Category: Light + Health

Light Therapy: What Is It, and Does It Work?

MEDICAL NEWS TODAY has published a comprehensive article about light therapy as it’s used to treat acne, wounds, and other skin ailments.

MEDICAL NEWS TODAY has published a comprehensive article about light therapy as it’s used to treat acne, wounds, and other skin ailments.

The principle behind the treatment is that various wavelengths of light can trigger healing processes in human skin.

The article describes applications and efficacy of various types of treatments, along with safety and application considerations.

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FDA Publishes Q&A on Ultraviolet Disinfection

The U.S. Food & Drug Administration (FDA) has published a Q&A about UV energy, forms of which have been demonstrated as effective in destroying SARS-CoV-2, the coronavirus that causes COVID-19.

The U.S. Food & Drug Administration (FDA) has published a Q&A about UV energy, forms of which have been demonstrated as effective in destroying SARS-CoV-2, the coronavirus that causes COVID-19.

The Q&A covers efficacy of disinfection, safety, and FDA and Environmental Protection Agency regulations regarding UV lamps.

Check it out here.

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LRC Issues New Guidance for Implementing Circadian-Effective Lighting in Schools and Hospital Patient Rooms While Minimizing Energy Use

The Lighting Research Center (LRC) at Rensselaer Polytechnic Institute has published new guidance documents for designing circadian-effective lighting in K-12 classrooms and hospital patient rooms while avoiding increased energy use.

The Lighting Research Center (LRC) at Rensselaer Polytechnic Institute has published new guidance documents for designing circadian-effective lighting in K-12 classrooms and hospital patient rooms while avoiding increased energy use.

The guidance documents provide background information and summaries of recent research into the benefits of lighting for circadian entrainment for K-12 students and hospital patients. The primary aim of the publications is to offer guidance for achieving effective, healthy lighting solutions in both applications while limiting increased energy use to the greatest extent possible.

For circadian entrainment and improvements in sleep quality and psychological health, high daytime light levels at the eye are necessary, followed by low evening/nighttime light levels in order to achieve a robust 24-hour light-dark pattern. However, the recommended light levels in K-12 classrooms and for general (non-exam) lighting in hospital patient rooms are generally too low for daytime circadian stimulation. Providing the necessary light levels using design strategies typically intended to deliver illuminance to the horizontal workplane (as opposed to vertical illuminance at the eye) can have the unwanted result of increasing energy use compared to lighting installations designed with only visual performance in mind.

To avoid increased energy use, designers should employ luminaires and luminaire locations that maximize the vertical-to-horizontal illuminance ratio while also avoiding discomfort glare, especially in patient rooms. Designers can also increase the circadian-effectiveness of the overhead lighting by increasing overall light levels to 500 lux on the workplane for at least 2 hours during the daytime and using a CCT of 3500K or higher. The most energy-efficient technique for designers to consider, however, is the addition of a supplemental layer of narrowband short-wavelength (blue) light in conjunction with typical overhead lighting. This method can avoid increasing overall light levels or using very cool CCTs while providing effective circadian lighting and only minimally increasing energy use.

Click here to download these guides.

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Lighting Research Center Releases Report on UV Disinfection Products

The Lighting Research Center (LRC) recently released Lighting Answers: UV Disinfection Products. This online publication includes information on products that produce optical radiation at specific ultraviolet (UV) or very short visible wavelengths, designed for use in disinfecting indoor building surfaces and/or air.

The Lighting Research Center (LRC) recently released Lighting Answers: UV Disinfection Products. This online publication includes information on products that produce optical radiation at specific ultraviolet (UV) or very short visible wavelengths, designed for use in disinfecting indoor building surfaces and/or air.

Three key aspects of UV disinfection are considered throughout the document: product effectiveness, radiation safety, and energy use in buildings.

The publication is organized into a question-and-answer format. Questions were developed based on the results of a survey sent by the LRC to lighting stakeholders in June 2020. Important aspects of UV disinfection discussed in the publication include the wavelengths of optical radiation commonly used for disinfection, key characteristics of UV disinfection products currently on the market, field measurement and assessment of UV disinfection products, and currently available codes and regulations pertaining to these products.

The publication also provides a concise guide for professionals who are considering the specification of UV disinfection products in buildings, including a discussion on selecting the dose of UV radiation needed to inactivate various types of pathogens (viruses, bacteria, or fungi). Finally, the publication includes the results of LRC testing of twelve UV disinfection products, representing a variety of product types.

