Wildfire Smoke in Northern California

Publication Date: 2025

Abstract

Wildfire smoke is a growing public health threat in the United States. Distinct from other climate change-related hazards, the fluctuating, recurrent nature of wildfire smoke may lead to variations in threat perception and response, even within families. Using a dyadic qualitative design, this study aimed to examine the distinct mental health concerns, risk perceptions, and protective behavior among two vulnerable but understudied age cohorts: young adults (ages 18-34) and members of the so-called sandwich generation (ages 50-64), who may be caring for their children and aging parents at the same time. Informed by a novel Wildfire Smoke Footprint Map developed by our study team, we identified two California counties with high historical smoke exposure—Sonoma County and Butte County—that also experienced a smoke event during the 2024 wildfire season (i.e., the Santa Rosa Point Fire and the Park Fire). We recruited families within each county to participate in in-depth interviews using a combination of purposive and snowball sampling. Interviews were conducted with each family member separately and iteratively compared during data analysis. To date, we have conducted 20 interviews. Preliminary findings suggest that, for both generations, wildfire smoke events have a sensitizing impact on mental health in the near-term (i.e., heightening the risk of a negative psychological response), with the smoke acting as a trigger of past wildfire-related traumas. However, despite heightened anxieties during an acute event, findings also suggest that recurrent exposure to wildfire smoke may have a numbing effect on motivation for taking personal protective action over the long term. These findings indicate the need for long-term disaster mental health supports beyond the acute exposure period, as well as programs and strategies to support long-term protective behavior.

Introduction

Anthropogenic climate change is increasing the frequency and severity of wildfires in the United States, posing substantial risk to public health and well-being. In California, 18 out of the 20 largest fires in the state’s history have occurred since 2003, with the five largest occurring since 2018 (CAL FIRE, n.d.¹). While the flames themselves present an acute threat to lives, housing, and local ecology, wildfire smoke emits pollutants that significantly threaten psychological, cardiovascular, respiratory, and neuro-cognitive health (Gould et al., 2024²; Grant & Runkle, 2022³; Liu et al., 2015⁴; Reid et al., 2016⁵). Wildfires now account for up to 25% of PM2.5 concentrations across the United States and up to 50% in Western states (Burke et al., 2021⁶). It is estimated that the number of premature deaths attributable to fire-related PM2.5 in the United States will double over the next 80 years (Ford et al., 2018⁷). In California alone, recent analyses estimate that as many as 55,710 people died prematurely between 2008 and 2018 as a result of wildfire-associated PM2.5 (Connolly et al., 2024⁸).

The increase in the volume and burden of smoke exposure, and its attendant risks to population health, has led for calls to re-think our framing of wildfire as a public health disaster; as a recent American Journal of Public Health editorial states, “It’s the smoke, not the fire” (Eisenman, 2023⁹). Wildfire smoke is a dispersive climate threat for those residents who are safe from the fire’s direct path but still bear the brunt of the aerosolized particulate matter. In this way, wildfire smoke simultaneously functions as a recurrent exposure and an interpretive event, its fluctuation leading to variation in threat perception and response, even within families.

This study focused on two understudied life stages: young adulthood (ages 18-34) and late middle age/early older adulthood (ages 50-64). People in these distinct phases of life face different stressors and have different levels of rootedness in place, threat salience, and perceived vulnerability to wildfire smoke. Despite experiencing elevated levels of climate anxiety (Hickman et al., 2021¹⁰), young adults are less likely to adhere to air quality alerts than middle-age and older adults (Postma et al., 2022¹¹). These behavior differences may manifest in different acute health outcomes. Between 2006 and 2020, for example, young adults in California were more likely to visit the emergency room for headache-related conditions during wildfire smoke events than older adults (Elser et al., 2023¹²), suggesting a need for improved public health intervention. The purpose of this study, therefore, was to examine how young adults and their parents experience recurrent wildfire smoke, including levels of perceived threat, anxiety, and protective strategies.

