Energy Innovation partners with the independent nonprofit Aspen Global Change Institute (AGCI) to provide climate and energy research updates. The research synopsis below comes from Savannah D’Evelyn, Ph.D., an environmental health scientist and bio-social scientist at the University of Washington. A full list of AGCI’s updates covering recent climate change and clean energy pathways research is available online at https://www.agci.org/solutions/quarterly-research-reviews.

In 2020, 25 million people across the United States were exposed to dangerous levels of wildfire smoke. This is a massive increase from just 10 years ago, when less than half a million people were exposed to unhealthy levels of smoke pollution. The recent spike in smoke exposures across the U.S.—often thousands of miles away from the fire itself—has brought wildfires and their smoke into the national spotlight. In recent years, smoke has become so commonplace in the summer that many people have started referring to fire season as a fifth season. As wildfires become more frequent and severe and extend into the fall and spring, residents in smoke-impacted regions must work to ensure their communities are not only fire-safe, but smoke-ready.

The concept of a “smoke-ready community” is relatively new. The U.S. Forest Service (USFS) started using the term in 2016 and has since partnered with the U.S. Environmental Protection Agency (EPA) to help communities prepare for the impacts of smoke during worsening fire seasons. The Interagency Wildland Fire Air Quality Response Program—a group within the USFS—defines smoke readiness as when “communities and individuals have the knowledge and ability to stay reasonably safe and healthy during smoke episodes.” While the definition is straightforward, implementation in smoke-impacted communities is complex—especially as the number of communities impacted by wildfire smoke grows with each season.

In order to stay safe and healthy during smoke season, both community leaders and individuals need to understand the health impacts of exposure, know the interventions they can take to mitigate health risks, have access to accurate air quality data, and most importantly, have access to clean indoor air. Recent research underscores opportunities to improve smoke readiness across these dimensions.

Understanding the health impacts of exposure

Improved communication around both the health impacts of smoke exposure and the steps that can be taken to reduce these exposures is essential to creating a smoke-ready community. Children, the elderly, outdoor workers, and people with pre-existing conditions are among those most impacted by exposure to wildfire smoke. Health risks of smoke exposure for these populations include decreased lung function, exacerbation of existing respiratory and cardiovascular disease, and increased risk of cardiac and neurologic events, among others. But healthy, adult populations are also susceptible to these risks. Short-term exposure can lead to minor symptoms such as eye, nose, and throat irritation, headaches, coughing, and wheezing.

The Confederated Tribes of the Colville Reservation, the Okanogan River Airshed Partnership, and the University of Washington recently collaborated to interview residents in rural Washington about their perception of smoke from wildland fire. Many participants shared that while they were concerned for their kids or grandparents, they didn’t think smoke was affecting them personally. Several participants commented on the acute, short-term impacts they experienced such as coughing or headaches, but explained that learning more about the health effects hadn’t been a priority.

Beyond the physical toll wrought by wildfire exposure, a study led by Anna Humphreys published in BMC Public Health investigated how community exposure to prolonged wildfire smoke impacted residents’ mental health and wellbeing. The authors found the main health impacts to be anxiety, depression and stress, respiratory illnesses, and exacerbation of pre-existing conditions, while social impacts included isolation and cancellation of community events. Both studies identified a need for improved communications around the health impacts of smoke exposure and the need for community resources to stay safe and healthy.

Interventions to mitigate health risk

Michael B. Hadley and colleagues proposed a list of individual and community-based interventions that can reduce the health risks of smoke exposure in a recent paper published in the American Heart Association journal Circulation. The paper states that while the physical health impacts of smoke exposure are significant, they are also avoidable. In particular, the authors suggest that intentional engagement with healthcare systems in intervention planning could be beneficial to smoke-readiness.

The study went on to identify key interventions, including
● preparing healthcare systems for wildfire smoke;
● identifying and educating vulnerable populations;
● minimizing outdoor activities;
● improving access to cleaner air environments;
● increasing use of air filtration devices and personal respirators; and
● aggressive management of chronic diseases and traditional risk factors.

