Wildfires are associated with increased emergency department visits for anxiety disorders in the western United States

Abstract

As wildfires increasingly impact the global economy and public health, understanding their effects is crucial. Particularly, the relationship between wildfires and anxiety disorders remains unclear. In this study, we explore this association by analyzing 1,897,865 emergency department visits for anxiety disorders in the western United States. We examined records from 2007 to 2018, using a case-crossover design and conditional logistic regression to assess the impact of wildfire-related exposures on these visits. Here we show that exposure to wildfire smoke ${PM}_{2.5}$ is positively linked with emergency department visits for anxiety disorders. This effect is more pronounced in women and girls and in older adults, highlighting their vulnerability. Notably, major smoke events (smoke ${PM}_{2.5}$ contributed ≥75% of the total ${PM}_{2.5}$ ) significantly amplify this risk. These findings underscore the psychological impacts of wildfires and their smoke, suggesting a need for targeted disaster risk reduction and climate risk management strategies, especially for vulnerable groups such as older adults and women. Our results call for increased climate awareness and tailored risk communication to mitigate these emerging health challenges.

Fig. 1 |. The age- and sex-stratified analysis for 48 hour smoke PM2.5.

Model 1 included only 48 hour smoke ${\mathrm{P}\mathrm{M}}_{2.5}$ and the covariates. Model 2 also adjusted for background ${\mathrm{P}\mathrm{M}}_{2.5}$. The ORs are for a 10 μg m⁻³ increase in smoke ${\mathrm{P}\mathrm{M}}_{2.5}$. The statistics were derived from a total of 1,897,865 participants, including 749,732 men and boys and 1,148,133 women and girls. The age group 5–17 consisted of 152,405 participants (56,767 boys and 95,638 girls). The age group 18–64 consisted of 1,575,972 participants (644,424 men and 931,548 women), and the age group 65+ consisted of 169,488 participants (48,541 men and 120,947 women, respectively). Data are presented as ORs and their 95% CI.

Fig. 2 |. The age- and sex-stratified analysis for smoke events and major smoke events.

Model 1 included only smoke events and other covariates. Model 2 also adjusted for background ${\mathrm{P}\mathrm{M}}_{2.5}$. The upper panels are for smoke events in which wildfire smoke ${\mathrm{P}\mathrm{M}}_{2.5}$ contributed ≥25% of the total ${\mathrm{P}\mathrm{M}}_{2.5}$. The lower panels are for major smoke events in which wildfire smoke ${\mathrm{P}\mathrm{M}}_{2.5}$ contributed ≥75% of the total ${\mathrm{P}\mathrm{M}}_{2.5}$. The statistics were derived from a total of 1,897,865 participants, including 749,732 men and boys and 1,148,133 women and girls. The age group 5–17 consisted of 152,405 participants (56,767 boys and 95,638 girls). The age group 18–64 consisted of 1,575,972 participants (644,424 men and 931,548 women), and the age group 65+ consisted of 169,488 participants (48,541 men and 120,947 women, respectively). Data are presented as ORs and their 95% CI.

Fig. 3 |. The age- and sex-stratified analysis for active fire points.

Model 1 included only the total number of active fire points in the past 48 hours and other covariates. Model 2 also adjusted for background ${\mathrm{P}\mathrm{M}}_{2.5}$. The statistics were derived from a total of 1,897,865 participants, including 749,732 men and boys and 1,148,133 women and girls. The age group 5–17 consisted of 152,405 participants (56,767 boys and 95,638 girls). The age group 18–64 consisted of 1,575,972 participants (644,424 men and 931,548 women), and the age group 65+ consisted of 169,488 participants (48,541 men and 120,947 women, respectively). Data are presented as ORs and their 95% CI.