Social Vulnerability in US Communities Affected by Wildfire Smoke, 2011 to 2021

Where There is Smoke: An Updated Review of Environmental Contributions to Chronic Rhinosinusitis

PURPOSE

The pathogenesis of chronic rhinosinusitis (CRS) is thought to include a complex interaction between environmental exposures and host immune responses that generates a self-perpetuating inflammatory process. As molecular pathways continue to be explored, the impact of environmental exposures on CRS pathogenesis and exacerbation must not be overlooked. This review will explore the association between environmental exposures and CRS, specifically focusing on tobacco smoke, occupational inhalational exposures, air pollution, particulate matter, and wildfire smoke.

MAJOR FINDINGS

Tobacco smoke is associated with increased prevalence of CRS symptoms and formal diagnosis with worse surgical outcomes observed in both adults and children exposed to tobacco smoke. Numerous occupational exposures have been associated with increased sinonasal symptoms, though exposures and disease definitions are often poorly characterized. Pollution and microparticle exposure has been associated with an increased likelihood of CRS diagnosis, as well as increased need for surgery. Last, while wildfire smoke has been attributed to increased hospital and emergency room visits for respiratory-related complaints, no primary research has yet been performed regarding CRS and wildfire smoke, though in-vitro studies support an association.

CONCLUSIONS

Population-based studies bolstered by in-vitro mechanistic data support an association between numerous environmental exposures and the onset and severity of CRS.

What drives parents' use of air quality indexes during wildfire smoke events: predictors of index knowledge, frequent checking, and following health guidance

Wildfire smoke poses a serious and growing health threat to communities in the United States (US), Canada, and beyond. Some populations-including children-are especially susceptible. Air Quality Indexes (AQIs) can inform parents about local air quality during smoke events and offer guidance on actions that protect children. In July-August 2023, parents from Oregon, Washington, California, and British Columbia (BC) (n = 2100) participated in an online cross-sectional study. Binary and ordinal logistic regression models were used to examine geographic, demographic, and psychosocial predictors of three dependent variables: knowledge of where to check AQI information, frequent checking of AQI information during wildfire seasons, and adherence to AQI health messages around reducing/rescheduling outdoor physical activity. Smoke-exposure analysis indicated widespread potential exposures to wildfire smoke across all four jurisdictions. Nonetheless, parents in BC, on average, were less likely to report knowing where to check AQI information, checked less frequently, and were less likely to adhere to AQI guidance than parents in the three US states. Adherence to AQI health messages did not differ by jurisdiction in the presence of other covariates, suggesting parents are equally likely to follow AQI guidance when they know where to find it and check it. Other consistent predictors of the three dependent variables included experience with prior smoke-related health impacts, smoke risk perceptions, and use of internet/mobile applications as sources of smoke information. These findings indicate that increased promotion of AQIs may benefit parents in some regions during wildfires. Future evaluations of smoke education initiatives could help health agencies share effective practices across jurisdictions and target interventions to increase AQI adoption.

Supplementary information

The online version contains supplementary material available at 10.1007/s11111-025-00491-w.

Awareness of wildfire smoke among U.S. adults with and without asthma

OBJECTIVE

To describe awareness of ambient wildfire smoke among U.S. adults with and without asthma.

METHODS

We analyzed data from the summer wave of the 2021 ConsumerStyles survey, a nationally representative survey of 4085 U.S. adults. Respondents self-reported their asthma status and awareness of wildfire smoke where they lived in the past 12 months. We linked survey responses by zip code of residence with satellite-detected wildfire smoke plume data that estimated the daily maximum smoke plume density over the preceding year. We estimated associations between asthma status and awareness of wildfire smoke across categories of maximum smoke plume density and days with medium- or heavy-density smoke as prevalence ratios (PRs) with 95% confidence intervals (CIs) using predicted marginal probabilities from logistic regression models.

RESULTS

Over 98% of the estimated population of U.S. adults lived in a zip code affected by ≥1 day of medium- or heavy-density wildfire smoke, which occurred on an average of 16 days in the past year. Awareness of wildfire smoke was reported by 19% of U.S. adults and was higher among adults with than without asthma (PR: 1.25; 95% CI: 1.01, 1.55), including in zip codes affected by heavy-density smoke (PR: 1.30, 95% CI: 1.04, 1.63) and with 22 or more days of medium- to heavy-density smoke (PR: 1.22, 95% CI: 1.01, 1.47).

CONCLUSIONS

Although awareness of wildfire smoke was higher among U.S. adults with than without asthma, low percentages of awareness overall indicate a need for health communication about wildfire smoke and its health risks.

