A multicounty analysis identifying the populations vulnerable to mortality associated with high ambient temperature in California

Contemporary income inequality outweighs historic redlining in shaping intra-urban heat disparities in Los Angeles

The roots of intra-urban heat disparity in the U.S. often trace back to historical discriminatory practices, such as redlining, which categorized neighborhoods by race or ethnicity. In this study, we compare the relative impacts of historic redlining and current income inequality on thermal disparities in Los Angeles. A key innovation of our work is the use of land surface temperature data from the ECOSTRESS instrument aboard the International Space Station, enabling us to capture diurnal trends in urban thermal disparities. Our findings reveal that present-day income inequality is a stronger predictor of heat burden than the legacy of redlining. Additionally, land surface temperature disparities exhibit a seasonal hysteresis effect, intensifying during extreme heat events by 5-7 °C. Sociodemographic analysis highlights that African-American and Hispanic populations in historically and economically disadvantaged areas are often the most vulnerable. Our findings suggest that while the legacy of redlining may persist, the present-day heat disparities are not necessarily an immutable inheritance, where targeted investments and interventions can pave the way for a more thermally just future for these communities.

Establishing and mapping heat-sensitive disease spectrum in eastern China: A comprehensive analysis of 1.4 million deaths involving 14 major disease categories

BACKGROUND

Although high temperatures can affect multiple systems and organs, the comprehensive assessment of heat-sensitive diseases remains unclear. We aimed to establish the heat-related sensitive disease spectrum and assess the relative importance of affected diseases from the health risk and burden perspectives.

METHODS

A space-time-stratified case-crossover analysis was used to examine the short-term association between high temperatures and cause-specific deaths in Jiangsu Province, China during the warm season of 2016 to 2019. A total of 14 major disease categories and 29 specific diseases were tested to identify heat-sensitive diseases. A multi-level comparison of heat-affected diseases was conducted based on the health risk and burden indicators including mortality risk, years of life lost (YLL) to measure disease burden, and value of YLL (VYLL) to measure economic burden.

RESULTS

High temperatures were associated with an increased risk of mortality from 23 specific diseases involving 12 major disease categories, including well-studied cardiovascular, respiratory, endocrine, and nervous diseases, and less-studied skin, urinary system diseases, mental and behavioral disorders, external causes, injury and poisoning, symptoms, signs and abnormal clinical, and neoplasms. The top three greatest heat-related risks of mortality from major disease categories were skin system (OR: 1.72, 95 % CI: 1.37-2.36), external causes of mortality (OR: 1.71, 95 % CI: 1.57-1.87), and nervous system (OR: 1.46, 95 % CI: 1.26-1.68), and cause-specific diseases were asthma (OR: 2.26, 95 % CI: 1.46-3.50), accidental drowning (OR: 1.85, 95 % CI: 1.42-2.40), and acute respiratory infections (OR: 1.80, 95 % CI: 1.02-3.16). In terms of both disease and economic burdens attributable to heat, cardiovascular diseases contributed to the greatest proportion, followed by neoplasms, external causes, and respiratory diseases. Within specific diseases, cerebrovascular diseases contributed the greatest disease and economic burdens, followed by ischemic heart disease, lung (neoplasm), and COPD. Furthermore, the largest heat-related reduction in life expectancy reached 5.27 years for external causes and 12.96 years for accidental drowning.

CONCLUSION

This study provides a heat-sensitive disease spectrum and resulting death risk and burden vary by different systems and specific diseases. Our findings may have implications for implementing heat-health action plans to mitigate the adverse effects of heat-sensitive diseases.

Sex differences in the impact of extreme heat on cardiovascular disease outcomes: a systematic review and meta-analysis

BACKGROUND

Climate change is intensifying extreme heat events, posing significant risks to cardiovascular health. While sex differences in heat vulnerability have been observed, the evidence remains inconsistent. This systematic review and meta-analysis examined sex-specific associations between extreme heat exposure and cardiovascular disease (CVD) outcomes over the past decade.

METHODS

We searched PubMed, Embase, and Scopus for studies published between 2004 and 2024 that reported sex-stratified cardiovascular outcomes associated with heat exposure following the PRISMA guidelines. The quality of the evidence was evaluated following the Navigation Guide Criteria. Random-effects meta-analysis was conducted to calculate pooled relative risk ratios (RRR) comparing males to females for studies addressing incremental temperature increase. Heat wave studies were synthesized narratively due to methodological heterogeneity.

