Improving Occupant Health with Ultraviolet Light

IMPROVING OCCUPANT HEALTH WITH ULTRAVIOLET LIGHT Healthy Materials Lab + MFA Lighting Design at Parsons School of Design

Acknowledgments Project Team Parsons Healthy Materials Lab MFA Lighting Design at Parsons School of Design Research & Publication Team Healthy Materials Lab Parsons School of Design The New School New York, NY Director, Alison Mears AIA, LEED AP Director of Design, Jonsara Ruth ASID, IIDA MFA Lighting Design Director, Craig Bernecker Industry Partners The Lighting Quotient Tambient Research Fellows Meryl Smith Katrina Matejcik Hana Wilson

February 2022

Content 1

Introduction 5

2

Viral Transmission 6

3

Viruses + Bacteria Beyond COVID-19

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UVGI Technology 8 History How it works Applications

Human Health + Safety 12 Material Health 14 Healthier Cleaning Protocols 15 5

Conclusion 16

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Glossary 17

7

References 19

Improving Occupant Health with Ultraviolet Light

Fig 1.1 Potential of Upper-Air UV-C Treatement Illustrated

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1/ Introduction

In June 2020, just months after the emergence of COVID-19, Parsons’ Healthy Materials Lab (HML) and the MFA Lighting Design program began collaborating on research and testing of lighting technology and practices that can reduce the spread of harmful viruses and bacteria.

ight fixtures already exist in every room. What if they could keep us healthy and safe, while providing illumination

Before the pandemic, indoor spaces were not typically seen as a threat to our health, but now the necessity for clean air in shared public spaces is more evident than ever. This research project explores the application of ultraviolet germicidal irradiation particularly for the treatment of upper-room air, with the aim of occupying shared spaces safely again.

The goal is to generate the most effective means of integrating this technology with architectural lighting in a sustainable, safe, non-intrusive, and affordable way. At HML, we aspire to make spaces healthier and safe for all occupants, including those on our own campus, in affordable housing, and beyond.

Here we share our collected key findings in regards to using UV-C light and Ultraviolet Germicidal Irradiation (UVGI) to improve occupant health across different types of spaces and various applications. This technology can be utilized to disinfect air, water and surfaces and shows true potential in mitigating potential dangers to occupants.

Glossary Terms Coronavirus: A family of related viruses. Many of them cause respiratory illnesses. COVID-19: The name of the illness caused by the coronavirus SARS-CoV-2. COVID-19 stands for “coronavirus disease 2019” UVC: refers to the band of UV light between 100nm and 280nm UVGI: Ultraviolet Germicidal Irradiation, a common process used to control the spread of dangerous microbes

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Improving Occupant Health with Ultraviolet Light

2/ Viral Transmission

When researching the possibilities of UV-C, it is important to first understand how viruses and bacteria are transmitted in order to target what type of application is best for each setting.

Viruses can be transferred by short or long-range airborne transmission and also the downstream settling of such droplets onto surfaces. Aerosols are very small droplets that are suspended in the air after fluids emitted are evaporated.

Aerosols are responsible for airborne transmission (inhalation).

Droplets that are larger will fall to the ground or surfaces before they evaporate and are responsible for local spread (touching an infected surface or being in contact with the source). According to the CDC, the risk of becoming infected with COVID-19 through contact with contaminated surfaces is possible, but is considered to be low. 1

ing to the Ultraviolet Light Disinfection Data Sheet by ChlorDiSys, viruses such as Polio, Parvo, Influenza, Hepatitis A and Staphylococcus, as well as bacteria such as various Salmonellas, Mycobacterium Tuberculosis and MRSA, showed a reduction in presence after exposure to doses of UV-C.

