Risk and burden of hospital admissions associated with wildfire-related PM2·5 in Brazil, 2000-15: a nationwide time-series study

Physicochemical Characterization of the Particulate Matter in New Jersey/New York City Area, Resulting from the Canadian Quebec Wildfires in June 2023

The global increase in wildfires, primarily driven by climate change, significantly affects air quality and health. Wildfire-emitted particulate matter (WFPM) is linked to adverse health effects, yet the toxicological mechanisms are not fully understood given its physicochemical complexity and the lack of spatiotemporal exposure data. This study focuses on the physicochemical characterization of WFPM from a Canadian wildfire in June 2023, which affected over 100 million people in the US Northeast, particularly around New Jersey/New York. Aerosol systems were deployed to characterize WFPM during the 3 day event, revealing unprecedented mass concentrations mainly in the WFPM0.1 and WFPM0.1-2.5 size fractions. Peak WFPM2.5 concentrations reached 317 μg/m3, nearly 10 times the National Ambient Air Quality Standard (NAAQS) 24 h average limit. Chemical analysis showed a high organic-to-total carbon ratio (96%), consistent with brown carbon wildfires nanoparticles. Large concentrations of high-molecular-weight PAHs were found predominantly bound to WFPM0.1, with retene, a molecular marker of biomass burning and a known teratogen, being the most abundant (>70%). Computational modeling estimated a total lung deposition of 9.15 mg over 72 h, highlighting the health risks of WFPM, particularly due to its long-distance travel capability and impact on densely populated areas.

Climate change and healthy ageing: An assessment of the impact of climate hazards on older people

Background

Climate change not only directly impacts older people's longevity but also healthy ageing, which is the process of maintaining physical and mental capacities while optimising functional abilities. The urgency to address both population ageing and climate change necessitates a rethink and assessment of the impact of climate change on older people. This includes identifying what can be done to anticipate, mitigate and adapt to climate change and engage older persons.

Methods

A review of climate change and healthy ageing forms the basis of evidence in this report. We developed a comprehensive search to assess current literature, combining terms related to ageing and climate change across four major data sets and assessing articles published up to the end of 2021.

Results

We summarised the current and future impact of climate change on older people and developed a framework identifying climate change impacts on older persons, recognising social and environmental determinants of healthy ageing. Major hazards and some key exposure pathways include extreme temperatures, wildfire, drought, flooding, storm and sea level rise, air quality, climate-sensitive infectious diseases, food and water insecurities, health and social care system displacement, migration, and relocation. Strategies to address climate change require interventions to improve systems and infrastructure to reduce vulnerability and increase resilience. As a heterogeneous group, older people's perceptions of climate change should be integrated into climate activism. Increasing climate change literacy among older people and enabling them to promote intergenerational dialogue will drive the development and implementation of equitable solutions. Pathways may operate via direct or indirect exposures, requiring longitudinal studies that enable assessment of exposures and outcomes at multiple time points, and analyses of cumulative impacts of hazards across the life course.

Conclusions

The lack of systematic reviews and primary research on the impact of most climate hazards, except for heat, on older people is apparent. Future research should include outcomes beyond mortality and morbidity and assess how older people interact with their environment by focusing on their capacities and optimising abilities for being and doing what they value.

Future fire-smoke PM2.5 health burden under climate change in Paraguay

Recent years have seen a rise in wildfire and extreme weather activity across the globe, which is projected to keep increasing with climate-induced conditions. Air pollution, especially fine particulate matter (PM2.5) concentration, is heavily affected by PM2.5 emissions from wildfire activity. Paraguay has been historically suffering from fires, with an average of 2.3 million hectares burnt per year during the 2003-2021 period. Annual PM2.5 concentration in Paraguay is 13.2 μg/m3, more than double the recommended by the WHO. We estimate that, historically, almost 40 % of fine air particulates can be attributed to fires. Using a random forest algorithm, we estimate future fire activity and fire related PM2.5 under different climate change scenarios. With global warming, we calculate that fire activity could increase by up to 120 % by 2100. Annual fire smoke PM2.5 from fires is expected to increase by 7.7 μg/m3 by 2100. Under these conditions, Paraguay is expected to suffer an increase in 3500 deaths per year attributable to fire smoke PM2.5 by 2100. We estimate the economic cost of fire smoke-related mortality by 2100 at US $ 5600 million, equivalent to 2.6 % of Paraguay's GDP, excluding other health- and productivity-related impacts on society.

When the smoke gets in your lungs: short-term effects of Indonesia's 2015 forest fires on health care use

BACKGROUND

The forest fires that ravaged parts of Indonesia in 2015 were the most severely polluting of this century but little is known about their effects on health care utilization of the affected population. We estimate their short-term impact on visit rates to primary and hospital care with particular focus on visits for specific smoke-related conditions (respiratory disease, acute respiratory tract infection (ARTI) and common cold).

METHOD

We estimate the short-term impact of the 2015 forest fire on visit rates to primary and hospital care by combining satellite data on Aerosol Optical Depth (AOD) with administrative records from Indonesian National Health Insurance Agency (BPJS Kesehatan) from January 2015-April  2016. The 16 months of panel data cover 203 districts in the islands of Sumatra and Kalimantan before, during and after the forest fires. We use the (more efficient) ANCOVA version adaptation of a fixed effects model to compare the trends in healthcare use of affected districts (with AOD value above 0.75) with control districts (AOD value below 0.75). Considering the higher vulnerability of children's lungs, we do this separately for children under 5 and the rest of the population adults (> 5), and for both urban and rural areas, and for both the period during and after the forest fires.

RESULTS

We find little effects for adults. For young children we estimate positive effects for care related to respiratory problems in primary health care facilities in urban areas. Hospital care visits in general, on the other hand, are negatively affected in rural areas. We argue that these patterns arise because accessibility of care during fires is more restricted for rural than for urban areas.

CONCLUSION

The severity of the fires and the absence of positive impact on health care utilization for adults and children in rural areas indicate large missed opportunities for receiving necessary care. This is particularly worrisome for children, whose lungs are most vulnerable to the effects. Our findings underscore the need to ensure ongoing access to medical services during forest fires and emphasize the necessity of catching up with essential care for children after the fires, particularly in rural areas.