Literature Review

Wildfire Smoke and Mental Health

Emerging evidence suggests that wildfire exposure may have acute and long-term mental health effects. An interrupted time series analysis of psychotropic medication prescriptions in California between 2011 and 2018 found a significant increase in antidepressant (RR, 1.04 [95% CI, 1.01-1.07]), anxiolytic (i.e., anxiety-reducing) (RR, 1.05 [95% CI, 1.02-1.09]), and mood-stabilizing medications (RR, 1.06 [95% CI, 1.01-1.13]) during fire periods (Wettstein & Vaidyanathan, 2024¹³). A recent systematic review of the health impacts of wildfire identified 21 studies where wildfire exposure was significantly associated with a range of mental health diagnoses, including posttraumatic stress disorder, major depressive disorder, generalized anxiety disorder, and severe psychological distress (Gao et al., 2023¹⁴). Only a handful of studies, however, have examined wildfire smoke as a hazard event distinct from the wildfire itself, making it difficult to parse which mental health impacts are attributable to heavy smoke exposure from those which are attributable to evacuation, displacement, or direct encounter with flames. Some research has shown that long-term wildfire smoke exposure is associated with mortality related to mental disorders (Ma et al., 2024¹⁵), including death from suicide (Molitor et al., 2023¹⁶). Further, a recent analysis of 2007-2018 emergency department visits in the Western United States found that people who were exposed to a major smoke event were more likely to seek emergency care for anxiety disorders (OR, 1.056 [95% CI, 1.009, 1.056]) (Zhu et al., 2024¹⁷). These early studies strongly bolster the argument that more research assessing smoke as a mental health risk factor distinct from wildfire is needed.

Moreover, the extent to which smoke exposure affects subacute mental health outcomes (i.e., an outcome not requiring hospitalization) is even less studied. Indeed, the focus in early studies on diagnostic codes has left unexplored what meanings, attributions, and risks individuals and communities ascribe to wildfire smoke and the mechanisms by which smoke impacts their mental health. For instance, it is possible that wildfire smoke impacts mental health via interrupted sleep patterns, changes in behavior (i.e., reduced physical activity), or disrupted work or educational routines (Gould et al., 2024). Eisenman and Galway (2022) conducted a scoping review to map potential pathways through which wildfire smoke impacts mental health and well-being. Drawing on evidence from 15 empirical studies, the authors illustrated individual, social, and ecologic mechanisms, building a conceptual framework adapted from Bronfenbrenner’s Ecological Systems Theory (Bronfenbrenner, 2005¹⁸; Eisenman & Galway, 2022¹⁹). However, this review only identified a single, qualitative study focused on chronic smoke exposure (Humphreys et al., 2022²⁰), highlighting a need to investigate how these mechanisms unfold over time to impact mental health in the context of recurrent smoke events. Research on other types of cumulative exposure environments suggests some possible ways that high-intensity smoke events may affect mental health. Some research has shown cumulative exposure leads to a sensitizing impact on mental health in the short-term, where those with previous experience with smoke events are at heightened risk for negative psychological response during subsequent events (Harville et al., 2018²¹). Studies also show that cumulative exposure may result in people becoming habituated to repeated exposure and engaging in greater risk-taking behavior during future events (Harville et al., 2018; Santana et al., 2021²²).

Disasters and the Life Course

The scholarship on disasters and health has primarily focused on the two poles of the life course: childhood (ages 0-18) and late adulthood (over age 65), each of which has distinct biological, social, and material needs during disaster (Adams et al., 2011²³; Beedasy et al., 2021²⁴; Fothergill & Peek, 2015²⁵; Lynch & Merdjanoff, 2023). While older adults may be uniquely vulnerable during the acute phase of disaster (Lynch & Merdjanoff, 2023²⁶), recent evidence suggests that the young-old—those who are aged 50-64—fare worse in the long-term as they are shouldered with the social, emotional, and financial burden of navigating the bureaucracy of recovery (Adams et al., 2011; Merdjanoff et al., 2019²⁷). The young-old are sometimes called the sandwich generation because they are often responsible for caring for children and aging parents at the same time; when climate disasters occur during this critical period in the life course, people may have to change their plans about sending their children to college, when (or whether) to retire, whether to relocate, or how to care for elderly parents. There is emerging evidence that chronic exposure to poor air quality is associated with impediments to healthy aging, including high stress, chronic disease burden, cognitive impairment, frailty, and decreased longevity (Ailshire et al., 2017²⁸; Cohen et al., 2022²⁹; Gould et al., 2024). Understanding the experiences, concerns, and needs of the young-old cohort will provide critical information to organizations that aim to support healthy aging in regions of California vulnerable to wildfire smoke events.

