Hong Kong – At an abandoned Hong Kong airport, cleaning crews constantly spray luggage trolleys, elevator buttons and check-in counters with antimicrobial solutions. In New York City, workers frequently disinfect surfaces on buses and subways. In London, many pubs spent a lot of money on extensive roof cleaning to reopen after the closure – Before closing again in November.
Around the world, workers are working to clean surfaces with soap, wipe and evaporate them with a sense of urgency. The goal: to fight the Coronavirus. But scientists increasingly say there is little evidence that contaminated surfaces can spread the virus. In crowded enclosed spaces like airports, they say, the virus that infected people exhale and that remains in the air is a much greater threat.
Wash hands with soap and water for 20 seconds – or purgatory In the absence of soap – it is still encouraged to stop the spread of the virus. But experts say cleaning surfaces does little to mitigate the threat of the virus indoors, and health officials are urged to focus instead on improving ventilation and cleaning indoor air.
Dr. Kevin B. US National Institutes of Health.
A false sense of security
Some experts suggest that Hong Kong, a crowded city of 7.5 million with a long history of infectious disease outbreaks, is a case study of the kind of practical surface cleaning that gives ordinary people a false sense of security about the coronavirus.
The Hong Kong Airport Authority used a “whole-body cleansing channel” similar to a phone booth to activate airport personnel in quarantine areas. The booth – which the airport says is the first of its kind in the world and is used only for trials by its crew – is part of an overall effort to make the facility a “safe environment for all users”.
Displays like these can be comforting to the public because they show local officials are taking the fight to Covid-19. But Shelley Miller, an aerosol expert at the University of Colorado Boulder, said the booth had no practical sense from an infection control standpoint.
Viruses are released through activities that spray respiratory droplets – talking, breathing, shouting, coughing, singing, and sneezing. Dr Miller said disinfectant sprays are often made of toxic chemicals that can drastically affect indoor air quality and human health.
“I can’t understand why anyone would think that disinfecting a person entirely would reduce the risk of transmitting the virus,” she said.
A range of respiratory illnesses, including the common cold and flu, are caused by germs that can spread from contaminated surfaces. So when an outbreak of the Coronavirus appeared last winter on the Chinese mainland, it seemed logical to assume that so-called fumitates were a primary means of spreading the pathogen.
Studies soon found that the virus appeared to live on some surfaces, including plastics and steel Up to three days. (Studies later showed that a large portion of this is likely dead parts of the virus that are not contagious.) The World Health Organization also confirmed that surface transmission was a risk, and said that airborne spread was only a concern when healthcare workers were involved in some Aerosol-producing medical procedures.
But scientific evidence was mounting that the virus could occur Stay high for hours In tiny droplets in stagnant air, they infect people while inhaling them – especially in Crowded interiors With poor ventilation.
In July, an article was published in The scalpel The medical journal argued that some scientists exaggerated the risks of contracting the Coronavirus from surfaces without considering evidence from studies of their closely related cousins, including the SARS virus, the engine of the 2002-2003 SARS epidemic.
“This is very strong evidence that at least for the original SARS virus, the transmission was very slight at most,” the author of the article, Rutgers University microbiologist, Emmanuel Goldman, said in an email. “There is no reason to expect the nearby SARS-CoV-2 to behave significantly in this kind of experiment,” he added, referring to the new coronavirus.
A few days after Dr. Goldman’s article appeared in The Lancet, there were more than 200 scientists He called who To acknowledge that coronavirus can spread through the air anywhere indoors. Bowing to tremendous public pressure over the issue, the agency acknowledged that indoor aerosol transmission could trigger outbreaks in poorly ventilated indoor spaces such as restaurants, nightclubs, offices and places of worship.
By October, the Centers for Disease Control and Prevention had come out, which had kept to the surface since May Not the primary way the virus spreadsHe was saying that the transmission of gastroesophageal droplets was.Main situation“From which.
But by then, the paranoia of touching anything from the handrail to the grocery bags had taken off. And the instinct to clean surfaces as a precaution against Covid – ”Theater cleanlinessAs The Atlantic called it – it was really deep-rooted.
“My tennis partner and I gave up on the handshake at the end of the match – but since I touched the tennis balls he touched, what’s the point?” Jeff Dyer Written in a March article For The New Yorker That Has Got A Zionist Germs.
Don’t touch this
From Nairobi to Milan to Seoul, sanitation workers in hazmat suits have smoked public places despite WHO warnings that chemicals can do more harm than good.
In Hong Kong, where 299 people died during the original SARS epidemic, elevator buttons are often covered with plastic that is cleaned multiple times a day. In some office buildings and subways, work crews wipe the escalator railings with sterilized rags as passengers board. Cleaners blew up public spaces with antimicrobial paint and added a fleet of robots to clean surfaces in subway wagons.
Many scholars in Hong Kong insist that deep cleaning can’t hurt, and have backed the government’s strict rules of social distancing and its months-long insistence on wearing a near-universal mask.
Procter & Gamble said sales of personal cleaning products grew by more than 30 percent in the quarter ending in September, with double-digit growth in every region of the world, including more than 20 percent in Greater China.
How about air?
The burden of Covid-19 in Hong Kong – more than 5,400 confirmed cases and 108 deaths – is relatively low for any city. However, some experts say it has been slow to address the risks of indoor aerosol transmission.
But with the Hong Kong authorities gradually relaxing restrictions on indoor gatherings, including permitting wedding parties In up to 50 people, there is a fear of new disease outbreaks inside.
Some experts say they are particularly concerned about the spread of coronavirus droplets through office vents, which are crowded because the city has not developed a strong culture of remote work.
“People remove the masks for lunch or when they return to their booths because they assume their booth is their own place,” said Yong King Lun, professor of chemical and biological engineering at the Hong Kong University of Science and Technology.
“But remember: the air you breathe is fundamentally shared.”
Mike Ives reports from Hong Kong, and Aporva Mandafilly from New York.