Studies: Wildfire smoke might add to COVID risk
SACRAMENTO, Calif. – Cases of COVID-19 rose sharply last year in Reno, Nevada, when a heavy layer of wildfire smoke settled over the city, according to scientists at the Desert Research Institute, and they and other scientists are postulating there is a link between air pollution and increased susceptibility to the new coronavirus.
“Our results showed a substantial increase in the COVID-19 positivity rate in Reno during a time when we were affected by heavy wildfire smoke from California wildfires,” said Daniel Kiser, a co-lead author of the study published in the Journal of Exposure Science and Environmental Epidemiology. “This is important to be aware of as we are already confronting heavy wildfire smoke ... with COVID-19 cases again rising in Nevada and other parts of the western U.S.”
Kiser, an assistant research scientist of data science at the institute, said he became interested in studying the effect of the microscopic particulate matter from wildfires after reading a Canadian scientist’s article on the dual effect of confronting both issues at the same time.
In the preface to her work, senior scientist Sarah Henderson of the British Columbia Center for Disease Control, wrote: “As we enter the wildfire season in the northern hemisphere, the potential for a dangerous interaction between SARS-CoV-2 and smoke pollution should be recognized and acknowledged. This is challenging because the public health threat of COVID-19 is immediate and clear, whereas the public health threat of wildfire smoke seems distant and uncertain in comparison. However, we must start preparing now to effectively manage the combination of public health threats.”
Kiser is hoping his research results will motivate people to get vaccinated and to wear masks to reduce their exposure to the virus and to tiny wildfire particulate matter that measures 2.5 micrometers or less.
That’s about 1/30th the size of a human hair at its largest. Scientists refer to it as PM 2.5 for short.
To analyze the relationship between this fine wildfire ash and COVID-19 positivity rates, Kiser and his team collected data from the Washoe County Health District and the region’s big hospital system, Renown Health.
He said they discovered that the PM 2.5 was responsible for a 17.7% increase in the number of COVID-19 cases that occurred during a period of prolonged smoke that took place between Aug. 16, 2020, and Oct. 10, 2020.
The relationship between COVID-19 positivity rates and air pollution in general has gained interest among scientists around the world, and Kiser and Elhanan cite research papers from Europe and Asia that explore the phenomenon as well.
Kent Pinkerton, an expert on air pollution on the faculty at the University of California, Davis, said there’s concern among physicians and scientists about the impact of climate change on cardiopulmonary health, a topic he’s currently addressing in an article he’s submitting to a medical journal.
“Hotter temperatures, climate change, wildfires, air pollution, all seem to have some association with a greater risk of COVID-19 cases,” Pinkerton said. “If you’re susceptible to air pollution, such as particulate matter, it could be that you just have a situation where you’ll be also much more susceptible to viral particles that might be in the air that you’re breathing.”