Human Health and Lighting with Dr. Mariana Figueiro

Nick Boever:
Mariana, it’s great to be able to have you here on the show, I’m a little disappointed that it’s only for a half hour, but I will plan to make the most of it. So for those who may not be familiar with you or your work, why don’t you give us an introduction?

Mariana Figueiro:
Sure. Well, first of all, thank you very much for having me. As you mentioned, I’m a professor and also director of a new center that has just been formed a little bit over a year and a half here at the Icahn School of Medicine at Mount Sinai. We were formerly part of the Lighting Research Center at RPI and we all moved to Mount Sinai for obvious reasons, which hopefully we’re going to be learning while we speak today in the podcast. Just one more thing about my background, I am an architect by training, then I got my Master’s in Lighting and my PhD in Multidisciplinary Science doing a lot of work on how light affects sleep and circadian rhythms.

Nick Boever:
Yeah. Wow. That’s definitely a broad range of expertise in the matter. I feel like it definitely helps to be able to have that architectural experience just in terms of being able to apply the lighting in those cases. And I hope as well, we’re able to talk about the different applications of circadian lighting and just lighting in general. I know I keep using the phrase circadian lighting, but it is an element of healthy lighting setups. But before we get into that, I am actually curious to talk about your move to this new position and to this new research area. What prompted that?

Mariana Figueiro:
Yeah. It’s interesting because, like you said, it’s not just about circadian lighting, it’s really about lighting in the built environment and light can really affect your visibility, it can affect your mood and how well you feel in this space and it can also affect your sleep and circadian rhythms. And we actually work in all of these areas and we used to do a lot of work in all of this areas at the Lighting Research Center, but we did increase a lot the work in the health area. And being associated with a medical school allowed us to have more reach into the clinical population. So it has been an amazing move, we have a lab set up upstate and so we were able to move all the staff. So it’s been an amazing combination, I think, of the science of light with the clinical application that Mount Sinai offers us.

Nick Boever:
Yeah. That’s definitely very important when it comes down to it just simply because a lot of the time I feel like it’s that core element that you really want to talk about when you’re talking about health in a space. I know at DesignWell, we like to use the term wellness, but whenever we say wellness, it’s wellness with scientific backing.

Mariana Figueiro:
That’s exactly right. Yes.

Nick Boever:
There’s always a reasoning behind it.

Mariana Figueiro:
Yeah.

Nick Boever:
So considering you’ve done years of research into the health effects and applications of lighting, I wanted to pick your brain a little bit on the many different applications of that. Because at DesignWell, we have a ton of different people in our audience, we have architects that work in healthcare, senior living, hospitality settings, home builders and custom integrators within the home setting. And we’ve already covered a lot, we’ve already talked a decent bit about the home setting in our publication. So I wanted to see what you had to say about the value of lighting outside of the home setting.

Mariana Figueiro:
Well, I mean, one of the important things to think about, it is a 24-hour light and dark that it’s important for us. So for the health effects of light, you really need to think about this whole 24-hour light exposure, what are you being exposed throughout your daily activities? So it’s not just the lighting in the homes where you start your day, but it’s lighting in the offices. Or if you are in healthcare facilities where you might be spending a lot more time in it, it’s having that very robust 24-hour light and dark. So we have had a lot of success working in assisted living facilities and nursing homes so we have shown that Alzheimer’s patients, for example, by giving them that robust light, dark pattern, what you’re doing is you’re improving their sleep and by improving the sleep, we’re seeing an improvement in cognition, a reduction in depression and agitation scores. So there’s a lot of benefits associated with that improvement in sleep, which comes from having that robust light and dark cycle over the course of the 24 hours.

Nick Boever:
Yeah. I just recently read on a study that was done regarding Alzheimer’s patients where it shed a little bit more insight into how light specifically can potentially help with Alzheimer’s in the future. It was a very interesting one. I was wondering if you happen to come across that, I imagine you had to have?

Mariana Figueiro:
Yeah. We have publications on that and we are currently running four different studies looking at different outcome measures with Alzheimer’s disease patients. So we joke that they might be your test case in a way so sometimes when you want to test products or test applications, they are the application that it’s almost perfect because they are in a confined environment for 24 hours. So it’s the same thing with healthcare facilities when you are in a hospital room, for example. So these are the applications where we can see the greatest impact because we know what they’re being exposed over the course of 24 hours. And we have had incredible success and to me, the most important thing is not just with the sleep part, but it’s also how it has reduced the depression and the agitation. So it has improved behavior and mood in this population, which has been a tremendous benefit to them.