RESULTS

Of 6126 articles, 79 met inclusion criteria (62 in meta-analysis, 17 in narrative synthesis), primarily from East Asia, Europe, and North America. A 1 °C temperature increase was associated with elevated cardiovascular risks for both sexes. The pooled relative risk ratio (RRR) comparing males to females was 1.008 [1.002-1.014] for mortality, suggesting slightly higher female vulnerability, but not for morbidity (RRR 0.996 [0.987-1.004]). Significant heterogeneity was noted (Mortality I² = 50.3%, Morbidity I² = 70.3%). Heat wave studies showed inconsistent sex-specific impacts across populations.

CONCLUSIONS

Females showed marginally higher vulnerability to heat-related cardiovascular mortality compared to males, while no significant sex differences were observed for morbidity outcomes. Future research should focus on understanding these mechanisms and developing sex-specific interventions.

Planetary health in action: developing a heatwave vulnerability tool for primary care

BACKGROUND

Heatwaves are becoming longer and more frequent. Despite the availability of open environmental data, little is operable and formatted for primary care use.

AIM

To create a user-friendly online mapping tool to assess the vulnerability of communities to heatwaves for use by primary care practitioners. This study questioned what knowledge needed to be deployed, who needed to participate, and how the knowledge should be shared.

DESIGN & SETTING

A participatory action-research project based on knowledge mobilisation (KM) in France, as part of the Green Data for Health Challenge.

METHOD

Knowledge was summarised on the factors most affecting heatwave vulnerability in a collaborative process, enabling a consensus on data variables and mobilised content for the online tool. Purposive sampling included primary care stakeholders with Regional Health Agencies (Agence Régionale de Santé; ARS), Public Health France (Santé Publique France; SPF), and data scientists.

RESULTS

Nineteen participants took part in 10 co-construction meetings, a brainstorming carousel strategy, and five weekly co-creation meetings between December 2022 and June 2023. The heatwave vulnerability variable was constructed using surface temperature, social deprivation, vegetation coverage, and presence of air-conditioning equipment. Identified experts mobilised data on the national composite indicator at the communal level for heatwave morbidity.

CONCLUSION

There is no standard platform for sharing environmental data in France. This co-creation study offers a new approach to incorporating environmental data on heatwaves into primary care consultations. We demonstrate the importance of KM in primary care to bridge the research-practice gap. Integrating primary care records with environmental data may promote broader applications for planetary health research.

Burden trends and future predictions for hypertensive heart disease attributable to non-optimal temperatures in the older adults amidst climate change, 1990-2021

Background

Hypertensive heart disease (HHD) is a significant form of end-organ damage caused by hypertension, with profound impacts on global health and quality of life. Temperature anomalies driven by climate change, particularly extremes of heat and cold, are increasingly recognized as major contributors to the cardiovascular disease burden, notably impacting HHD. However, the specific spatiotemporal trends and gender-based differences in the burden of non-optimal temperatures on older adults HHD patients remain insufficiently explored. This study aims to evaluate the regional, gender-specific trends in the burden of HHD attributed to non-optimal temperatures among the older adults from 1990 to 2021, and to project future trends in HHD burden under climate-induced temperature anomalies from 2022 to 2050.

Methods

Data were sourced from the Global Burden of Disease Study (GBD 2021), which provides estimates of mortality and disability-adjusted life years (DALYs) at global, regional, and national levels. Age-standardized rates (ASR) and estimated annual percentage changes (EAPC) were analyzed. Future burden projections were modeled using age-period-cohort (APC) and Bayesian APC models to assess temperature impact by gender and age differences. Data analysis was conducted using R and STATA, examining the variations in temperature effects by gender and age.

Results

Between 1990 and 2021, cold-related HHD burden among the older adults significantly exceeded that of heat-related burden. However, heat-related HHD burden demonstrated a marked upward trend, projected to continue rising over the next two decades, particularly in low-income and tropical regions. Gender-specific analysis revealed that cold-related HHD burden was more pronounced in women, while heat-related burden was notably higher in men. Additionally, male heat-related HHD mortality rates have shown a substantial increase over the past 30 years, whereas female rates have exhibited a comparatively modest decline.

Conclusion

Although cold remains the dominant non-optimal temperature factor, rising global temperatures suggest an increasing burden of heat-related HHD among the older adults. Efforts should prioritize strengthening resilience in vulnerable regions and populations, with targeted interventions to mitigate future health risks associated with temperature extremes.

Climate Change and Cardiovascular Disease: Who Is Vulnerable?

