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Biotechnology

Why China is still obsessed with disinfecting everything

Most public health bodies dealing with covid have long since moved on from the idea of surface transmission. China’s didn’t—and that helps it control the narrative about the disease’s origins and danger.

May 19, 2022
Workers disinfect the street outside Shijiazhuang Railway Station
Workers disinfect the street outside Shijiazhuang Railway Station
Liang Zidong/Xinhua/Alamy Live News

In a one-minute video that went viral in China in early May, three government workers in hazmat suits spray disinfectant all over someone’s home: inside the fridge, under the television, over the couch. On social media, Chinese people worried about whether their home would experience the same treatment if they were unlucky enough to catch the virus.

Outside China, people have mostly moved on from worrying about catching covid from surfaces, as study after study has found that the risk is relatively low. In many places, disinfecting everything is a relic from the start of the pandemic. But China seems to be stuck in an early-2020 time warp. After the video circulated, a local government official claimed that disinfecting covid-19 patients’ homes was “in accordance with expert opinions.” 

As China grapples with its biggest-ever spike of covid cases, the government’s decision to keep pushing the narrative that surfaces pose a significant infection risk means time and money are being poured into the wrong things during a crisis, scientists say. Measures to stop airborne transmission are far more effective. 

The policy of prioritizing disinfection is part of a wider state-controlled narrative that’s politicizing the health crisis and is designed to legitimize the government’s response. It also plays into China’s favored narrative about covid’s origins: that it could have been imported into Wuhan through frozen food.

Diverging pandemic paths

The scientific debate about how much surfaces contribute to covid’s spread is pretty much over internationally. For example, a study from the University of Michigan, published in April 2022 in the Journal of Exposure Science & Environmental Epidemiology, estimated that the chance of catching covid from a contaminated surface is 1 in 100,000—well below the benchmark researchers suggested as a tolerable risk. 

And while the risk isn’t zero, the vast majority of public health bodies, including the World Health Organization, have judged that it’s too low to warrant active measures except recommending hand-washing. Outside China, most countries long ago gave up encouraging people to disinfect things as a way to avoid covid. The US Centers for Disease Control and Prevention updated its guidance a full two years ago, in May 2020, to reflect the fact that it’s mostly unnecessary. 

Instead, the overwhelming consensus is that aerosols and droplets transmit the virus much more readily than surfaces. Indeed, the same April 2022 Michigan study found that airborne transmission is 1,000 times more likely than surface transmission.

“People only have the bandwidth to do so many protective health behaviors. It's ideal for them to be focusing on the things that are going to have the biggest impact on reducing their risks,” says Amy Pickering, an assistant professor of environmental engineering at the University of California, Berkeley. “And that would be mask-wearing, social distancing, avoiding crowded indoor spaces.”

The media and government in China often point to research to justify the continued fear of surface transmission. Studies carried out by researchers in Hong Kong, Japan, and Australia have found that covid viruses can survive days or weeks on various surfaces. 

But many have not been peer-reviewed, and anyway, these lab results don’t reflect real life, says Ana K. Pitol, a postdoctoral researcher at the Liverpool School of Tropical Medicine in the UK. “If you put a huge droplet inside a medium that protects the virus, and you put it inside a container, and you put it in an incubator, of course, it will survive many days, sometimes even weeks,” she says. “But the question we should be asking is how long it survives in a realistic situation.”

China’s decision to focus on surfaces comes at a cost, experts say. For example, over-disinfecting can cause chemical pollution that creates its own health hazards, as Chinese scientists warned early on in 2020. As disinfection campaigns intensify with the spike in cases, such worries have been borne out. There have been reports in Shanghai that the careless use of industrial disinfectant in residential buildings has caused irritation reactions in people and killed a pet dog. Even when used safely, scientists worry, these splashy disinfection campaigns are not a good investment of resources. 

Pushing a political narrative

China has an ulterior motive to keep pushing excessive cleaning. The idea that all surfaces are dangerous has been deeply entangled with justifications for harsh lockdown measures and has even bolstered state-promoted conspiracy theories about the virus’s origins. Backtracking on that narrative could be politically tricky.

In October 2020, Chinese health authorities reported that they’d detected living coronavirus samples on imported frozen seafood for the first time in the Chinese city Qingdao. Since then, the government and media have repeatedly talked about the possibility of getting covid through frozen food packaging. They have even suggested that the very first covid outbreak, in Wuhan, was caused by a virus imported from Italy or the United States. The Chinese government even lobbied the World Health Organization to consider this possibility when it conducted its own investigation into covid’s origins. 

The idea has become more popular this year with the emergence of the more infectious omicron variant. 

In January, Beijing reported its first local case of 2022. Since the patient hadn’t traveled anywhere that was experiencing active covid cases, health officials ended up proposing that the person had been exposed to covid-19 RNA by handling international mail from Canada on the job. Even though there was no proof the viral material found on the letters was the cause, and not the result, of the illness, the official contact tracing report said “it can’t be ruled out that the person was infected with the virus through items coming from abroad” and offered tips on disinfecting international packages. 

Around the same time, other Chinese cities, including Shenzhen and Zhuhai, also reported early omicron patients who worked with imported merchandise, further fueling the narrative. 

When reporters asked Wu Zunyou, the chief epidemiologist at China’s CDC, in April about whether the omicron variant introduces a higher risk of surface transmission, Wu gave a vague answer. While acknowledging that droplets are the main transmission method, he again raised the specter of infection via packaging: “The risks of contaminated surfaces causing infections are relatively small, but if there are repeated exposures and no attention is paid to hand hygiene or personal protection, then the risks will increase significantly. That’s why we are regularly testing people who work in outdoor cold-chain logistics and outdoor shipping.”

The stark contrast between how surface transmission risks are understood within and outside China underlines the reality that public health policies can be more in line with political goals than scientific facts.

“The [public health] measures themselves have become part of this political mission, and they are mostly incentivized by state interests and ways to solidify and enhance state control and state power,” says Yangyang Cheng, a research scholar at Yale Law School who studies the development of science and technology in China.

The surface-transmission narrative also serves another purpose in the current context, says Cheng, which is that disinfection campaigns are handy political theater. “To clean the surface is also much easier in terms of cost than to filter the air … however, that takes a lot more investment and very few states seem to be doing that. So states decide to just either not care, as in [the US], or in China doing these kinds of really performative actions,” Cheng says. 

In April, Jilin, one of the Chinese provinces that suffered a spike in local covid cases this year, announced that it had “disinfected a total area of 61,978,900 square meters”—the equivalent of over 8,000 football fields. And that is just one Chinese province. During the 2022 Beijing Winter Olympics, robots that clean surfaces and spray disinfectants offered a chance for China to show off its tech savvy.

But very recently there have been some small signs of change. On May 17, a Shanghai CDC official cautioned against over-disinfection in a press conference, likely a response to the reports of disinfection campaigns gone awry. The official, Zhu Renyi, specifically rejected the use of robots and drones but was adamant that delivery packages must still be disinfected: “[Packages] should receive a comprehensive disinfection and only be distributed after the required disinfection time, half an hour, has been reached.” 

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