mental-health – Lighting by Jeffrey

The Health Cost of Energy Efficiency

Since I have spent time trying to understand the health implications of light, I have read scores of scientific reports on the subject. The work of Dr. Mariana Figueiro is of course very central and most people in the lighting industry have had the privilege to read and listen to her talk about practical solutions for light and health. The name that comes up second is Dr. Martin Moore-Ede. He has probably been a louder voice with a perceived higher level of worry about the new LED and how they interact with human health.

His most recent realm of concern has been aimed at how LED manufacturers achieve more (and more) efficient LED light sources. He believes that the newer LED are eliminating output in specific color ranges to achieve the required efficacy. By so doing, the human body is not receiving enough light to satiate the demand of certain opsins in our body.

As you know, I’m not a doctor. Lord help us if indeed that were the case, so I’ll try to explain this as simply as I can, one lighting person to another. If you’re a doctor or a scientist, please stop here and read another blog post!

You, me and all other humans have a series of opsins in our body. These opsins are receptors in our eye’s photoreceptors that detect light in their various wavelengths and responds in some sort of predetermined physiological way. For example, Opsin #1 provides us with color vision and Opsin #2 allows us to see in minimal light and the dark. Most every LED works fine delivering light in this wavelength range.

Opsins #3, #4 and #5 are non-visual opsins. Receiving light in their required wavelength aid in human health. If an inadequate amount of light is delivered in these wavelengths, human health suffers. The correct amount of light at 480nm drives our circadian cycle, thanks to the work of Opsin #4. Opsin #3 requires light at 430nm and Opsin #5 requires a wavelength of 380nm. All three help regulate glucose levels, energy and retinal refraction. The increase in myopia (nearsightedness) is linked to reduced levels of the violet-rich (380nm) light needed by Opsin #5.

Light at the far-right end of the visible spectrum, moving into infrared light is likewise important for human health. This light, peaking at 825nm, is not detected by opsins because it has the ability to penetrate deeply into the skin. Proper amounts of light in this range have shown to improve blood flow, skin health and assorted healing properties.

Imagine you are a caveman or an early farmer, living off the land with no electric light. Much of your life is spent outside, planting, foraging, playing or cleaning. Daylight naturally delivers light in the full spectrum. The body receives an ample quantity in each wavelength, for each purpose. Skip ahead to today where children play inside and adults work in an indoor office or factory. To get the proper amount of light in the proper wavelength we must rely on artificial light.

Full spectrum LED lighting can provide light across all wavelengths, thereby delivering all the light needed for human health. As efficacy requirements are raised and consumers demanded less expensive options, manufactures have built LED that produces light across a narrower band of light. Most of the lumen measurement is concentrated in the green-yellow range (500nm-600nm.) While less expensive, they fail to provide the lower and higher wavelengths needed by these opsins and our skin.

Where Does That Leave Consumers?

The easiest answer is, “Spend more time outside!” Of course, that is somewhat impractical in today’s world. Your second option should then be natural light indoors. Place work desks near windows, prevent light inhibition, avoid using fenestration materials that filter out light wavelengths (if you have the option) and as a last resort, buy better lighting.

The color spectrum of natural light stretching across the area visible to humans

This is an image of the color spectrum of natural light across the area visible to humans. (380nm to 750nm) Ultraviolet light would be off the chart, on the left and infrared light is situated off the chart, on the right. While there are some peaks in the blue area, most of the colors are equally and evenly delivered.

If selecting artificial daytime light, you want to look at a spectrum diagram of the light and select one that is as close to this as possible. It is important to know that artificial daytime light should ONLY be used during the day. We need great light during the day and minimal levels of warm/red light at night. Using full spectrum light at night might have an adverse impact on our circadian system. Again, go back to our analogy of a pre-electricity farmer. Even on a great day, the sun did not shine for 24 hours. Think of a full spectrum light as a replacement for sun, not a light bulb. (Some full spectrum LED is available with a nighttime mode that removes the blue, thus creating a warmer evening illumination.)

Remember too, Full Spectrum lighting is NOT the same as Daylighting. Most daylight LED is simply 5000K to 6500K and not likely to be spread across the full spectrum. Full spectrum lights do not have to be 5000K or 6500K, but might.