Climate change involves a shift in earth's climate indicators over extended periods of time due to human activity. Anthropogenic air pollution has resulted in trapping heat, contributing to global warming, which contributes to worsening air pollution through facilitating oxidizing of air constituents. It is becoming more evident that the effects of climate change, such as air pollution and ambient temperatures, are interconnected with each other and other environmental factors. While the relationship between climate change components and cardiovascular disease is well documented in the literature, their interaction with one another along with individuals' biological and social risk factors is yet to be elucidated. In this review, we summarize that pathophysiological mechanisms by ambient temperatures directly affect cardiovascular health and describe the most vulnerable subgroups, defined by age, sex, race, and socioeconomic factors. Finally, we provide guidance on the importance of integrating climate, environmental, social, and health data into common platforms to inform researchers and policies.

New York State Climate Impacts Assessment Chapter 07: Human Health and Safety

New Yorkers face a multitude of health and safety risks that are exacerbated by a changing climate. These risks include direct impacts from extreme weather events and other climate hazards, as well as indirect impacts occurring through a chain of interactions. Physical safety, physical health, and mental health are all part of the equation-as are the many nonclimate factors that interact with climate change to influence health outcomes. This chapter provides an updated assessment of all these topics at the intersection of climate change, public health and safety, and equity in the state of New York. Key findings are presented below.

Impact of heat on emergency hospital admission in Texas: geographic and racial/ethnic disparities

BACKGROUND

Studies exploring the racial/ethnicity disparity of the impact of heat on hospital admission are notably limited, especially in Texas, a state with a diverse population and consistently ranking among the top ten U.S. states for heat-related deaths per capita from 2018 to 2020.

OBJECTIVE

Our objective is to determine the correlation between elevated temperatures and emergency hospital admissions for various causes and age groups across 12 Metropolitan Statistical Areas(MSAs) in Texas. Additionally, we aim to investigate health inequalities in the five largest MSAs in Texas between 2004 and 2013.

METHODS

We used MSA-level hospital admission and weather data to estimate the relationship between heat and emergency hospital admissions. We applied a Generalized Additive Model and random effects meta-analysis to calculate MSA-specific associations and overall correlation, repeating the analysis for age groups and specific causes of admission. We also investigated health disparities across racial and ethnic groups and performed a sensitivity analysis.

RESULTS

The results showed that a 1 °C increase in temperature was associated with a 0.50% (95% CI [0.38%, 0.63%]) increase in all-cause emergency hospital admissions. Heat's impact on hospital admissions varied among age groups and causes, with children under 6 years showing the highest effect estimate (0.64% (95% CI [0.32%,0.96%])). Statistically significant associations were found for Cardiovascular Diseases (0.27% (95% CI [0.07%,0.47%])), Ischemic Heart Diseases (0.53% (95% CI [0.15%,0.92%])), Pneumonia (0.70% (95% CI [0.25%,1.16%])), and Respiratory Diseases (0.67% (95% CI [0.18%,1.17%])). Health disparities were found among racial and ethnic groups in the five largest MSAs.

IMPACT STATEMENT

Studies exploring the impact of heat on hospital admission in Texas are notably limited. Our research provided a comprehensive examination of the connection between heat and emergency hospital admissions throughout Texas. Furthermore, we are the first to examine racial/ethnic disparities, identifying African American and Hispanic groups as disproportionately affected. These insights provide valuable insights for policymakers to allocate resources and implement strategies to mitigate the negative consequences of rising temperatures.

Heat Waves and Adverse Health Events Among Dually Eligible Individuals 65 Years and Older

Importance

Extensive research has found the detrimental health effects of heat waves. However, a critical gap exists in understanding their association with adverse health events among older dually eligible individuals, who may be particularly susceptible to heat waves.

Objective

To assess the association between heat waves and adverse health events among dually eligible individuals 65 years and older.

Design, Setting, and Participants

This retrospective time-series study assessed the association between heat waves in warm months from 2016 to 2019 and zip code tabulation area (ZCTA)-day level adverse health events. Dually eligible individuals 65 years and older who were continuously enrolled in either a Medicare fee-for-service plan or a Medicare Advantage plan with full Medicaid benefits from May to September in any given year were identified. All ZCTAs in the US with at least 1 dually eligible individual in each study year were included. Data were analyzed from September 2023 to August 2024.

Exposure

Heat waves, defined as 3 or more consecutive extreme heat days (ie, days with a maximum temperature of at least 90 °F [32.2 °C] and in the 97th percentile of daily maximum temperatures for each ZCTA during the study period).

Main Outcomes and Measures

Daily counts of heat-related emergency department visits and heat-related hospitalizations for each ZCTA.

