The Future of Mass Disinfection

The EPA is researching methods for disinfecting large public spaces in order to slow the spread of Covid-19

Staff members disinfect a shopping mall at the Hanzheng Street in Wuhan. The shopping mall was thoroughly cleaned and disinfected before businesses were reopened. Photo: Wang Yuguo/Xinhua/Getty Images

Last week, the Environmental Protection Agency (EPA) announced that it’s researching ways to disinfect large public spaces, like schools or office buildings, in order to slow the spread of Covid-19. The research will be used to guide public agencies and private businesses around the country on how to kill potential traces of the virus in their facilities.

The EPA already maintains a registry of disinfectants, like Barbicide, Asepticare, and Cavicide, that have been approved to kill the novel coronavirus. But because people and institutions around the country have inquired about the safety of new deep cleaning tools that aren’t on the official registry, the EPA is now researching the efficacy of ultraviolet light, ozone molecules, steam, and electrostatic sprayers and foggers, equipped with EPA-approved disinfectants, for large-scale cleaning efforts.

“People have asked us, ‘Can I use a UV lamp or can I use an ozone generator to clean off packages when they come into our facility?’ or ‘Can I use them for cleaning up or disinfecting a room or perhaps the inside of a vehicle?’” Greg Sayles, PhD, director of the EPA’s Center for Environmental Solutions and Emergency Response, tells OneZero. “[The EPA doesn’t] really know how well they work and we don’t really know how to [best] apply them.”

The EPA, with funding from the Coronavirus Aid, Relief, and Economic Security (CARES) Act, is researching how effective the disinfectant tools are at killing the coronavirus on different types of surfaces. For the ones that work well, they’ll develop guidelines for using them.

“That kind of thing would be applicable if, sadly, we have another pandemic.”

While the EPA’s research is just beginning, several other countries — and even some institutions in the United States — are already using disinfectants on a large scale. Photos published last month in The Atlantic show workers in China, the Philippines, Iran, Italy, and several other countries, many in hazmat suits, spraying large clouds and streams of disinfectant in offices as well as on city streets, escalators, and even people.

Applying disinfectants over large areas to mitigate the spread of Covid-19 has had mixed results. In one instance in mainland China, more than 100 wild animals died of poisoning after Chongqing, a megacity in the southwestern part of the country, was sprayed with disinfectant. And several health experts told Reuters that mass disinfecting could be harmful to public health and is not as effective as targeted cleaning of frequently used surfaces and promoting good personal hygiene.

“I don’t believe it adds anything to the response and could be toxic on people,” Dr. Dale Fisher told Reuters. Fisher is an infectious disease physician who chairs the World Health Organization’s Global Outbreak Alert and Response Network. “The virus does not survive for long in the environment and people do not generally touch the ground.”

But research published in the New England Journal of Medicine in mid-April found that Covid-19 can stay on some surfaces up to 72 hours, suggesting that mass disinfection of indoor spaces has some use. “You want to make sure an indoor space is decontaminated before you allow people back in,” Joshua Santarpia, PhD, a professor of pathology and microbiology at the University of Nebraska Medical Center, told the New York Times.

The EPA has had its eye on other countries’ mass disinfection efforts but wants to do more research before making any recommendations.

“I think it’s been very interesting to see these countries put [those methods] to work,” Sayles says. “I think what we’re trying to do here is do a solid scientific study to understand how well they work in order to inform our own use of them in this country.”

One method the EPA is researching, though, electrostatic sprayers, is already being used in the United States to combat the coronavirus. These sprayers add a positive charge to disinfectant so that it better adheres to the surfaces they are meant to clean more than disinfectant from regular sprayers would. Boston began using them to clean public schools in March. The Washington Metropolitan Area Transit Authority in the D.C. area has been using electrostatic sprayers on its subway cars since 2003. The case is the same for Bay Area Rapid Transit (BART), which runs through San Francisco. Jim Allison, a BART spokesperson, tells OneZero that after BART service ends for the night, trains are disinfected with electrostatic sprayers.

BART was using electrostatic sprayers with disinfectant before the outbreak began, but has started cleaning train stations and cars more frequently since the pandemic hit.

Some of the other methods are already being used, too. The Fort Lauderdale Fire Department has begun using ozone to disinfect its emergency vehicles. The machine they are using releases ozone molecules into the air to kill off potential traces of the virus. Dr. William Schaffner, an infectious disease physician and professor at the Vanderbilt University School of Medicine, told Shape that steam cleaning was, even before the coronavirus crisis, regularly used to disinfect medical equipment used in the laboratory. And the EPA aren’t the only ones researching the use of certain types of UV light to disinfect large spaces. Universities and private companies are researching the use of UV light to eradicate the coronavirus.

The EPA’s research on large-scale disinfectants could last up to a year, but they’re also looking for results within the next month that they can hopefully use to help contain this pandemic. Sayles says that the work the EPA is doing now “absolutely” will have applications for future pandemics, which the world’s leading scientists predict will be more common. Part of its current disinfectants research is a project in partnership with the Centers for Disease Control and New York Transit Authority, he says. Together, they’re looking for long-lasting disinfectant solutions for public spaces that are used frequently.

“That kind of thing would be applicable if, sadly, we have another pandemic,” he says.

Drew Costley is a Staff Writer at FutureHuman covering the environment, health, science and tech. Previously @ SFGate, East Bay Express, USA Today, etc.

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