Ambient fine particulate matter and daily mortality: a comparative analysis of observed and estimated exposure in 347 cities.

BACKGROUND: Model-estimated air pollution exposure products have been widely used in epidemiological studies to assess the health risks of particulate matter with diameters of ≤2.5 µm (PM2.5). However, few studies have assessed the disparities in health effects between model-estimated and station-observed PM2.5 exposures. METHODS: We collected daily all-cause, respiratory and cardiovascular mortality data in 347 cities across 15 countries and regions worldwide based on the Multi-City Multi-Country collaborative research network. The station-observed PM2.5 data were obtained from official monitoring stations. The model-estimated global PM2.5 product was developed using a machine-learning approach. The associations between daily exposure to PM2.5 and mortality were evaluated using a two-stage analytical approach. RESULTS: We included 15.8 million all-cause, 1.5 million respiratory and 4.5 million cardiovascular deaths from 2000 to 2018. Short-term exposure to PM2.5 was associated with a relative risk increase (RRI) of mortality from both station-observed and model-estimated exposures. Every 10-µg/m3 increase in the 2-day moving average PM2.5 was associated with overall RRIs of 0.67% (95% CI: 0.49 to 0.85), 0.68% (95% CI: -0.03 to 1.39) and 0.45% (95% CI: 0.08 to 0.82) for all-cause, respiratory, and cardiovascular mortality based on station-observed PM2.5 and RRIs of 0.87% (95% CI: 0.68 to 1.06), 0.81% (95% CI: 0.08 to 1.55) and 0.71% (95% CI: 0.32 to 1.09) based on model-estimated exposure, respectively. CONCLUSIONS: Mortality risks associated with daily PM2.5 exposure were consistent for both station-observed and model-estimated exposures, suggesting the reliability and potential applicability of the global PM2.5 product in epidemiological studies.

Differentiated impacts of short-term exposure to fine particulate constituents on infectious diseases in 507 cities of Chinese children and adolescents: A nationwide time-stratified case-crossover study from 2008 to 2021.

This study assesses the association of short-term exposure to PM2.5 (particles ≤2.5 µm) on infectious diseases among Chinese children and adolescents. Analyzing data from 507 cities (2008-2021) on 42 diseases, it focuses on PM2.5 components (black carbon (BC), ammonium (NH4+), inorganic nitrate (NO3-), organic matter (OM), and sulfate (SO42-)). PM2.5 constituents significantly associated with incidence. Sulfate showed the most substantial effect, increasing all-cause infectious disease risk by 2.72 % per interquartile range (IQR) increase. It was followed by BC (2.04 % increase), OM (1.70 %), NO3- (1.67 %), and NH4+ (0.79 %). Specifically, sulfate and BC had pronounced impacts on respiratory diseases, with sulfate linked to a 10.73 % increase in seasonal influenza risk and NO3- to a 16.39 % rise in tuberculosis. Exposure to PM2.5 also marginally increased risks for gastrointestinal, enterovirus, and vectorborne diseases like dengue (7.46 % increase with SO42-). Sexually transmitted and bloodborne diseases saw an approximate 6.26 % increase in incidence, with specific constituents linked to diseases like hepatitis C and syphilis. The study concludes that managing PM2.5 levels could substantially reduce infectious disease incidence, particularly in China's middle-northern regions. It highlights the necessity of stringent air quality standards and targeted disease prevention, aligning PM2.5 management with international guidelines for public health protection.

Association of cause-specific hospital admissions with high and low temperatures in Thailand: a nationwide time series study.