Viruses + Bacteria Beyond COVID-19 Looking beyond the era of COVID19, UV-C light can be used to inactivate various types of viruses, bacterias, molds and spores that can be harmful to human health. Different viruses and bacteria require different doses of UV-C irradiation to inactivate them. Accord1 https://www.cdc.gov/coronavirus/2019ncov/more/science-and-research/surfacetransmission.html

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Glossary Terms Bacteria: a member of a large group of unicellular microorganisms which have cell walls but lack organelles and an organized nucleus, including some which can cause disease Virus: an infective agent that typically consists of a nucleic acid molecule in a protein coat, is too small to be seen by light microscopy, and is able to multiply only within the living cells of a host

Fig 2.1 Types of Transmission Adapated from: Raymond Tellier, Yuguo Li, Benjamin J. Cowling & Julian W. Tang “Recognition of aerosol transmission of infectious agents: a commentary” 2019

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Improving Occupant Health with Ultraviolet Light

3/ UVGI Technology

UV-C refers to the range of Ultraviolet light with wavelengths between 200 nm and 280 nm. UVGI (Ultraviolet Germicidal Irradiation) refers to applying UV-C for germicidal proposes to inactivate viruses and harmful bacteria. UV-C radiation is the most effective for germicidal systems. UV-A, UV-B and low energy 405 nm radiation have some germicidal and antibacterial properties, but are not as effective as UV-C. Ultraviolet Germicidal Irradiation (UVGI) is most effective using a wavelength of 254 nm.

254nm: peak germicidal effectiveness, exposure unsafe for humans

222nm: far UV-C wavelength is also effective, it is potentially safe for human exposure

Fig 3.1 Light Spectrum Diagram Source: Sterilray “Skin Safety” 2019, https://sterilray.com/skin-safety/

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History of UV-C The study of ultraviolets light effects on different microorganisms dates back to the 1800s, beginning with the study of sunlight itself. Ultraviolet wavelengths that penetrate our earth’s atmosphere from the sun are in the UV-A range.

Studies specifically involving UV-C and isolating a specific range of UVGI began in the early 1900s. Today, further advancements, applications and regulation of this technology are still being tested.

Since the 1870s ultraviolet light has been known to inactivate microorganisms.

How can UV-C be best used to inactivate viruses, specifically SARS-CoV-2 without harming our health or indoor environments?

UV-C for Germicidal Irradiation Timeline 1855 Arloing and Daclaux demonstrated sunlight killed Bacillus anthracis and Tyrothrix scaber 1877 Downes and Blunt reported bacteria were inactivated by sunlight – violet blue spectrum most effective 1889 Widmark confirmed UV rays from arc lamps were responsible for inactivation 1892 Geisler used a prism and heliostat to show sunlight and electric arc lamps are lethal to Bacillus Typhosus 1903 Banard and Morgan determined UV spectrum 226-328 nm is biocidal 1932 Ehris and Noethling isolated biocidal spectrum to 253.7 nm 1957 Riley proves effectiveness for Tb control 1994 CDC acknowledges UV effectiveness for Tb control 1999 WHO recommends UVGI for Tb control 2014 UV-C used as part of the terminal cleaning procedure within the Nebraska Biocontainment Unit upon ebola patient discharge 2020 UV-C Disinfection recommended for the disinfection of N95 masks and other PPE during SARS-CoV-2 pandemic.

Fig 3.2 Historical Timeline of UV-C and UVGI Source: ClorDisys “Ultraviolet Light Disinfection Data Sheet” 2020

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How it Works

Improving Occupant Health with Ultraviolet Light

The range of UV light detailed on the previous pages is absorbed into the DNA and RNA of bacteria, viruses, molds, etc.

This process changes the structure of the DNA and RNA, inactivating the microorganism by preventing the cells from replicating. If cells within microorganisms cannot replicate, the virus and bacteria cannot grow to a level that is infectious.

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Air, water, surfaces, and objects can be disinfected using this technology. UVGI can be used submerged in water to kill harmful viruses and bacteria that live in water. Portable units can be moved around to disinfect different surfaces in a room. Sterilizing Cabinets can be used to disinfect small objects such as cellphones or PPE (Personal Protective Equipment) such as masks. And, it can be incorporated into a building’s HVAC (Heating, Ventilation and Air Conditioning) systems to disinfect air, recirculate the clean air into spaces and reduce airborne pathogens.

Applications in Occupiable Spaces When treating an occupiable room or space with UVGI, it is important to review the various types of fixtures and applications as some are unsafe to use when people are in the space. For example, general direct treatment of a room would include light fixtures that face down from the ceiling, however, this is unsafe for human occupancy. Additionally, the moveable approach using portable fixtures is also unsafe for occupancy. If you were to use indirect uplight fixtures or fixtures incorporated into the HVAC system, it is safe for occupants to be in the room because they will not be directly exposed to the UV-C light waves.