These interventions could reduce a wide range of the physical impacts of smoke exposure if implemented by individuals, healthcare organizations, and communities as a whole. It is also important that these interventions are not only considered during smoke season, but before, during, and after smoke events (Figure 1).

Access to accurate air quality information

Unfortunately, many communities lack access to the air quality information they need to make informed decisions and to implement these types of interventions. Neighborhood-specific air quality data is limited in rural regions and EPA-regulated air quality monitors are often clustered around urban areas, leaving rural areas without accurate or reliable air quality information. This can be particularly challenging when the air is smoky, as air quality levels can change quickly by neighborhood and accurate information is needed to make informed decisions.

For a paper published in the International Journal of Environmental Research and Public Health, Amanda Durkin and co-authors examined the motivations and experiences of residents who agreed to host an air quality monitor in their homes as part of a low-cost community monitoring network. Residents stated that they used the monitors throughout smoke season to understand air quality conditions and make decisions to minimize exposure, such as determining when to wear an N95 mask, finding clean air elsewhere in the region, and deciding to exercise indoors or outdoors.

Access to clean air

Communities faced with poor air quality are commonly told to remain indoors. While not realistic for everyone, this recommendation also assumes that indoor air quality is significantly better than outdoor air. In a Proceedings of the National Academy of Sciences (PNAS) study led by Yutong Liang, authors crowdsourced indoor and outdoor air quality data from PurpleAir sensors in homes around the San Francisco and Los Angeles metropolitan areas during the 2020 fire season. Authors found that indoor particulate matter (PM) tripled on fire days compared to indoor air on non-fire days, and that infiltration of smoke was significantly worse in homes built before 2000.

Steps can be taken to improve indoor air quality, such as improving the seals around doors and windows, upgrading HVAC systems with higher quality filters, or introducing portable air cleaners. A study led by Jianbang Xiang in Science of The Total Environment measured PM levels in homes during the 2020 smoke season in Seattle and found that while infiltration rates were high, HEPA-based portable air cleaners significantly reduced indoor PM levels. Increased use of air cleaners—especially for more vulnerable populations—could have a significantly positive impact on health during smoke season.

Based on this information, several communities have implemented portable air cleaner loan programs during fire season. In northern California, the Bay Area Air District has partnered with the Public Health Institute to provide over 3,000 portable air filtration units to low-income residents diagnosed with poorly controlled asthma. The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) has also developed Guideline 44P to provide HVAC and building measures to minimize occupant exposures during wildfire smoke events (Figure 2).

Some communities are working to improve access to clean air for residents by implementing clean air centers, or community buildings that can reliably provide improved air quality during periods of wildfire smoke. Of course, these spaces come with their own challenges. In a study led by Ryan J. Treves published in Society and Natural Resources, researchers interviewed both government employees involved in the implementation of clean air centers as well as community members impacted by smoke exposure in California. The challenges of implementing an effective clean air center included poor communication with vulnerable populations and the inability to provide transportation and access to those most in need. Community participants described feeling unprepared for and frightened by smoke season. While they were interested in the concept of clean air centers, they lacked the knowledge about how to access and utilize them.

The literature on the utilization and efficacy of clean air centers is incredibly limited. In a web series on clean air spaces hosted by the EPA, experts identified designated clean air spaces as an area of future research, noting that clean air centers could potentially be effective in building community resilience to smoke if combined with other interventions.

Conclusion

In the (currently hypothetical) ideal smoke-ready community, everybody is aware of the health impacts of smoke exposure and knows what steps they can take to reduce exposure; all individuals have access to accurate and reliable air quality information that can inform their decisions around smoke exposure, regardless of the community’s location; and all residents have access to clean air, whether they are an at-risk individual, outdoor worker, or a healthy adult. Wildfires are not going away anytime soon. As more communities are exposed, additional research can help us better understand the health effects of smoke exposure and the best measures to mitigate harm. This research, combined with additional resources and capacity, can ensure communities are ready when the smoke inevitably comes.