In similar ways, young adults are largely absent from the disaster literature as a focus of study (O’Donohue et al., 2021³⁰). What we know about their disaster experiences comes mostly from studies of adolescence or the general adult population. From the recent literature on children and disasters, we see evidence of a dose-response relationship, where greater event exposure is associated with higher odds of psychosocial distress in adolescence (Auchincloss et al., 2024³¹; Edwards et al., 2024³²; Meltzer et al., 2021³³). In the first review of its kind focused on young adult psychological health and well-being following disaster events, O’Donohue and colleagues (2021) identified elevated depression, anxiety, post-traumatic stress disorder and substance use among this age cohort. However, the review also found limited research that examined young adults as a distinct age group disaggregated from the broader adult population, and almost no qualitative research which situates young adults’ experiences of these symptoms within a wider sociocultural context. The following year the same author team published an analysis of the psychological impact of the 2014 Hazelwood smoke event in Victoria, Australia, and found that age was an effect modifier of the association between exposure to PM2.5 and smoke event-related psychological distress (O’Donohue et al., 2022³⁴). For every 10 μg/m3 increase in mean PM2.5 exposure, there was a 2.08-point increase (95% CI: 0.11 to 4.10) in distress scores among the young adult age group, compared to no change among those aged 65 and over (−0.04; 95% CI: -0.75 to 0.67). This suggests a possible link between exposure to wildfire smoke and adverse psychological outcomes among young adults, but the effects of repeated exposure in young adulthood is underexamined.

Research Questions

While there is substantial evidence that wildfire smoke exposure is associated with negative health consequences in the near-term (Gould et al., 2024), the impact of smoke exposure on mental health and well-being over the life course is understudied. There is an urgent need to examine the impacts of recurrent wildfire smoke exposure on mental health, well-being, and behavior, especially as anthropogenic climate change places communities at risk of repeated exposures and prolonged smoke events (Humphreys et al., 2022). In this study, we answered the following research questions:

• What are the distinct mental health concerns of young adults (ages 18-34) and adults in the sandwich generation (ages 50-64) who were exposed to smoke events during the 2024 California wildfire season?
• How do sandwich generation parents and their young adult children living in high exposure regions in California perceive risks related to wildfire smoke?
• What risk or protective behaviors did members of these generational cohorts engage in during the 2024 California wildfire season?

Research Design

In this study, we used a dyadic qualitative design to conduct in-depth interviews with families residing in historically high wildfire smoke-exposed counties who also experienced a smoke event during the 2024 fire season. As described above, the ephemeral nature of smoke exposure also renders smoke events as interpretive events, with their threat salience founded on the subjective experience and social positioning of the individuals exposed. Thus, we felt that a qualitative study design would be the most appropriate approach to answer our research questions. We chose a dyadic interviewing methodology, which elicits narratives separately from multiple members of a relationship, because it allows for the analysis of similarities and differences both within and between relationships (Witting et al., 2021³⁵). This approach enabled us to gain insight into how recurrent smoke exposure may impact family dynamics and manifest differently across the life course.

Study Site and Access

To identify the California counties where we wanted to recruit interviewees for this study, we used a novel Wildfire Smoke Footprint Map, which we have developed in collaboration with our partners at the National Center for Atmospheric Research (NCAR) for a separate research project on aging and wildfires (Abramson, 2022-2025³⁶). The map is a dynamic dataset which uses historical data from the NCAR Fire Inventory to simulate the formation and evolution of carbon monoxide (CO) and primary PM2.5 and PM10 aerosols emitted by fires in California since 2005 (Lacey et al., 2025³⁷). We used the map to identify California counties that met the following sampling criteria:

1. The county had high cumulative wildfire smoke exposure, which was measured by smoke concentrations averaged across the 2005-2018 fire seasons.
2. The county experienced an acute wildfire smoke event during the 2024 fire season.

We chose two counties that met both sampling criteria: Sonoma and Butte Counties. Both counties have been subject to multiple, high intensity wildfire smoke events in the past decade, including the Tubbs Fire (2017), Camp Fire (2018), Kincaid Fire (2019), Glass Fire (2020), and August Complex gigafire (2020). Both counties also experienced acute wildfire smoke events during 2024: the Point Fire (Sonoma) and the Park Fire (Butte). The Point Fire ignited on June 16 and burned for eight days across 1,207 acres, causing Sonoma county to declare a local emergency, issuing an evacuation order and air quality alerts for unhealthy levels of particulate matter (County of Sonoma, 2024³⁸). On July 24, the Park Fire ignited in Chico’s Bidwell Park in Butte Country, and grew to be the largest fire of the 2024 season—ultimately burning 429,603 acres—and the fourth largest in state history (CAL FIRE, n.d.).

Interviews

Sampling Strategy

To facilitate an in-depth exploration of family smoke exposures, experiences, and risk perceptions across the two communities, we aimed to sample 10 parent-child dyads from Sonoma County and 10 parent-child dyads from Butte County. While both counties have similar gender and age composition, Butte County is less densely populated, has a higher proportion of residents living in poverty, and is less racially diverse. Select sociodemographic characteristics of Butte and Sonoma County are summarized below in Table 1, using 2024 population estimates from the U.S. Census Bureau (n.d.³⁹).

