As vaccines continue to roll out and life starts to get a little more normal, Studio Roosegaarde is releasing a project that could help it stay that way—and maybe mitigate other viruses in the future.
The project, called Urban Sun, is a light fixture designed for public spaces, which the Dutch design firm says can “safely clean up to 99.9% of the coronavirus” by emitting far-UVC light at a specific wavelength (222 nanometers) that early research shows can deactivate viruses without harming humans.
Studio Roosegaarde tested and launched Urban Sun in Rotterdam, The Netherlands, in accordance with that city’s health guidelines, according to Studio Roosegaarde founder Daan Roosegaarde, who said it was also measured and calibrated by the VSL Dutch National Metrology Institute and is supported by Jet Bussemaker, Dutch president of the Council of the Public Health & Society Board. Roosegaarde came up with the idea after reading an article in Nature on how far-UVC light could be safely used to eradicate viruses (in comparison to the standard 254-nanometer wavelength, which is hazardous to humans) in 2019. It has even more importance now that COVID-19 has slammed communities across the globe, but it’s not COVID-19 specific: it will work for all viruses, Roosegaarde says.
The lamp itself is quite simple: both far-UVC and visible light emit from its top, creating a bright yellow cone of light that shines down. The team added the visible light element, which isn’t necessary for the sterilization to work, so passersby have a sense of which area is being sterilized by UVC, which isn’t visible to the human eye. The light, which hasn’t yet been permanently installed, is meant for large public spaces and is elevated between between 35 and 115 feet off the ground depending on location. That enables the UV light to be as large as 125 feet in diameter. It reduces the presence of coronavirus within that area by up to 99.9% within about three minutes, according to the studio. Each design would be site specific, in order to account for things like wind and the flow of people.
Ultraviolet light has long been used as a sterilizer, banishing harmful viral particles from surfaces and from HVAC systems to disinfect air. It’s also worth noting that there are a few different kinds of ultraviolet light: UVA, UVB, and UVC. (You come into contact with UVA and UVB rays from the sun.) UVC is generally damaging to human tissue, but Urban Sun’s technology is based in part on research from Columbia University, which suggests that the 222-nanometer UVC lightwaves are safe for human exposure. The project also drew on research from the American Journal of Infection Control, which notes the disinfectant properties of 222 nanometer UVC lightwaves.
Roosegaarde says Urban Sun was also designed in collaboration with hundreds of engineers and scientists.
Although these reports all indicate that UVC at 222 nanometers has the potential to disinfect without harming human tissue, there’s still reason to be cautious. In the U.S., the FDA has said that lamps with a “peak wavelength of 222nm may cause less damage to the skin, eyes, and DNA than the 254-nanometer wavelength, but long-term safety data is lacking.” Steven DenBaars, a professor at UC Santa Barbara who specializes in lighting, expressed skepticism to Fast Company last April.
Roosegaarde emphasized that Urban Sun isn’t meant to replace the vaccine or health measures already in place, and though he doesn’t consider it to be a “solution for everything,” he’s hopeful it could become a part of normal life. Roosegaarde says his studio has already been contacted by groups including the Tokyo Olympics and Expo Dubai. And even if it’s too early for real world application, for Roosegaarde, it “shows the beauty of design and science.”