Wildland firefighter exposure to smoke and COVID-19: A new risk on the fire line

Abstract

Throughout the United States, wildland firefighters respond to wildfires, performing arduous work in remote locations. Wildfire incidents can be an ideal environment for the transmission of infectious diseases, particularly for wildland firefighters who congregate in work and living settings. In this review, we examine how exposure to wildfire smoke can contribute to an increased likelihood of SARS-CoV-2 infection and severity of coronavirus disease (COVID-19). Human exposure to particulate matter (PM), a component of wildfire smoke, has been associated with oxidative stress and inflammatory responses; increasing the likelihood for adverse respiratory symptomology and pathology. In multiple epidemiological studies, wildfire smoke exposure has been associated with acute lower respiratory infections, such as bronchitis and pneumonia. Co-occurrence of SARS-CoV-2 infection and wildfire smoke inhalation may present an increased risk for COVID-19 illness in wildland firefighters due to PM based transport of SARS CoV-2 virus and up-regulation of angiotensin-converting enzyme II (ACE-2) (i.e. ACE-2 functions as a trans-membrane receptor, allowing the SARS-CoV-2 virus to gain entry into the epithelial cell). Wildfire smoke exposure may also increase risk for more severe COVID-19 illness such as cytokine release syndrome, hypotension, and acute respiratory distress syndrome (ARDS). Current infection control measures, including social distancing, wearing cloth masks, frequent cleaning and disinfecting of surfaces, frequent hand washing, and daily screening for COVID-19 symptoms are very important measures to reduce infections and severe health outcomes. Exposure to wildfire smoke may introduce additive or even multiplicative risk for SARS-CoV-2 infection and severity of disease in wildland firefighters. Thus, additional mitigative measures may be needed to prevent the co-occurrence of wildfire smoke exposure and SARS-CoV-2 infection.

PM2.5, NO2, wildfires, and other environmental exposures are linked to higher Covid 19 incidence, severity, and death rates

“…Other studies and reviews have reported that exposure to wildfire smoke in firefighters are associated with significantly greater risk of respiratory infections such as pneumonia and acute bronchitis (Navarro et al 2021 ).…”

“…Viability/survival of SARS Cov2/Covid 19 has been estimated at 9 h for hands as compared to influenza (another RNA respiratory virus) of 1.8 h (Hirose et al 2020 ). Some studies have suggested that particulate pollution may increase airborne survival of many types of viruses times by binding to bacteria and providing protection from UV light and by reducing dehydration (Navarro et al 2021 ; Reche et al 2018 ).…”

Wildfire Smoke Exposure: Covid19 Comorbidity?

“…Wildfire pollution health impacts are likely the greatest amongst proximate communities and for exposed minority and impoverished "essential" worker populations whose employment requires significant outdoor time, largely without appropriate protection (N95 mask). Of particular concern is wildfire firefighter smoke exposure, which could lead to higher Covid19 risk and who currently only use cloth masks for protection [17]. On a local level, by analogy, biomass or wood burning in homes for aesthetics, heating, or cooking may be increasing risks for homeowners and their neighbors.…”

Burns and Fatal Acute Lung Injury Ignited by a Smartphone Charger during Non-Invasive Ventilation for COVID-19

“…Vigilance for potential hazards of oxygen therapy must be maintained. There is speculation that lung injury may be multiplicative from the combination of smoke inhalation and SARS-CoV-2 [9], but no prior case has been reported.…”