Results

The study sample included 5 448 499 beneficiaries 65 years and older in 28 404 ZCTAs across 50 states and Washington, DC; the mean (SD) proportion of female beneficiaries and beneficiaries 85 years and older in each ZCTA was 66% (7%) and 20% (8%), respectively. The incidence rate for heat-related emergency department visits was 10% higher during heat wave days compared to non-heat wave days (incidence rate ratio [IRR], 1.10; 95% CI, 1.08-1.12), and the incidence rate of heat-related hospitalizations was 7% higher during heat wave days (IRR, 1.07; 95% CI, 1.04-1.09). There were similar patterns in other adverse health events, including a 4% higher incidence rate of death during heat wave days (IRR, 1.04; 95% CI, 1.01-1.07). The magnitude of these associations varied across some subgroups. For example, the association between heat waves and heat-related emergency department visits was statistically significant only for individuals in 3 of 9 US climate regions: the Northwest, Ohio Valley, and the West.

Conclusions and Relevance

In this time-series study, heat waves were associated with increased adverse health events among dually eligible individuals 65 years and older. Without adaptation strategies to address the health-related impacts of heat, dually eligible individuals are increasingly likely to face adverse outcomes.

Climate change and public health in California: A structured review of exposures, vulnerable populations, and adaptation measures

California faces several serious direct and indirect climate exposures that can adversely affect public health, some of which are already occurring. The public health burden now and in the future will depend on atmospheric greenhouse gas concentrations, underlying population vulnerabilities, and adaptation efforts. Here, we present a structured review of recent literature to examine the leading climate risks to public health in California, including extreme heat, extreme precipitation, wildfires, air pollution, and infectious diseases. Comparisons among different climate-health pathways are difficult due to inconsistencies in study design regarding spatial and temporal scales and health outcomes examined. We find, however, that the current public health burden likely affects thousands of Californians each year, depending on the exposure pathway and health outcome. Further, while more evidence exists for direct and indirect proximal health effects that are the focus of this review, distal pathways (e.g., impacts of drought on nutrition) are more uncertain but could add to this burden. We find that climate adaptation measures can provide significant health benefits, particularly in disadvantaged communities. We conclude with priority recommendations for future analyses and solution-driven policy actions.

The 2018 Heat Wave's Impact on the Mortality of Older People in Seoul, South Korea

Few studies on social welfare in South Korea have examined the effects of climate change, especially heat waves on vulnerable populations. The present study aims to investigate how heat waves affect vulnerable populations. This study utilized a cross-sectional study design, using the daily heat index and heat-related mortality data for Seoul, South Korea, in summer 2018. The research used micro-raw data of deaths caused by hypertensive, ischemic heart, and cerebrovascular diseases, as well as heat index data. An effect was observed for the heat index on mortality for individuals over 65 years of age, men, people with spouses, and those ages 75-79 years.

Indoor overheating: A review of vulnerabilities, causes, and strategies to prevent adverse human health outcomes during extreme heat events

The likelihood of exposure to overheated indoor environments is increasing as climate change is exacerbating the frequency and severity of hot weather and extreme heat events (EHE). Consequently, vulnerable populations will face serious health risks from indoor overheating. While the relationship between EHE and human health has been assessed in relation to outdoor temperature, indoor temperature patterns can vary markedly from those measured outside. This is because the built environment and building characteristics can act as an important modifier of indoor temperatures. In this narrative review, we examine the physiological and behavioral determinants that influence a person's susceptibility to indoor overheating. Further, we explore how the built environment, neighborhood-level factors, and building characteristics can impact exposure to excess heat and we overview how strategies to mitigate building overheating can help reduce heat-related mortality in heat-vulnerable occupants. Finally, we discuss the effectiveness of commonly recommended personal cooling strategies that aim to mitigate dangerous increases in physiological strain during exposure to high indoor temperatures during hot weather or an EHE. As global temperatures continue to rise, the need for a research agenda specifically directed at reducing the likelihood and impact of indoor overheating on human health is paramount. This includes conducting EHE simulation studies to support the development of consensus-based heat mitigation solutions and public health messaging that provides equitable protection to heat-vulnerable people exposed to high indoor temperatures.

