Cleaning surfaces does not help contain respiratory viruses – 12/27/2023 – Balance and Health

In early 2020, desperate to avoid infection with a new coronavirus, we all scrubbed surfaces, washed our hands, and sneezed by covering our noses and mouths with our shirt sleeves (called “elbow sneezing”). But the threat wasn’t actually in the countertops and doorknobs.

The virus was in the air and spread through coughing, talking and even singing a song. The pandemic raged for six months before global health authorities acknowledged that the virus was airborne.

That revelation triggered another: If indoor air quality had been a priority, the impact of the pandemic in the United States would have been smaller.

After more than three years, almost nothing has changed. Many continue to crowd into offices, classrooms, restaurants and stores with inadequate and often deteriorating ventilation systems, often in buildings with closed windows.

Scientists agree that the next pandemic will almost certainly also arise from an airborne virus. But improving air quality is not just important for combating infectious diseases: contaminated air indoors can harm the heart, lungs and brain, reducing life expectancy and impairing cognition. Furthermore, fires, outdoor air pollution and climate change will render palliative solutions, such as opening windows or bringing outside air into spaces, ineffective.

Instead, we will have to start thinking about the air in schools, restaurants, offices, trains, airports and cinemas as places that influence human health. To improve the situation, it will be necessary to have funds, scientific guidance on air quality and, above all, political will to change.

“The push for clean water is considered one of the top ten public health achievements of the last century, and the same needs to be done for air,” says Linsey Marr, an expert on airborne virus transmission at Virginia Tech.

Paradigm change

The discussion about indoor air quality could have gained prominence earlier if the medical community had not believed that respiratory diseases such as the flu are transmitted almost exclusively through droplets expelled by coughing or sneezing. The observation that people closer to sick people seemed to be more prone to infection may have fueled this idea, leading medical experts to recommend hand washing and social distancing as the best procedures for containing a respiratory virus.

But scientists proved decades ago that large droplets can evaporate and shrink when expelled, turning into tiny aerosols that remain in the air. In other words, a flu patient is not only expelling the virus through large droplets – he can exhale, cough or sneeze droplets of various sizes, and the smaller ones will spread through the air and be inhaled directly into the lungs – a scenario that requires a prevention is very different from cleaning surfaces or washing your hands, according to Yuguo Li, an air quality expert at the University of Hong Kong.

For Li and other experts, it was obvious from the beginning of the pandemic that the coronavirus was airborne. A close relative that emerged in Asia in 2002, the Sars coronavirus, for example, was transported in this way. Why would the new virus be different?

Some scientists realized that health agencies were avoiding publicizing that transmission was via aerosols in closed environments because this would require high-quality masks, air filtration and closing buildings – in other words, a gigantic reaction. “I was shocked by the paralysis of the public health community in the face of the demand for more conclusive data,” says William Bahnfleth, an architectural engineering expert at Pennsylvania State University.

It took the CDC (US Centers for Disease Control and Prevention) until April 2020 to recommend the use of a mask and until October of the same year to recognize the transmission of the coronavirus through aerosols, and even then only indirectly. The WHO (World Health Organization) was forced to review its guidance in July 2020, after 239 experts demanded such a position through a statement.

The decisive moment came in the fall of 2021, when three major medical journals published articles about the airborne transmission of coronavirus. Still, the WHO did not use the word “airborne” to describe the virus until December 2021, and the CDC has not yet done so. “I worked with them on editing the science brief on transmission, and it was clear they didn’t want to use that word. It’s crazy,” Marr says of the CDC.