Wildfire-related PM2.5 and cardiovascular mortality: A difference-in-differences analysis in Brazil

Brazil has experienced unprecedented wildfires recently. We aimed to investigate the association of wildfire-related fine particulate matter (PM2.5) with cause-specific cardiovascular mortality, and to estimate the attributable mortality burden. Exposure to wildfire-related PM2.5 was defined as exposure to annual mean wildfire-related PM2.5 concentrations in the 1-year prior to death. The variant difference-in-differences method was employed to explore the wildfire-related PM2.5-cardiovascular mortality association. We found that, in Brazil, compared with the population in the first quartile (Q1: ≤1.82 μg/m3) of wildfire-related PM2.5 exposure, those in the fourth quartile (Q4: 4.22-17.12 μg/m3) of wildfire-related PM2.5 exposure had a 2.2% (RR: 1.022, 95% CI: 1.013-1.032) higher risk for total cardiovascular mortality, 3.1% (RR: 1.031, 95% CI: 1.014-1.048) for ischaemic heart disease mortality, and 2.0% (RR: 1.020, 95% CI: 1.002-1.038) for stroke mortality. From 2010 to 2018, an estimation of 35,847 (95% CI: 22,424-49,177) cardiovascular deaths, representing 17.77 (95% CI: 11.12-24.38) per 100,000 population, were attributable to wildfire-related PM2.5 exposure. Targeted health promotion strategies should be developed for local governments to protect the public from the risk of wildfire-related cardiovascular premature deaths.

Ambient PM2.5 and productivity-adjusted life years lost in Brazil: a national population-based study

Enormous health burden has been associated with air pollution and its effects continue to grow. However, the impact of air pollution on labour productivity at the population level is still unknown. This study assessed the association between premature death due to PM2.5 exposure and the loss of productivity-adjusted life years (PALYs), in Brazil. We applied a novel variant of the difference-in-difference (DID) approach to assess the association. Daily all-cause mortality data in Brazil were collected from 2000-2019. The PALYs lost increased by 5.11% (95% CI: 4.10-6.13%), for every 10 µg/m3 increase in the 2-day moving average of PM2.5. A total of 9,219,995 (95% CI: 7,491,634-10,921,141) PALYs lost and US$ 268.05 (95% CI: 217.82-317.50) billion economic costs were attributed to PM2.5 exposure, corresponding to 7.37% (95% CI: 5.99-8.73%) of the total PALYs lost due to premature death. This study also found that 5,005,306 PALYs could be avoided if the World Health Organization (WHO) air quality guideline (AQG) level was met. In conclusion, this study demonstrates that ambient PM2.5 exposure is associated with a considerable labour productivity burden relating to premature death in Brazil, while over half of the burden could be prevented if the WHO AQG was met. The findings highlight the need to reduce ambient PM2.5 levels and provide strong evidence for the development of strategies to mitigate the economic impacts of air pollution.

Dust particulate matter increases pulmonary embolism onset: A nationwide time-stratified case-crossover study in China

BACKGROUND

Particulate matter (PM) has been found to elevate the risk of pulmonary embolism (PE) onset. Among the contributors to PM, dust PM stands as the second natural source, and its emissions are escalating due to climate change. Despite this, information on the effect of dust PM on PE onset is scarce. Hence, this study aims to investigate the impacts of dust PM10, dust PM2.5-10, and dust PM2.5 on PE onset.

METHODS

A nationwide time-stratified case-crossover study was conducted between 2015 and 2020, using data from 18,616 PE onset cases across 1,921 hospitals in China. The analysis employed a conditional logistic regression model to quantify the associations between dust PM10, dust PM2.5-10, and dust PM2.5 and PE onset. Furthermore, the study explored the time-distributed lag pattern of the effect of dust PM on PE development. Stratified analyses were performed based on sex, age, region, and season.

RESULTS

Dust PM10, dust PM2.5-10, and dust PM2.5 exhibited significant health effects on PE onset, particularly concerning exposure on the same day. The peak estimates were observed at lag 01 day, with the odds ratio being 1.011 [95 % confidence interval (CI): 1.003, 1.019], 1.014 (95 % CI: 1.003, 1.026), and 1.039 (95 % CI: 1.011, 1.068), for a 10 μg/m3 increase in the concentration of dust PM10, dust PM2.5-10, and dust PM2.5, respectively. In addition, the study identified a higher risk of PE onset associated with dust PM exposure during the warm season than that in cool season, particularly for dust PM2.5.

CONCLUSIONS

The findings from this study suggest that short-term exposure to dust PM, particularly dust PM2.5, may trigger PE onset, posing a significant health threat. Implementing measures to mitigate dust PM emissions and protect patients with PE from dust PM exposure is imperative.

Climate crisis risks to elderly health: strategies for effective promotion and response

The climate crisis significantly impacts the health and well-being of older adults, both directly and indirectly. This issue is of growing concern in Canada due to the country's rapidly accelerating warming trend and expanding elderly population. This article serves a threefold purpose: (i) outlining the impacts of the climate crisis on older adults, (ii) providing a descriptive review of existing policies with a specific focus on the Canadian context, and (iii) promoting actionable recommendations. Our review reveals the application of current strategies, including early warning systems, enhanced infrastructure, sustainable urban planning, healthcare access, social support systems, and community engagement, in enhancing resilience and reducing health consequences among older adults. Within the Canadian context, we then emphasize the importance of establishing robust risk metrics and evaluation methods to prepare for and manage the impacts of the climate crisis efficiently. We underscore the value of vulnerability mapping, utilizing geographic information to identify regions where older adults are most at risk. This allows for targeted interventions and resource allocation. We recommend employing a root cause analysis approach to tailor risk response strategies, along with a focus on promoting awareness, readiness, physician training, and fostering collaboration and benchmarking. These suggestions aim to enhance disaster risk management for the well-being and resilience of older adults in the face of the climate crisis.

"Air That Once Was Breath" Part 1: Wildfire-Smoke-Induced Mechanisms of Airway Inflammation - "Climate Change, Allergy and Immunology" Special IAAI Article Collection: Collegium Internationale Allergologicum Update 2023

BACKGROUND

Wildfires are a global concern due to their wide-ranging environmental, economic, and public health impacts. Climate change contributes to an increase in the frequency and intensity of wildfires making smoke exposure a more significant and recurring health concern for individuals with airway diseases. Some of the most prominent effects of wildfire smoke exposure are asthma exacerbations and allergic airway sensitization. Likely due to the delayed recognition of its health impacts in comparison with cigarette smoke and industrial or traffic-related air pollution, research on the composition, the mechanisms of toxicity, and the cellular/molecular pathways involved is poor or non-existent.

SUMMARY

This review discusses potential underlying pathological mechanisms of wildfire-smoke-related allergic airway disease and asthma. We focused on major gaps in understanding the role of wildfire smoke composition in the development of airway disease and the known and potential mechanisms involving cellular and molecular players of oxidative injury at the epithelial barrier in airway inflammation. We examine how PM2.5, VOCs, O3, endotoxin, microbes, and toxic gases may affect oxidative stress and inflammation in the respiratory mucosal barrier. We discuss the role of AhR in mediating smoke's effects in alarmin release and IL-17A production and how glucocorticoid responsiveness may be impaired by IL-17A-induced signaling and epigenetic changes leading to steroid-resistant severe airway inflammation.

KEY MESSAGE

Effective mitigation of wildfire-smoke-related respiratory health effects would require comprehensive research efforts aimed at a better understanding of the immune regulatory effects of wildfire smoke in respiratory health and disease.

