Coronavirus identified in air pollution particles — but that doesn't mean it spreads that way

Now that the coronavirus has infected more than 3 million people worldwide, the question of how SARS-CoV-2 spreads has become increasingly relevant. Experts remain confident, as of now, that the virus is passed from individuals through respiratory droplets. But a new study out of Italy — first covered by the Guardian — suggests more research on whether it can be spread through the air.

Published on the health science site Medrxiv, the study analyzed air pollution particles in Bergamo, Italy, from late February to early March. Scientists there found the presence of a specific COVID-19 gene in the air pollution particles, concluding that it’s the “first preliminary evidence” that “SARS-CoV-2 RNA can be present on outdoor particulate matter.”

Researchers note that “no assumptions can be made” about the presence of the virus in air pollution particles and the fact that northern Italy experienced a high volume of coronavirus cases. Dr. Amesh Adalja, an infectious disease expert and senior scholar at the Johns Hopkins Center for Health Security, stresses that the findings should not be cause for alarm.

“If you look in air samples and air pollution particles, there have been many studies that have shown different microorganisms traveling along with them,” Adalja tells Yahoo Life, noting that other coronaviruses such as SARS (or severe acute respiratory syndrome) have been found in air particles as well. “There are lots of examples where you can find this type of dispersal pattern of microorganisms. But that doesn’t necessarily translate into an infection risk.”

Dr. William Schaffner, an epidemiologist at the Vanderbilt University School of Medicine, agrees. “[The authors] don’t know that the virus is living. So this may be only viral fragments, you know,” Schaffner tells Yahoo Life. “Let’s just say it is living, just for the sake of discussion, because that’s the kind of the worst-case scenario. Even then, is there an infectious dose?”

A study from Italy found a gene specific to the coronavirus in air pollution particles. Experts say it's no reason to panic. (Photo: Getty Images).
A study from Italy found a gene specific to the coronavirus in air pollution particles. Experts say it's no reason to panic. (Photo: Getty Images).

Schaffner says the mere presence of living SARS-CoV-2 particles (the virus that causes COVID-19) in the air wouldn’t necessarily be enough to cause someone to get infected. “You have to get a certain amount of virus in your body before it can establish an infection,” Schaffner says. “And even if it were living, it’s not clear to me that this would be an infectious dose of the virus.”

Adalja bolsters this by noting that if the virus were spread through contaminated particles, the current number of infections would likely be drastically different. “You would have a lot wider-spread infections; you would have a lot more people who are inexplicably infected,” he says. “It would really be a different dispersal pattern. The cases wouldn’t be connected to each other because they wouldn’t be caused through contact.”

So while Adalja finds the study interesting, he’s not at all concerned about its implications. “This is an interesting finding and not surprising, but is it a major way that this virus is using to infect people?” he asks. “The answer is no.”

As of now, the Centers for Disease Control and Prevention maintains that the best way to prevent the coronavirus from spreading is to wash your hands regularly for 20 seconds with soap and warm water, as well as wearing a mask around others and following social distancing guidelines.

(Graphic: Quinn Lemmers for Yahoo Life)
(Graphic: Quinn Lemmers for Yahoo Life)

For the latest coronavirus news and updates, follow along at https://news.yahoo.com/coronavirus. According to experts, people over 60 and those who are immunocompromised continue to be the most at risk. If you have questions, please reference the CDC’s and WHO’s resource guides. 

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