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LIGHTFAIR Launches Industry Newsletter

LIGHTFAIR recently announced a new digital newsletter, “The future. Illuminated.” Released quarterly, the newsletter presents content from industry thought leaders, product information from show exhibitors, and updates about the annual tradeshow and conference.

LIGHTFAIR recently announced a new digital newsletter, “The future. Illuminated.” Released quarterly, the newsletter presents content from industry thought leaders, product information from show exhibitors, and updates about the annual tradeshow and conference.

The first issue was themed around Lighting and Wellbeing with content by circadian lighting specialists, lighting designers, photo biologists and more. Articles include “The Biology of Light,” demonstrating how light enters and travels inside the human body; “Lighting for the Spectrum,” exploring applying circadian lighting in the homes of children with autism; “Adapting Circadian Science to Circumstance,” discussing the role of client and designer in health-focused lighting; “A Cleaner Ride in NYC,” explaining how the Metropolitan Transportation Authority is using ultraviolet light lamps as disinfectant; and FAQs about GUV applications answered by the IES Photobiology Committee. Deborah Burnett and James Benya also weigh in on the different dimensions of wellness in the “Reflections on Staying Well” series. Finally, the issue spotlights past IALD president and president of CM Kling + Associates David Ghatan and cinematographer turned lighting designer and president of Innovative Lighting Concepts Michael Kershner.

Click here to subscribe free.

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PNNL Studies Energy Impacts of Circadian Lighting

The Pacific Northwest National Laboratory (PNNL) recently published a new report analyzing the energy impact of lighting designs that satisfy three prominent circadian lighting guidelines. The researchers discovered a potentially significant increase in light levels and associated energy consumption.

The Pacific Northwest National Laboratory (PNNL) recently published a new report analyzing the energy impact of lighting designs that satisfy three prominent circadian lighting guidelines. The researchers discovered a potentially significant increase in light levels and associated energy consumption.

An open office and a classroom were modeled, with the luminaire lumen output, spectral power distribution, surface reflectance distribution, and desk orientation varying between the simulations in order to explore the magnitude of the different parameters. The simulations aimed to comply with the design guidelines WELL v2 Q2 2019, UL Design Guideline 24480, and Collaborative for High Performance Schools Core Criteria 3.0. A total of 45 unique simulation conditions were evaluated in the two models.

The researchers determined that meeting current IES light level recommendations did not satisfy existing equivalent melanopic lux and circadian stimulus values for any of the office and classroom circadian lighting recommendations. They found significant increases in indoor light levels and corresponding lighting energy use; in some cases, meeting the circadian metric recommendations required an average illuminance that was more than double the IES recommendations, which may negatively affect lighting quality and increase energy use. Based on the results, the study estimates that lighting energy use may increase by 10% to 100% because of the higher luminaire light levels used to meet the circadian lighting design recommendations listed in current building standards.

Said PNNL:

Further research may show more-efficient ways to meet design recommendations through varied light distribution or optimized spectral characteristics, as well as advanced control systems. Until circadian lighting design metrics and effective delivery of light stimulus are better understood in realistic settings with recognizable health and well-being benefits, the tradeoffs between design recommendations and energy efficiency goals cannot be fully expressed.

Click here to check out the report.

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Top 10 Germicidal UV Lighting Questions Get Answered with LESA Center Director and Rensselaer Lighting Expert Robert Karlicek

As long as the threat and reality of pandemic-level super viruses continue to wreak havoc, the topic of germicidal lighting for indoor disinfection is bound to come up. Before blasting surfaces with ultraviolet (UV) light, however, there are some important things to consider and a few facts.

Guest post by Leah Scott

As long as the threat and reality of pandemic-level super viruses continue to wreak havoc, the topic of germicidal lighting for indoor disinfection is bound to come up. Before blasting surfaces with ultraviolet (UV) light, however, there are some important things to consider and a few facts.

First, viruses cannot really be ‘killed’ by light because they are not really alive, rather they must be deactivated or suppressed. Therapeutics are developed to suppress viruses inside a living host but to truly stop viruses from being transmitted through surface-to-human or airborne cross-contamination, requires a different application. In a recent webinar from the International Association of Lighting Design (IALD), Center director Dr. Robert Karlicek, Jr., explains the process of ‘deactivating’ the RNA or DNA (a protein structure that acts as the organism’s messaging system) of viruses, which can be done by using specific UV irradiation applications.

