4 May 2020

Here's What Disinfectants and UV Light Really Do to Your Body


THESE ARE STRANGE times, when the hashtag #DontDrinkBleach trends on Twitter and the makers of Lysol feel compelled to respond to “recent speculation and social media activity” by putting up a statement that “under no circumstance should our disinfectant products be administered into the human body (through injection, ingestion, or any other route).” It’s easy to laugh, as many have, about President Donald Trump’s musing about killing the virus that causes Covid-19 by ingesting disinfectant or somehow shining UV light inside the human body. Yet medical professionals at poison control centers around the country aren’t amused.

In the 18 hours after Trump’s Thursday evening press briefing, the New York City Poison Control Center handled nine cases of exposure to Lysol, 10 related to exposure to bleach, and 11 exposures to other household products, New York City Health Department spokesperson Patrick Gallahue told WIRED. In the same 18-hour time frame in 2019, no callers mentioned Lysol specifically, two called about bleach exposure, and there were only 13 total cases related to a household cleaning product. Even looking overall at the week of April 20, poison control calls related to bleach or disinfectant spiked in New York City just on Thursday and Friday.


Even before the now infamous press briefing, poison control hotlines were buzzing, up 20 percent from last year with disinfectant-related calls, according to statistics from the National Poison Data System. Mostly, callers said, their kid drank the hand sanitizer—should they rush them to the emergency room? Or they mixed chlorine bleach with vinegar or ammonia for some extra-powerful cleaning, and now they were coughing and having trouble breathing. Or they soaked their apples in Lysol and felt queasy after eating them.

All of those things are bad—don’t do them! But even worse is the idea of taking cleaners developed for external surfaces like countertops and deliberately putting them inside the human body. (To recap, Trump said: "I see the disinfectant, where it knocks it out in a minute. One minute. Is there a way we can do something like that, by injection inside, or almost a cleaning? Because you see it gets on the lungs and does a tremendous number on the lungs.") The problem is that a disinfectant would do “a tremendous number” on your cells, too—killing them.

“What might seem obvious to somebody that this is a bad idea might not really seem obvious to everybody,” says Diane P. Calello, a medical toxicologist who is executive and medical director of the New Jersey Poison Information and Education System. “And hearing it on the news makes it seem OK.”

Here’s why it’s not. While medical treatments and disinfectants have a common goal—killing germs—their mechanisms are completely different, and they are designed for different environments. As helpful as they are at zapping germs on your kitchen table or door handles, bleach and disinfectants are indiscriminate destroyers, disintegrating human cells as well as microbes. The main ingredient in household bleach is sodium hypochlorite, which reacts with water to form hypochlorous acid, which breaks down organic matter. “If you look at it under a microscope, you can see the organism slowly dissolving,” says Charles Gerba, an environmental microbiologist at the University of Arizona.

When you put a bleach solution on surfaces in your house, it kills most organisms in about 30 seconds, he says. A very low concentration kills bacteria in drinking water, making it safe to drink. But if you soak it on your skin in higher concentrations, bleach can cause skin irritation, and—in its industrial, concentrated form—blistering. If you swallow bleach, the acid produced by the chlorine reaction will damage cells in the throat and digestive tract.

When a poison control center receives a call about someone who injected themselves with bleach, it’s often a tragic suicide attempt, Calello says. Occasionally, someone has a misguided idea about “cleansing” the blood, she says. “Those chemicals are just not meant to be in the human body in any way. They’re not meant to be on your skin, much less in your veins,” she says. “If you inject bleach or ammonia or any disinfectants, it automatically starts to kill the lining of your blood vessels and your blood cells and your organs.”

Household disinfectants such as Lysol work by destroying the outer layer of a virus, and they can be toxic to human cells. Wiping your hands with a disinfecting wipe won’t hurt you because it’s a dilute solution, but pouring disinfectant on your hands could cause irritation. “I think it’s important to make a distinction between what we do to clean our skin and what we do to disinfect our environment,” Calello says.

For cleaning skin, Callello continues, “The CDC (Centers for Disease Control and Prevention) recommends cleaning with soap and water, which rinses off debris and dirt.” Soap tears away the virus’s outer fatty layer gently enough that it destroys the virus without harming your skin.

What about UV light? At last Thursday’s press briefing, Bill Bryan, a senior official at the Department of Homeland Security, presented unpublished data about the effect of higher outdoor temperatures and humidity on Covid-19. That led Trump to riff in the direction of coronavirus response coordinator Dr. Deborah Birx: “Supposing we hit the body with a tremendous—whether it’s ultraviolet or just a very powerful light. And I think you said that hasn’t been checked, but you’re going to test it. Supposing you brought the light inside the body, which you can do, either through the skin or some other way. I think you said you’re going to test that too.”

UV light—particularly the shortest wavelength, known as UVC—kills viruses by damaging their DNA or RNA, crippling their ability to make copies of themselves. Hospitals have been using UVC lamps and even UVC robots to disinfect the air in rooms. But just as with disinfectants, UVC light doesn’t discriminate in what it kills. This light can also damage human cells, potentially harming the cornea, causing sunburn, and raising the risk of skin cancer, says physicist David Brenner, who is director of the Center for Radiological Research at Columbia University. That’s why hospital staff turn on the lamps only when the rooms are empty.

Theoretically, it would be possible to snake a tube with a UV light into a person’s airway, but that would be a very bad idea. “That would be damaging to all the cells inside the body,” says Brenner. And in any case, the light wouldn’t reach all areas of the lungs. “The UV light can’t go around corners,” he says. “I don’t think you’d be killing all the viruses by any means.” Any remaining viruses would simply multiply, leaving the person still trying to fight off a Covid-19 infection—but now with potential cellular damage from the UV light.

Brenner has been studying far-UVC, a wavelength that can kill viruses but can’t penetrate beyond the top layer of human skin, which is made up of dead cells. Brenner says that kind of light could be used to safely kill germs in the air, not just in hospitals, but in airports, transit stations, and other places where people gather. Still, he points out, the idea would be to use far-UVC for environmental surface decontamination, not internally to treat patients.

Medicine, of course, works differently. Antiviral drugs being designed to kill the SARS-CoV-2 virus that causes Covid-19 would target it very specifically, rather than killing a broad spectrum of microbes or endangering human cells. So far, there are no FDA-approved medical treatments for Covid-19, although drugmakers are racing to find ways to kill the novel coronavirus.

The SARS-CoV-2 virus uses its crown-like spike proteins to enter human cells, where it commandeers the genetic machinery to make copies of itself. An experimental drug called remdesivir, originally developed to attack the virus that causes Ebola, might block the virus from making an enzyme it needs to create those copies. Other ideas for treatments include using protease inhibitors to kill the virus, or stopping it from binding to the ACE2 receptors on human cells. For people who haven’t been infected, the best course of treatment would be preventative: A vaccine could teach the immune system how to kill the virus, and antibodies gathered from the blood plasma of those who have already survived the disease could help them fight the virus while their own immunity ramps up.

In a battle against an elusive, invisible enemy, it is natural to seek the strongest possible protection. But the best methods are tried and true: hand-washing and hand sanitizer. Reserve disinfecting products for inanimate surfaces only. Keep all your cleaners out of reach of young children. And if you think you need a treatment for the inside of your body, call your doctor.

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