Background: Non-optimum temperatures are associated with a considerable mortality burden. However, evidence of temperature with all-cause and cause-specific hospital admissions in tropical countries like Thailand is still limited. Methods: Daily all-cause and cause-specific hospital admissions for outpatient and inpatient visits were collected from 77 provinces in Thailand from January 2013 to August 2019. A two-stage time-series approach was applied to assess the association between non-optimum temperatures and hospital admission. We first fitted the province-specific temperature-morbidity association and then obtained the national association in the second stage using a random-effects meta-analysis regression. The attributable fraction (AF) of hospital admissions with 95% empirical confidence interval (eCI) was calculated. Findings: A total of 878,513,460 all-cause outpatient admissions and 32,616,600 all-cause inpatient admissions were included in this study. We observed a J-shaped relationship with the risk of hospital admissions increasing for both cold and hot temperatures. The overall AFs of all-cause hospital admissions due to non-optimum temperatures were 7.57% (95% eCI: 6.47%, 8.39%) for outpatient visits and 6.17% (95% eCI: 4.88%, 7.20%) for inpatient visits. Hot temperatures were responsible for most of the AFs of hospital admissions, with 6.71% (95% eCI: 5.80%, 7.41%) for outpatient visits and 4.50% (95% eCI: 3.62%, 5.19%) for inpatient visits. The burden of hospital admissions was greater in females and in children and adolescents (0-19 years). The fractions of hospital admissions attributable to non-optimum temperatures exhibited variation among disease categories and geographical areas. Interpretation: The results indicate that low and high temperature has a significant impact on hospital admissions, especially among the females, and children and adolescents (0-19 years). The current investigation could provide evidence for policymakers to develop adaptation strategies and mitigate the adverse effects of climate change on public health in Thailand and other tropical countries. Funding: National Research Council of Thailand (NRCT): E-Asia Joint Research Program: Climate change impact on natural and human systems (N33A650979).

Estimates of global mortality burden associated with short-term exposure to fine particulate matter (PM2·5).

BACKGROUND: The acute health effects of short-term (hours to days) exposure to fine particulate matter (PM2·5) have been well documented; however, the global mortality burden attributable to this exposure has not been estimated. We aimed to estimate the global, regional, and urban mortality burden associated with short-term exposure to PM2·5 and the spatiotemporal variations in this burden from 2000 to 2019. METHODS: We combined estimated global daily PM2·5 concentrations, annual population counts, country-level mortality rates, and epidemiologically derived exposure-response functions to estimate the mortality attributable to short-term PM2·5 exposure from 2000 to 2019, in the continental regions and in 13 189 urban centres worldwide at a spatial resolution of 0·1°â€ˆ× 0·1°. We tested the robustness of our mortality estimates with different theoretical minimum risk exposure levels, lag effects, and exposure-response functions. FINDINGS: Approximately 1 million (95% CI 690 000-1·3 million) premature deaths per year from 2000 to 2019 were attributable to short-term PM2·5 exposure, representing 2·08% (1·41-2·75) of total global deaths or 17 (11-22) premature deaths per 100 000 population. Annually, 0·23 million (0·15 million-0·30 million) deaths attributable to short-term PM2·5 exposure were in urban areas, constituting 22·74% of the total global deaths attributable to this cause and accounting for 2·30% (1·56-3·05) of total global deaths in urban areas. The sensitivity analyses showed that our worldwide estimates of mortality attributed to short-term PM2·5 exposure were robust. INTERPRETATION: Short-term exposure to PM2·5 contributes a substantial global mortality burden, particularly in Asia and Africa, as well as in global urban areas. Our results highlight the importance of mitigation strategies to reduce short-term exposure to air pollution and its adverse effects on human health. FUNDING: Australian Research Council and the Australian National Health and Medical Research Council.

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.

Tropical cyclone-specific mortality risks and the periods of concern: A multicountry time-series study.

BACKGROUND: More intense tropical cyclones (TCs) are expected in the future under a warming climate scenario, but little is known about their mortality effect pattern across countries and over decades. We aim to evaluate the TC-specific mortality risks, periods of concern (POC) and characterize the spatiotemporal pattern and exposure-response (ER) relationships on a multicountry scale. METHODS AND FINDINGS: Daily all-cause, cardiovascular, and respiratory mortality among the general population were collected from 494 locations in 18 countries or territories during 1980 to 2019. Daily TC exposures were defined when the maximum sustained windspeed associated with a TC was ≥34 knots using a parametric wind field model at a 0.5° × 0.5° resolution. We first estimated the TC-specific mortality risks and POC using an advanced flexible statistical framework of mixed Poisson model, accounting for the population changes, natural variation, seasonal and day of the week effects. Then, a mixed meta-regression model was used to pool the TC-specific mortality risks to estimate the overall and country-specific ER relationships of TC characteristics (windspeed, rainfall, and year) with mortality. Overall, 47.7 million all-cause, 15.5 million cardiovascular, and 4.9 million respiratory deaths and 382 TCs were included in our analyses. An overall average POC of around 20 days was observed for TC-related all-cause and cardiopulmonary mortality, with relatively longer POC for the United States of America, Brazil, and Taiwan (>30 days). The TC-specific relative risks (RR) varied substantially, ranging from 1.04 to 1.42, 1.07 to 1.77, and 1.12 to 1.92 among the top 100 TCs with highest RRs for all-cause, cardiovascular, and respiratory mortality, respectively. At country level, relatively higher TC-related mortality risks were observed in Guatemala, Brazil, and New Zealand for all-cause, cardiovascular, and respiratory mortality, respectively. We found an overall monotonically increasing and approximately linear ER curve of TC-related maximum sustained windspeed and cumulative rainfall with mortality, with heterogeneous patterns across countries and regions. The TC-related mortality risks were generally decreasing from 1980 to 2019, especially for the Philippines, Taiwan, and the USA, whereas potentially increasing trends in TC-related all-cause and cardiovascular mortality risks were observed for Japan. CONCLUSIONS: The TC mortality risks and POC varied greatly across TC events, locations, and countries. To minimize the TC-related health burdens, targeted strategies are particularly needed for different countries and regions, integrating epidemiological evidence on region-specific POC and ER curves that consider across-TC variability.