Table 1. Sociodemographic Profile of Butte and Sonoma Counties, California

Within each county, participants were sampled via purposive and snowball sampling, facilitated by local advocacy groups (Fire Safe Sonoma; Sonoma County Climate Action Network), community colleges (Butte College; Santa Rose Junior College), and universities (Chico State University). Following qualitative study design principles, we did not aim for a generalizable sample of northern Californians, but rather aimed to attain a sample with a diversity of lived experiences related to wildfire smoke exposure across age, ethnicity, gender, and length of residence.

Participant Recruitment, Consent, and Other Details

In early October 2024, the lead author conducted an in-person field visit to facilitate participant recruitment. This included conducting key informant interviews with representatives of local organizations about community needs and concerns related to wildfire smoke. The lead author also visited local colleges, universities, student organizations, community groups, and public libraries, and sought permission to disseminate recruitment flyers on campus bulletin boards and organizational LISTSERVs. The flyer included a QR code which linked to a screener form to assess participant eligibility and general availability for an interview. (A copy of the flyer is available in the Appendix.) Individuals were eligible for participation if they met the following criteria: (a) were between the ages of 18-34 or 50-64, (b) were a part-time or full-time resident of Sonoma or Butte counties; (c) experienced a smoke event during the 2024 fire season; and (d) had at least one living family member in the opposing age group willing to participate in a separate interview. The screener also included sociodemographic questions to assess race, ethnicity, and length of residency in California. If respondents were eligible, they were contacted to schedule an interview. At the end of each interview, participants were asked to provide contact information for the parent or adult child that they wanted to be invited for the dyad interview. To facilitate snowball sampling, each participant was also asked if they had any friends or neighbors who met the eligibility criteria and who they would like to refer for an interview. All participants were compensated with a $75 Amazon gift card as a thank you for their time.

Interview Sample

By the end of 2024, we had conducted 20 interviews (n=16 Sonoma County, n=4 Butte County). This total includes eight parents between the ages of 50 and 69 (mean age: 54.5) and 12 young adults between the ages of 19 and 34 (mean age: 22.1). At the time this report was written, all completed parent/ young adult dyads were from Sonoma County. Young adults had lived in California for an average of 21.5 years; parents an average of 43.1 years. Table 2 summarizes characteristics of this preliminary interview sample.

Table 2. Select Characteristics of Interview Sample

Interview Setting

All interviews were conducted by the lead author, either in-person during the October 2024 field visit, or remotely via telephone or secure videoconference (Zoom). In person interviews took place at a location of the participants’ choosing, including local coffee shops or a quiet outdoor space on campus. Interviews lasted between 40 and 90 minutes and explored the following topics: (a) Experiences during the 2024 smoke event(s), including mental health changes or concerns; (b) Behaviors during the smoke event and perceived efficacy of any mitigation behaviors; and (c) Perceptions of short and long-term health risks of wildfire smoke for themselves, for other family members. All interviews were audio recorded with participant consent, and professionally transcribed verbatim for analysis.

Data Analysis Procedures

Cleaned transcripts were checked for accuracy and uploaded into NVivo (version 14.0) for data management and analysis. For this interim analysis, we adopted a flexible coding approach to identify preliminary themes. Flexible coding, a novel approach outlined by Deterding and Waters (2021) is a sociological data reduction technique that begins with index coding, wherein large, topic-based codes are used to organize interviews into discrete content areas. Index codes for this analysis were generated based on domains of the interview guide and our main research questions (e.g., “Smoke Exposure,” “Mental Health Impacts,” “Protective Behaviors,” “Information Seeking,” and “Risk Perceptions”). Coding resulted in these index codes encompassing large segments of the interview transcripts. During the coding process, the lead author generated reflective memos for each transcript to annotate emerging key concepts within each index. These memos were used to create analytic codes that could be applied to each indexed section. Following recommendations for flexible coding, analytic codes were applied to one research question at a time (Deterding & Waters, 2021⁴⁰). Finally, we conducted a preliminary analysis of the eight dyads to assess the degree of convergence and divergence between young adults and their parents within each index.

