People not immune to health impact of LEDs, according to the AMA | EDN–according-to-the-AMA?_mc=sm_edn&hootPostID=de10415dc860da5de122a6a05f70f7c3

High power led lights have health effects to us.


  1. Tomi Engdahl says:

    Blue LED Streetlights Keeping You Awake?

    If you’ve played around with “white” LEDs, you already know that there’s no such thing. There’s warm white and cool white and any numbers of whites in-between. And when white LEDs were new, the bluer “cool white” variety were significantly more prevalent.

    Enough US states have swapped out their old street lights with LEDs that it may be having a measurable effect on people and on the animals around us. This is the claim in a recent position paper by the American Medical Association’s Council on Science and Public Health.

    Science strongly suggests that heavy doses of light can keep people from falling asleep, and that brighter LED streetlamps may be making the problem worse.

    Blue light additionally diffracts funny in your eyeball
    Add together tired drivers and glare-inducing streetlights

    The benefits of LED lighting are huge, however.

  2. Tomi Engdahl says:

    LightingEurope and IALD issue position paper on human-centric lighting

    Seeking both to ensure a unified understanding of the meaning of human-centric lighting or HCL and guide deployment, LightingEurope and the International Association of Lighting Designers have defined expected benefits, typical enabling technologies, and potential applications.

    The position paper opens by noting that HCL should deliver some combination of “excellent visual, biological, and emotional effects of light.” The CIE (International Commission on Illumination) is advocating similar concepts for what it calls integrative lighting.

    Visual benefits are fairly well understood at this point. The position paper defines biological benefits as alertness, cognitive performance, and good sleep-wake cycles among others. Examples of emotional benefits might be an improved mood or impulse control.

    The position paper on human-centric lighting describes the natural cycle of light effects on the human body’s internal clock, and gives examples of how to mimic that cycle with electric light.

    The document states, “Human Centric Lighting is aimed at providing the right light for our activities at the right place at the right time.”

    Human-centric lighting illuminates the possibilities for wellbeing

    HCL’s first frontier: Hospitals

    There is perhaps no environment more immediately suited to HCL than hospitals. It stands to reason that patients would rest better if bright lights didn’t keep them awake at night. And that they would simply feel better if poorly-lit wards and rooms didn’t induce a general fogginess. Better still if tunable lights mimicked the shifting pattern of sunlight for a strong daytime semblance. To take all of that to a logical conclusion: Patients who rest and feel better surely must recover faster.

    Moeslund and Langhorn look after patients who have suffered brain traumas from car accidents, falls, strokes, aneurysms, and other conditions. According to the two nurses, the system, provided by Danish circadian and ergonomic lighting specialists at Chromaviso, appears to be having the desired effect.

    Prior to installing the Chromaviso lighting and control system, patients would typically sleep fitfully and were disoriented, often not knowing what time of day or night it was, Moeslund noted.

    But that is now changing. Moeslund recalls how one patient, benefitting from the Chromaviso lighting system, slept so soundly that the staff could not wake him at 6 a.m. for a scheduled check. “But after the lights started slowly turning on at 6:30, he woke up,” she recalled

    “The light itself is not healing, but it improves what you would expect as basic human functions,” Skov Hansen said. “It’s like walking – entrainment to day and night is one of the basic functions we have. We need sleep each and every night, and we need it in constant occurrence. And it is light that is the main entraining factor. The main source to synchronization is the light and the daily pattern of light and darkness.”

    Blue days, dark nights

    Lighting-based circadian entrainment works in many ways. Much of it is related to coordinating artificial light’s intensity and spectral makeup (the varying blends of blue, red, green, and other wavelengths that combine to form different color temperatures of white light) throughout the day to a pattern that follows the sun’s time-honored daily routine of a spring-like day. For millions of years, the sun has delivered an increasingly blue-rich icy white color through its peak hours of brightness. It shifts toward warmer reds and ambers as it moves toward sunset.

    Blue enriched light stimulates the circadian rhythm, also known as the body clock.

    Circadian lighting systems administer light that follows the gradual shift from invigorating, intense blue-rich white down to relaxing reds and oranges in the evening. The red and orange facilitate the flow of the sleep-promoting hormone melatonin. Too intense blue-rich light in the evening and night would disturb the production cycle of melatonin and thereby would disturb sleep.

    On the Kelvin (K) temperature scale, the cool blue-rich whites counterintuitively have higher numbers, measuring around 5000K, 6000K, or more. Warm, reddish whites have lower numbers. Conventional incandescent lamps, considered warm, are associated with 2700K or lower.

