Associations Between Wildfire‐Related PM_2.5 and Intensive Care Unit Admissions in the United States, 2006–2015

Abstract

Wildfire smoke is a growing public health concern in the United States. Numerous studies have documented associations between ambient smoke exposure and severe patient outcomes for single‐fire seasons or limited geographic regions. However, there are few national‐scale health studies of wildfire smoke in the United States, few studies investigating Intensive Care Unit (ICU) admissions as an outcome, and few specifically framed around hospital operations. This study retrospectively examined the associations between ambient wildfire‐related PM 2.5 at a hospital ZIP code with total hospital ICU admissions using a national‐scale hospitalization data set. Wildfire smoke was characterized using a combination of kriged PM 2.5 monitor observations and satellite‐derived plume polygons from National Oceanic and Atmospheric Administration's Hazard Mapping System. ICU admissions data were acquired from Premier, Inc. and encompass 15%–20% of all U.S. ICU admissions during the study period. Associations were estimated using a distributed‐lag conditional Poisson model under a time‐stratified case‐crossover design. We found that a 10 μg/m 3 increase in daily wildfire PM 2.5 was associated with a 2.7% (95% CI: 1.3, 4.1; p = 0.00018) increase in ICU admissions 5 days later. Under stratification, positive associations were found among patients aged 0–20 and 60+, patients living in the Midwest Census Region, patients admitted in the years 2013–2015, and non‐Black patients, though other results were mixed. Following a simulated severe 7‐day 120 μg/m 3 smoke event, our results predict ICU bed utilization peaking at 131% (95% CI: 43, 239; p < 10 −5 ) over baseline. Our work suggests that hospitals may need to preposition vital critical care resources when severe smoke events are forecast.

Combined Effect of Hot Weather and Outdoor Air Pollution on Respiratory Health: Literature Review

“…A very significant consideration is the occurrence of wildfires caused by hot weather, which are associated with dangerous levels of pollutants and therefore affect respiratory health [9,63,108,124,125]. A vivid manifestation is the several large wildfires of unprecedented scale and duration that occurred recently, including wildfires in European Russia in 2010 [108,126], Australia in 2019 to 2020, the Amazon rainforest in Brazil in 2019 and 2020, the western United States in 2018 and 2020, and British Columbia, Canada in 2017 and 2018, with the huge impact on the population in terms of adverse effects on respiratory health [127].…”

“…In multiple studies, air pollution from wildfire smoke was associated with more asthma exacerbations, ED visits, and hospitalizations for bronchitis, dyspnea, and COPD symptoms. Wood smoke particles can activate systemic and pulmonary inflammation, even in healthy human subjects [1,125,[128][129][130][131][132][133][134][135][136].…”

“…Long-term prevention efforts should aim to improve the general health condition of people at risk, implementing special prevention plans for cities [125,137,198,199] and conceptualizing special green and blue infrastructure in the built environment [199][200][201], with the paramount need to establish joint heat and air pollution warning systems [59,66,186,193,202]. Sustainable urban planning and smart city design developing integrated sustainability performance for innovative energy systems in smart cities could significantly reduce both UHIs and air pollution [203,204], enhance human thermal comfort, and decrease heat-and pollution-related mortality, thus saving lives [200].…”

Future Property Risk Estimation For Wildfire In Louisiana, USA

“…In recent decades, studies on environmental impacts of wildfire have emphasized the role of wildfire dynamism and variability at the regional level (Morgan et al 2001, Vázquez et al 2002, Cleland et al 2004, De la Riva et al 2004, Schoennagel et al 2004, Malamud et al 2005, Moreira et al 2009, de Zea Bermudez et al 2010, Aldersley et al 2011, Garcia-Gonzalo et al 2014Ferreira et al 2014, Marques et al 2017, Strydom and Savage 2017, Colantoni et al 2020, in part because climate change implications on ecosystems (Davis et al 2019) present unique challenges for hazard management in each wildfire regime (Pacheco et al 2015). Regarding human health impacts of wildfire, the southeastern U.S. has been found to be most affected by hospital admissions and premature deaths due to wildfire events in the U.S.A. (Fann et al 2018), in addition to generally unhealthy conditions due to wildfire-related smoke (Kaulfus et al 2017, Sorensen et al 2021. From a property loss perspective, wildfire impacts have been substantial, especially at the WUI.…”

Quantifying the Health Benefits of Face Masks and Respirators to Mitigate Exposure to Severe Air Pollution

“…Climate change has increased the frequency and severity of wildfires in the western United States, thereby increasing the number of smoke‐impacted days in populated areas (Ford et al., 2018; O’Dell et al., 2019; Westerling et al., 2006). Wildfire smoke events can produce an appreciable public health burden as a result of large population exposure to potentially high concentrations of PM 2.5 (Brey et al., 2018; Sorensen et al., 2021; Val Martin et al., 2015). Of the constituents in smoke, PM 2.5 is thought to be the primary contaminant leading to increased risk factors of ill health, though gas phase components may also contribute to negative health outcomes (e.g., O’Dell et al., 2020).…”