Fig 3.3 What can be disinfected using Ultraviolet Germicidal Light?

Glossary Terms DNA: a self-replicating material that is present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information RNA: ribonucleic acid, a nucleic acid present in all living cells. Its principal role is to act as a messenger carrying instructions from DNA for controlling the synthesis of proteins, although in some viruses RNA rather than DNA carries the genetic information

Fig 3.4 Applications for Occupliable Spaces Adapated from: ARUP, “Applications of UV-C for Biodisinfection.” September 2020

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Improving Occupant Health with Ultraviolet Light

4/ Human Health + Safety

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Care needs to be taken when installing and utilizing these wavelengths of ultraviolet light. Direct exposure to UV-C radiation can result in a burning sensation in the eyes that one can compare to sunburn and reddening of the skin.

Sensors and timers are not always reliable for preventing direct exposure to UV-C. In an accident exposure case, 90 minutes of direct exposure caused 76% of occupants to experience eye and skin irritation symptoms. 1 A study conducted from 1997 to 2004 found that careful application of upperroom UVGI can be achieved without an apparent increase in the incidence of the most common side effects of accidental UV overexposure.2 An additional study found that when the entire upper volume of the room (above 6.5 feet) is flooded with high intensity UV-C irradiation, occupants will not be at risk for a high dose of exposure. 3

1 Trevisan, Andrea & Piovesan, Stefano & Leonardi, Andrea & Bertocco, Matteo & Nicolosi, Piergiorgio & Pelizzo, Maria Guglielmina & Angelini, Annalisa. (2006). Unusual High Exposure to Ultraviolet-C Radiation.

2 Nardell, Edward A et al. “Safety of upperroom ultraviolet germicidal air disinfection for room occupants: results from the Tuberculosis Ultraviolet Shelter Study.” Public health reports (Washington, D.C. : 1974) vol. 123,1 (2008): 52-60. doi:10.1177/003335490812300108 3 Melvin W. First, Robert A. Weker, Shojiro Yasui & Edward A. Nardell (2005) Monitoring Human Exposures to Upper-Room Germicidal Ultraviolet Irradiation, Journal of Occupational and Environmental Hygiene, 2:5, 285-292, DOI: 10.1080/15459620590952224

Therefore, ceiling and wall mounted UV-C Upper Air Treatment fixtures are low-risk and safe for occupants when installed correctly. These fixtures are mounted far above the head heights of occupants and the light shines up toward the ceiling so that occupants will not be directly exposed.

Accidental direct exposure to UV light can cause skin and eye irritations. Studies about long term effects on human health are limited. We are researching and testing how to best use this technology to make indoor spaces healthier while avoiding harm to human health and material health.

Fig 4.1 UV-C Absorption and Penetration depths of Eyes and Skin after exposure

Fig 4.2 Mounting height diagram for Constant Indirect Uplight Fixtures

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Improving Occupant Health with Ultraviolet Light

Material Health + Exposure

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Materials found in spaces also have reactions when exposed to UV-C. Metals and ceramics are unaffected due to their tightly packed atoms.1 However, the reflectivity of certain metals needs to be considered when using UV-C. Wood is only affected on the surface level, its structure is not affected. Due to the make-up of its surface, UV-C can only penetrate 80 micrometers into wood.2 Glass may see some discoloration also known as solarization. Polymers or plastics are far more susceptible to be damaged by UV-C exposure. UV-C can break the long chains of molecules of which plastics are made. The breaking of these changes causes the degradation of polymers and can off-gas toxic by-prod-

ucts into the surrounding environment, which can be harmful to humans. In addition, when bonds are directly broken, they can release chemicals into the air such as formaldehyde and ethyl alcohol, which are both listed as probable human carcinogens.3

1 Chris Rockett, UV Solutions Mag, UV Degradation Effects in Materials – An Elementary Overview, 2019 2 David N.-S. Hon,Shang-Tzen Chang, Surface degradation of wood by ultraviolet light, 1984

3 Kauffman, R.E. & Wolf, J.D. Study of the degradation of typical HVAC materials, filters, and components irradiated by UVC energy - Part 3: Manufactured components. ASHRAE Transactions. 2013

In conclusion, it is hard to say precisely how UV-C radiation will affect different materials. Materials are often only tested for resistance to UV-A and UV-B (sun damage) since UV-C does not penetrate the Earth’s atmosphere.

