A Prescription for Healthy Lighting?

A Prescription for Healthy Lighting?

By James R. Benya, PE, FIES, FIALD

At the 2018 Strategies in Light conference, my partner Deborah Burnett and I moderated a panel of noted circadian researchers and educators. They had all completed real world studies using LED lighting to deliver measurable health-related benefits for shift workers and special populations. The panelists each presented their methodology and how it could be used to deliver measurable improvements for occupant sleep, increased productivity, reduced absenteeism and other benefits associated with a healthy circadian rhythm for general populations. After the presentations and considerable discussion on stage, the attendees were asked whether they could comprehend and apply the science without the help of qualified experts. From an audience of over 150 people including architects, lighting specifiers, interior designers, product manufacturers, salespersons, contractors, and academics, only two persons thought they could do it. The session ended with all in attendance voicing an overwhelming need for researchers to settle differences and establish standards and metrics for circadian supportive lighting metrics for general populations.

There is little question today in 2022 that this topic remains hot stuff and debated ferociously. Indeed, it has been a 20-year struggle to conduct research and then to enlighten our community to the relationship between light and sleep, wellness, productivity, alertness, and emotional wellbeing. Without a complete accredited specification from medical science for the technology, how to use it, what to expect, and what can go wrong, no one should design lighting systems that promise health benefits to their clients, their employees, their families or anyone else without expert assistance. While the medical and scientific communities continue to work to understand and perfect the science and its proper application, the lighting design and applications world continues to face the nonstop marketing of products called human-centric lighting that promise a variety of benefits. It has been frustrating to sort through the claims and to explain our concerns and reservations to clients, many of whom have experienced some of the same marketing. Even the most well-established lighting companies jumped on the circadian bandwagon without first having a sound scientific basis.(1) Unfortunately, misinformation, bad science and leaps of faith continue to flourish. I ultimately chose to rely heavily on Deborah’s expertise, along with the published CIE statements findings from leading independent research programs like the Lighting Research Center and from several companies with proven products and protocols for specific population groups such as shift workers and dementia care facilities as cornerstones of solid science and professional management of information.(2)

Perhaps the most important effort until now to develop a standard for healthy lighting design for general populations came from WELL, the international voluntary building standard that has been developed throughout the last decade. We used WELL V.1 in our ASID Headquarters project(3) and found it to have some interesting flaws, such as not allowing for daylight to be counted towards daily light exposure even though the space was almost 100% daylighted.(4)

And then……

Two weeks ago, I received an email from Dr. George C. (Bud) Brainard, a preeminent scientist and expert in the field of circadian health and science. He advised me that a worldwide scientific consensus has arrived! There, published in the open access journal PLoS Biology on March 17, 2022, were the long-awaited circadian metrics and appurtenant explanations: “Recommendations For Daytime, Evening, And Nighttime Indoor Light Exposure To Best Support Physiology, Sleep, And Wakefulness In Healthy Adults."(5) The paper is a technical toolkit intended for lighting specification and practice including specific recommended metrics, photometric technical detail and a brief literature review of most biological and visual system functions suitable for all levels of lighting practice. As background and tribute to the papers’ scientific rigor in developing the recommendations, the genesis of this work was developed as the result of the Second International Workshop on Circadian and Neurophysiological Photometry in 2019. The invitation-only conference consisted of each of the 18 named authors of the paper, an international who’s who in research into the field of human photobiology and applied LED technologies. And now, the lighting community finally has a first-generation guideline by which to begin the process of specifying circadian supportive lighting for general populations!

However, an Rx for Light Is NOT quite here… yet!

Are we ready to begin the codification process and provide lighting practitioners and manufacturers the details needed to successfully specify every project no matter who occupies the spaces? The answer is actually a great big NO. In a recent LEDs Magazine interview(6), another preeminent circadian pioneer, Dr. Russell Foster of Oxford University states unequivocally about these recommendations, “We’re not ready yet... we’re shuffling closely toward it, but there are major questions that remain unresolved. Yes, the (newly released recommendations paper) toolkit is better than anything we’ve had before, but it is not the complete answer yet.”

To their credit, the authors undertook to and delivered a document we can easily interpret and readily understand. But we must give careful consideration for how and when we put these recommendations forth into professional practice standards. Dr. Foster’s worries speak directly to the unfortunate quandary that faces any complex scientific advance. For instance, Deborah was an invited attendee to a 2011 meeting of the German DIN where the proposal on the floor was to adopt a “healthy lighting” standard. DIN in English stands for German National Standards, more or less equivalent to a combination of UL and the National Electric Code. Promoted by European lamp companies, it would have made the 2011 version of “human-centric lighting” into a major code. What a mistake that would have been! If you don’t believe me, go ahead and try to get a bad code changed or an outdated code updated!

That said, the lighting industry and all lighting designers should carefully review these Recommendations in their current form. Please remember this paper is a huge milestone, but it is far from finished. What it provides at best is a broad interpretation of recommended lighting for all general populations. It should not be used for lighting of spaces for special populations, ranging from NICUs and ICUs to all places of healthcare, night workspaces, and elderly homes and care. The authors of this paper realize that light affects each occupant differently and assume that we understand that, so that special lighting recommendations for specific populations are not included. In our design work, we need to integrate these concepts when appropriate among the many considerations in contemporary lighting design practice. But if there is one major takeaway about lighting design practice today, it is this: consider these recommendations to supplement your knowledge base and the recommended practices of the IES for indoor lighting of most buildings. It’s a great step towards achieving the promise of using lighting to promote better health and wellness. ■

1. I recall stepping into a major lamp company booth at Light+Build 2008 to receive a “jolt” of their 17,000K fluorescent lamps.

2. Burnett, D. Prescribe with Caution, LD&A, October 2016

3. IES International Illumination Award of Excellence, 2018 and the only project in the world to receive WELL Platinum under V.1 and LEED Platinum under V4.1

4. WELL 2.1 not only fixes the flaws we found, it embraces the findings in the paper in footnote 5.

5. Brown TM, Brainard, GC, Cajochen, C, Czeisler, CA, Hanifin, JP, Lockley SW, et al. (2022) Recommendations for daytime, evening, and nighttime indoor light exposure to best support physiology, sleep, and wakefulness in healthy adults. PLoS Biol 20(3): e3001571. https://doi.org/ 10.1371/journal.pbio.3001571

6. Mark Halper, LEDs Magazine, March 2, 2022, “Circadian pioneer says we’re not ready for circadian lighting. Does he really mean it?”