Health Impacts of Wildfire Smoke on Children and Adolescents: A Systematic Review and Meta-analysis

PURPOSE OF REVIEW

Wildfire smoke is associated with human health, becoming an increasing public health concern. However, a comprehensive synthesis of the current evidence on the health impacts of ambient wildfire smoke on children and adolescents, an exceptionally vulnerable population, is lacking. We conduct a systematic review of peer-reviewed epidemiological studies on the association between wildfire smoke and health of children and adolescents.

RECENT FINDINGS

We searched for studies available in MEDLINE, EMBASE, and Scopus from database inception up to October 11, 2022. Of 4926 studies initially identified, 59 studies from 14 countries were ultimately eligible. Over 33.3% of the studies were conducted in the USA, and two focused on multi-countries. The exposure assessment of wildfire smoke was heterogenous, with wildfire-specific particulate matters with diameters ≤ 2.5 µm (PM2.5, 22.0%) and all-source (22.0%) PM2.5 during wildfire period most frequently used. Over half of studies (50.6%) focused on respiratory-related morbidities/mortalities. Wildfire smoke exposure was consistently associated with enhanced risks of adverse health outcomes in children/adolescents. Meta-analysis results presented a pooled relative risk (RR) of 1.04 (95% confidence interval [CI], 0.96-1.12) for all-cause respiratory morbidity, 1.11 (95% Ci: 0.93-1.32) for asthma, 0.93 (95% CI, 0.85-1.03) for bronchitis, and 1.13 (95% CI, 1.05-1.23) for upper respiratory infection, whilst - 21.71 g for birth weight (95% CI, - 32.92 to - 10.50) per 10 µg/m3 increment in wildfire-specific PM2.5/all-source PM2.5 during wildfire event. The majority of studies found that wildfire smoke was associated with multiple adverse health outcomes among children and adolescents, with respiratory morbidities of significant concern. In-utero exposure to wildfire smoke may increase the risk of adverse birth outcomes and have long-term impacts on height. Higher maternal baseline exposure to wildfire smoke and poor family-level baseline birthweight respectively elevated risks in preterm birth and low birth weight associated with wildfire smoke. More studies in low- and middle-income countries and focusing on extremely young children are needed. Despite technological progress, wildfire smoke exposure measurements remain uncertain, demanding improved methodologies to have more precise assessment of wildfire smoke levels and thus quantify the corresponding health impacts and guide public mitigation actions.

Mortality burden attributable to exceptional PM2.5 air pollution events in Australian cities: A health impact assessment

Background

People living in Australian cities face increased mortality risks from exposure to extreme air pollution events due to bushfires and dust storms. However, the burden of mortality attributable to exceptional PM2.5 levels has not been well characterised. We assessed the burden of mortality due to PM2.5 pollution events in Australian capital cities between 2001 and 2020.

Methods

For this health impact assessment, we obtained data on daily counts of deaths for all non-accidental causes and ages from the Australian National Vital Statistics Register. Daily concentrations of PM2.5 were estimated at a 5 km grid cell, using a Random Forest statistical model of data from air pollution monitoring sites combined with a range of satellite and land use-related data. We calculated the exceptional PM2.5 levels for each extreme pollution exposure day using the deviation from a seasonal and trend loess decomposition model. The burden of mortality was examined using a relative risk concentration-response function suggested in the literature.

Findings

Over the 20-year study period, we estimated 1454 (95 % CI 987, 1920) deaths in the major Australian cities attributable to exceptional PM2.5 exposure levels. The mortality burden due to PM2.5 exposure on extreme pollution days was considerable. Variations were observed across Australia. Despite relatively low daily PM2.5 levels compared to global averages, all Australian cities have extreme pollution exposure days, with PM2.5 concentrations exceeding the World Health Organisation Air Quality Guideline standard for 24-h exposure. Our analysis results indicate that nearly one-third of deaths from extreme air pollution exposure can be prevented with a 5 % reduction in PM2.5 levels on days with exceptional pollution.

Interpretation

Exposure to exceptional PM2.5 events was associated with an increased mortality burden in Australia's cities. Policies and coordinated action are needed to manage the health risks of extreme air pollution events due to bushfires and dust storms under climate change.

Associations between landscape fires and child morbidity in southern Mozambique: a time-series study

BACKGROUND

Epidemiological evidence linking exposure to landscape fires to child health remains scarce. We assessed the association between daily landscape fire smoke and child hospital visits and admissions in the Manhiça district, Mozambique, an area characterised by frequent forest and cropland fires.

METHODS

In this time-series analysis (2012-20), our primary metric for exposure to landscape fires was fire-originated PM2·5 from smoke dispersion hindcasts. We also assessed total and upwind fire exposure using daily satellite-derived fire density data. Daily numbers of hospital visits and admissions were extracted from an ongoing paediatric morbidity surveillance system (children aged ≤15 years). We applied quasi-Poisson regression models controlling for season, long-term trend, day of the week, temperature, and rainfall, and offsetting by annual population-time at risk to examine lag-specific association of fires on morbidity.

FINDINGS

A 10 μg/m3 increase in fire-originated PM2·5 was associated with a 6·12% (95% CI 0·37-12·21) increase in all-cause and a 12·43% (5·07-20·31) increase in respiratory-linked hospital visits on the following day. Positive associations were also observed for lag 0 and the cumulative lag of 0-1 days. Null associations were observed for hospital admissions. Landscape fires mostly occurred in forested areas; however, associations with child morbidity were stronger for cropland than for forest fires.

INTERPRETATION

Landscape fire smoke was associated with all-cause and respiratory-linked morbidity in children. Improved exposure assessment is needed to better quantify the contribution of landscape fire smoke to child health in regions with scarce air pollution monitoring.

FUNDING

H2020 project EXHAUSTION, Academy of Finland, Spanish Ministry of Science and Innovation, Generalitat de Catalunya, and Government of Mozambique and Spanish Agency for International Cooperation and Development.