Wildland fire smoke adds to disproportionate PM2.5 exposure in the United States

Wildland fire (i.e., prescribed fire and wildfire) smoke exposure is an emerging public health threat, in part due to climate change. Previous research has demonstrated disparities in ambient fine particulate matter (PM2.5) exposure, with Black people, among others, exposed to higher concentrations; yet it remains unclear how wildland fire smoke may contribute to additional disproportionate exposure. Here, we investigate the additional PM2.5 burden contributed by wildland fire smoke in the contiguous United States by race and ethnicity, urbanicity, median household income, and language spoken at home, using modeled total, non-fire, and fire PM2.5 concentrations from 2007 to 2018. Wildland fires contributed 7% to 14% of total population weighted PM2.5 concentrations annually, while non-fire PM2.5 concentrations declined by 24% over the study period. Wildland fires contributed to greater PM2.5 exposure for Black and American Indian or Alaska Native people, and those who live in non-urban areas. Disproportionate mean non-fire PM2.5 concentrations for Black people (9.1 μg/m3, compared to 8.7 μg/m3 overall) were estimated to be further exacerbated by additional disproportionate concentrations from fires (1.0 μg/m3 , compared to 0.9 μg/m3 overall). These results can inform equitable strategies by public health agencies and air quality managers to reduce smoke exposure in the United States.

The Effect of Wildfires on Asthma and Allergies

Climate change is a major driver of the frequency and severity of wildfires caused by extended periods of drought and hotter, drier weather superimposed on the legacy of fire suppression in the Mountain West of the United States. In recent years, increased wildfire smoke has negated the improvements in air quality made by clean energy transitions. Wildfire smoke is a complex mixture of gases and solids, a chief constituent of which is fine particulate matter (PM2.5). Exposure to PM2.5 is associated with adverse respiratory outcomes, including exacerbations of asthma and chronic obstructive pulmonary disease. In the face of increasing wildfire smoke exposures, it is critical that adaptation and mitigation strategies be put in place to minimize health effects. Individual strategies include modifying behavior and creating clean air spaces in homes to avoid wildfire smoke exposure. Community strategies include regulations promoting fire-resistant buildings and landscaping; establishing wildfire monitoring and alert systems; providing safe clean spaces where individuals can minimize wildfire smoke exposure and find evacuation routes; and creating health care response teams. Mitigation to prevent wildfires includes forest management and establishing monitoring systems and protocols to control forest fires in the wildland urban interface before they increase in size and intensity. Research into understanding the mechanism by which wildfire smoke mediates adverse health effects can inform guidelines to mitigate its health effects further.

Carcinogenic and non-carcinogenic risks caused by rice contamination with heavy metals and their effect on the prevalence of cardiovascular disease (Using machine learning)

INTRODUCTION

The safety and health of food products are essential in the food industry, and the risk of contamination from various contaminants must be evaluated. Exposure to HMs from the environment (especially food) causes various adverse effects on the body and increases the risk of cardiovascular disease (CVD).

MATERIAL AND METHOD

Volunteers in the study comprised both healthy individuals and those with CVD. Patients were chosen using a cohort database of CVD individuals. A random choice of samples was conducted. Medical information (individuals with CVD) related to the participants was obtained from the Hoveyzeh Cohort Study Center. CVD-HM relationships were assessed using various machine-learning techniques.

RESULT

Based on the results of the GAM statistics approach, the baseline levels (β) of As, Cd, and Cr in rice have been calculated to be 1.05, 1.19, and 1.11, respectively. Based on the investigation's results, rice acts as a mediator between high-magnitude actions and the prevalence of CVD. Eating rice increases the probability of CVD by 0.18 and raises As eating by 0.494. The results showed that rice consumption in the research area is not associated with non-carcinogenic and carcinogenic risk (CRs and ILCRs for both categories were less than 1∗10-6).

CONCLUSION

There was neither a carcinogenic nor non-carcinogenic threat to adults or children and many hazardous HMs existed at the accepted thresholds. A notable relationship was seen between rice contaminated with HM and CVD.

Blinded by smoke: Wildfire smoke exposure and eye irritation in australian wildland firefighters

PURPOSE

Wildfire occurrence is increasing worldwide, putting firefighters and general public at increased risk of eye injuries from smoke exposure. This study explored ocular symptoms and use of protective eyewear amongst wildland firefighters in Australia.

METHODS

Australian wildland firefighters were invited to complete an online survey about the occurrence of eye irritation, use of protective eyewear and behaviours associated with occupational smoke exposure. Responses were analysed using logistic regression and qualitative inductive content analysis.

RESULTS

338 wildland firefighters completed the survey. Eye irritation was reported by 90 % of firefighters at least sometimes during work and by 70 % after work. Frequency of eye irritation was greater amongst females than males (OR 2.01, CI 1.22-3.31, p < 0.001). Protective eyewear was used often or always by 67 % of firefighters on the fireground, however 55 % had to remove their protective eyewear due to sweat, fogging or another reason. Goggles were more likely to be removed compared to sunglasses and safety glasses (OR 4.28, CI 2.75-6.68, p < 0.001). Firefighters reported that, at times smoke exposure necessitated eye closure and impaired vision on the fireground. Firefighters also reported that protective eyewear helped to reduce eye symptoms, but its consistent use on the fireground was difficult. The severity and recovery from eye symptoms varied between participants.

