By Brian Liebel
I sit writing this article on April 15—normally tax day, but not this year…this year is different. This year, personal interactions and community events have been replaced by meetings on computer screens resembling the Brady Bunch, and “socially distance” has become a verb.1 This year, many in our lighting community face uncertainty. For some, this year will be tragic.
Exactly one month ago, on March 15, 2020, the total number of deaths in the U.S. attributed to COVID-19 was 69. Today, April 15, 2020, that count is 32,443.2 Worldwide, the death counts in the same period jumped from 6,520 to 138,475. It seems unbelievable and surreal, but this is fact, not fiction. I can’t predict how many more people will have passed by the time you read this article; what I do know is that we think differently, act differently, and are sensitized differently than ever before. We ask ourselves, what can we do to help? This is the story of how some of our members are dedicating their time, talents and expertise to reduce the transmission of this disease. By the time you read this, I hope we have made a difference.
The SARS-CoV-2 virus, which causes the COVID-19 disease, is transmitted by breathing in virus-infested air, or by touching surfaces where resting viruses lie and then touching your face. These viruses are like parasites, reproducing by attaching to host cells within your body and then killing them as they use those cells to reproduce more viruses. You might breathe in the virus and be a carrier for several days without symptoms, which means that when you breathe out, you could be spreading the virus without knowing it. Without a cure or vaccine for COVID-19, we are left with one pathway to slow this pandemic: reduce virus transmission, which means protecting ourselves and others by wearing masks, and doing what we can to remove or deactivate viruses when they are suspended in air or resting on surfaces. This is where germicidal ultraviolet (GUV) comes to play; GUV radiant energy damages the DNA or RNA of viruses such that they are effectively neutralized.
While UV radiation is not considered “light,” it is produced by lamps, and this is where IES has the expertise within its committees to address this issue. Ultraviolet is part of the electromagnetic spectrum residing between 100 and 400 nm, whereas visible light is typically between 380 and 780 nm.3 GUV refers to the most efficacious range for virus deactivation, which is the UV-C range, from 200 to 280 nm. Using their expertise, the IES Photobiology Committee and Testing Procedures Committee have taken significant steps during this last month to assess GUV and its possible role in reducing the transmission of the SARS-CoV-2 virus.
The IES Photobiology Committee is responsible for writing standards that consider the biological effects of radiant energy. The committee has considerable knowledge and experience about GUV and its effect on viruses, as well as potential risks for skin and eye damage. The committee ramped up quickly to produce a Committee Report, CR-2-20-V1,4 which is freely available on the IES website and provides over 40 FAQs and safety information on the topic. Dr. David Sliney, the chair of the Photobiology Committee, and Mr. Richard Vincent of the Icahn School of Medicine at Mount Sinai also prepared a webinar, which is posted with the Report. The Report was approved through our ANSI-approved standards development process and is therefore a consensus document. The two main methods for combating viruses described are:
- GUV upper-room disinfection: The use of indirect fixtures (nothing aiming down) to disperse GUV into the upper cavity of a room will cause deactivation of circulating airborne viruses when they reach the upper cavity via natural convection or forced air movement. When designed and maintained properly, this method is safe and highly effective, and is more efficacious than in-duct solutions because the airborne viruses are generated by the humans in the space and therefore deactivated faster.
- GUV surface disinfection: GUV can be a highly effective method for disinfecting surfaces, although it generally considered supplemental to other methods. This is because GUV requires direct line-of-sight to disinfect any surface, and it does not penetrate through materials like dust. GUV robots used in isolated rooms may solve some of these shortcomings. In recognition of its relative effectiveness, the U.S. Center for Disease Control and Prevention (CDC) recently listed this method for decontaminating and reuse of filtering facepiece respirators (FFRs) during this crisis.5
The primary purpose of IES CR-2-20-V1 is to help workers and patients in healthcare facilities who are exposed to this highly contagious virus on an hourly basis. Consider what it is like, spending 12 hours a day knowing that you are essentially taking an “air bath” of coronavirus every minute you are there. While GUV systems don’t guarantee total eradication of the virus, they can reduce the number of active viruses and therefore the probability of transmission. GUV may not be perfect, but it can be a significant help for those who are at such high risk.
The IES Testing Procedures Committee (TPC) is on a separate mission, which is to develop accredited industry standards for testing and reporting UV lamp and fixture output. If you are asking yourself, “does this mean we don’t have accredited standards for that yet?” you are not alone. According to Cameron Miller from the U.S. National Institute of Standards and Technology (NIST), UV technologies are difficult to measure due to many special circumstances, not the least of which have to do with having the correct sensors and environmental controls available to get reliable results. This is because of the potential damage from ultraviolet radiation, and the safety measures necessary to have in place during testing to protect the workers. The TPC is starting with two standards, one for UV LED testing and the other for low-pressure mercury lamp testing. The goal will be to have these standards in place by the end of this year.
Sometimes, nuances of lighting design and research interpretation become long committee discussions that delay the process of consensus. This year is different, and I am thankful to all our committee members and other volunteers for their dedication to helping us move forward during this critical time.
When you read this, check how many more lives have passed since April 15, 2020. This year is different. This year, we must take prompt and decisive action.
2. See Worldometer, https://www.worldometers.info/coronavirus/country/us/. There are several websites that may have different information but the overall trends and impacts reported are consistent.
3. The actual range of visible light varies depending on age and light level.
4. For the complete report and webinar, see: https://www.ies.org/standards/committee-reports/. For the online version of the FAQ, see https://www.ies.
org/standards/committee-reports/ies-committee-report-cr-2-20-faqs/. CR-2-20-V1 will be updated as more questions and answers become available.
5. From the CDC website: https://www.cdc.gov/coronavirus/2019-ncov/hcp/