Climate Change and Children's Health: Building a Healthy Future for Every Child

Observed changes in temperature, precipitation patterns, sea level, and extreme weather are destabilizing major determinants of human health. Children are at higher risk of climate-related health burdens than adults because of their unique behavior patterns; developing organ systems and physiology; greater exposure to air, food, and water contaminants per unit of body weight; and dependence on caregivers. Climate change harms children through numerous pathways, including air pollution, heat exposure, floods and hurricanes, food insecurity and nutrition, changing epidemiology of infections, and mental health harms. As the planet continues to warm, climate change's impacts will worsen, threatening to define the health and welfare of children at every stage of their lives. Children who already bear higher burden of disease because of living in low-wealth households and communities, lack of access to high quality education, and experiencing racism and other forms of unjust discrimination bear greater risk of suffering from climate change hazards. Climate change solutions, advanced through collaborative work of pediatricians, health systems, communities, corporations, and governments lead to immediate gains in child health and equity and build a foundation for generations of children to thrive. This technical report reviews the nature of climate change and its associated child health effects and supports the recommendations in the accompanying policy statement on climate change and children's health.

Adaptation behaviors modify the effects of body fat on heat-related symptoms among Taiwanese elderly

BACKGROUND

The aging process increases body fat and susceptibility to heat-related illnesses. The relationship between body composition and symptoms associated with exposure to extreme heat among the elderly is unclear. Additionally, the influence of individual adaptive behaviors in mitigating these risks has not been adequately explored.

OBJECTIVES

This study aimed to evaluate the association between body composition and heat-related symptoms as well as the potential modifying effects of heat adaptation behavior.

METHODS

The body composition of elderly individuals was measured using bioelectrical impedance analysis. Face-to-face interviews were conducted a year later to determine the heat-related symptoms and adaptive behaviors practiced for the extremely hot days of the previous year. The association between body composition indices and the presence of more than two symptoms was assessed using logistic regression analysis, while stratified analysis and interaction term in models were used to evaluate the effect modifications of adaptive behaviors.

RESULTS

Of the 859 participants, 16% reported more than two heat-related symptoms. Increased body fat mass index (fat mass in kg/squared height in meters) was associated with an elevated risk of more heat-related symptoms (odds ratio 1.11, 95% confidence interval 1.02-1.20). Each combination of staying indoors, using an umbrella and hat, and using air conditioning at noon reduced the risk association between body fat and symptoms. For females, a combination of reducing physical activity and staying indoors provided similar protective effect. Surprisingly, bathing more frequently in hot weather with heated instead of non-heated water augmented the risk correlation. Neither fan usage nor window opening displayed protective effects.

CONCLUSIONS

Elevated body fat levels, indicative of obesity, corresponded with an increased risk of heat-related symptoms. Integrating multiple adaptive behaviors can diminish the negative health impact of body fat on heat-induced symptoms. However, certain commonly adopted practices might not confer expected benefits.

Assessment of mortality risks due to a strong cold spell in 2022 in China

Background

With the intensification of global climate warming, extreme low temperature events such as cold spells have become an increasingly significant threat to public health. Few studies have examined the relationship between cold spells and mortality in multiple Chinese provinces.

Methods

We employed health impact functions for temperature and mortality to quantify the health risks of the first winter cold spell in China on November 26th, 2022, and analyzed the reasons for the stronger development of the cold spell in terms of the circulation field.

Results

This cold spell was a result of the continuous reinforcement of the blocking high-pressure system in the Ural Mountains, leading to the deepening of the cold vortex in front of it. Temperature changes associated with the movement of cold fronts produced additional mortality risks and mortality burdens. In general, the average excess risk (ER) of death during the cold spell in China was 2.75%, with a total cumulative excess of 369,056 deaths. The health risks associated with temperatures were unevenly distributed spatially in China, with the ER values ranging from a minimum of 0.14% to a maximum of 5.72%, and temperature drops disproportionately affect southern regions of China more than northern regions. The cumulative excess deaths exibited the highest in eastern and central China, with 87,655 and 80,230 respectively, and the lowest in northwest China with 27,474 deaths. Among the provinces, excess deaths pronounced the highest in Shandong with 29,492 and the lowest in Tibet with only 196.

Conclusion

The study can provide some insight into the mortality burden of cold spells in China, while emphasising the importance of understanding the complex relationship between extreme low temperature events and human health. The outcomes could provide valuable revelations for informing pertinent public health policies.

Pregnancy and newborn health - heat impacts and emerging solutions

Evidence is accumulating, both in the US and abroad, of the apparent serious health impacts of various environmental exposures tied to climate change. High ambient temperature, or heat, is a worsening global health risk. Heat risk is affected by many factors such as the magnitude, duration, and timing of exposure - such as specific, critical windows during pregnancy. This article focuses on the association of heat with both adverse pregnancy and newborn health outcomes. Regarding pregnancy, studies link heat and preterm birth, low birth weight and stillbirth. Multiple potential mechanisms support the biological plausibility of these associations. Emerging evidence suggests that heat, via epigenetics, may affect maternal health far beyond pregnancy. For newborn health impacts, heat is associated with increased hospitalization, neurologic and gastrointestinal dysfunction, and infant death. Research gaps include the need to study neonates separately from children and determining the mechanisms linking heat to adverse outcomes. We also highlight disparate adverse reproductive health outcomes for communities of color and low income tied to disproportionate exposures to environmental stressors like heat. Finally, we summarize educational and clinical tool resources for clinicians, information for patients, and opportunities for near-term action using the precautionary principle framework.