CONCLUSION

Australian wildland firefighters frequently experience eye irritation from smoke exposure, and this can affect operational capabilities. These findings can support the development of evidence-based strategies to help protect and aid recovery of the eye surface following smoke exposure.

Wildfires and Human Health

This JAMA Insights explores the adverse effects of wildfires on human health and health care systems and offers suggestions on how clinicians can help mitigate the health threats posed by wildfires.

Wildfires and climate justice: future wildfire events predicted to disproportionally impact socioeconomically vulnerable communities in North Carolina

Wildfire events are becoming increasingly common across many areas of the United States, including North Carolina (NC). Wildfires can cause immediate damage to properties, and wildfire smoke conditions can harm the overall health of exposed communities. It is critical to identify communities at increased risk of wildfire events, particularly in areas with that have sociodemographic disparities and low socioeconomic status (SES) that may exacerbate incurred impacts of wildfire events. This study set out to: (1) characterize the distribution of wildfire risk across NC; (2) implement integrative cluster analyses to identify regions that contain communities with increased vulnerability to the impacts of wildfire events due to sociodemographic characteristics; (3) provide summary-level statistics of populations with highest wildfire risk, highlighting SES and housing cost factors; and (4) disseminate wildfire risk information via our online web application, ENVIROSCAN. Wildfire hazard potential (WHP) indices were organized at the census tract-level, and distributions were analyzed for spatial autocorrelation via global and local Moran's tests. Sociodemographic characteristics were analyzed via k-means analysis to identify clusters with distinct SES patterns to characterize regions of similar sociodemographic/socioeconomic disparities. These SES groupings were overlayed with housing and wildfire risk profiles to establish patterns of risk across NC. Resulting geospatial analyses identified areas largely in Southeastern NC with high risk of wildfires that were significantly correlated with neighboring regions with high WHP, highlighting adjacent regions of high risk for future wildfire events. Cluster-based analysis of SES factors resulted in three groups of regions categorized through distinct SES profiling; two of these clusters (Clusters 2 and 3) contained indicators of high SES vulnerability. Cluster 2 contained a higher percentage of younger (<5 years), non-white, Hispanic and/or Latino residents; while Cluster 3 had the highest mean WHP and was characterized by a higher percentage of non-white residents, poverty, and less than a high school education. Counties of particular SES and WHP-combined vulnerability include those with majority non-white residents, tribal communities, and below poverty level households largely located in Southeastern NC. WHP values per census tract were dispersed to the public via the ENVIROSCAN application, alongside other environmentally-relevant data.

Exposure to Smoke From Wildfire, Prescribed, and Agricultural Burns Among At-Risk Populations Across Washington, Oregon, and California

Wildfires, prescribed burns, and agricultural burns all impact ambient air quality across the Western U.S.; however, little is known about how communities across the region are differentially exposed to smoke from each of these fire types. To address this gap, we quantify smoke exposure stemming from wildfire, prescribed, and agricultural burns across Washington, Oregon, and California from 2014 to 2020 using a fire type-specific biomass burning emissions inventory and the GEOS-Chem chemical transport model. We examine fire type-specific PM2.5 concentration by race/ethnicity, socioeconomic status, and in relation to the Center for Disease Control's Social Vulnerability Index. Overall, population-weighted PM2.5 concentrations are greater from wildfires than from prescribed and from agricultural burns. While we found limited evidence of exposure disparities among sub-groups across the full study area, we did observe disproportionately higher exposures to wildfire-specific PM2.5 exposures among Native communities in all three states and, in California, higher agricultural burn-specific PM2.5 exposures among lower socioeconomic groups. We also identified, for all three states, areas of significant spatial clustering of smoke exposures from all fire types and increased social vulnerability. These results provide a first look at the differential contributions of smoke from wildfires, prescribed burns, and agricultural burns to PM2.5 exposures among demographic subgroups, which can be used to inform more tailored exposure reduction strategies across sources.

