Can COVID-19 Spread Through Air Pollution?

COVID-19 has been discovered amongst particles of air pollution and could be being spread further afield due to the contamination, according to scientists from Italy. In a study conducted by the University of Bologna and led by Leonardo Setti, researchers found a gene that is highly specific to coronavirus among samples of air collected at an industrial site in Bergamo province in the north of the country.

While their work is only preliminary and has yet to receive peer-reviewed status, it does corroborate the findings of other studies and experts agree that its hypothesis is plausible. If true, the environmental implications of coronavirus (and vice versa) may be more closely intertwined than previously assumed.

Gathering knowledge

The question of whether coronavirus can be transmitted in an airborne format is one that is not yet fully understood, which is why Setti and his team undertook their research. “I am a scientist and I am worried when I don’t know,” he explained. “If we know, we can find a solution. But if we don’t know, we can only suffer the consequences.”

In order to carry out their investigation, the team employed standard techniques to collect a range of ambient air samples from an industrial location in Bergamo province, which was the hardest hit region of the country. Once they removed the samples to their laboratory for analysis, they isolated and identified a gene that was particularly unique to COVID-19. Those findings were later verified at an independent laboratory.

It has already been discovered that while larger germs from coughs and sneezes fall to the ground within a metre or two of the sufferer, microscopic droplets of the virus (less than 5 microns in diameter) can remain airborne for hours at a time, potentially travelling much further afield. It is not yet known whether pollution can enhance the range of those tiny airborne droplets, or indeed whether they are still infectious enough to spread the disease.

More research required

Much uncertainty clearly remains, but the fact that the 2003 SARS virus (also a coronavirus) was spread through the air does not bode well for the current pandemic. Setti’s theory is that when a COVID-19 droplet of less than 1 micron in diameter attaches itself to a pollution particle up to 10 microns in size, it’s less dense and as such can benefit from the upswell of the air for longer.

Experts in the field have agreed that Setti’s ideas are plausible, but stressed that further evidence was required in order to confirm his findings. That’s because theoretical plausibility does not always translate to biological reality, so more studies – and especially, more peer-reviewed studies – must be conducted before the conclusions can be relied upon.

If true, it could explain why certain regions of the world appear to have been more susceptible to the virus than others. Northern Italy is one of the most polluted areas of Europe, thus potentially explaining why it has also been one of the most heavily hit in the world. Meanwhile, air quality in cities is generally far poorer than in the countryside, meaning urban dwellers could be at higher risk of contracting the disease – and not just because of the greater population.