Advancing the community health vulnerability index for wildland fire smoke exposure

Wildland fire smoke risks are not uniformly distributed across people and places, and the most vulnerable communities are often disproportionately impacted. This study develops a county level community health vulnerability index (CHVI) for the Contiguous United States (CONUS) using three major vulnerability components: adaptive capacity, sensitivity, and exposure at the national and regional level. We first calculated sensitivity and adaptive capacity sub-indices using nine sensitivity and twenty adaptive capacity variables. These sub-indices were then combined with an exposure sub-index, which is based on the Community Multiscale Air Quality data (2008-2018), to develop CHVI. Finally, we conducted several analyses with the derived indices to: 1) explore associations between the level of fine particulate matter from wildland fires (fire-PM2.5) and the sub-indices/CHVI; 2) measure the impact of fire-PM2.5 on the increase in the annual number of days with 12-35 μg/m3 (moderate) and >35 μg/m3 (at or above unhealthy for sensitive groups) based on the US EPA Air Quality Index categories, and 3) calculate population size in different deciles of the sub-indices/CHVI. This study has three main findings. First, we showed that the counties with higher daily fire-PM2.5 concentration tend to have lower adaptive capacity and higher sensitivity and vulnerability. Relatedly, the counties at high risk tended to experience a greater increase in the annual number of days with 12-35 μg/m3 and >35 μg/m3 than their counterparts. Second, we found that 16.1, 12.0, and 17.6 million people out of 332 million in CONUS reside in the counties in the lowest adaptive capacity decile, highest sensitivity decile, and highest vulnerability decile, respectively. Third, we identified that the US Northwest, California, and Southern regions tended to have higher vulnerability than others. Accurately identifying a community's vulnerability to wildfire smoke can help individuals, researchers, and policymakers better understand, prepare for, and respond to future wildland fire events.

Short-Term Exposure to Ambient Air Pollution and Influenza: A Multicity Study in China

BACKGROUND

Air pollution is a major risk factor for planetary health and has long been suspected of predisposing humans to respiratory diseases induced by pathogens like influenza viruses. However, epidemiological evidence remains elusive due to lack of longitudinal data from large cohorts.

OBJECTIVE

Our aim is to quantify the short-term association of influenza incidence with exposure to ambient air pollutants in Chinese cities.

METHODS

Based on air pollutant data and influenza surveillance data from 82 cities in China over a period of 5 years, we applied a two-stage time series analysis to assess the association of daily incidence of reported influenza cases with six common air pollutants [particulate matter with aerodynamic diameter ≤ 2.5 μ m (PM 2.5 ), particulate matter with aerodynamic diameter ≤ 10 μ m (PM 10 ), NO 2 , SO 2 , CO, and O 3 ], while adjusting for potential confounders including temperature, relative humidity, seasonality, and holiday effects. We built a distributed lag Poisson model for one or multiple pollutants in each individual city in the first stage and conducted a meta-analysis to pool city-specific estimates in the second stage.

RESULTS

A total of 3,735,934 influenza cases were reported in 82 cities from 2015 to 2019, accounting for 72.71% of the overall case number reported in the mainland of China. The time series models for each pollutant alone showed that the daily incidence of reported influenza cases was positively associated with almost all air pollutants except for ozone. The most prominent short-term associations were found for SO 2 and NO 2 with cumulative risk ratios of 1.094 [95% confidence interval (CI): 1.054, 1.136] and 1.093 (95% CI: 1.067, 1.119), respectively, for each 10   μ g / m 3 increase in the concentration at each of the lags of 1-7 d. Only NO 2 showed a significant association with the daily incidence of influenza cases in the multipollutant model that adjusts all six air pollutants together. The impact of air pollutants on influenza was generally found to be greater in children, in subtropical cities, and during cold months.

DISCUSSION

Increased exposure to ambient air pollutants, particularly NO 2 , is associated with a higher risk of influenza-associated illness. Policies on reducing air pollution levels may help alleviate the disease burden due to influenza infection. https://doi.org/10.1289/EHP12146.

Mortality risks from a spectrum of causes associated with sand and dust storms in China

Sand and Dust Storms (SDS) pose considerable health risks worldwide. Previous studies only indicated risk of SDS on overall mortality. This nationwide multicenter time-series study aimed to examine SDS-associated mortality risks extensively. We analyzed 1,495,724 deaths and 2024 SDS events from 1 February to 31 May (2013-2018) in 214 Chinese counties. The excess mortality risks associated with SDS were 7.49% (95% CI: 3.12-12.05%), 5.40% (1.25-9.73%), 4.05% (0.41-7.83%), 3.45% (0.34-6.66%), 3.37% (0.28-6.55%), 3.33% (0.07-6.70%), 8.90% (4.96-12.98%), 12.51% (6.31-19.08%), and 11.55% (5.55-17.89%) for ischemic stroke, intracerebral hemorrhagic stroke, hypertensive heart disease, myocardial infarction, acute myocardial infarction, acute ischemic heart disease, respiratory disease, chronic lower respiratory disease, and chronic obstructive pulmonary disease (COPD), respectively. SDS had significantly added effects on ischemic stroke, chronic lower respiratory disease, and COPD mortality. Our results suggest the need to implement public health policy against SDS.

Global population exposure to landscape fire air pollution from 2000 to 2019

Wildfires are thought to be increasing in severity and frequency as a result of climate change1-5. Air pollution from landscape fires can negatively affect human health4-6, but human exposure to landscape fire-sourced (LFS) air pollution has not been well characterized at the global scale7-23. Here, we estimate global daily LFS outdoor fine particulate matter (PM2.5) and surface ozone concentrations at 0.25° × 0.25° resolution during the period 2000-2019 with the help of machine learning and chemical transport models. We found that overall population-weighted average LFS PM2.5 and ozone concentrations were 2.5 µg m-3 (6.1% of all-source PM2.5) and 3.2 µg m-3 (3.6% of all-source ozone), respectively, in 2010-2019, with a slight increase for PM2.5, but not for ozone, compared with 2000-2009. Central Africa, Southeast Asia, South America and Siberia experienced the highest LFS PM2.5 and ozone concentrations. The concentrations of LFS PM2.5 and ozone were about four times higher in low-income countries than in high-income countries. During the period 2010-2019, 2.18 billion people were exposed to at least 1 day of substantial LFS air pollution per year, with each person in the world having, on average, 9.9 days of exposure per year. These two metrics increased by 6.8% and 2.1%, respectively, compared with 2000-2009. Overall, we find that the global population is increasingly exposed to LFS air pollution, with socioeconomic disparities.

Wildfire Exposure and Health Care Use Among People Who Use Durable Medical Equipment in Southern California

BACKGROUND

People using electricity-dependent durable medical equipment (DME) may be vulnerable to health effects from wildfire smoke, residence near wildfires, or residence in evacuation zones. To our knowledge, no studies have examined their healthcare utilization during wildfires.

METHODS

We obtained 2016-2020 counts of residential Zip Code Tabulation Area (ZCTA) level outpatient, emergency department (ED), and inpatient visits made by DME-using Kaiser Permanente Southern California members 45+. We linked counts to daily ZCTA-level wildfire particulate matter (PM) 2.5 and wildfire boundary and evacuation data from the 2018 Woolsey and 2019 Getty wildfires. We estimated the association of lagged (up to 7 days) wildfire PM 2.5 and residence near a fire or in an evacuation zone and healthcare visit frequency with negative binomial and difference-in-differences models.