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.

Applying traffic camera and deep learning-based image analysis to predict PM2.5 concentrations.

BACKGROUND: Air pollution has caused a significant burden in terms of mortality and mobility worldwide. However, the current coverage of air quality monitoring networks is still limited. OBJECTIVE: This study aims to apply a novel approach to convert the existing traffic cameras into sensors measuring particulate matter with a diameter of 2.5 µm or less (PM2.5) so that the coverage of PM2.5 monitoring could be expanded without extra cost. METHODS: In our study, the traffic camera images were collected at a rate of 4 images/h and the corresponding hourly PM2.5 concentration was collected from the reference grade PM2.5 station 3 km away. A customized neural network model was trained to obtain the PM2.5 concentration from images followed by a random forest model to predict the hourly PM2.5 concentration. The saliency maps and the feature importance were utilized to interpret the neural network. RESULTS: Proposed novel approach has a high prediction performance to predict hourly PM2.5 from traffic camera images, with a root mean square error (RMSE) of 0.76 µg/m3 and a coefficient of determination (R2) of 0.98. The saliency map shows neural network focuses on unobstructed far-end road surfaces while the random forest feature importance highlights the first quarter image's significance. The model performance is robust whether weather conditions are controlled or not. CONCLUSION: Our study provided a practical approach to converting the existing traffic cameras into PM2.5 sensors. The deep learning method based on the Resnet architecture in our study can broaden the coverage of PM2.5 monitoring with no additional infrastructure needed.

Maternal greenness exposure and preterm birth in Brazil: A nationwide birth cohort study.

In the dynamic landscape of maternal and child health, understanding the intricate interplay between environmental factors and pregnancy outcomes is of paramount importance. This study investigates the relationship between maternal greenness exposure and preterm births in Brazil using data spanning from 2010 to 2019. Satellite-derived indices, including the Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI), were employed to assess greenness exposure during whole pregnancy in maternal residential area. Employing Cox proportional hazard models, we calculated the hazard ratios (HRs) with 95% confidence intervals (CIs) for changes in NDVI, while adjusting for individual and area-level covariates. In total, 24,010,250 live births were included. Prevalence of preterm birth was 11.5%, with a modest but statistically significant decreasing trend (p = 0.013) observed across the nation over the study period. The findings reveal a significant association between greenness exposure and a reduced risk of preterm birth. Specifically, for every 0.1 increase in NDVI, there was a 2.0% decrease in the risk of preterm birth (95%CI: 1.9%-2.2%). Stratified analyses based on maternal education and ethnicity indicated potential effect modifications, with stronger protective effects observed among younger mothers and those with less years of education. Sensitivity analyses using EVI yielded consistent results. In conclusion, this study suggests that higher maternal greenness exposure is linked to a decreased risk of preterm birth in Brazil. These findings imply that enhancing residential greenspaces could be a valuable public health strategy to promote maternal and child health in Brazil.

Climate change, environmental extremes, and human health in Australia: challenges, adaptation strategies, and policy gaps.