UVC radiation, which can deactivate viruses, can also be very harmful to living things, not just the ‘bad viruses’ being deactivated. It can also damage surfaces resulting in accelerated degradation of materials such as plastics, wood, or fabrics over a long exposure period. With rapid progress on the development of powerful UVC LEDs, new UVC system form factors, and potential for pulsed operation may offer advantages for UVGI system operation not easily supported by UV lamp technologies, making customized UVGI applications, device power, environmental impact, and lifetime limitations less of an issue.

With the growing interest around coronaviruses (i.e. SARS CoV2 and COVID19), interest in UVGI has also substantially renewed. To address some of the most pressing and common questions, Karlicek answers the top 10 most asked questions around UVGI for germicidal disinfection:

1. Can UVC radiation kill SARS CoV 2?
Yes, several groups have demonstrated that UVC radiation can quickly deactivate the SARS CoV 2 virus that causes COVID-19. To be effective, however, the delivery dose needs to be high enough and the required dose depends on several environmental factors (surface or airborne, relative humidity, and other environmental factors) that impact the delivery of UVC radiation to the virus’ RNA. The higher the dose, the faster the process, and the greater the percentage of virus deactivated.

2. Is 405 nm disinfection technology effective for deactivating viruses (including SARS CoV)?
The short answer is no. While there is some research that shows an effect of 405 nm light (as well as UVA radiation), the mechanism requires the presence of other molecules that absorb at 405 nm or UVA radiation to generate reactive oxygen compounds, that, in turn, attack the virus. It is a slow, concerted process that is not worth considering for virus deactivation systems.

3. Can UVC LEDs be used for germicidal applications?
Absolutely, and there is considerable published evidence for the effectiveness of UVC LEDs in germicidal applications including SARS CoV 2. Also, the output power, reliability and cost-effectiveness of UVC LED solutions are continually improving with continuing research on the design and manufacturing of UVC LEDs. Note that both UVC mercury lamps (254 nm) and UVC LEDs have lifetimes that are considerably shorter than LEDs used in solid-state lighting, so that should be factored into the design of GUV systems using either technology.

4. Is Far UVC (222 nm) effective in deactivating microbes and viruses?
Yes, 222 nm excimer lamps are effective in deactivating microbes and viruses. Like any UVC radiation, the required 222 nm dose for a given desired deactivation will depend on the pathogen and the environmental conditions. (See Question 1)

5. Is Far UVC germicidal radiation safe for humans?
A significant amount of research on 222 nm excimer lamp (so-called Far UVC) disinfection impact on possible damage to animal tissue (skin and eyes) suggests that it may be safe for humans. While this work is encouraging, it is the opinion of some in UV industry groups and several photo-biologists that more research is needed, in particular with long term exposure. The safety argument is simple: at these UVC wavelengths, the radiation cannot penetrate human skin or eyes to cause damage to human DNA. Of course, this presumes that all human skin exposed to 222 nm radiation is intact (not abraded wounded or diseased, etc.). For the time being, it is advisable to use 222 nm systems only when humans are not present.

6. Do UVC sources produce ozone?
Not if properly selected. Some mercury lamps are manufactured specifically for generating ozone by using specialized quartz tubing transparent to radiation below 200 nm, so care must be exercised in selecting mercury lamps for use in UVGI applications that cannot generate ozone, but still emit 254 nm radiation efficiently.

7. How can UVC sources be used safely around people?
So long as humans are not in the direct line for exposure to the UVC radiation there should be no issues. Ordinarily, UVC systems are used only when people are not present or in disinfecting air (either inside of ductwork of HVAC systems or with specially designed optics to irradiate the upper portions of room-air) with little or no radiation to the people below. Some UVC lamps come with presence detection systems that turn off when persons approach, but these systems will have to have very low false-negative error rates (turning on when the system falsely thinks that people are not present).

8. Does UVC radiation damage other materials that it irradiates?
Many types of materials will slowly degrade with extended exposure to UVC materials. The type and extent of damage depend on the materials exposed. If prolonged UVC exposure of interior surfaces in the built environment becomes commonplace, more research on the development of UVC resistant paints, fabrics, carpeting, and furniture surfaces will be needed to ensure an adequate service life of the exposed surfaces.

