Experts have long warned that ultraviolet lamps can harm humans if used improperly—when the exposure is outside the body, much less inside
There is no evidence that sunlight can cure coronavirus disease on the human body. Same for disinfectant and bleach. So please, do not inject disinfectant and do not believe there is some cure for the disease coming from ultraviolet light.
Some dermatologic conditions, like psoriasis or some lymphomas, can be treated with UV light. But for the most part, other diseases do not respond in the same way.
A study that went online recently suggested that ultraviolet light was associated with lower growth rates of the virus. The study, done by ecological modelers at the University of Connecticut, has not yet been peer-reviewed.
Ultraviolet light, long-established for water and air sanitizing, has also been shown to kill the virus on surfaces.
“We found that ultraviolet light was most strongly associated with lower Covid-19 growth rates,” the scientists wrote. Projections of the overall effects, they continued, suggest that the disease “will decrease temporarily during summer, rebound by autumn, and peak next winter.” But they cautioned that uncertainty about the study’s projected outcomes “remains high.”
Researchers have shown that continuous low dose-rate of UV light in indoor public locations could be a promising, safe, and inexpensive tool to reduce the spread of airborne-mediated microbial diseases.
But for the human body, experts have long warned that ultraviolet lamps can damage DNA and turn healthy human cells cancerous.
“Ultraviolet light, more specifically UVC, is harmful to us. It can damage your DNA and cause cancer,” said Dr. Jayasree Nair, a neonatologist who has spent 17 years in the cancer research profession.
“You can kill germs on non-living materials but it would be impossible for ultraviolet rays to reach deep within the body to kill the virus in the lungs and other organs. Disinfectants are of the same kind, it can harm us.”
The World Health Organization also noted that UV lamps should not be used to sterilize hands or other areas of skin as UV radiation can cause skin irritation. “Small amounts of UV are essential for the production of vitamin D in people, yet overexposure may result in acute and chronic health effects on the skin, eye, and immune system,” it said.
Sunlight has a dual nature. Wavelengths from 10 to 400 nanometers are known as ultraviolet. The parts of this spectrum that reach the Earth’s surface are the longer UVA and UVB rays, vital for all life, and for humans to produce vitamin D and other essential body processes, but also causing sunburn, skin cancer, and wrinkles depending on one’s skin type.
Less famous, but more dangerous UVC light never appears on sunblock labels because these solar rays are too short to penetrate the Earth’s atmosphere. From about 254 to 270 nanometers, these deadly wavelengths, labeled UVGI for germicidal irradiation, rapidly deactivate viruses such as swine flu, severe acute respiratory syndrome coronavirus, and H5N1.
So can we add UVC lights to our houses then? Well, the catch is that UVC light, like UVA and UVB, is an indiscriminate killer. Enough UVC light—the level of power used to sterilize surgical rooms—would burn you and potentially give you skin cancer. That’s why it’s only being used in controlled environments. Humans don’t enter the sealed water purification tanks that are being blasted with UVC light. Motion sensors ensure no one is in a surgical room when the UVC light goes on.
But again, do not drink or ingest bleach. Disinfectants don’t kill only the virus. They may kill you, too. If you come across someone who has ingested or injected household disinfectants, call the National Poison Management and Control Center at 8-554-8400 local 3976.