    LED circadian lighting system will soar to the Space Station

    What better place, then, to set up a living laboratory of LED-based circadian lighting than the Space Station? That’s exactly what Brainard and his colleagues from Harvard University and NASA’s Johnson Space Center are doing.

    They’ve developed a system of tunable LED lights that have three basic settings: general vision for most of the day, circadian phase shifting/acute alerting when required, and a pre-sleep setting to induce restfulness.

  3. Tomi Engdahl says:

    European lighting regulations could help usher in human-centric lighting (MAGAZINE)

    European regulators may have a play in delivering the Holy Grail of lighting for health and wellbeing. A simple directive or two mandating Internet connections may be all that it takes for now.

    As charted by Brussels-based industry association LightingEurope, HCL will emerge as the top business force in a few years’ time, and will continue to gain prominence after that (Fig. 1).

    Human-centric lighting represents a big part of a necessary sea change in the lighting industry business model, and one that could help ensure a future for the 1000+ companies, 100,000+ jobs, and €20 billion of yearly revenue of LightingEurope member companies, including 33 manufacturers. Everyone knows that the century-old business model of selling replacement incandescent bulbs is falling apart now that LED lamps have become commonplace and are expected to last for a decade or three. In its place, says LightingEurope, bring on the HCL.

    The general idea is that lights will adjust their on/off, brightness, colors, and color temperatures to levels that optimize any particular setting. A schoolroom, hospital ward, or open-plan office might emphasize blue hues during the morning to stimulate alertness; reds and oranges might take over in appropriate settings in the evening for a calming effect. Brightness levels might increase in a public place when more visually-challenged senior citizens than better-sighted teenagers are present. And so on.

    HCL systems are already taking hold in hospitals and healthcare settings, and will slowly work their way into the workplace.

    Consider, for a moment, that HCL aside, the industry is for other reasons already counting on selling the products, systems, and services that make it operational, and that support a profitable business model. As such, lighting infrastructure will morph into an information technology scheme. It will be full of sensors that detect things like human presence, motion, and natural light. Lights will connect both wirelessly and through Ethernet cable to phones, gadgets, and central control computers.

    But for the most part, today’s intelligent lighting schemes focus on energy savings and on data collection to help facilities managers make better use of their property and help retailers spot shopping trends and engage with customers.

    With that in mind, LightingEurope is squarely engaged in two European Commission (EC) initiatives that could ultimately help establish IT systems as an integral aspect of lighting. Both concern themselves not with HCL per se but with energy savings.

  4. Tomi Engdahl says:

    How LEDs are eliminating mistakes in the operating room (MAGAZINE)

    Light, liver, and the pursuit of happiness: Surgeons in Scandinavia swear that Chromaviso’s tunable color system helps them see better, improves results, and sends everyone home in a better frame of mind, as MARK HALPER discovers.

    One word that no one wants to hear in the operating room is “mistake.” Yet, like anyone else, surgeons have good days in the office and they have bad ones. If they can’t see inside their patients properly, for example, slip-ups can happen. Ouch.

    Moral of the story: Make sure the lighting is good.

    Interested in articles & announcements on human-centric lighting and tunable lighting?

    That is exactly what is happening across Scandinavia and other Nordic countries, where some 90 hospitals have modernized more than 500 endoscopic and related surgery and examination rooms with tunable, colored LED lighting. Doctors, nurses, and clinicians swear it has not only improved their ability to see anatomical details, but that it has also boosted their alertness and reduced their stress levels.

    To make the computer screens easier to see in these minimally invasive procedures, hospitals typically turn the lighting way down in endoscopic procedure rooms, unlike the bright white light associated with open body surgery. The low light levels can induce drowsiness – not a desirable attribute for getting the job done. It can make instruments hard to find. And even the little amount of room lighting that is used can cause glare and reflection on the video display.

    To make a long story short: Durup approached a couple of lighting specialists who in 2006 would go on to found a company called Chromaviso and develop a system of tunable, colored LED room lighting to address these shortcomings.

    Chromaviso, based in Aarhus, Denmark, is the company that has supplied the 90 sites. Today, it promotes the system with the tagline, “Better screen, less fatigue, fewer mistakes.”