Ethical Considerations and Researcher Positionality

We obtained ethical approval from the New York University Institutional Review Board on August 30, 2024. We obtained informed verbal consent from all participants prior to the interview and emailed them a copy of the consent document for their own records. Multiple steps were taken to ensure participant confidentiality and maintain data security throughout all phases of the study, including allowing participants to use a pseudonym during the interview, identifying transcripts and recordings using only a study ID number, and storing all research files on a secure shared drive (NYU Box) accessible only by trained members of the research team listed on the protocol. The lead author is a doctoral student in the Social and Behavioral Sciences department at the NYU School of Global Public Health and the co-authors, who are also her mentors, are PhD-level social scientists with expertise in natural hazard and disaster research. The lead author grew up in the Northeastern United States, and while she has worked on multiple research projects related to natural hazards, she does not have lived experience with major wildfire smoke events (beyond the New York City smoke event of June 2023, and hearing stories from family members in Southern California). Therefore, she entered the field setting as an outsider, with the goal of learning from the lived expertise of the study participants. At the start of each interview, she would share that she grew up in New England, not California, and hoped to learn from the perspective of those who grew up in an environment different from her own. She incorporated her outsider status into interview probes (e.g., “What is something that someone who didn’t grow up here wouldn’t necessarily know about wildfire smoke?” “How would you describe the feeling of a smoke event to someone who has never experienced one?”) to help encourage participants to situate themselves as the experts in their narratives. This orientation toward the interviews helped build rapport and trust between interviewer and interviewee, and allowed for the spontaneous emergence of key ideas that would not have been possible through a priori probes alone.

Findings

This section summarizes preliminary findings from the interviews and is organized into subsections that correspond to our research questions. We selected exemplary quotes to represent the emerging themes in the data and to ground the findings in participants’ own words.

Mental Health: Smoke as a Sensory Trigger

Across interviews, both young adults and their parents described the psychological as well as somatic impacts of wildfire smoke exposure. As one young adult in Butte County explained, “The thing about the smoke is it isn't just psychological and it isn't just physical. It's the combinations of both.” Participants expressed how the smell of smoke would trigger memories of previous wildfire exposures, exacerbating anxiety, panic, or a fight or flight response, even, as some participants shared, if they knew that the fire itself was miles away. As another young adult in Sonoma explained:

But I would say it just, like, annoys me when lingering county smoke comes in, because then it just puts me into kind of like a, not like a false panic, but like, it's like, I'm anxious and I know I shouldn't be because it's so far away. But like, I know it's like happening somewhere else. My brain likes to jump to like, “what if this, what if like that happens?”

Many of the families that we spoke with had experienced direct impacts (e.g., evacuation, property damage, displacement) from successive wildfire events since 2017. Following these exposures, multiple young adults shared that they were diagnosed with anxiety disorder, with symptoms exacerbated by wildfire smoke or changing wind conditions. The following two quotes from young adults in Sonoma and Butte are representative of these experiences:

I have generalized anxiety disorder. So, I don't know if that developed… actually thinking about it, that developed after probably the first fire in high school is when I started to experience it. And I think a lot of it was to do with like fire and like wind and smoke. Even fog triggers… I wouldn't say I have post-traumatic stress syndrome, but I know I get really stressed out when there's fires. And it's like that. For example, last night it was foggy and my first thought was smoke, but I was like, it's literally 30 degrees. It's just cold. But it's just kind of that initial reaction. Like same feelings that I was feeling like every single time I evacuate.

Because I remember [when the Park Fire ignited], I didn't sleep that day. I didn't sleep, but I was already going through some [stuff], you know, mentally. But that was like, it was like, oh, f---. I remember telling my family, like, I'm panicking. My friends were like, “No, we'll be fine. We'll be okay. We'll be fine.”’ And I’m like, “No, like, y'all don't even understand. Like, remember, this is what, this is what we thought… you guys, this is the reaction I was having during the Camp Fire and we saw how that went.” […] It's just bringing back these memories of it.

A few of the young adults in our sample shared feelings that their generation is uniquely susceptible to the mental health effects of wildfire smoke compared to older adults, in part due to their traumatic exposures at an early age. As one young adult in Butte County shared:

Even when the Park fire happened, which should have been terrifying to a lot of people… I was the person who was the most intense. Like, the other people who were very serious about [the fire] were my age, because I remember the older adults [were] just like, “whatever” […] Because they've been through it longer. And also, I think we [young people] remembered the Camp Fire a little, maybe more traumatically.

Another young adult in Sonoma County similarly shared that she feels “more anxious” during smoke events than her parents:

I feel like my mom kind of brushes it off a little more than I do. I feel like I definitely am the one that's more anxious and kind of frantic at times, because I feel like I can recall times where I've been anxious about something and my mom's like, “It's fine, you're fine, don't worry about it.” So, I think I'm definitely more on the worried side than my parents are. I think it's just because I experienced it at such… I was a younger age. Like I couldn't drive, I couldn't do anything for myself. So, I think that's really what our differences are.