Nick Boever:
Yeah. It’s something that I definitely like to see whenever I hear about it. I’ve covered a few projects on the site that deal with specifically dementia patients and how circadian lighting in those situations can be used to help them. I’m curious if in your own experiences, just through research, have you come across a lot of facilities where this is in widespread use or?

Mariana Figueiro:
Actually, unfortunately, no. And I think that I keep asking myself why not? Because it is such an obvious application to be able to use that. And a lot of people use circadian lighting as an umbrella for really all the benefits of lighting, not just by promoting that robust light, dark pattern, but also delivering good visibility. And one area that we’re also working with is falls risk. So we have looked at horizontal, vertical lights, night lights that gives you the perceptual cues. So you can put that around door frames and bathrooms, for example. And that helps people, first of all, see when they get up, second, have those perceptual cues and third, know where they’re going because that’s where the bathroom is. So we have had very good pilot data showing that there’s a benefit of that too. So you think about this 24-hour lighting scheme, as I like to call it, where you have this robust light, dark pattern during the day and night and then you have that nightlight that helps with reducing falls and obviously good visibility, no matter what time of day

Nick Boever:
Now, I feel with the nightlight, you may agree with me on this one. One of the things that I have seen used and I actually have a few friends who do this in their home, they have a very similar nightlight set up, but they’ll use blue lighting so that, that doesn’t impact their circadian rhythm when they get up to go to the bathroom, it’s a much dimmer blue lighting so that it doesn’t activate the eyes. Is there-

Mariana Figueiro:
Well, the recommendation would be, don’t use the blue, you can use warm and candescent light colors, very dim and it should not impact your sleep, but it should allow you to go to the bathroom safely and return back to bed safely, which is really the important part of it and the need for this type of night lighting.

Nick Boever:
Right. I’m actually glad that you brought up, not just the different usages of lighting, but also the different positioning of lighting. Because I feel as though when it comes down to this 24 hour day, night cycle, a lot of people and a lot of the marketing material for manufacturers, they get hung up on two aspects of it and that’s the color temperature and the intensity tuning of whatever light fixture they’re using. So I wanted to pick your brain on the idea of, what have you found when it comes to achieving positive impact with lighting design?

Mariana Figueiro:
Well, I think that obviously spectrum and amount are important lighting characteristics and we should have brighter days and darker nights. And you can do that two ways. You can do that by dimming up or dimming down or you can do that by dimming up and dimming down and changing the color, having more bluish, white colors during the day and more warm colors in the evening. But I do want to emphasize two things about the circadian system is timing is very important. So you can have the same lighting given in the morning or giving at night and it’s going to have a different impact on the circadian system. So you have to keep track of time and when you give and when you remove light.

And then the second one is distribution. Designers tend to think of horizontal illuminance or light on the work surface and for the circadian you want vertical light, you want light at the eye. So being able to have that light bounce back into the space and being able to, everywhere you’re looking, you’re getting that light at the eye is extremely important. So amount and spectrum are things that the manufacturer can control. But I think the lighting designers they can control… Well, the timing would be controls, but the distribution is something that the designer really have a good hand at it and it’s a very important characteristic.

Nick Boever:
And I’m assuming your opinion on the role of a light sensor coming into this to help with that control system, probably key in this entire idea, correct?

Mariana Figueiro:
Correct. Because the visual system doesn’t really care about timing. You turn on the lights, the visual system will start working very quickly. The circadian system’s a little bit slower to respond so it takes more of a continuous light to respond. Even though there has been some work showing that flashes of light can affect the circadian system, but they have to be continuous flashes of light, not just one flash of light. So we tend to think of a more continuous light exposure and when you’re getting that light exposure. So if you want to change spectrum, if you want to change amount, you really need to know when to do that. And a control system can help because now you can pre-program so that happens passively. So you don’t have to worry about it, this is going to happen throughout the day without you thinking about it, for example.

Nick Boever:
Now I’m curious as to how you measure a lot of the elements within a circadian system. And more importantly, since we’re focusing on a B2B audience with DesignWell, how lighting designers and custom integrators might be able to find proprietary tools to measure that for themselves to see how effective these systems are?

Mariana Figueiro:
This is actually an excellent question just because you have a tunable lighting system in the space, it doesn’t mean you have circadian effective light. So being able to, first of all, do the calculations a priority and then do the measurements once it’s installed is extremely important. So we offer a free online calculator that can help people combine the spectrum and the amount to be able to get started, at least, on doing an initial plan. And then, we developed as a research tool, a small device that is a sensor that can measure light calibrated for the circadian system. Now, there are now manufacturers that are doing that so there are people that are making these devices available and also there are portable spectroradiometers nowadays. So the designer can go in, do the spectroradiometric measurements and then bring it back to this calculator that I mentioned and then they can at least know whether they’re meeting that target circadian effective light that they design for.