    Zoning in

    The system, called Chromaviso Ergonomic Lighting, emits different light colors and levels in various areas of an operating or examination room, with the aim of improving visibility, increasing staff wakefulness, reducing stress, and calming nerves for doctors, nurses, clinicians, and patients alike

    On the visibility side, for example, it emits green light from behind the screen to reduce reflection and enhance the depth and contrast on the monitor, as well as to help open the surgeon’s pupils. And it shines red light from behind the surgeons to cut down on screen glare (Fig. 3). It provides white light in areas of the room where anesthetists work and where nurses have to find equipment. Chromaviso says that this “zoned” lighting approach is a critical feature of its system.

    “What we have to remember is that when the surgeon is looking at the monitor, he looks at very tiny blown-up details, and he gets very anxious about what he sees and what he does not,” said Chromaviso co-founder Claus Puggaard. “So any white light – natural or artificial – he dims it down or shuts it off.”

    Thus the move to colored, non-glaring, non-reflective lighting. And it’s not just the surgeons who are benefiting.

    Needles and patients and things, oh my

    “When it was dark inside the room, our nurses would have problems finding needles and things, and anesthesiologists would have problems to see their patients, and so on,” Durup said. “So we have different demands, and that’s why we do zoned lighting.”

    While green, red, and white light are common outputs from the Chromaviso system, they are not the only ones. Sometimes other colors are optimal. At Odense, Durup says the hospital often mixes yellow with red to help staff spot blood vessels when they are inserting intravenous tubes. And it tunes behind-screen lighting to violet in order to provide a better view of X-ray and ultrasound screens, which show in shades of gray that green would render more difficult to see

    But it is the common combination of red and green during surgery that can provide an added benefit of relaxing the staff, an effect that Chromaviso’s Puggaard says relates to the complementary nature of red and green wavelengths, which reflect and absorb in a balancing proportion. Other color combinations do not have the same calming influence.

    “You can see a lot of things in the red light, but it also has a psychologically activating function as well,” said Durup. “Where you have working staff, they should not be asleep, but they should be actuated a little bit. Red is the optimal lighting for the background.”

    Odense is also using the warmer light to calm patients as they enter the operating theater, before they are anesthetized. The person arrives to warm amber tones that change once the surgery begins (Fig. 5). If the patient is awake after the surgery, the same warm tones might bathe the room. Afterwards, bright white light shines to assist cleaning.

    The Chromaviso system relies on DMX wiring, which Puggaard says is the best way to provide signal speed and to ensure uptime.

    It all comes at a price of around €20,000 ($21,400) to outfit a standard operating room with a basic package. Extras can push it up to around €40,000 or €50,000 and include things like tie-ins to the building management system, enhanced color mixes, additional zones, and Wi-Fi that allows controls from a tablet. The cost constraints of healthcare systems can sometimes stymie uptake.

  5. Tomi Engdahl says:

    European Union organization says LEDs have no direct adverse health effect

    The European Union Scientific Committee on Health, Environment and Emerging Risks published research stating that there is no health risk for healthy humans to be exposed to LEDs in the normal use of lighting and display products.

    The European Union (EU) Scientific Committee on Health, Environment and Emerging Risks (SCHEER) has published a lengthy draft report entitled “Potential risks to human health of LEDs.” The overall conclusion in the report states. “The Committee concludes that there is no evidence of direct adverse health effects from LEDs in normal use (lighting and displays) by the general healthy population.”

    Of course, there has been a long debate in the lighting sector as to whether the short-wavelength blue energy peak associated with most phosphor-converted white LEDs can pose a risk to the human eye as solid-state lighting (SSL) usurps the lighting market. The US Department of Energy (DOE) has addressed the issue several times.

    The EU had tasked SCHEER with studying the issue exhaustively with the specific direction to evaluate the impact of blue energy on human eyes and skin. The committee determined that typical human exposure to such blue energy from lighting and displays is far lower than exposure safety limits that have been previously established. And the report said the lack of ultraviolet (UV) light in LED sources may reduce the risk humans face from UV in other light sources including the Sun.

    The report does warn of potential issues with LEDs including discomfort and disability glare associated with SSL implementations in auto headlamps and other applications. Those issues are solely present in LEDs. The report also mentions glare related to street lighting but points out that glare has been a problem primarily where lighting design and luminaire selection has favored energy efficiency over quality. In any case, the glare issue is said to have a temporary and not permanent impact on healthy humans.

    The report further concludes that some LED products can have a greater impact on circadian rhythm relative to legacy sources, yet it goes on to say that there is no current evidence that circadian disturbance leads to adverse health effects.


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