China is obsessed with disinfection against Covid. But is it causing more harm than good?

Workers in protective suits disinfect an area outside a barricaded community that was locked down for health monitoring after recent cases of Covid-19 were found in the area on March 28, in Beijing, China.

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Hong Kong (CNN)Hazmat suit-clad workers spraying clouds of disinfectant over city streets, building fronts, park benches and even parcels have become a common sight in pandemic-era China.

In Shanghai, the epicenter of the country's largest outbreak, state media report that thousands of workers have been organized into teams to disinfect areas, with a focus on those known to have hosted Covid patients -- a move the government sees as key to curbing the spread of the Omicron variant.
But the practice often extends much further. Seemingly any outdoor area is at risk of being targeted by workers wielding leaf-blower-style disinfectant machines, as China's rigorous "zero-Covid" policy drives an obsession with sanitizing everything.
    In Shanghai, fire fighters have been plucked from their duties to take up roles as disinfectors, a local youth league has recruited volunteers for disinfection squads, and emergency rescue teams from far-flung parts of China have been enlisted in the drive -- often strapping on heavy equipment and full hazmat.
      In some Shanghai neighborhoods, special chemical producing stations have been set up, while in others vehicles have been outfitted with chemical tanks and cannon-like devices to shoot disinfectant onto the streets, according to local media. Disinfection robots have been stationed at railway stations, and have been set up to patrol some quarantine centers.
      But these efforts -- and others, like the insistence that workers wear hazmat suits and the blaring, recorded messages playing on loop reminding people of how to prevent the disease -- may be a waste of time, effort and resources.
      Experts say transmission of the virus via contaminated surfaces is exceptionally low -- and that sanitizing outdoor areas such as parks and city streets is largely pointless and worse still, could even pose a danger to public health.
        "The robots and street-spraying are performative acts designed to bolster public trust in government actions," said Nicholas Thomas, an associate professor at City University of Hong Kong, who pointed to how Chinese authorities have long cited environmental contamination as part of their rhetoric that the virus may not have originated in China.
        "It is a problem when politics dominates and diverges from the science of the pandemic response -- more and more effort has to be placed on bolstering the politics through acts that do not necessarily increase the bio-safety of the affected populations to the same degree as the effort it requires to undertake them," he said.

        Imported virus?

        Mass disinfection is part of a long-standing campaign in China to combat a Covid-19 transmission risk that much of the world has considered too minimal to warrant measures past hand-washing and maintaining disinfection of certain surfaces, like those in busy public places and where food is handled or Covid-19 patients are treated.
        In a science brief last year, the US Centers for Disease Control and Prevention said scientific studies suggest that each contact with a surface contaminated with Covid-19 has less than a 1 in 10,000 chance of causing an infection. Such research has prompted many to view an overt focus on disinfection as "hygiene theater" as opposed to any meaningful disease prevention measure.
        Mass disinfection has not been part of disease control measures in Western countries "because public health authorities followed the science," according to Emanuel Goldman, a professor of microbiology at the Rutgers-New Jersey Medical School.
        "(It's) highly unlikely that any cases result from touching contaminated surfaces. The virus dies quickly outside an infected person ... and transfers very inefficiently by fingers," he said. "Hand washing with soap, or alcohol hand wipes, is all you need to get the incidence down to zero."
        In China, where stringent practices have focused on eliminating any spread of the virus, concerns about contaminated surfaces date back to the early months of the pandemic, especially after Chinese officials said an outbreak at a market in Beijing likely began due to a worker being infected from handling imported, frozen salmon contaminated with virus.
        Though the World Hea