One more thing. The sun is very bright. Light bulbs are not the same as the sun. You can get the right color of light from a lamp, but not the same amount. Think of full spectrum artificial light as a supplement to the sun, not a replacement.

I hope this has helped a bit. This remains a complicated issue. We are hoping artificial light can alter lifestyle changes. Perhaps it can help, but it is unlikely to replace the body’s need for sunlight. When possible, get outdoors, plant some flowers, drag the laptop onto the patio when you’re working and do your homework on a lawn chair. Your body will thank you…and you’ll sleep better, too.

Human Centric Lighting vs. Circadian Supportive Lighting

I believe we lighting people have a tendency to mix or confuse Human Centric Lighting with Circadian Supportive Lighting. It was a point well-made by a lecturer at the recent Cleveland Electric Expo. I’ve written a lot about Circadian needs and concerns, but I really haven’t touched on Human Centric Lighting. I hope this brief description helps clarify the differences.

First, let’s remember that Circadian lighting is basically a replica of natural light, regardless of what we humans are doing, the sun rises and falls. The sun doesn’t care about us, it is totally independent. At a base level, this is the light our body craves. The main point the speaker made was that Human Centric Lighting was more of a design practice, with a goal to improve the life of the human who uses the space. Designers must balance the physiological needs with the practical demands of life. That can be done is a number of ways.

Quality of Light

The point of the light is to bring out the beauty of the surroundings and the space being lit. To do so, the quality of the luminaire must be high. Selecting good light insures the result will be excellent.

Natural Light

The goal is to end up with light that feels natural, not forced or fake. It should have a connection to daylight in color and direction.

Connection to the Outdoors

The built environment should have a link to the surrounding landscape. A harmonious blend makes the space feel real and comfortable. People will enjoy occupying the space because of these connections.

Adaptive and Personal Controls

We all feel better when we have control. Control of the lighting is included in that emotion. Intelligent solutions should adapt to the user. If automation is not being used, then the occupant should have the ability to personally adjust and regulate the light as needed.

Shading

Shading is a crucial part of lighting, especially with the inclusion of more natural light. Direct sun can produce a lot of glare. Proper shading can ameliorate that problem and create a comfortable place. For successful shading, a designer must consider the proper material and how use will impact energy consumption.

Benefits

Human Centric Lighting has been found to deliver benefits to businesses, employees and tenants.

Where Do I Start?

When thinking about Human Centric Light, one must consider natural light first. It is consistent and dependable, so how does the sun fall on the building? With more daylighting employed, how will that natural light enter and work within the interior space? How will you, as a designer balance the desirable natural light with the designed interior space? You will need to have adjustable interior light that can match the natural light in intensity and color. That will require control systems and shading (as mentioned above.)

Now, take a minute to understand what the body needs. (Circadian Supportive Lighting) How can we balance that need and the needs of modern people? Working adults cannot awake at 8:00AM in the winter and still hope to get paid, so we make a sacrifice. What is the task? What type of light will accomplish that? Can it be done with the least possible offense? We introduce lighting into the space that will deliver what is needed in the most respectful way possible.

During the day, our bodies want to absorb as much light as possible, but as people, we need to perform tasks and glare can be a huge deterrent. We might need some glare shields. We might need controls. Applying the points listed above lets us do that.

Unless we are a 19^th century farmer, it is unlikely we will go to sleep at sunset, so a good lighting designer will provide light that allows us to perform any necessary life tasks, while preparing our bodies for sleep, perhaps six hours later. Light, of the right color and delivered in the most amiable way will have minimal impact to our circadian needs.

Understand the circadian needs; add only the light needed to supplement tasks in a way that connects the user to the space; make sure that light is of high quality and add shading and controls to increase its value.

This is new territory for all of us. When I first started in the lighting business, we simply worried about filling all the outlet boxes in the ceiling and walls. As we entered the new millennium we learned about the power of our circadian rhythm and its impact on our life and health. Plants and animals had similar needs. That has complicated things, at the same time we began to adopt a new light type. We are now like the guy on the Ed Sullivan show who balanced a dozen plates on wobbly sticks. Each plate needs attention or the whole act will come tumbling down.