Where is smoke, there is COVID, new study finds

Smoke from wildfires may help increase coronavirus infection rates, according to a new study from the Center for Genomic Medicine at the Desert Research Institute (DRI), Washoe County Health District (WCHD) and Renown Health (Renown ) in Reno, Nevada.

The researchers pointed out that their findings strengthen arguments that other sources of PM2.5 could also lead to increased susceptibility to the novel coronavirus. Previous studies around the world have found associations between high levels of air pollution and increased infectivity and severity of COVID-19.

The increased susceptibility to the virus associated with PM2.5 could arise from a number of different causes.

One possible cause is that PM2.5 increases susceptibility to respiratory viruses through altered immune responses, including inflammation. Smoke from forest fires may also have helped the virus survive and spread further, as small particles have been shown to increase the spread and survival of bacterial, fungal and viral bioaerosols.

Another possible cause is that high concentrations of ambient nitrogen dioxide (NO2) and PM2.5 lead to overexpression of the ACE2 receptor, the receptor through which the coronavirus enters cells, in the respiratory tract. It is not clear whether such an effect occurs with short-term or just long-term exposure to air pollution.

The researchers noted that infection rates can also be affected by non-biological factors, such as people congregating indoors rather than outdoors due to the smoke. Political decisions about whether or not to maintain indoor public spaces could also have an effect.

The study found that PM2.5 concentrations tended to lead to increased positivity rates two to six days after the concentrations were recorded, indicating a relatively short-term cumulative effect of PM2.5 from forest fires on COVID-19 rates.

“Our results showed a substantial increase in the COVID-19 positivity rate in Reno at a time when we were affected by thick wildfire smoke from the California wildfires,” said Daniel Kiser, MS, co – Study lead author and assistant data science researcher at DRI, according to DRI. “It’s important to be aware of this as we are already dealing with thick wildfire smoke from the Beckwourth compound fire and with COVID-19 cases on the rise again in Nevada and others. parts of the western United States. “

The study’s publication comes as a massive wildfire burns nearly 500 square miles of Oregon. Earlier this year, a number of large forest fires broke out across Israel. Israel is currently suffering from an increase in coronavirus cases.