Generally speaking, UV-C can only penetrate through a small portion of the surface, so any defect will be superficial and not structural.

Sample

Overall Damage

Polypropylene

Minor

Polyethylene

Minor

Polytetrafluoroethylene

Moderate

Clear polymethyl methacrylate

Moderate

Polyoxymethylene

Moderate

Polyester

Moderate

Polycarbonate

High

Nylon

High

Acrylonitrile butadiene styrene

High

White polymethyl methacrylate

High

Figure 4.3 Risks of damage to plastics when exposed to UV-C Source: chart adopted from Peter Teska, UV Solutions Mag, Risks of Surface Damage to Polymeric (Plastic) Surfaces from UV-C Exposure, 2020

Healthier Cleaning Protocols Using UVGI is a residue-free form of disinfection. It is important to note the difference between disinfecting and cleansing.

Disinfecting is the killing of germs on a surface or in the air, and cleansing means the actual removal of germs, dirt and impurities. UVGI can effectively disinfect surfaces but it mustn’t replace manual cleaning. A two step method is suggested which includes using a solvent product to clean/cleanse to take away excess dust, dirt, and deactivated particles on the surface.1 Healthier cleaning options can replace harmful solvents.

Sales of aerosol disinfectant sprays have increased by 385% and hand sanitizer by 600% since the start of the COVID-19 pandemic (Nielsen, March 2020).

UVGI disinfection can be a safer, healthier alternative to harmful solvents and aerosol disinfectants.

The EPA (Environmental Protection Agency) has a list of bleach and ammonium-free alternatives which are not as harmful to human health. Healthier alternatives to harmful solvents that are effective against COVID-19 include: 2 • Hydrogen Peroxide based disinfectants such as Sani-HyPerCide Germicidal Disposable Wipes • Lonza LLC and CURoxide • Citric Acid based disinfectants such as Arm & Hammer Essentials™ Disinfecting Wipes • LEXX™ Liquid Sanitizer, Cleaner Concentrate and CleanCide Wipes • Lactic Acid based options such as Fangio, Gurney and CleanCide Wipes

1 Casini, Beatrice et al. “Evaluation of an Ultraviolet C (UVC) Light-Emitting Device for Disinfection of High Touch Surfaces in Hospital Critical Areas.”

International journal of environmental research and public health vol. 16,19 3572. 24 Sep. 2019, doi:10.3390/ ijerph16193572 2 EPA, Disinfectants for Coronavirus (COVID-19) Glossary Terms Cleaning/Cleansing: Refers to the removal of germs, dirt, and impurities from surfaces. It does not kill germs, but by removing them, it lowers their numbers and the risk of spreading infection Disinfection: This process does not necessarily clean dirty surfaces or remove germs, but by killing germs on a surface after cleaning, it can further lower the risk of spreading infection

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5/ Conclusion

Improving Occupant Health with Ultraviolet Light

UVGI can be used to reduce the spread of airborne viruses and bacteria in indoor environments. We are testing how this technology can utilize existing light fixtures in schools and other public spaces like the hallways of public housing developments.

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Many commonly used disinfectants include antimicrobials, which is a group of chemicals that are associated with developmental, hormonal, and reproductive problems. UVGI could be a healthier option.

UVGI uses specific wavelengths of non-visible ultraviolet light to inactivate viruses and bacteria. Healthcare facilities often use UVGI to sanitize both air and surfaces. However, accidental exposure to specific wavelengths of ultraviolet light can cause eye and skin irritations. UVGI can safely reduce viral transmission by orienting the fixtures towards the ceiling and carefully designing the controls.

As people occupy the room, thermal plumes from body heat and/or air flow from ventilation devices such as fans or an open window, will carry exhaled air upwards to the fixtures, where it will be treated by exposure to Upper-Air UVGI. Then the disinfected air can safely return to the lower, occupied portion of the room.