In contrast, the parents we spoke with described the dual burden of managing their own stress and anxiety, while trying their best to project a sense of calm to their children. As one parent in Sonoma emphasized, “It's the stress [that] on top of the health stuff is the emotional toll it takes, the mental health. And I think having a kid makes that, like amplifies that…” Another parent in Sonoma expressed similar concerns:

And it's interesting, because I'm sure [my child] has a different perspective on things. You know, because he had parents [to protect him]. Like I remember when my parents were like… at the end of the day, I knew that they were going to take care of me. And then when you're the parent, that's so scary. Because this is like your heart is walking around outside your body, you have to protect them no matter what. And stuff like that happens and you're just like, oh my God. I can't, I'm so upset that my kid is having to go through this.

The parents in our interview sample also expressed fears about the potential long-term impacts of recurrent smoke events—periods of acute anxiety and disrupted routines—on children’s mental health. As another parent said:

And it's so hard and, again, I think watching your kids… you know they seem okay but like are they really okay? [A]nd then you know you try your best to not be terrified in front of them or, you know, worried that you know your home might not be there. Not only that, but even if we weren't physically affected [by an event] in the sense that our house was in danger, it’s just [dealing with] the smoke, having to stay inside for so long.

Participants shared how smoke events could be simultaneously anxiety-inducing and numbing. Members of both generations described how the changes to daily life during smoke events led to mood changes and enhanced depressive symptoms. As one Sonoma parent described:

I mean, there's definitely an element of mood-changing because it impacts your day-to-day, you know, what you normally do. And, you know, you change plans or you choose not to be outdoors. You don't take your dogs for a walk. You don't open up your windows. So, yeah, I think overall, it definitely, I think with that, it's just I think anxiety also increases during those times because your normal day-to-day is disrupted.

A few young adult participants linked their experiences during smoke events to memories of lockdown and social distancing during the early phase of the COVID-19 pandemic. As one young adult from Sonoma described, the rapid environmental and social changes during their middle and high school years had a “numbing” effect on their mental health:

During COVID when we had a big fire come up, it wasn't… like a threat to us or anything, but we were getting the smoke from it. When everything turned orange I took a big motivational hit because I was just like, it was like that lack of sun and it looks… everything looks depressing outside. I went through like a brief like depression period where I just lost a lot of motivation for stuff because it was just like… you know like COVID going on and all that. So that stacked up. But it's mostly like anxiety and I think like you just like freak out because you're just like, everything looks different. I've become more numb to fires these days. Like it's so routine now for us. Like [during] fire season like… you don't go outside. You can't like… there's ash all over the air.

This sense of simultaneous sensitization and numbing pervaded interviews, highlighting the emotional toll of successive exposure events. As one young adult in Sonoma described, “I would say like long-term effects [for] mental health, it just creates a sense of anxiety, but also a weird desensitization, too.” Similarly, another young adult in Butte expressed:

The Park Fire this year was terrifying. It was just a couple miles away from where we live. And we were never evacuated at my house, but a lot of people I know were. A lot of people I know lost their homes for the second time. It's just, yeah, as a community we come together in those times, and I think that that's really special and really powerful. But it's hard. It's so hard to continue to do that year after year, season after season, and not get burnt out on the emotional capacity that that takes.

Risk Perceptions and Protective Behaviors

The concurrent sensitizing impact of wildfire smoke, and the normalization of recurrent exposure, creates tension between short-term protective behaviors and concerns about long-term health. As one young adult in Sonoma described,

This has been a problem since seventh grade for me at this point. Like I spent a good chunk of my life like having to deal with it. So now it's like you're kind of used to it. It's a routine.

Participants mentioned multiple mobile applications that they use to monitor air quality, windspeed, and fire containment, including AirNow, Nixle, WatchDuty, Purple Air, Windy, MyRadar, Firespot, the iPhone weather app, and the CalFire website. Within the dyads, multiple children said that they use the apps to monitor air quality and fire risk in their hometown whereas parents reported using them to check how the air was in their child’s college town. This became a way for them to check in on family members and have peace of mind.