RESULTS

Among 236,732 DME users, 10 µg/m 3 increases in wildfire PM 2.5 concentration were associated with the reduced rate (RR = 0.96; 95% confidence interval [CI] = 0.94, 0.99) of all-cause outpatient visits 1 day after exposure and increased rate on 4 of 5 subsequent days (RR range 1.03-1.12). Woolsey Fire proximity (<20 km) was associated with reduced all-cause outpatient visits, whereas evacuation and proximity were associated with increased inpatient cardiorespiratory visits (proximity RR = 1.45; 95% CI = 0.99, 2.12, evacuation RR = 1.72; 95% CI = 1.00, 2.96). Neither Getty Fire proximity nor evacuation was associated with healthcare visit frequency.

CONCLUSIONS

Our results support the hypothesis that wildfire smoke or proximity interrupts DME users' routine outpatient care, via sheltering in place. However, wildfire exposures were also associated with increased urgent healthcare utilization in this vulnerable group.

Air pollution from forest burning as environmental risk for millions of inhabitants of the Brazilian Amazon: an exposure indicator for human health

In this study, we propose an indicator of air pollution exposure to identify potential hazardous areas for human health in the Amazon and Central-West Regions of Brazil from 2010 to 2019. This indicator aggregates both concentrations and time of exposure to fine particulate matter (PM2.5), according to the current limit recommended by the World Health Organization (WHO). We used daily PM2.5 averages obtained from the Brazilian Health Integrated Environmental Information System (SISAM) to calculate the percentages of days with PM2.5 concentrations exceeding the limit of 15µg/m³ per year and per month. From 2010 to 2019, the months from August to October presented the largest areas and the highest percentages of days with unacceptable pollution concentration values, harmful to human health. These areas were concentrated in the Arc of Deforestation. Therefore, 60% of the residents of the Amazon and Central-West regions were subjected to inadequate air quality for approximately six months per year. The proposed indicator is reproducible and appropriate to monitor areas of exposure and risk for human health.

Wildland fire, air pollution and cardiovascular health: is it time to focus on the microvasculature as a risk assessment tool?

Climate change favors weather conditions conducive to wildland fires. The intensity and frequency of forest fires are increasing, and fire seasons are lengthening. Exposure of human populations to smoke emitted by these fires increases, thereby contributing to airborne pollution through the emission of gas and particulate matter (PM). The adverse health outcomes associated with wildland fire exposure represent an important burden on the economies and health systems of societies. Even though cardiovascular diseases (CVDs) are the main of cause of the global burden of diseases attributable to PM exposure, it remains difficult to show reliable associations between exposure to wildland fire smoke and cardiovascular disease risk in population-based studies. Optimal health requires a resilient and adaptable network of small blood vessels, namely, the microvasculature. Often alterations of this microvasculature precede the occurrence of adverse health outcomes, including CVD. Biomarkers of microvascular health could then represent possible markers for the early detection of poor cardiovascular outcomes. This review aims to synthesize the current literature to gauge whether assessing the microvasculature can better estimate the cardiovascular impact of wildland fires.

Association between long-term exposure to wildfire-related PM2.5 and mortality: A longitudinal analysis of the UK Biobank

Little is known about the associations between long-term exposure to wildfire-related fine particulate matter (PM_2.5) and mortality. We aimed to explore theses associations using the data from the UK Biobank cohort. Long-term wildfire-related PM_2.5 exposure was defined as the 3-year cumulative concentrations of wildfire-related PM_2.5 within a 10-km buffer surrounding the residential address for each individual. Hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated using the time-varying Cox regression model. We included 492,394 participants aged between 38 and 73 years. We found that after adjusting for potential covariates, a 10 μg/m³ increase of wildfire-related PM_2.5 exposure was associated with a 0.4% higher risk of all-cause mortality (HR = 1.004 [95% CI: 1.001, 1.006]) and nonaccidental mortality (HR = 1.004 [95% CI: 1.002, 1.006]), and a 0.5% higher risk of neoplasm mortality (HR = 1.005 [95% CI: 1.002, 1.008]). However, no significant associations were observed between wildfire-related PM_2.5 exposure and mortality from cardiovascular, respiratory, and mental diseases. Additionally, no significant modification effects of a series of modifiers were observed. Targeted health protection strategies should be adopted in response to wildfire-related PM_2.5 exposure, in order to reduce the risk of premature mortality.

Productivity-adjusted life years lost due to non-optimum temperatures in Brazil: A nationwide time-series study

Non-optimal temperatures are associated with premature deaths globally. However, the evidence is limited in low- and middle-income countries, and the productivity losses due to non-optimal temperatures have not been quantified. We aimed to estimate the work-related impacts and economic losses attributable to non-optimal temperatures in Brazil. We collected daily mortality data from 510 immediate regions in Brazil during 2000 and 2019. A two-stage time-series analysis was applied to evaluate the association between non-optimum temperatures and the Productivity-Adjusted Life-Years (PALYs) lost. The temperature-PALYs association was fitted for each location in the first stage and then we applied meta-analyses to obtain the national estimations. The attributable fraction (AF) of PALY lost due to ambient temperatures and the corresponding economic costs were calculated for different subgroups of the working-age population. A total of 3,629,661 of PALYs lost were attributed to non-optimal temperatures during 2000-2019 in Brazil, corresponding to 2.90 % (95 % CI: 1.82 %, 3.95 %) of the total PALYs lost. Non-optimal temperatures have led to US$104.86 billion (95 % CI: 65.95, 142.70) of economic costs related to PALYs lost and the economic burden was more substantial in males and the population aged 15-44 years. Higher risks of extreme cold temperatures were observed in the South region in Brazil while extreme hot temperatures were observed in the Central West and Northeast regions. In conclusion, non-optimal temperatures are associated with considerable labour losses as well as economic costs in Brazil. Tailored policies and adaptation strategies should be proposed to mitigate the impacts of non-optimal temperatures on the labour supply in a changing climate.

Long-term impact of the 2014 Hazelwood coal mine fire on emergency department presentations in Australia

BACKGROUND

In 2014, wildfires ignited a coal mine in Australia, burning for 6 weeks, releasing large amounts of fine particulate matter ≤2.5 μm in diameter (PM_2.5). We investigated the association between individual PM_2.5 exposure and emergency department presentations (EDPs) within 5 years post-fire.

METHODS

Survey and exposure data for 2725 residents from an exposed and unexposed town were linked with ED administrative data from 2009 to 2019. The association between individual PM_2.5 and EDPs was assessed using recurrent survival analysis.

RESULTS

A 10 μg/m³ increase in PM_2.5 was associated with a 10% increase in respiratory EDPs (HR = 1.10; 95%CI:1.00-1.22) over 5 years post-fire. Increased risks of EDPs for ischaemic heart disease (HR = 1.39; 95%CI:1.12-1.73), atherothrombotic disease (HR = 1.27; 95%CI:1.08-1.50), and cardiovascular disease (HR = 1.10, 95%CI:0.99-1.22) were evident within 2.5 years.

CONCLUSION

PM_2.5 exposure from a 6-week mine fire increased the 5-year risk of respiratory conditions. An increased risk of CVD within 2.5 years post-fire subsided after this time.