Nick Boever:
And I’m glad you brought up manufacturers as a whole because I know you’ve done a lot of collaborations with a lot of different lighting manufacturers, many of whom have their own human-centric lighting, circadian lighting, whatever you want to call it, solution. And so I guess it’s also very important to actually talk about the hardware as it comes into play because there are elements to it that impact how effectively it can recreate that solar setup. So I was wondering what your insight into that is?

Mariana Figueiro:
Yeah. To me, the most important part, as I mentioned, is not just having the ability of tuning the spectrum and the amount, but having the ability to think about time and think about distribution. Oh my God, there’s so many products out there. And again, I do work very closely with all the manufacturers, we tend to be agnostic to a particular product, but we want to be able to work with the manufacturer so that we can provide them the research so that they can use that research to develop the product, to make it available for the designers. Because there’s no point in having this great research if the designer can’t specify something that would fulfill the needs of the research.

So I think that, as with everything, there are great manufacturers that are really taking the science very seriously and then there are people that are just taking advantage of the buzzword and using it for everything. So my insight is make sure you do your own calculations, don’t trust what the manufacturers… Not that you don’t trust the manufacturers, but make sure you check and make sure you understand what you’re getting from the manufacturer as a designer. Because the designers can have very creative solutions that sometimes they’re not going to get directly from the manufacturers. But the manufacturers are a great resource too because they are working in this area, they’re trying to provide the designers with the best products they can provide. So the manufacturers we work with, we have a lighting health partnership that has manufacturers that are part of it and they are very serious about, “Let’s get the science right.” Which I really love to work with them because of that.

Nick Boever:
And I think a lot of the time too, especially nowadays, especially when it comes to architectural lighting, manufacturers have become a lot more accommodating in the different design elements of that. Where even if there are specific fixtures that may not fit perfectly, they’re willing to do these custom builds for.

Mariana Figueiro:
Yeah. And I think that the light-emitting diodes or LEDs are giving a lot more flexibility to both the designers and the manufacturers. It is such a flexible light source that nowadays you are able to custom make without being prohibitive and expensive. It used to be very expensive to be able to do that and now I think the technology is there, I think the manufacturers… Very interesting, a lot of the manufacturers are hiring software designers or it’s a completely different group of people that are now part of lighting manufacturers because now lighting is not just a light bulb that you change, it’s really a system. So you’re seeing a lot more of the manufacturers having completely different groups of people that didn’t use to work in the lighting industry before, which has been a great benefit for lighting.

Nick Boever:
Yeah, definitely. Especially considering in the earlier days when LEDs first started coming out, there was the whole issue with the flicker that would sometimes occur between the dimming. And now that doesn’t really seem to be too much of a concern, although it’s definitely something that I think designers should be looking out for when it comes to sourcing a product.

Mariana Figueiro:
And I think it’s back to, if you work with the right manufacturer, you are going to get a good product because it is just a matter of how much you spend to solve these issues. And some of the manufacturers are very concerned about it and are investing in solving these issues and others are not. So I think that, again, it’s good for the designers to know that the problems exist and ask these questions to the manufacturers so that they know that they’re working with the right group of people.

Nick Boever:
Now that we’ve had a chance to talk about just all of the aspects that go into this, I know you work primarily in research, but given what you’ve noticed with the applications, would you consider circadian lighting or just a health-centric lighting system in general to be a one-size-fits-all solution? Or do you think there’s a heavy value in having a conversation start at the ground level for designing these types of systems?

Mariana Figueiro:
No, it is not a one size solution. I think, really, the lighting designer should come in very early in the process and work with the architect and work with the electrical engineer to be able to implement these solutions because different places are going to ask for different solutions. Now we do have a basic minimum, which are bright days and dark nights. So if you don’t have a budget, this is the minimum you can get. But then if you have a budget, you have things like the aesthetics and the passive changes in the environment. If you have a lot of daylight in the space, you can have a lighting system that would be changing in tune with the day lighting outdoors, for example.

So these are really things that are going to depend on, what is your customer? How much money your customer has? And what is the space you’re lighting? So no, I think this is not a one-size-fits-all, even though, like I said, there can be simple solutions where you have one package and you can implement that. And I’d rather people have that than don’t have anything, but if you have the opportunity to go a step further, I certainly recommend that.

