Abstract
IMPORTANCE: Climate-driven wildfires are increasing in frequency and severity, but their association with midterm and long-term health trajectories during the course of recovery remain poorly characterized, particularly in underserved populations. OBJECTIVE: To assess the midterm health outcomes of wildfire exposure, including respiratory and mental health, and evaluate the interaction of social support with these health burdens. DESIGN, SETTING, AND PARTICIPANTS: The Maui Wildfire Exposure Study (MauiWES) is a community-based, cohort study that enrolled 1174 adults in 2024, 6 to 14 months after the 2023 Maui wildfires. Participants completed exposure assessments, spirometry, biomonitoring, and validated mental health evaluations. Data were accrued from January 26 to September 30, 2024. EXPOSURE: Living or working in or near areas affected by the August 2023 Maui wildfires. MAIN OUTCOMES AND MEASURES: Primary outcomes included lung function (forced expiratory volume in the first second of expiration [FEV1] and forced vital capacity [FVC]), blood pressure, depressive symptoms (10-item Center for Epidemiologic Studies Depression Scale), anxiety (7-item Generalized Anxiety Disorder Scale), and days affected by health issues. Social support was assessed using the Multidimensional Scale of Perceived Social Support. RESULTS: Among 1174 participants (median age, 47 [IQR, 36-59] years; 684 [59.1%] female; 108 [9.3%] Asian; 239 [20.5%] Filipino; 203 [17.4%] Hispanic or Latino; 238 [20.4%] Native Hawaiian or Other Pacific Islander; 343 [29.4%] White), 150 of 670 (22.4%) exhibited FEV1 of less than 80% predicted, 725 of 1152 (62.9%) had high blood pressure (>130/80 mm Hg), and 554 of 1110 (49.9%) reported depressive symptoms. Participants residing within the fire perimeter had significantly lower lung function compared with those outside (FEV1 β, -5.97 [95% CI, -10.81 to -1.14] percentage points predicted). Acute wildfire exposure was associated with an increase in days affected by health issues (β, 20.03 [95% CI, 8.87-31.18] days) and elevated depressive symptoms (β, 9.43 [95% CI, 0.61-18.25] points). Higher social support was associated with fewer days affected by health issues (β, -5.08 [95% CI, -8.50 to -1.65] days) but did not mitigate low lung function. CONCLUSIONS AND RELEVANCE: In this cohort study of adults affected by the Maui wildfires, substantial midterm cardiopulmonary and psychological health burdens were observed. Higher social support was associated with improved mental health outcomes but did not appear to buffer physiological outcomes such as reduced lung function. These findings highlight the need for disaster response models that integrate clinical surveillance, targeted mental health interventions, and culturally anchored community-based support. As climate-driven disasters intensify, proactive strategies to monitor and mitigate their long-term health effects will be essential to protect vulnerable populations and enhance resilience.