Climate change presents a major public health concern in Australia, marked by unprecedented wildfires, heatwaves, floods, droughts, and the spread of climate-sensitive infectious diseases. Despite these challenges, Australia's response to the climate crisis has been inadequate and subject to change by politics, public sentiment, and global developments. This study illustrates the spatiotemporal patterns of selected climate-related environmental extremes (heatwaves, wildfires, floods, and droughts) across Australia during the past two decades, and summarizes climate adaptation measures and actions that have been taken by the national, state/territory, and local governments. Our findings reveal significant impacts of climate-related environmental extremes on the health and well-being of Australians. While governments have implemented various adaptation strategies, these plans must be further developed to yield concrete actions. Moreover, Indigenous Australians should not be left out in these adaptation efforts. A collaborative, comprehensive approach involving all levels of government is urgently needed to prevent, mitigate, and adapt to the health impacts of climate change.

Research on leakage environmental risk assessment and risk prevention and control measures in the long-term landfill process of ultra-alkaline fly ash.

In this study, we simulated the actual landfill disposal process using accelerated carbonization experiments, based on the leaching characteristics of heavy metals from "alkaline" fly ash, and used the LandSim-HELP coupling model to assess the environmental risk of the leaching. The results showed that the leaching data of "alkaline" fly ash before carbonization showed the illusion of admission to landfill with only a small amount of chemical addition or even without curing/stabilization. The leached concentrations of Zn and Cd from "alkaline" fly ash after carbonation were significantly higher. The risk assessment of the leakage of heavy metals in the case of a single artificial composite liner system showed that the exposure concentrations of Pb, Zn, and Cd in samples exceeded Standard for groundwater quality (GB/T 14848-2017) the Class III permissible limits after carbonation; exposure risk for Cd was exceeded in all samples. However, although the use of a double-layer artificial composite liner to improve the level of impermeability effectively reduced the risk of Cd leaching, so that none of the non-carcinogenic risks exceeded the standard, the carcinogenic risk of Cd in the carbonized samples exceeded the factor of 1.1-4.5 of the acceptable hazard quotient, and the contamination characteristics of the alkaline fly ash still need to be kept in view.

Mortality risks associated with floods in 761 communities worldwide: time series study.

OBJECTIVE: To evaluate lag-response associations and effect modifications of exposure to floods with risks of all cause, cardiovascular, and respiratory mortality on a global scale. DESIGN: Time series study. SETTING: 761 communities in 35 countries or territories with at least one flood event during the study period. PARTICIPANTS: Multi-Country Multi-City Collaborative Research Network database, Australian Cause of Death Unit Record File, New Zealand Integrated Data Infrastructure, and the International Network for the Demographic Evaluation of Populations and their Health Network database. MAIN OUTCOME MEASURES: The main outcome was daily counts of deaths. An estimation for the lag-response association between flood and daily mortality risk was modelled, and the relative risks over the lag period were cumulated to calculate overall effects. Attributable fractions of mortality due to floods were further calculated. A quasi-Poisson model with a distributed lag non-linear function was used to examine how daily death risk was associated with flooded days in each community, and then the community specific associations were pooled using random effects multivariate meta-analyses. Flooded days were defined as days from the start date to the end date of flood events. RESULTS: A total of 47.6 million all cause deaths, 11.1 million cardiovascular deaths, and 4.9 million respiratory deaths were analysed. Over the 761 communities, mortality risks increased and persisted for up to 60 days (50 days for cardiovascular mortality) after a flooded day. The cumulative relative risks for all cause, cardiovascular, and respiratory mortality were 1.021 (95% confidence interval 1.006 to 1.036), 1.026 (1.005 to 1.047), and 1.049 (1.008 to 1.092), respectively. The associations varied across countries or territories and regions. The flood-mortality associations appeared to be modified by climate type and were stronger in low income countries and in populations with a low human development index or high proportion of older people. In communities impacted by flood, up to 0.10% of all cause deaths, 0.18% of cardiovascular deaths, and 0.41% of respiratory deaths were attributed to floods. CONCLUSIONS: This study found that the risks of all cause, cardiovascular, and respiratory mortality increased for up to 60 days after exposure to flood and the associations could vary by local climate type, socioeconomic status, and older age.

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.

Global short-term mortality risk and burden associated with tropical cyclones from 1980 to 2019: a multi-country time-series study.