Nick Boever:
I think it also definitely comes down to the goals of the circadian lighting, which is something that I found just is a constant when it comes to wellness design in general, is to really ascertain the goals of a space when you’re designing it. And obviously that’s something that is a lot easier to do when the space is being built versus after it has been built. And that’s definitely a conversation.

Mariana Figueiro:
And the population, I mean, young adults are going to need different types of light than older adults, for example. So you really need to know who you’re designing it for, what are the goals? Do you want to do circadian entrainment? Do you want to do acute alertness? So there are different things. Are you doing it on a 24-hour facility that you have day shift and night shift nurses or night shift workers, the lighting solutions are going to be different. So absolutely it’s not a one-size-fits-all at all.

Nick Boever:
Now we’re closing in on the end of our time here, unfortunately. There was one question that I did want to ask you before we go, considering you’re so… Again, I feel like I’ve been saying it constantly, but you’re so deeply entrenched in the category. But let’s look a little bit towards the future, I remember a while back there was a New York Times article talking about Ketra. I think it was written back in 2020, talking about how circadian lighting is eventually going to become the standard for interior lighting in the future. And I wanted to get your thoughts on this sentiment. If you think this is going to be the case or if you think there are any barriers in place right now that are preventing us from getting there?

Mariana Figueiro:
Well, I think I have two answers for you on that. I think it should be the case because I think that we currently are in very dim light spaces during the day and perhaps very bright spaces in the evening. So I think we need to fix that. And I think the products are there, the science is there and I think that there’s no reason why we wouldn’t do it. Now, are we going to get there? I don’t know because unfortunately in lighting, a lot of times we’re racing to the bottom and ROI becomes the most important thing. And I think we have to change our minds about that, we have to start thinking about not just energy, not just cheap products, but we really need to think about the value of lighting and what lighting can give you in terms of health and wellbeing.

And I think this is an education and I try to do my share, but I’m only one. And it’s hard to change people’s perception of, “Well, I’m not going to invest that much money because what’s in there for me?” Or the other question that I get a lot, so what’s the proof of it? And we have plenty of field studies saying bright days will lead to better sleep at night. And there’s not a lot of productivity which people ask, but the truth is if you have a good night’s sleep, you are going to work better the following day. And many other things may influence your productivity, but the chances are that you’re going to be good to get to work the following day. So I think that, will it be? I don’t know yet because there’s a big cultural change now. Should it be? It’s an absolutely, yes.

Nick Boever:
Pretty much my idea currently as well, I always want to say when it comes to these situations that it’s, “Yes, it 100% should. I definitely want it to become the actual thing.” But speaking to what you were saying too, there are elements of circadian lighting and just wellness lighting in general, especially when you’re talking about lighting that operates on this circadian clock, there are definite sustainability elements to it too that ultimately do play into the ROI in those situations. Especially if you’re running, as we talked about, those more advanced systems with the light sensors so that it can automatically adjust throughout the day.

Mariana Figueiro:
Absolutely. I mean, you can help with the sustainability part by having your control system and dimming it down when you have to dim it down, when the space is unoccupied. I mean, there’s a lot of alternatives that you can do. But again, that adds cost and what people think about is cost and that’s where we have to change the culture. Cost is not everything when it comes to all the benefits that you can have from lighting.

Nick Boever:
I was going to say, I guess before we go, one last question that just popped into my head and this is coming from… I recently did a talk for Kavis is on wellness in the home. And one of the questions that came up at the talk that I didn’t necessarily have an answer for immediately was pertaining to that topic of ROI. It was, what is the tangible, monetary benefits of this? And I was wondering if you’ve done any research into that, not necessarily from a sustainability or building efficiency perspective, but I have seen some studies done on that when it comes to public health and how certain-

Mariana Figueiro:
Yeah. It’s interesting because I have a proposal in and to actually go into nursing homes to do that. So I haven’t done it yet, but I think that is the next step of our work is to start looking at ROI in different ways. How do you reduce falls? Or how do you reduce turnover of staff because the patients are sleeping better? How do you increase patient satisfaction in a hospital facility? Because nowadays patient satisfaction, everybody is interested in that. So I haven’t done it yet, but I have it on my to-do list because I think this is definitely a next step for it.

Nick Boever:
That’s definitely what I’m feeling, if only because that was the first time the question came up and it made me pause for a moment and I was like, “Oh, we should probably be looking into this.”

Mariana Figueiro:
That’s correct. I completely agree with that.

Nick Boever:
Well, it was great getting a chance to talk with you. It’s so unfortunate that our time is up, but I just wanted to thank you again for coming on to the podcast and sharing your expertise with everybody at DesignWell.

Mariana Figueiro:
Well, thanks for having me. It was a pleasure.