Long-term impacts of non-occupational wildfire exposure on human health: A systematic review

The intensity and frequency of wildfires is increasing globally. The systematic review of the current evidence on long-term impacts of non-occupational wildfire exposure on human health has not been performed yet. To provide a systematic review and identify potential knowledge gaps in the current evidence of long-term impacts of non-occupational exposure to wildfire smoke and/or wildfire impacts on human health. We conducted a systematic search of the literature via MEDLINE, Embase and Scopus from the database inception to July 05, 2022. References from the included studies and relevant reviews were also considered. The Newcastle-Ottawa Scale (NOS) and a validated quality assessment framework were used to evaluate the quality of observational studies. Study results were synthesized descriptively. A total of 36 studies were included in our systematic review. Most studies were from developed countries (11 in Australia, 9 in Canada, 7 in the United States). Studies predominantly focused on mental health (21 studies, 58.33%), while evidence on long-term impacts of wildfire exposure on health outcomes other than mental health is limited. Current evidence indicated that long-term impacts of non-occupational wildfire exposure were associated with mortality (COVID-19 mortality, cardiovascular disease mortality and acute myocardial disease mortality), morbidity (mainly respiratory diseases), mental health disorders (mainly posttraumatic stress disorder), shorter height of children, reduced lung function and poorer general health status. However, no significant associations were observed for long-term impacts of wildfire exposure on child mortality and respiratory hospitalizations. The population-based high-quality evidence with quantitative analysis on this topic is still limited. Future well-designed studies considering extensive wildfire smoke air pollutants (e.g., particulate matter, ozone, nitrogen oxides) and estimating risk coefficient values for extensive health outcomes (e.g., mortality, morbidity) are warranted to fill current knowledge gaps.

Short-term air pollution exposure and hospital admissions for cardiorespiratory diseases in Brazil: A nationwide time-series study between 2008 and 2018

The established evidence associating air pollution with health is limited to populations from specific regions. Further large-scale studies in several regions worldwide are needed to support the literature to date and encourage national governments to act. Brazil is an example of these regions where little research has been performed on a large scale. To address this gap, we conducted a study looking at the relationship between daily PM_2.5, NO₂, and O₃, and hospital admissions for circulatory and respiratory diseases across Brazil between 2008 and 2018. A time-series analytic approach was applied with a distributed lag modeling framework. We used a generalized conditional quasi-Poisson regression model to estimate relative risks (RRs) of the association of each air pollutant with the hospitalization for circulatory and respiratory diseases by sex, age group, and Brazilian regions. Our study population includes 23, 791, 093 hospital admissions for cardiorespiratory diseases in Brazil between 2008 and 2018. Among those, 53.1% are respiratory diseases, and 46.9% are circulatory diseases. Our findings suggest significant associations of ambient air pollution (PM_2.5, NO₂, and O₃) with respiratory and circulatory hospital admissions in Brazil. The national meta-analysis for the whole population showed that for every increase of PM_2.5 by 10 μg/m³, there is a 3.28% (95%CI: 2.61; 3.94) increase in the risk of hospital admission for respiratory diseases. For O₃, we found positive associations only for some sub-group analyses by age and sex. For NO₂, our findings suggest that a 10 ppb increase in this pollutant, there was a 35.26% (95%CI: 24.07; 46.44) increase in the risk of hospital admission for respiratory diseases. This study may better support policymakers to improve the air quality and public health in Brazil.

A causal modelling framework for short-term effects of PM2.5 on hospitalisations: A nationwide time series study in Brazil

Accurate estimates of the causal effect of air pollution on health outcomes, are critical when calculating attributable disease burdens. Brazil has a large population exposed to fast-growing emissions of air pollutants, however no national level studies have been conducted to examine the causal effect of PM_2.5 exposure on health outcomes. This study proposes a novel approach, to accurately estimate the causal relationship between daily PM_2.5 exposure and hospitalisations, across 1,814 Brazilian cities during 2000-2015. A variant of the difference-in-differences (DID) approach was applied under a counterfactual framework. Daily time series data were divided into panels. Seasonality and long-term trend were controlled using indicators for the panel. Variables which do not change within a short-period were controlled using a dummy variable for the day. Controls for variables which vary day by day, were included in the model. We found the proposed model exhibited competitive power performance in detecting causal associations between short-term PM_2.5 exposure and hospitalisations in Brazil. A 10 μg/m³ increase in PM_2.5 concentrations over four days (lag 0-3) was associated with a 1.06 % (95 % CI: 0.94 to 1.17) increase in all-cause hospitalisations and accounted for 1.26 % (95 % CI: 1.12-1.39) of total hospitalisations. Larger effects were found for children aged 0-4 years and the elderly aged 80+ years, suggesting policies should be developed to minimise the exposure of these age groups.

2030 Agenda: discussion on Brazilian priorities facing air pollution and climate change challenges

The advance of human activities in a disorderly way has accelerated in recent decades, intensifying the environmental impacts directly linked to these practices. The atmosphere, essential for the maintenance of life, is increasingly saturated with pollutants, offering risks to practically all the inhabitants of the planet, a process that, in addition to causing illness and early mortality, is related to serious financial losses (including in the production of goods), dangerous temperature increase and severe natural disasters. Although this perception is not recent, the global initiative to control the different mechanisms that trigger the commitment of biodiversity and irreversible climate changes arising from pollution is still very incipient, given that global initiatives on the subject emerged just over 50 years ago. Brazil is a territory that centralizes many of these discussions, as it still faces both political and economic obstacles in achieving a sustainable growth model as it was agreed through the United Nations 2030 Agenda. Even though there is little time left for the completion of these goals, much remains to be done, and despite the fulfillment of this deadline, the works will certainly need to be extended for much longer until an effective reorientation of consciousness occurs. Scientific researches and discussions are fundamental tools to the understanding of issues still little explored in this field.

Wildfire-related PM2.5 and DNA methylation: An Australian twin and family study

BACKGROUND

Wildfire-related fine particulate matter (PM_2.5) has many adverse health impacts, but its impacts on human epigenome are unknown. We aimed to evaluate the associations between long-term exposure to wildfire-related PM_2.5 and blood DNA methylation, and whether the associations differ from those with non-wildfire-related PM_2.5.

METHODS

We studied 479 Australian women comprising 132 twin pairs and 215 of their sisters. Blood-derived DNA methylation was measured using the HumanMethylation450 BeadChip array. Data on 3-year (year of blood collection and previous two years) average wildfire-related and non-wildfire-related PM_2.5 at 0.01°×0.01° spatial resolution were created by combining information from satellite observations, chemical transport models, and ground-based observations. Exposure data were linked to each participant's home address, assuming the address did not change during the exposure window. For DNA methylation of each cytosine-guanine dinucleotide (CpG), and for global DNA methylation represented by the average of all measured CpGs or CpGs in repetitive elements, we evaluated their associations with wildfire- or non-wildfire-related PM_2.5 using a within-sibship analysis controlling for factors shared between siblings and other important covariates. Differentially methylated regions (DMRs) were defined by comb-p and DMRcate.