BACKGROUND: The global spatiotemporal pattern of mortality risk and burden attributable to tropical cyclones is unclear. We aimed to evaluate the global short-term mortality risk and burden associated with tropical cyclones from 1980 to 2019. METHODS: The wind speed associated with cyclones from 1980 to 2019 was estimated globally through a parametric wind field model at a grid resolution of 0·5°â€ˆ× 0·5°. A total of 341 locations with daily mortality and temperature data from 14 countries that experienced at least one tropical cyclone day (a day with maximum sustained wind speed associated with cyclones ≥17·5 m/s) during the study period were included. A conditional quasi-Poisson regression with distributed lag non-linear model was applied to assess the tropical cyclone-mortality association. A meta-regression model was fitted to evaluate potential contributing factors and estimate grid cell-specific tropical cyclone effects. FINDINGS: Tropical cyclone exposure was associated with an overall 6% (95% CI 4-8) increase in mortality in the first 2 weeks following exposure. Globally, an estimate of 97 430 excess deaths (95% empirical CI [eCI] 71 651-126 438) per decade were observed over the 2 weeks following exposure to tropical cyclones, accounting for 20·7 (95% eCI 15·2-26·9) excess deaths per 100 000 residents (excess death rate) and 3·3 (95% eCI 2·4-4·3) excess deaths per 1000 deaths (excess death ratio) over 1980-2019. The mortality burden exhibited substantial temporal and spatial variation. East Asia and south Asia had the highest number of excess deaths during 1980-2019: 28 744 (95% eCI 16 863-42 188) and 27 267 (21 157-34 058) excess deaths per decade, respectively. In contrast, the regions with the highest excess death ratios and rates were southeast Asia and Latin America and the Caribbean. From 1980-99 to 2000-19, marked increases in tropical cyclone-related excess death numbers were observed globally, especially for Latin America and the Caribbean and south Asia. Grid cell-level and country-level results revealed further heterogeneous spatiotemporal patterns such as the high and increasing tropical cyclone-related mortality burden in Caribbean countries or regions. INTERPRETATION: Globally, short-term exposure to tropical cyclones was associated with a significant mortality burden, with highly heterogeneous spatiotemporal patterns. In-depth exploration of tropical cyclone epidemiology for those countries and regions estimated to have the highest and increasing tropical cyclone-related mortality burdens is urgently needed to help inform the development of targeted actions against the increasing adverse health impacts of tropical cyclones under a changing climate. FUNDING: Australian Research Council and Australian National Health and Medical Research Council.

Health Effects of Cyclones: A Systematic Review and Meta-Analysis of Epidemiological Studies.

BACKGROUND: More intense cyclones are expected in the future as a result of climate change. A comprehensive review is urgently needed to summarize and update the evidence on the health effects of cyclones. OBJECTIVES: We aimed to provide a systematic review with meta-analysis of current evidence on the risks of all reported health outcomes related to cyclones and to identify research gaps and make recommendations for further research. METHODS: We systematically searched five electronic databases (MEDLINE, Embase, PubMed, Scopus, and Web of Science) for relevant studies in English published before 21 December 2022. Following the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) guidelines, we developed inclusion criteria, screened the literature, and included epidemiological studies with a quantitative risk assessment of any mortality or morbidity-related outcomes associated with cyclone exposures. We extracted key data and assessed study quality for these studies and applied meta-analyses to quantify the overall effect estimate and the heterogeneity of comparable studies. RESULTS: In total, 71 studies from eight countries (the United States, China, India, Japan, the Philippines, South Korea, Australia, Brazil), mostly the United States, were included in the review. These studies investigated the all-cause and cause-specific mortality, as well as morbidity related to injury, cardiovascular diseases (CVDs), respiratory diseases, infectious diseases, mental disorders, adverse birth outcomes, cancer, diabetes, and other outcomes (e.g., suicide rates, gender-based violence). Studies mostly included only one high-amplitude cyclone (cyclones with a Saffir-Simpson category of 4 or 5, i.e., Hurricanes Katrina or Sandy) and focused on mental disorders morbidity and all-cause mortality and hospitalizations. Consistently elevated risks of overall mental health morbidity, post-traumatic stress disorder (PTSD), as well as all-cause mortality or hospitalizations, were found to be associated with cyclones. However, the results for other outcomes were generally mixed or limited. A statistically significant overall relative risk of 1.09 [95% confidence interval (CI): 1.04, 1.13], 1.18 (95% CI: 1.12, 1.25), 1.15 (95% CI: 1.13, 1.18), 1.26 (95% CI: 1.05, 1.50) was observed for all-cause mortality, all-cause hospitalizations, respiratory disease, and chronic obstructive pulmonary disease hospitalizations, respectively, after cyclone exposures, whereas no statistically significant risks were identified for diabetes mortality, heart disease mortality, and preterm birth. High between-study heterogeneity was observed. CONCLUSIONS: There is generally consistent evidence supporting the notion that high-amplitude cyclones could significantly increase risks of mental disorders, especially for PTSD, as well as mortality and hospitalizations, but the evidence for other health outcomes, such as chronic diseases (e.g., CVDs, cancer, diabetes), and adverse birth outcomes remains limited or inconsistent. More studies with rigorous exposure assessment, of larger spatial and temporal scales, and using advanced modeling strategy are warranted in the future, especially for those small cyclone-prone countries or regions with low and middle incomes. https://doi.org/10.1289/EHP12158.