However, while some parents used air quality alerts to gauge their current decision-making about engaging in outdoor activity, they also expressed concerns about potential long-term effects of poor air quality on their children’s health, and whether there was a true “safe” threshold of exposure. As one parent in Sonoma described, frequent smoke events created tension as they were forced to make tradeoffs around what was “best” for their child’s development, since limiting outdoor exposure could also mean constraining physical activity and social interaction:

And there's times where I haven't sent my son [to soccer practice] just because, like for me, any like bad air is like not good. Like there's you know other things that you can do to like maybe run on the treadmill at home, as opposed to running out on the soccer field when we don't know long term what… what that threshold really is. Like we might learn later […] So I feel like my kids are in that kind of little bubble where it's like we don't know what the long long-term effects of what they have already been exposed to. Like going to school walking from class to class, like is that even safe? Like you know you're torn as a parent because it's like you don't want your kids to you know miss out on any more school than they already have collectively over the years. But at the same time like, again, we don't know exactly what, what is a safe level […] I just wish that there was more data. Like, you know, what is acceptable and what activities are acceptable? Like, those guidelines are pretty broad because, you know, I am assuming when they say, ‘sensitive groups,’ maybe [they mean] somebody with asthma or emphysema or any upper respiratory stuff. But what about other people who have different type of ailments?

This ambiguous risk threshold extended to decisions surrounding use of personal protective equipment during smoke events, such as wearing an N95 mask. Some participants, especially those with respiratory conditions, used the Environmental Protection Agency (EPA) Air Quality Index—where values over 100 are considered unhealthy for sensitive groups, and values over 150 unhealthy for the general population—to gauge their mask usage. As one young adult Sonoma explained: “I would say when the air quality reaches 150, that's when like, that's my cutoff where I'm like, yeah, I need to put on a mask.” On the other hand, others calculated their risk based on time spent outdoors. As one parent in Sonoma noted:

So this summer, [my child] was outside because he was working at a camp. And so I think he did mask up. But I work in an office […] So I was only exposed to the smoke basically between, uh, you know, walking to my car and then walking into the house.

However, many participants also described masking fatigue during wildfire season. As one young adult in Butte shared:

It used to be N95, [but] then it became at some point along the lines, f--- it, I've done worse. Once you go through, once you go through not seeing the sun for at least a week maybe probably longer um… […] I also think that there is some fatigue. Yeah, I don't want to put on an N95 a couple times a summer.

In a persistent exposure environment, wildfire smoke was simultaneously described as mentally distressing and desensitizing as participants became accustomed to their changing environment. As another young adult in Butte described, as smoke events increase in frequency, higher particulate exposure becomes the new normal:

I wonder how much of that is, we became so conditioned by 2020 to stop noticing [smoke days]. Because it's truthfully, it’s not like there haven't been bad fires necessarily. It's just that, like, you know, the idea that you have to put a frog in cold water and then turn up the heat slowly. You can't just drop them directly in the boiling water.

For young adults and parents alike, fatigue also came from a sense that it was “too late,” that they were fated to future health consequences from accumulated exposure. As one young adult in Sonoma described:

Going through that exposure at such a young age, like that like does worry me. Like, I don't know, like, does that mean I have more of a chance for lung cancer? Does that mean like… did I inhale something that shouldn't have been burnt that can like cause a mutation in my like DNA? Like what implications does this have? That's like probably I think about the most, I don't think about the immediate stuff […] more, what is this gonna do to me in like the future? Especially with playing sports, when they would like not cancel practices or games and like we would play in them. And like heavy breathing in that smoke cannot be good with all of the ash too.

The tension between previous, present, and anticipated future exposure, therefore, served to simultaneously desensitize participants to ongoing risks, as well as exacerbate general anxiety about long-term outcomes.

Discussion

The findings from these preliminary interviews support our initial hypothesis that wildfire smoke events have a sensitizing impact on mental health in the near-term. During the major smoke events of the 2024 California wildfire season, participants described symptoms of anxiety, distress, and depression, as the smoke served as a trigger for previous traumatic exposures. However, beyond acute experiences of environmental exposure and psychosomatic response, these preliminary findings also suggest that recurrent exposure to wildfire smoke can have a numbing effect, habituating participants to smoke events and hampering protective action. In contrast to our initial hypothesis that young people may be less likely to respond to smoke events due to a sense of youthful invincibility, what emerges in these interviews is a sense of growing fatigue and fatalism toward the inevitability of their exposure.