At the onset of the pandemic, we wondered how this technology could be used in a wider variety of spaces, including our own school. MFA Lighting Design Director and Professor Craig Bernecker, is testing light fixtures to determine the feasibility and safety of using them on The New School campus. The integration of UVGI technology with architectural lighting sparks interest in what this could mean beyond our own institution’s walls. Could this be a safe and simple way to keep the air clean in other densely occupied spaces such as community spaces and housing developments?

6/ Glossary

Aerosols: particles in suspension in a gas, such as small droplets in air. Also include ‘droplet nuclei’ which are small particles with an aerodynamic diameter of 10 nm or less, typically produced through the process of rapid desiccation of exhaled respiratory droplets.

Airborne transmission: is defined as the spread of an infectious agent caused by the dissemination of droplet nuclei (aerosols) that remain infectious when suspended in air over long distances and time.

Bacteria: a member of a large group of unicellular microorganisms which have cell walls but lack organelles and an organized nucleus, including some which can cause disease.

Cleaning/Cleansing: refers to the removal of germs, dirt, and impurities from surfaces. It does not kill germs, but by removing them, it lowers their numbers and the risk of spreading infection.

Coronavirus: a family of related viruses.

Many of them cause respiratory illnesses. Coronaviruses cause COVID-19, SARS, MERS, and some strains of influenza, or flu. The coronavirus that causes COVID-19 is officially called SARS-CoV-2, which stands for severe acute respiratory syndrome coronavirus 2.1 COVID-19: the name of the illness caused by the coronavirus SARS-CoV-2.

COVID-19 stands for “coronavirus disease 2019.”2

1 “Coronaviruses.” National Institute of Allergy and Infectious Diseases, U.S. Department of Health and Human Services, https://www.niaid.nih. gov/diseases-conditions/coronaviruses.

2 “Coronavirus.” World Health Organization, World Health Organization, https://www.who.int/ health-topics/coronavirus#tab=tab_1.

Disinfection: this process does not necessarily clean dirty surfaces or remove germs, but by killing germs on a surface after cleaning, it can further lower the risk of spreading infection.

Droplet nuclei (aerosols): airborne particles formed from evaporation of fluids emitted from infected hosts when they cough, sneeze, or talk, containing bacteria or viruses able to transmit disease from person to person. Droplet nuclei generally have an aerodynamic diameter less than 5 nm, which allows them to remain suspended in air for long periods; thus, they can be carried on normal air currents in a room and beyond to adjacent spaces. When inhaled, droplet nuclei can penetrate into the alveolar region of the lung.

DNA: a self-replicating material that is present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information.

Erythema: reddening of the skin, with or without inflammation, caused by the actinic effect of solar radiation or artificial optical radiation.

Exposure: being subjected to something (e.g., infectous agents, irradiation, particulates, and/or chemicals) that could have harmful effects. For example, a person exposed to M. tuberculosis does not necessarily become infected.

Far UV-C: light generated by filtered excimer lamps emitting in the 207 to 222 nm wavelength range.3

3 Buonanno, M., Welch, D., Shuryak, I. et al. Far-UVC light (222 nm) efficiently and safely inactivates airborne human coronaviruses. Sci Rep 10, 10285 (2020). https://doi.org/10.1038/s41598-02067211-2

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Improving Occupant Health with Ultraviolet Light

Glossary Continued

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Fomite: objects or materials which are likely to carry infection, such as clothes, utensils, and furniture.

Germicidal: capable of killing or inactivating microorganisms.

Microorganisms: a microscopic organism, especially a bacterium, virus, or fungus.

RNA: ribonucleic acid, a nucleic acid present in all living cells. Its principal role is to act as a messenger carrying instructions from DNA for controlling the synthesis of proteins, although in some viruses RNA rather than DNA carries the genetic information.

Natural Ventilation: occurs when the air in a space is changed with outdoor air without the use of mechanical systems, such as a fan.

Personal Protective Equipment (PPE): protective clothing, helmets, goggles, respirators, or other gear designed to protect the wearer from injury from a given hazard, typically used for occupational safety and health purposes.

Photokeratitis: corneal inflammation after overexposure to ultraviolet radiation.