A longitudinal study on the effect of extreme temperature on non-accidental deaths in Hulunbuir City based on DLNM model

OBJECTIVE

To explore the frequency and effect of extreme temperature on the non-accidental death rate in Hulunbuir, a Chinese ice city.

METHODS

From 2014 to 2018, mortality data of residents residing in Hulunbuir City were collected. The lag and cumulative effects of extreme temperature conditions on non-accidental death and respiratory and circulatory diseases were analyzed by distributed lag non-linear models (DLNM).

RESULTS

The risk of death was the highest during high-temperature conditions, the RR value was 1.111 (95% CI 1.031 ~ 1.198). The effect was severe and acute. The risk of death during extreme low-temperature conditions peaked on the fifth day, (RR 1.057; 95% CI 1.012 ~ 1.112), then decreased and was maintained for 12 days. The cumulative RR value was 1.289 (95% CI 1.045 ~ 1.589). Heat significantly influenced the incidence of non-accidental death in both men (RR 1.187; 95% CI 1.059-1.331) and women (RR 1.252; 95% CI 1.085-1.445).

CONCLUSIONS

Regardless of the temperature effect, the risk of death in the elderly group (≥ 65 years) was significantly higher than that of the young group (0-64 years). High-temperature and low-temperature conditions can contribute to the increased number of deaths in Hulunbei. While high-temperature has an acute effect, low-temperature has a lagging effect. Elderly and women, as well as people with circulatory diseases, are more sensitive to extreme temperatures.

Optimal heat stress metric for modelling heat-related mortality varies from country to country

Combined heat and humidity is frequently described as the main driver of human heat-related mortality, more so than dry-bulb temperature alone. While based on physiological thinking, this assumption has not been robustly supported by epidemiological evidence. By performing the first systematic comparison of eight heat stress metrics (i.e., temperature combined with humidity and other climate variables) with warm-season mortality, in 604 locations over 39 countries, we find that the optimal metric for modelling mortality varies from country to country. Temperature metrics with no or little humidity modification associates best with mortality in ~40% of the studied countries. Apparent temperature (combined temperature, humidity and wind speed) dominates in another 40% of countries. There is no obvious climate grouping in these results. We recommend, where possible, that researchers use the optimal metric for each country. However, dry-bulb temperature performs similarly to humidity-based heat stress metrics in estimating heat-related mortality in present-day climate.

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

Objectives. To describe demographic and social characteristics of US communities exposed to wildfire smoke. Methods. Using satellite-collected data on wildfire smoke with the locations of population centers in the coterminous United States, we identified communities potentially exposed to light-, medium-, and heavy-density smoke plumes for each day from 2011 to 2021. We linked days of exposure to smoke in each category of smoke plume density with 2010 US Census data and community characteristics from the Centers for Disease Control and Prevention's Social Vulnerability Index to describe the co-occurrence of smoke exposure and social disadvantage. Results. During the 2011-to-2021 study period, increases in the number of days of heavy smoke were observed in communities representing 87.3% of the US population, with notably large increases in communities characterized by racial or ethnic minority status, limited English proficiency, lower educational attainment, and crowded housing conditions. Conclusions. From 2011 to 2021, wildfire smoke exposures in the United States increased. As smoke exposure becomes more frequent and intense, interventions that address communities with social disadvantages might maximize their public health impact. (Am J Public Health. 2023;113(7):759-767. https://doi.org/10.2105/AJPH.2023.307286).

Exploring the Influence of Summer Temperature on Human Mobility During the COVID-19 Pandemic in the San Francisco Bay Area

Studies on the relationship between temperature and local, small scale mobility are limited, and sensitive to the region and time period of interest. We contribute to the growing mobility literature through a detailed characterization of the observed temperature-mobility relationship in the San Francisco Bay Area at fine spatial and temporal scale across two summers (2020-2021). We used anonymized cellphone data from SafeGraph's neighborhood patterns data set and gridded temperature data from gridMET, and analyzed the influence of incremental changes in temperature on mobility rate (i.e., visits per capita) using a panel regression with fixed effects. This strategy enabled us to control for spatial and temporal variability across the studied region. Our analysis suggested that all areas exhibited lower mobility rate in response to higher summer temperatures. We then explored how several additional variables altered these results. Extremely hot days resulted in faster mobility declines with increasing temperatures. Weekdays were often more resistant to temperature changes when compared to the weekend. In addition, the rate of decrease in mobility in response to high temperature was significantly greater among the wealthiest census block groups compared with the least wealthy. Further, the least mobile locations experienced significant differences in mobility response compared to the rest of the data set. Given the fundamental differences in the mobility response to temperature across most of our additive variables, our results are relevant for future mobility studies in the region.