RESULTS

The 3-year average wildfire-related PM_2.5 (range: 0.3 to 7.6 µg/m³_, mean: 1.6 µg/m³) was negatively, but not significantly (p-values greater than 0.05) associated with all seven global DNA methylation measures. There were 26 CpGs and 33 DMRs associated with wildfire-related PM_2.5 (Bonferroni adjusted p-value < 0.05) mapped to 47 genes enriched for pathways related to inflammatory regulation and platelet activation. These genes have been related to many human diseases or phenotypes e.g., cancer, mental disorders, diabetes, obesity, asthma, blood pressure. These CpGs, DMRs and enriched pathways did not overlap with the 1 CpG and 7 DMRs associated with non-wildfire-related PM_2.5.

CONCLUSIONS

Long-term exposure to wildfire-related PM_2.5 was associated with various blood DNA methylation signatures in Australian women, and these were distinct from those associated with non-wildfire-related PM_2.5.

Short-term exposure to wildfire-related PM2.5 increases mortality risks and burdens in Brazil

To assess mortality risks and burdens associated with short-term exposure to wildfire-related fine particulate matter with diameter ≤ 2.5 μm (PM_2.5), we collect daily mortality data from 2000 to 2016 for 510 immediate regions in Brazil, the most wildfire-prone area. We integrate data from multiple sources with a chemical transport model at the global scale to isolate daily concentrations of wildfire-related PM_2.5 at a 0.25 × 0.25 resolution. With a two-stage time-series approach, we estimate (i) an increase of 3.1% (95% confidence interval [CI]: 2.4, 3.9%) in all-cause mortality, 2.6% (95%CI: 1.5, 3.8%) in cardiovascular mortality, and 7.7% (95%CI: 5.9, 9.5) in respiratory mortality over 0-14 days with each 10 μg/m³ increase in daily wildfire-related PM_2.5; (ii) 0.65% of all-cause, 0.56% of cardiovascular, and 1.60% of respiratory mortality attributable to acute exposure to wildfire-related PM_2.5, corresponding to 121,351 all-cause deaths, 29,510 cardiovascular deaths, and 31,287 respiratory deaths during the study period. In this study, we find stronger associations in females and adults aged ≥ 60 years, and geographic difference in the mortality risks and burdens.

Association between PM2.5 and respiratory hospitalization in Rio Branco, Brazil: Demonstrating the potential of low-cost air quality sensor for epidemiologic research

BACKGROUND

There is currently a scarcity of air pollution epidemiologic data from low- and middle-income countries (LMICs) due to the lack of air quality monitoring in these countries. Additionally, there is limited capacity to assess the health effects of wildfire smoke events in wildfire-prone regions like Brazil's Amazon Basin. Emerging low-cost air quality sensors may have the potential to address these gaps.

OBJECTIVES

We investigated the potential of PurpleAir PM2.5 sensors for conducting air pollution epidemiologic research leveraging the United States Environmental Protection Agency's United States-wide correction formula for ambient PM_2.5.

METHODS

We obtained raw (uncorrected) PM_2.5 concentration and humidity data from a PurpleAir sensor in Rio Branco, Brazil, between 2018 and 2019. Humidity measurements from the PurpleAir sensor were used to correct the PM_2.5 concentrations. We established the relationship between ambient PM_2.5 (corrected and uncorrected) and daily all-cause respiratory hospitalization in Rio Branco, Brazil, using generalized additive models (GAM) and distributed lag non-linear models (DLNM). We used linear regression to assess the relationship between daily PM_2.5 concentrations and wildfire reports in Rio Branco during the wildfire seasons of 2018 and 2019.

RESULTS

We observed increases in daily respiratory hospitalizations of 5.4% (95%CI: 0.8%, 10.1%) for a 2-day lag and 5.8% (1.5%, 10.2%) for 3-day lag, per 10 μg/m³ PM_2.5 (corrected values). The effect estimates were attenuated when the uncorrected PM_2.5 data was used. The number of reported wildfires explained 10% of daily PM2.5 concentrations during the wildfire season.

DISCUSSION

Exposure-response relationships estimated using corrected low-cost air quality sensor data were comparable with relationships estimated using a validated air quality modeling approach. This suggests that correcting low-cost PM_2.5 sensor data may mitigate bias attenuation in air pollution epidemiologic studies. Low-cost sensor PM_2.5 data could also predict the air quality impacts of wildfires in Brazil's Amazon Basin.

Protecting Cardiovascular Health From Wildfire Smoke

Wildfire smoke is a rapidly growing threat to global cardiovascular health. We review the literature linking wildfire smoke exposures to cardiovascular effects. We find substantial evidence that short-term exposures are associated with key cardiovascular outcomes, including mortality, hospitalization, and acute coronary syndrome. Wildfire smoke exposures will continue to increase over the majority of Earth's surface. For example, the United States alone has experienced a 5-fold increase in annual area burned since 1972, with 82 million individuals estimated to be exposed to wildfire smoke by midcentury. The associated rise in excess morbidity and mortality constitutes a growing global public health crisis. Fortunately, the effect of wildfire smoke on cardiovascular health is modifiable at the individual and population levels through specific interventions. Health systems therefore have an opportunity to help safeguard patients from smoke exposures. We provide a roadmap of evidence-based interventions to reduce risk and protect cardiovascular health. Key interventions include preparing health systems for smoke events; identifying and educating vulnerable patients; reducing outdoor activities; creating cleaner air environments; using air filtration devices and personal respirators; and aggressive management of chronic diseases and traditional risk factors. Further research is needed to test the efficacy of interventions on reducing cardiovascular outcomes.

Exposure to wildfire-related PM2.5 and site-specific cancer mortality in Brazil from 2010 to 2016: A retrospective study

BACKGROUND

Long-term exposure to fine particles ≤2.5 μm in diameter (PM2.5) has been linked to cancer mortality. However, the effect of wildfire-related PM2.5 exposure on cancer mortality risk is unknown. This study evaluates the association between wildfire-related PM2.5 and site-specific cancer mortality in Brazil, from 2010 to 2016.

