Driven by warming temperatures and other issues, like forest management decisions and urban growth, Western wildfire seasons are starting earlier and burning with greater intensity on average. Rising temperatures are contributing to droughts and causing snowpacks to melt earlier, compounding wildfire threats.
With the fiercening of flames has come a blotting of the skies—smoke waves have been smothering communities from quiet foothill towns to major metropolitan centers, forcing cancellations of local events, driving vulnerable residents indoors and exacerbating existing health risks. The rise in smoke levels during warmer months is undermining improvements in air quality driven by the regulations on pollution from fossil fuel use and other sources.
Scientists project the intensification of smoke waves to continue as temperatures continue to increase due to heat-trapping pollution. Forests and grasslands dry out as temperatures increase, fueling larger and more frequent blazes.
Forest management practices also influence wildfire seasons. The use of prescribed burns are one of the tools available to land managers, in which crews ignite and manage low-intensity fires on forest floors to reduce fuel, but they are used inconsistently nationwide.
Wildfires can affect ozone pollution levels and release broad arrays of dangerous chemicals into the atmosphere, but it’s the tiniest of the particles that usually cause the biggest threats—PM2.5, which refers to particles or droplets in the air that are two and a half microns or less in width. These particles can lodge deep in the lungs and even enter the bloodstream, increasing risks of heart attack, diabetes and many other ailments.
Lung health is important for surviving COVID. Exposure to particulate matter from wildfire smoke could increase risks of death from coronavirus. So, too, does the use of tear gas by police forces during demonstrations. Research involving soldiers exposed to high concentrations of tear gas during combat training concluded that exposure increased risks of developing acute respiratory infections, with risks greatest at the highest concentrations.
Exposure to pollution from tailpipes, refineries and other industrial sources has been shown to increase deaths from COVID. That puts Americans who live with polluted air, many of them low-income and people of color with limited access to healthcare, at greater risks of dying from the disease.
Wildfire smoke can trigger and exacerbate a long list of health problems including asthma attacks, headaches and runny noses. And health impacts can linger long after smoke from a fire has cleared. Research from University of Montana scientists showed how particulate matter from wildfires increased the risk of influenza months later.