Dean's COVID-19 Commentary

Labor Day inevitably brings challenges as summer ends — unmet goals for the summer are remembered, and the frenzy of the academic fall begins. This Labor Day stands alone: a pandemic is in progress; ash from the Cameron Fire falls in the backyard; and a pending swing from 100 degree high temperatures during recent days to a forecasted 70 degree drop with snow on the day after Labor Day. And there is more: continued protests, sometimes violent; divisive electioneering around race; conflicting messaging around efficacy and safety of vaccines for SARS-CoV-2; and uncertainty about the course of the pandemic heading into the fall.

Let's start with the weather. Colorado is in drought and again on pace to have one of its warmest years. Drought and heat have brought wildfires and wildfire smoke. On Sunday, the Cameron Fire in Larimer County, now the sixth largest in Colorado history, surged, sending smoke and ash throughout the Front Range. This summer's Pine Gulch Fire that burned more than 139,000 acres is now the state's largest fire on record. Climate change is the inescapable explanation for the rising temperatures, drought, and more severe wildfires over recent decades. In our region, we are experiencing the predictions of the Fourth National Climate Assessment: drought, wildfires, and threatened agriculture. The American Indians of the Southwest are particularly vulnerable. Today's cold and snow are not a respite from climate change. More extreme variability of weather is projected by climate models. 

Air quality has been noticeably poor with limited visibility because of the fine particles in wildfire smoke. Sunday's levels of fine particulate matter air pollution, so-called PM_2.5, exceeded the 24-hour National Ambient Air Quality Standard and air pollution was at unhealthy levels, based on EPA's Air Quality Index. A wide range of adverse health effects have been causally linked to PM_2.5. Whether there are particular risks associated with wildfire smoke has been investigated, but the question remains unanswered. At CSU, Emily Fischer, Jeff Collett, and others are investigating the chemistry of wildfire smoke, flying heavily instrumented airplanes through plumes of fresh smoke. Colleen Reid, an epidemiologist at the University of Colorado Boulder, has focused her research on the health effects of wildfires; her 2016 review remains informative. 

Turning to Labor Day and the COVID-19 pandemic, there are many concerns as the fall begins: we spend less time outdoors and close homes and buildings, reducing ventilation; some schools and universities have reopened; and influenza looms. There is an overarching sense of COVID-19 fatigue that threatens continued adherence to protective behavioral measures. In March, we met the challenge of providing remote education and continuing school operations in the face of the lockdown. Now, with the fall semester, we are adjusting to life in a pandemic that does not yet have a clear end date. Hang in there. 

Entering the fall, Colorado's SARS-CoV-2 epidemic is at a stable point with R, the effective reproductive number, hovering below one. The epidemic curve is flattened for now, but the weeks ahead are critical as we anticipate the consequences of colder weather and of students returning to classes. I am continually reminded (by many) that epidemic models only capture the course of an infectious disease and not the broader societal consequences, such as economic losses, unemployment, and stress and mental illness. With the current flattened epidemic curve in Colorado, there are reasonable arguments that businesses further reopen. Perhaps they can, but I caution that we should wait for any adverse consequences of school reopening and colder weather that might manifest over the next few weeks. 

Get your flu shot and stay warm,