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 (PM2.5) and mortality. We aimed to explore theses associations using the data from the UK Biobank cohort. Long-term wildfire-related PM2.5 exposure was defined as the 3-year cumulative concentrations of wildfire-related PM2.5 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 PM2.5 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 PM2.5 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 PM2.5 exposure, in order to reduce the risk of premature mortality.

Efficiency of portable air purification on public buses: A pilot study.

High concentrations of fine particulate matter (PM2.5) have been frequently reported in public transit systems and can cause adverse health effect. The portable air purifier is an inexpensive solution that could potentially clean in-cabin PM2.5. This study aims to find the PM2.5 removal efficiency of portable air purifiers in a public transit bus. In various scenarios, after artificially preloading the in-cabin PM2.5 concentration to 400 µg/m3, the concentrations were measured every 10 s, with and without the intervention of air purifiers. In a test bus with a volume of approximately 62.5 m3, three portable air purifiers were capable of reducing the average concentration of PM2.5 by 42-74%, from 400 µg/m3, to levels below 15 µg/m3, the acceptable short-term exposure concentration recommended by WHO. When high concentrations of outdoor PM2.5 entered the bus, purifiers maintained a relatively low level of in-cabin PM2.5. Air purifiers were more effective in reducing in-cabin PM2.5 than traditional air filtration and ventilation methods (air conditioning system filtration and door opening) in public transit buses. The deployed air purifiers reduced the concentration of particulate matter inside the bus, which may reduce the health risk of PM2.5 exposure and the spreading of airborne infections in public transit, thus, implying the potential to enhance passengers' and drivers' health.

Wildfire-related PM2.5 and health economic loss of mortality in Brazil.

BACKGROUND: Wildfire imposes a high mortality burden on Brazil. However, there is a limited assessment of the health economic losses attributable to wildfire-related fine particulate matter (PM2.5). METHODS: We collected daily time-series data on all-cause, cardiovascular, and respiratory mortality from 510 immediate regions in Brazil during 2000-2016. The chemical transport model GEOS-Chem driven with Global Fire Emissions Database (GFED), in combination with ground monitored data and machine learning was used to estimate wildfire-related PM2.5 data at a resolution of 0.25°â€ˆ× 0.25°. A time-series design was applied in each immediate region to assess the association between economic losses due to mortality and wildfire-related PM2.5 and the estimates were pooled at the national level using a random-effect meta-analysis. We used a meta-regression model to explore the modification effect of GDP and its sectors (agriculture, industry, and service) on economic losses. RESULTS: During 2000-2016, a total of US$81.08 billion economic losses (US$5.07 billion per year) due to mortality were attributable to wildfire-related PM2.5 in Brazil, accounting for 0.68% of economic losses and equivalent to approximately 0.14% of Brazil's GDP. The attributable fraction (AF) of economic losses due to wildfire-related PM2.5 was positively associated with the proportion of GDP from agriculture, while negatively associated with the proportion of GDP from service. CONCLUSION: Substantial economic losses due to mortality were associated with wildfires, which could be influenced by the agriculture and services share of GDP per capita. Our estimates of the economic losses of mortality could be used to determine optimal levels of investment and resources to mitigate the adverse health impacts of wildfires.