Impact of heat on all-cause and cause-specific mortality: A multi-city study in Texas

BACKGROUND

Studies on the health effects of heat are particularly limited in Texas, a U.S. state in the top 10 highest number of annual heat-related deaths per capita from 2018 to 2020. This study assessed the effects of heat on all-cause and cause-specific mortality in 12 metropolitan statistical areas (MSAs) across Texas from 1990 to 2011.

METHODS

First, we determined the heat thresholds for each MSA above which the relation between temperature and mortality is linear. We then conducted a distributed lag non-linear model for each MSA, followed by a random effects meta-analysis to estimate the pooled effects for all MSAs. We repeated this process for each mortality cause and age group to achieve the effect estimates.

RESULTS

We found a 1 °C temperature increase above the heat threshold is associated with an increase in the relative risk of all-cause mortality of 0.60% (95%CI [0.39%, 0.82%]) and 1.10% (95%CI [0.65%, 1.56%]) for adults older than 75. For each MSA, the relative risk of mortality for a 1 °C temperature increase above the heat threshold ranges from 0.10% (95%CI [0.09%, 0.10%]) to 1.29% (95%CI [1.26%, 1.32%]). Moreover, elevated temperatures showed a slight decrease in cardiovascular mortality (0.37%, 95%CI [-0.35%, 1.09%]) and respiratory disease (1.97%, 95%CI [-0.11%, 4.08%]), however this effect was not considered statistically significant..

CONCLUSION

Our study found that high temperatures can significantly impact all-cause mortality in Texas, and effect estimates differ by MSA, age group, and cause of death. Our findings generate critical information on the impact of heat on mortality in Texas, providing insights for policymakers on resource allocation and strategic intervention to reduce heat-related health effects.

Non-optimal apparent temperature and cardiovascular mortality: the association in Puducherry, India between 2011 and 2020

BACKGROUND

Cardiovascular diseases (CVDs), the leading cause of death worldwide, are sensitive to temperature. In light of the reported climate change trends, it is important to understand the burden of CVDs attributable to temperature, both hot and cold. The association between CVDs and temperature is region-specific, with relatively few studies focusing on low-and middle-income countries. This study investigates this association in Puducherry, a district in southern India lying on the Bay of Bengal, for the first time.

METHODS

Using in-hospital CVD mortality data and climate data from the Indian Meteorological Department, we analyzed the association between apparent temperature (Tapp) and in-hospital CVD mortalities in Puducherry between 2011 and 2020. We used a case-crossover model with a binomial likelihood distribution combined with a distributed lag non-linear model to capture the delayed and non-linear trends over a 21-day lag period to identify the optimal temperature range for Puducherry. The results are expressed as the fraction of CVD mortalities attributable to heat and cold, defined relative to the optimal temperature. We also performed stratified analyses to explore the associations between Tapp and age-and-sex, grouped and considered together, and different types of CVDs. Sensitivity analyses were performed, including using a quasi-Poisson time-series approach.

RESULTS

We found that the optimal temperature range for Puducherry is between 30°C and 36°C with respect to CVDs. Both cold and hot non-optimal Tapp were associated with an increased risk of overall in-hospital CVD mortalities, resulting in a U-shaped association curve. Cumulatively, up to 17% of the CVD deaths could be attributable to non-optimal temperatures, with a slightly higher burden attributable to heat (9.1%) than cold (8.3%). We also found that males were more vulnerable to colder temperature; females above 60 years were more vulnerable to heat while females below 60 years were affected by both heat and cold. Mortality with cerebrovascular accidents was associated more with heat compared to cold, while ischemic heart diseases did not seem to be affected by temperature.

CONCLUSION

Both heat and cold contribute to the burden of CVDs attributable to non-optimal temperatures in the tropical Puducherry. Our study also identified the age-and-sex and CVD type differences in temperature attributable CVD mortalities. Further studies from India could identify regional associations, inform our understanding of the health implications of climate change in India and enhance the development of regional and contextual climate-health action-plans.

