Fires

ImportanceClimate-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.ObjectiveTo 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 participantsThe 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.ExposureLiving or working in or near areas affected by the August 2023 Maui wildfires.Main outcomes and measuresPrimary 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.ResultsAmong 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 relevanceIn 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.

BackgroundBurn injuries, which are caused by fire, heat, and hot substances, are considered a chronic condition due to their long-term effects on the health of affected individuals. Moreover, burn injuries constitute a significant public health issue that cannot be overlooked within the global healthcare system.Materials and methodsThis study comprehensively analyzed the burden of burn injuries, focusing on variations by Socio-Demographic Index (SDI) levels and Global Burden of Disease (GBD) regions, sex-based disparities, Frontier analysis, and future trend forecasting using the Bayesian Age-Period-Cohort (BAPC) model.ResultsCompared to 1990, the global burden of burn injuries decreased in most regions worldwide in 2021. The majority of regions showed a negative Estimated Annual Percentage Change (EAPC), indicating a continuous decline in Age-Standardized Rate (ASR) annually. And the ASR decreased with the increasing SDI. Moreover, the forecasted trend from 2021 to 2030, indicates a continued decline with a well-fitted projection model.ConclusionsDespite the observed and projected decline in global ASR of burn, the burden of burn remains a significant concern that should not be underestimated.

Global forests provide key ecosystem services, from climate regulation to biodiversity habitat, but are under increasing pressure from the combined impacts of climate and land use change. Here, we show that forest disturbance due to fire is growing globally, with the most dramatic increases in intact forest landscapes, highlighting an existential threat to remaining high biomass, high biodiversity forests. The global annual area of forest disturbance due to fire for 2023 and 2024 was highest since the beginning of monitoring in 2001. Compared to 2002-2022 average annual forest disturbance due to fire, the 2023-2024 average was 2.2 times higher globally and 3 times higher in the Tropics. More than ¼ of all 2024 forest disturbance from fire occurred in tropical forests. We found a statistically significant increasing trend of forest disturbance due to fire from 2002 to 2024 in all climate domains except Subtropical. High forest, low deforestation tropical countries were not exempt, with Guyana and the Republic of the Congo experiencing record forest disturbance due to fire. Our results agree with recently estimated increases in global forest fire emissions and active fire detections. The unprecedented scale of fires in the world's most remote forests is a potential harbinger of ecosystem tipping points. Protecting these remaining unfragmented high conservation value forests from this threat poses a daunting and as yet undeveloped policy and capacity challenge.

Global fire regimes are changing, raising concerns about the ability of fire-prone ecosystems to maintain biodiversity. We tested whether the pyrodiversity-biodiversity hypothesis (i.e., variation in postfire characteristics promotes biodiversity) or alternative hypotheses better explain patterns of biodiversity in a true island system. Using fixed-area sampling plots in a chronosequence of 42 boreal lake islands spanning gradients in island area (1-350.4 ha), isolation (0.1-7.9 km from mainland), and fire history (1-231+ year since fire), we tested whether alpha and beta diversity of beetles, plants, and birds increased with spatial (within-island variation in burn severity) and temporal (variation in time since fire among islands) pyrodiversity, respectively. Species richness of plants and birds increased with spatial pyrodiversity indicating that habitat heterogeneity from localized variation in burn severity supported more species in some groups. Beta diversity of all taxa increased with temporal pyrodiversity, highlighting the importance of conserving age-class variation within the boreal patch mosaic. In contrast, the habitat amount hypothesis and island biogeography theory were weak predictors of species richness across all taxa, and island area and isolation did not consistently affect beta diversity among the islands. Our findings emphasize the importance of maintaining pyrodiversity in boreal landscapes to combat biodiversity loss in the age of "megafires" and suggest leveraging the fire refugia effects of large lakes within the region to conserve vital components of temporal pyrodiversity such as old-growth forests.