UVC: refers to the band of UV light between 100 nm and 280 nm.

UVGI: Ultraviolet Germicidal Irradiation, applying UV-C for germicidal proposes to inactivate viruses and harmful bacteria.4 Ventilation: the process of changing or replacing air in any space to remove moisture, odors, smoke, heat, dust, and airborne contaminants. Ventilation includes both the exchange of air to the

4 “Upper-Room Ultraviolet Germicidal Irradiation (UVGI).” Centers for Disease Control and Prevention, https://www.cdc.gov/ coronavirus/2019-ncov/community/ventilation/uvgi. html#anchor_1617895084369.

outside as well as circulation of air within the building.

Virus: any of a large group of submicroscopic infectious agents that are usually regarded as non living extremely complex molecules, that typically contain a protein coat surrounding an RNA or DNA core of genetic material but no semipermeable membrane, that are capable of growth and multiplication only in living cells, and that cause various important diseases in humans, animals, and plants, the causative agent of an infectious disease.

Wavelength: distance between repeating units of a wave pattern.

7/ References

Buonanno, M., Welch, D., Shuryak, I. et al. Far-UVC light (222 nm) efficiently and safely inactivates airborne human coronaviruses. Sci Rep 10, 10285 (2020). https://doi.org/10.1038/s41598-02067211-2 Cleaning and disinfecting - beta.epa. gov. (n.d.), https://beta.epa.gov/sites/ default/files/2021-04/documents/cleaning-disinfecting-one-pager.pdf.

First, Melvin W., Weker, Robert A., Yasui, Shojiro., Nardell, Edward A. (2005) Monitoring Human Exposures to UpperRoom Germicidal Ultraviolet Irradiation, Journal of Occupational and Environmental Hygiene, 2:5, 285-292, DOI: 10.1080/15459620590952224 Illuminating Engineering Society. (n.d.). https://media.ies.org/docs/standards/ IES-CR-2-20-V1-6d.pdf.

Kauffman, R.E. & Wolf, J.D.. (2013). Study of the degradation of typical HVAC materials, filters, and components irradiated

by UVC energy - Part 3: Manufactured components. ASHRAE Transactions. 119.

203-213.

Nardell, Edward A et al. “Safety of upperroom ultraviolet germicidal air disinfection for room occupants: results from the Tuberculosis Ultraviolet Shelter Study.” Public health reports (Washington, D.C. : 1974) vol. 123,1 (2008): 52-60. doi:10.1177/003335490812300108 Raeiszadeh, Milad. & Adeli, Babak. ACS Photonics (2020) A Critical Review on Ultraviolet Disinfection Systems against COVID-19 Outbreak: Applicability,

Validation, and Safety Considerations (11), 2941-2951 DOI: 10.1021/acsphotonics.0c01245 Rockett, Chris. (2020, March 5). UV degradation effects in materials – an elementary overview “ Uv solutions.

UV Solutions. https://uvsolutionsmag. com/articles/2019/uv-degradation-effects-in-materials-an-elementary-overview/.

Skin safety - far-UV sterilray™. Far-UV Sterilray™. (2021, August 8). https://sterilray.com/skin-safety/.

Tellier, R., Li, Y., Cowling, B. J., & Tang, J. W. (2019). Recognition of aerosol transmission of infectious agents: A commentary.

BMC Infectious Diseases, 19(1). https:// doi.org/10.1186/s12879-019-3707-y Teska, Peter. (2020, June 9). Risks of surface damage to polymeric (plastic) surfaces from UV-C exposure “ UV solutions. UV Solutions. https://uvsolutionsmag.com/articles/2020/risks-ofsurface-damage-to-polymeric-plasticsurfaces-from-uv-c-exposure/.

Trevisan, Andrea & Piovesan, Stefano & Leonardi, Andrea & Bertocco, Matteo & Nicolosi, Piergiorgio & Pelizzo, Maria Guglielmina & Angelini, Annalisa. (2006).

Unusual High Exposure to Ultraviolet-C Radiation.

Ultraviolet light disinfection data sheet . ClorDiSys. (2020, December). https:// www.clordisys.com/pdfs/misc/ UV%20Data%20Sheet.pdf.

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