METHODS AND FINDINGS

Nationwide cancer death records were collected during 2010-2016 from the Brazilian Mortality Information System. Death records were linked with municipal-level wildfire- and non-wildfire-related PM2.5 concentrations, at a resolution of 2.0° latitude by 2.5° longitude. We applied a variant difference-in-differences approach with quasi-Poisson regression, adjusting for seasonal temperature and gross domestic product (GDP) per capita. Relative risks (RRs) and 95% confidence intervals (CIs) for the exposure for specific cancer sites were estimated. Attributable fractions and cancer deaths were also calculated. In total, 1,332,526 adult cancer deaths (age ≥ 20 years), from 5,565 Brazilian municipalities, covering 136 million adults were included. The mean annual wildfire-related PM2.5 concentration was 2.38 μg/m3, and the annual non-wildfire-related PM2.5 concentration was 8.20 μg/m3. The RR for mortality from all cancers was 1.02 (95% CI 1.01-1.03, p < 0.001) per 1-μg/m3 increase of wildfire-related PM2.5 concentration, which was higher than the RR per 1-μg/m3 increase of non-wildfire-related PM2.5 (1.01 [95% CI 1.00-1.01], p = 0.007, with p for difference = 0.003). Wildfire-related PM2.5 was associated with mortality from cancers of the nasopharynx (1.10 [95% CI 1.04-1.16], p = 0.002), esophagus (1.05 [95% CI 1.01-1.08], p = 0.012), stomach (1.03 [95% CI 1.01-1.06], p = 0.017), colon/rectum (1.08 [95% CI 1.05-1.11], p < 0.001), larynx (1.06 [95% CI 1.02-1.11], p = 0.003), skin (1.06 [95% CI 1.00-1.12], p = 0.003), breast (1.04 [95% CI 1.01-1.06], p = 0.007), prostate (1.03 [95% CI 1.01-1.06], p = 0.019), and testis (1.10 [95% CI 1.03-1.17], p = 0.002). For all cancers combined, the attributable deaths were 37 per 100,000 population and ranged from 18/100,000 in the Northeast Region of Brazil to 71/100,000 in the Central-West Region. Study limitations included a potential lack of assessment of the joint effects of gaseous pollutants, an inability to capture the migration of residents, and an inability to adjust for some potential confounders.

CONCLUSIONS

Exposure to wildfire-related PM2.5 can increase the risks of cancer mortality for many cancer sites, and the effect for wildfire-related PM2.5 was higher than for PM2.5 from non-wildfire sources.

Global climate change and human health: Pathways and possible solutions

Global warming has been changing the planet's climate pattern, leading to increasing frequency, intensity and duration of extreme weather events and natural disasters. These climate-changing events affect various health outcomes adversely through complicated pathways. This paper reviews the main signs of climate change so far, e.g., suboptimal ambient temperature, sea-level rise and other conditions, and depicts the interactive pathways between different climate-changing events such as suboptimal temperature, wildfires, and floods with a broad range of health outcomes. Meanwhile, the modifying effect of socioeconomic, demographic and environmental factors on the pathways is summarised, such that the youth, elderly, females, poor and those living in coastal regions are particularly susceptible to climate change. Although Earth as a whole is expected to suffer from climate change, this review article discusses some potential benefits for certain regions, e.g., a more liveable environment and sufficient food supply. Finally, we summarise certain mitigation and adaptation strategies against climate change and how these strategies may benefit human health in other ways. This review article provides a comprehensive and concise introduction of the pathways between climate change and human health and possible solutions, which may map directions for future research.

Excess emergency department visits for cardiovascular and respiratory diseases during the 2019-20 bushfire period in Australia: A two-stage interrupted time-series analysis

The health effects of the unprecedented bushfires in Australia in 2019-20 have not been fully examined. We aimed to examine the excess emergency department (ED) visits related to the 2019-20 bushfires in New South Wales (NSW). We obtained weekly data of ED visits for cardiovascular and respiratory diseases in all the 28 Statistical Area Level 4 (SA4) regions in NSW during the bushfire seasons from 2017 to 2020. A two-stage interrupted time-series analysis was applied to quantify the excess risk for ED visits in 2019-20. The total number of excess ED visits, excess percentages, and their empirical confidence intervals (eCIs) were calculated to estimate the impacts of the bushfire season. A total of 416,057 records of cardiorespiratory ED visits were included in our analysis. The bushfire season in 2019-20 was significantly associated with a 6.0% increase (95% eCI: 1.9, 10.3) in ED visits for respiratory diseases and a 10.0% increase (95% eCI: 5.0, 15.2) for cardiovascular diseases, corresponding to 6177 (95% eCI: 1989, 10,166) and 3120 (95% eCI: 1628, 4544) excess ED visits, respectively. The percentage of excess ED visits was higher in regions with lower SES and high fire density. In the context of climate change, more targeted strategies should be developed to prevent adverse bushfire effects and recover from such extreme environmental events.

Environmental risk factors and cardiovascular diseases: a comprehensive review

Noncommunicable diseases (NCDs) are fatal for more than 38 million people each year and are thus the main contributors to the global burden of disease accounting for 70% of mortality. The majority of these deaths are caused by cardiovascular disease. The risk of NCDs is strongly associated with exposure to environmental stressors such as pollutants in the air, noise exposure, artificial light at night and climate change, including heat extremes, desert storms and wildfires. In addition to the traditional risk factors for cardiovascular disease such as diabetes, arterial hypertension, smoking, hypercholesterolemia and genetic predisposition, there is a growing body of evidence showing that physicochemical factors in the environment contribute significantly to the high NCD numbers. Furthermore, urbanization is associated with accumulation and intensification of these stressors. This comprehensive expert review will summarize the epidemiology and pathophysiology of environmental stressors with a focus on cardiovascular NCDs. We will also discuss solutions and mitigation measures to lower the impact of environmental risk factors with focus on cardiovascular disease.

Exposure to landscape fire smoke reduced birthweight in low- and middle-income countries: findings from a siblings-matched case-control study

Background:

Landscape fire smoke (LFS) has been associated with reduced birthweight, but evidence from low- and middle-income countries (LMICs) is rare.

Methods:

Here, we present a sibling-matched case–control study of 227,948 newborns to identify an association between fire-sourced fine particulate matter (PM_2.5) and birthweight in 54 LMICs from 2000 to 2014. We selected mothers from the geocoded Demographic and Health Survey with at least two children and valid birthweight records. Newborns affiliated with the same mother were defined as a family group. Gestational exposure to LFS was assessed in each newborn using the concentration of fire-sourced PM_2.5. We determined the associations of the within-group variations in LFS exposure with birthweight differences between matched siblings using a fixed-effects regression model. Additionally, we analyzed the binary outcomes of low birthweight (LBW) or very low birthweight (VLBW).

Results:

According to fully adjusted models, a 1 µg/m³ increase in the concentration of fire-sourced PM_2.5 was significantly associated with a 2.17 g (95% confidence interval [CI] 0.56–3.77) reduction in birthweight, a 2.80% (95% CI 0.97–4.66) increase in LBW risk, and an 11.68% (95% CI 3.59–20.40) increase in VLBW risk.

Conclusions:

Our findings indicate that gestational exposure to LFS harms fetal health.

Funding:

PKU-Baidu Fund, National Natural Science Foundation of China, Peking University Health Science Centre, and CAMS Innovation Fund for Medical Sciences.