According to a recent study by the Boston University School of Public Health (BUSPH), individuals with restricted access to air conditioning are more likely to seek emergency medical treatment for health issues arising from exposure to wildfire smoke. The study, awaiting publication in the journal Environmental Research: Health, highlights the link between inhaling delicate particulate matter (PM2.5) from California’s wildfire smoke and an uptick in visits to emergency departments. These visits encompass various causes, with a notable emphasis on respiratory diseases, and display significant variations based on age and racial demographics. Notably, the risk escalates for those residing in zones where air conditioning systems are less prevalent.
This revelation is particularly timely, as firefighters are combating several wildfires across Southern California, including the Palisades fire, which has been described as the largest and most devastating in Los Angeles County’s history. In light of these ongoing wildfires, health officials advise locals who can safely stay in their homes to utilize air conditioners and air purifiers to mitigate the inhalation of smoke. Despite these recommendations, there has been scant research on how the availability of air conditioning might influence the health impacts of wildfire smoke, a gap this study seeks to fill.
Dr. Jennifer Stowell, the lead researcher and a climate and health scientist at BUSPH, emphasized the potential role of air conditioning systems in modifying the health outcomes of smoke exposure. The study primarily focuses on the likelihood of having access to air conditioning rather than the types of air conditioning systems or their actual usage. Dr Stowell notes that further research is critical as the frequency and intensity of wildfires increase due to climate change. This makes California a prime example with its expanding fire seasons and escalating fire severity. A crucial next step is enhancing our understanding of air conditioning access.
The research team utilized a comprehensive national healthcare database to examine over 50,000 emergency department visits during the California wildfire seasons from 2012 to 2019. They assessed the detrimental health effects of PM2.5 exposure on all participants and specific subgroups, establishing that exposure to wildfire smoke primarily leads to emergency visits for respiratory conditions. However, it does not significantly impact cardiovascular health. The findings indicated a heightened risk among children under 10, adults aged 20 to 74, and particularly within the Black community. However, increased rates were also observed among White, Hispanic, and Asian/Pacific Islander groups.
Individuals in areas with lower air conditioning availability faced a 22-percent increased risk of emergency department visits for respiratory issues linked to wildfire smoke. The study underlines the importance of understanding how air conditioners, which can serve as tools to filter pollutants, are accessed by various populations. This insight is vital as wildfires are expected to become more frequent, particularly in the Wildland-Urban Interface (WUI)—areas where human settlements meet dense vegetation, as is currently the case in Los Angeles County.
Dr Stowell also points out the specific dangers of WUI fires, which include the combustion of man-made materials and the resultant release of toxic chemicals. She discusses the current out-of-season fires in LA, driven by severe Santa Ana winds, as an example of how climate change could intensify such unusual weather patterns, leading to more frequent late-season fires.
Regarding residential air conditioning, the effectiveness of these systems in removing PM2.5 depends on the type of filters used. While HEPA filters can trap most particles larger than 0.3 µm, they are costlier compared to more standard options like fibreglass or generic pleated filters, which are less effective against finer particulate matter. Systems with a Minimum Efficiency Reporting Value (MERV) rating of seven or higher are deemed most effective but more expensive.
The implications of these findings are significant, prompting calls for more substantial policy initiatives to reduce health risks from wildfire smoke. Dr Stowell stresses the need for policymakers to improve public understanding of air filter types and ratings and suggests economic assistance for marginalized groups disproportionately affected by these health impacts. In response to the current wildfires, she advocates for proactive government measures to enhance emergency preparedness and policies to lessen exposure risks before such events occur. This comprehensive study sheds light on the acute challenges of wildfire smoke and charts a path forward for more resilient public health responses in smoke-prone regions.
More information: Jennifer Stowell et al, Emergency department visits in California associated with wildfire PM2.5: differing risk across individuals and communities, Environmental Research: Health. DOI: 10.1088/2752-5309/ad976d
Journal information: Environmental Research: Health Provided by Boston University School of Public Health