9. How do you measure UVC irradiance and dose?
UVC irradiance is measured in watts per unit area (typically W/cm2 in the US) and dose is calculated by multiplying the irradiance by the exposure time in seconds to get energy per unit area (typically joules(J)/cm2). Care needs to be used in selecting and using UVC radiometers as they are typically accurate over different ranges of UVC wavelengths, and may or may not accurately measure UVC irradiance coming into the sensor from an angle, and periodic re-calibration of these types of radiometers is important to ensure that adequate germicidal dose.

10. What regulations or agencies regulate the application of UVC sources for germicidal application?
Various agencies have oversight of some aspects of UVGI systems and applications. The FDA’s Q&A report on UVC disinfection is one and also describes when FDA has regulatory responsibilities for UVC devices sold as medical equipment. For UVC devices sold as electronic equipment, regulatory control is less clear.

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Product Monday: UV-C Products by Signify

Signify’s new commercial UV-C disinfection luminaires offer building owners a potential tool for disinfecting air, surfaces, and objects.

Signify‘s new commercial UV-C disinfection luminaires offer building owners a potential tool for disinfecting air, surfaces, and objects.

Alkco germicidal UV luminaires and solutions include indirect, upper-air fixtures to disinfect air, direct UV-C luminaires to disinfect surfaces, and pass-through UV-C chambers to disinfect objects.

The products are designed with a range of safeguards, including a timer option to delay operation until after people and animals are no longer in the vicinity and a sensor that automatically switches the luminaires off if any people or animals are detected.

The effectiveness of Signify’s UV-C light sources on the inactivation of SARS-COV-2, the virus that causes COVID-19, has been validated in laboratory testing conducted at the National Emerging Infectious Diseases Laboratories at Boston University.

Click here to learn more.

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Product Monday: UVC Luminaires by Hubbell

Hubbell Lighting’s SpectraClean 254 expands the company’s SpectraClean portfolio, which launched in 2019 with 405-nm solutions. The portfolio features a series of luminaires that combine visible white with 254-nm UVC energy to meet ambient and task lighting requirements while providing a continuous, unobtrusive disinfection option for commercial applications.

Hubbell Lighting’s SpectraClean 254 expands the company’s SpectraClean portfolio, which launched in 2019 with 405-nm solutions. The portfolio features a series of luminaires that combine visible white with 254-nm UVC energy to meet ambient and task lighting requirements while providing a continuous, unobtrusive disinfection option for commercial applications.

SpectraClean 254 targets the inactivation of airborne viruses, such as SARS-CoV-2 (COVID-19) and influenza.

Click here to learn more.

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Leviton Licenses GE Current’s 365DisInFX UVA Tech

Leviton Lighting recently announced it has entered into a licensing agreement with GE Current to acquire its 365DisInFxTM UVA technology, a new disinfection lighting technology, for incorporation into the company’s lighting portfolio. The patented technology can help to disinfect surfaces in occupied spaces, with immediate applications in healthcare, commercial, and educational facilities via Leviton Lighting & Controls luminaires.

Leviton Lighting recently announced it has entered into a licensing agreement with GE Current to acquire its 365DisInFxTM UVA technology, a new disinfection lighting technology, for incorporation into the company’s lighting portfolio. The patented technology can help to disinfect surfaces in occupied spaces, with immediate applications in healthcare, commercial, and educational facilities via Leviton Lighting & Controls luminaires.

Current’s 365DisInFx UVA technology uses UV-A LEDs to reduce the potential spread of certain common infection-causing pathogens in virtually any space. This allows for spaces to be disinfected in real time while occupants are present. The UVA light emitted from the luminaire is invisible to the human eye. When installed and used as directed, luminaires incorporating this disinfection technology are designed to meet IEC photobiological safety standard 62471.

365DisInFX UVA technology works by delivering light in the 300nm spectrum that excites certain molecules found inside microbes. This excitation causes reactions that result in oxidative cell damage to pathogens, rendering them inactive. This patented technology has been demonstrated as being effective against common pathogens, including Staphylococcus aureus (including MRSA), Enterococcus faecalis, Escherichia coli, Acintobacter baumannii, Pseudomonas aeruginosa, and Candida albicans and aurias, as well as on pathogen analogs such as bacteriophage MS2.

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