positively to balanced, moderate lighting scenes.

These ideas were put to the test in the field study, which was conducted at a Gerry Weber store in Herford, Germany. Zumtobel designed an LED accent lighting solution identified as specifically satisfying the preferences of Harmonizers, a key target market for the retailer. As shown above, Harmonizers belong to the Balance Limbic Type and therefore react positively to moderate accent lighting. The new look at of the Herford store was designed to generate a bright and friendly atmosphere with a warm 3000K color appearance.

General purchasing behavior before and after installation of the new lighting was measured and observed over two months. A sampling of customers was tested using the Limbic Emotional Assessment tool and also interviewed about their shopping experience.

Gerry Weber reported a 10 percent increase in sales compared to a reference store, with an even higher average sales increase among the specific target group for which the lighting solution was optimized.

Horschlager Martin, head of retail operations for Gerry Weber, concluded: “For us as an international fashion brand, it was fascinating to see clear scientific findings that prove the significant influence of light at the point of sale …We have seen how profitable the Limbic lighting concept proved in our Herford store, with a marked increase in sales during the test period.”

Gerry Weber store before installation of the new lighting. Image courtesy of Zumtobel.

Gerry Weber store before installation of the new lighting. Image courtesy of Zumtobel.

Gerry Weber store after installation of the new lighting. Image courtesy of Zumtobel.

Gerry Weber store after installation of the new lighting. Image courtesy of Zumtobel.

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NLB Panel on Light and Health

EdisonReport’s Randy Reid leads a National Lighting Bureau panel including Mariana Figueiro, Kevin Kampschroer and Mary Beth Gotti. They discuss lighting’s effects on circadian health.

EdisonReport’s Randy Reid leads a National Lighting Bureau panel including Mariana Figueiro, Kevin Kampschroer and Mary Beth Gotti. They discuss lighting’s effects on circadian health.

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USAI on Circadian Lighting

USAI Lighting recently published an interesting article about circadian lighting on its website. This is a big frontier in lighting, with extraordinary potential. Check it out here.

usaiUSAI Lighting recently published an interesting article about circadian lighting on its website. This is a big frontier in lighting, with extraordinary potential.

Check it out here.

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