Spatial Heterogeneity of the Respiratory Health Impacts of Wildfire Smoke PM2.5 in California

Wildfire smoke fine particles (PM2.5) are a growing public health threat as wildfire events become more common and intense under climate change, especially in the Western United States. Studies assessing the association between wildfire PM2.5 exposure and health typically summarize the effects over the study area. However, health responses to wildfire PM2.5 may vary spatially. We evaluated spatially-varying respiratory acute care utilization risks associated with short-term exposure to wildfire PM2.5 and explored community characteristics possibly driving spatial heterogeneity. Using ensemble-modeled daily wildfire PM2.5, we defined a wildfire smoke day to have wildfire-specific PM2.5 concentration ≥15 μg/m3. We included daily respiratory emergency department visits and unplanned hospitalizations in 1,396 California ZIP Code Tabulation Areas (ZCTAs) and 15 census-derived community characteristics. Employing a case-crossover design and conditional logistic regression, we observed increased odds of respiratory acute care utilization on wildfire smoke days at the state level (odds ratio [OR] = 1.06, 95% confidence interval [CI]: 1.05, 1.07). Across air basins, ORs ranged from 0.88 to 1.57, with the highest effect estimate in San Diego. A within-community matching design and spatial Bayesian hierarchical model also revealed spatial heterogeneity in ZCTA-level rate differences. For example, communities with a higher percentage of Black or Pacific Islander residents had stronger wildfire PM2.5-outcome relationships, while more air conditioning and tree canopy attenuated associations. We found an important heterogeneity in wildfire smoke-related health impacts across air basins, counties, and ZCTAs, and we identified characteristics of vulnerable communities, providing evidence to guide policy development and resource allocation.

"Air That Once Was Breath" Part 2: Wildfire Smoke and Airway Disease - "Climate Change, Allergy and Immunology" Special IAAI Article Collection: Collegium Internationale Allergologicum Update 2023

BACKGROUND

Population growth and climate change have led to more frequent and larger wildfires, increasing the exposure of individuals to wildfire smoke. Notably, asthma exacerbations and allergic airway sensitization are prominent outcomes of such exposure.

SUMMARY

Key research questions relate to determining the precise impact on individuals with asthma, including the severity, duration, and long-term consequences of exacerbations. Identifying specific risk factors contributing to vulnerability, such as age, genetics, comorbidities, or environmental factors, is crucial. Additionally, reliable biomarkers for predicting severe exacerbations need exploration. Understanding the long-term health effects of repeated wildfire smoke exposures in individuals with asthma and addressing healthcare disparities are important research areas.

KEY MESSAGES

This review discusses the need for comprehensive research efforts to better grasp wildfire smoke-induced respiratory health, particularly in vulnerable populations such as farmworkers, firefighters, pregnant women, children, the elderly, and marginalized communities. Effective mitigation would require addressing the current limitations we face by supporting research aimed at a better understanding of wildfire smoke-induced airway disease.

Clearing the Air: Understanding the Impact of Wildfire Smoke on Asthma and COPD

Wildfires are a global natural phenomenon. In North America, wildfires have not only become more frequent, but also more severe and longer in duration, a trend ascribed to climate change combined with large fuel stores left from modern fire suppression. The intensification of wildfire activity has significant implications for planetary health and public health, as exposure to fine particulate matter (PM2.5) in wildfire smoke is linked to adverse health effects. This review focuses on respiratory morbidity from wildfire smoke exposure. Inhalation of wildfire PM2.5 causes lung injury via oxidative stress, local and systemic inflammation, airway epithelium compromise, and increased vulnerability to infection. Wildfire PM2.5 exposure results in exacerbations of pre-existing asthma and chronic obstructive pulmonary disease, with an escalation in healthcare utilization, including emergency department visits and hospitalizations. Wildfire smoke exposure may be associated with asthma onset, long-term impairment of lung function, and increased all-cause mortality. Children, older adults, occupationally-exposed groups, and possibly women are the most at risk from wildfire smoke. Future research is needed to clarify best practices for risk mitigation and wildfire management.

Bridging Culture and Language: Encouraging Bilingual/Multicultural Individuals to Act as Information Navigators for Their Loved-Ones and Communities during the COVID-19 Pandemic

Linguistically diverse communities face barriers to receiving appropriate health information. COVID-19 exacerbated these health-communication inequities. University of Washington researchers surveyed bilingual staff, students, and medical interpreters - desiring training to become effective communicators of COVID-19 information to their social networks and language communities. In response, the COVID-19 Information Navigator Training was developed and pre-tested with professional networks and members of the target audience. The final training comprised three interactive modules and short quizzes. Evaluation surveys measured Information Navigators' confidence in providing COVID-19 information to their social networks. Surveys included questions on the participants' language or cultural community, the perceived value of the training, and their ability to communicate COVID-19 information. Among 393 participants who enrolled in the training, 284 completed the survey. Significant differences in confidence before and after the course were found in detecting COVID misinformation in the news and social media (pre-course mean: 3.83, post-course mean: 4.63; absolute mean difference was 0.82 points higher in the post-evaluation on the 5-point likert scale, 95% CI: 0.70-0.93, p < .01). Training multicultural volunteers to disseminate information to their social networks is a promising strategy for reaching linguistically diverse communities with up-to-date information during health emergencies.