SACRAMENTO, Calif. — Cases of COVID-19 rose sharply last year in Reno, Nevada, when heavy layer of wildfire smoke settled over the city, according to scientists at the Desert Research Institute, and they and other scientists are postulating that 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 Scienc...