These emerging findings highlight the particular impact of wildfire smoke on the mental health of young adults. For this particular generational cohort, it is striking to observe how experiences of wildfire smoke are intertwined with the experiences of the COVID-19 pandemic: From adolescence into early adulthood, these young adults have experienced periodic disruptions to their schooling, outdoor activities, and social events. In the words of one young participant: “I think back to my high school years, and it was like fire, fire, pandemic, fire during the pandemic. Like it was just a lot. There was no normalcy for me in my high school years.” Perhaps, then, it is no wonder that among these young adults the smell of wildfire smoke is met with simultaneous fear and fatigue, that refreshing air quality mobile apps on their phones becomes more of a nervous tic than a preventative action, or that their risk threshold for masking increases throughout the season. For these young adults, the convergence of multiple hazards that accumulate over time creates a sense of fear and uncertainty about future ill-health for themselves and their family members, unsure whether poor outcomes can be prevented, or if it is already too late.

Conclusions

Implications for Practice or Policy

These findings point to the value of treating wildfire smoke not only for its acute impacts, but also for its accumulating impacts on mental and physical health. The sensitizing effect of wildfire smoke exposure—which serves as a potential trigger for a trauma response—underscores the need to extend disaster mental health services beyond the immediate aftermath of a wildfire, particularly for families who had to evacuate, were displaced, or who experienced housing damage (including smoke damage). As these interviews reveal, the mental trauma from childhood wildfire exposure can persist into young adulthood. Young adults and adolescents need counseling support that helps them develop coping strategies to manage stress responses during future smoke events. Parents also need additional mental health support. Sandwich generation adults who participated in this study described the burden of managing their own stress while putting on a “brave face” for their family, sometimes at the expense of their own mental health needs. Uncertainty over past actions, such as whether they made the “right” choices to protect their family and minimize exposure, can also enhance distress. This not only highlights the need for parent-specific mental health resources, but also decision support tools to assess risk during smoke events (for instance, providing clear examples of “sensitive groups” that may be at greater risk of harm due to poor air quality). The preliminary findings of this study also suggest that providing air quality information alone may not be enough to encourage protective behavior, particularly in recurrent exposure environments. This echoes findings from previous research on social media posts and internet activity during wildfire smoke events (Burke et al., 2022⁴¹). The authors of that study concluded,

[A]wareness of smoke concentrations does not appear to be a primary constraint on individual behavior in the face of wildfire smoke exposure … This suggests that policies targeting information provision [alone] about smoke are insufficient, and perhaps not central, to enabling protective behavior. (p. 1356)

Beyond passive information provision, future interventions should leverage social science theories of behavior change to bridge the gap between what people intend to do to protect themselves from perceived risks and what they actually do in practice, also known as the “intention-action gap” (Prince et al., 2024, p. 2⁴²). The app-based citizen science approach recently outlined by Prince and colleagues (2024), which proposes using the Smoke Sense app to crowdsource and disseminate local information about air quality and smoke, as well as nudge protective behaviors (i.e. closing windows, masking), is a promising example of a way to engage communities and establish positive social norms around protective action during smoke events.

Limitations

This study acknowledges several limitations. While we aimed to purposively sample dyads residing in counties with high accumulated smoke exposure, there may be selection bias in that only those participants who had significantly adverse experiences with smoke exposure, or heightened health concerns, would agree to participate in an interview. Conversely, it is also possible that participants who had especially traumatic experiences would not be comfortable participating in an interview, and we may be missing the most extreme cases of mental health burden. While we offered the option of in-person, Zoom-based, and telephone interviews to accommodate participant schedules and technology access, it is also possible that we could not reach families with limited bandwidth. Finally, all interviews were conducted in English, meaning that we were unable to gather the narratives and experiences of families who spoke other languages at home, including immigrant families who may face unique structural and social vulnerabilities during wildfire smoke events.

Future Research Directions

During the 2025 wildfire season, we will continue recruiting dyads in Butte and Sonoma counties until we reach our target sample of 40 parent and adult child pairs. At present, we have only enrolled complete dyads from Sonoma County. Thus, we are missing the voices of those in the sandwich generation whose reside in Butte County, which is less densely populated, less socioeconomically advantaged, and has a recent history of traumatic wildfire exposure. We therefore plan to focus our recruitment efforts on Butte County in this next phase and have reached out to the Butte County’s Department of Employment and Social Services, who have expressed interest in supporting our outreach efforts. In addition, to facilitate the recruitment of dyads with young adults entering the post-collegiate stage of life (i.e., mid-twenties), we plan to expand the parental age range up to age 70. As the average retirement age in the United States continues to trend upward, an increasing number of adults in their late 60s may continue to experience sandwich generation life stressors and constraints, potentially influencing their susceptibility and response to wildfire smoke exposure.

Acknowledgments. We thank Dr. Julie Postma for sharing her subject matter expertise on climate change and health, her support with flyers, and for providing a warm welcome to Chico, CA.

References