Effects of ambient temperature on mortality among elderly residents of Chengdu city in Southwest China, 2016-2020: a distributed-lag non-linear time series analysis

BACKGROUND

With complex changes in the global climate, it is critical to understand how ambient temperature affects health, especially in China. We aimed to assess the effects of temperature on daily mortality, including total non-accidental, cardiovascular disease (CVD), respiratory disease, cerebrovascular disease, and ischemic heart disease (IHD) mortality between 2016 and 2020 in Chengdu, China.

METHODS

We obtained daily temperature and mortality data for the period 2016-2020. A Poisson regression model combined with a distributed-lag nonlinear model was used to examine the association between temperature and daily mortality. We investigated the effects of individual characteristics by sex, age, education level, and marital status.

RESULTS

We found significant non-linear effects of temperature on total non-accidental, CVD, respiratory, cerebrovascular, and IHD mortality. Heat effects were immediate and lasted for 0-3 days, whereas cold effects persisted for 7-10 days. The relative risks associated with extreme high temperatures (99th percentile of temperature, 28 °C) over lags of 0-3 days were 1.22 (95% confidence interval [CI]: 1.17, 1.28) for total non-accidental mortality, 1.40 (95% CI: 1.30, 1.50) for CVD morality, 1.34 (95% CI: 1.24, 1.46) for respiratory morality, 1.33 (95% CI: 1.20, 1.47) for cerebrovascular mortality, and 1.38 (95% CI: 1.20, 1.58) for IHD mortality. The relative risks associated with extreme cold temperature (1st percentile of temperature, 3.0 °C) over lags of 0-14 days were 1.32 (95% CI: 1.19, 1.46) for total mortality, 1.45 (95% CI: 1.24, 1.68) for CVD morality, 1.28 (95% CI: 1.09, 1.50) for respiratory morality, 1.36 (95% CI: 1.09, 1.70) for cerebrovascular mortality, and 1.26 (95% CI: 0.95, 1.68) for IHD morality. We found that hot and cold affects were greater in those over 85 years of age, and that women, individuals with low education levels, and those who were widowed, divorced, or never married, were more vulnerable.

CONCLUSIONS

This study showed that exposure to hot and cold temperatures in Chengdu was associated with increased mortality, with people over 85 years old, women, those with low education levels, and unmarried individuals being more affected by hot and cold temperatures.

Air pollution, climate conditions and risk of hospital admissions for psychotic disorders in U.S. residents

BACKGROUND

The physical environmental risk factors for psychotic disorders are poorly understood. This study aimed to examine the associations between exposure to ambient air pollution, climate measures and risk of hospitalization for psychotic disorders and uncover potential disparities by demographic, community factors.

METHODS

Using Health Cost and Utilization Project (HCUP) State Inpatient Databases (SIDs), we applied zero-inflated negative binomial regression to obtain relative risks of hospitalization due to psychotic disorders associated with increases in residential exposure to ambient air pollution (fine particulate matter, PM_2.5; nitrogen dioxide, NO₂), temperature and cumulative precipitation. The analysis covered all-age residents in eight U.S. states over the period of 2002-2016. We additionally investigated modification by age, sex and area-level poverty, percent of blacks and Hispanics.

RESULTS

Over the study period and among the covered areas, we identified 1,211,100 admissions due to psychotic disorders. For each interquartile (IQR) increase in exposure to PM_2.5 and NO₂, we observed a relative risk (RR) of 1.11 (95% confidence interval (CI) = 1.09, 1.13) and 1.27 (95% CI = 1.24, 1.31), respectively. For each 1 °C increase of temperature, the RR was 1.03 (95% CI = 1.03, 1.04). Males were more affected by NO₂. Older age residents (≥30 yrs) were more sensitive to PM_2.5 and temperature. Population living in economically disadvantaged areas were more affected by air pollution.

CONCLUSIONS

The study suggests that living in areas with higher levels of air pollutants and ambient temperature could contribute to additional risk of inpatient care for individuals with psychotic disorders.

Analysis of the heat- and cold-related cardiovascular mortality in an urban mediterranean environment through various thermal indices

During the last decades the effects of thermal stress on public health have been a great concern worldwide. Thermal stress is determined by air temperature in combination with other meteorological parameters, such as relative humidity and wind speed. The present study is focused on the Mediterranean city of Thessaloniki, Greece and it aims to explore the association between thermal stress and mortality from cardiovascular diseases, using both air temperature and other thermal indices as indicators. For that, an over-dispersed Poisson regression function was used, in combination with distributed lag non-linear models, in order to capture the delayed and nonlinear effects of temperature. Our results revealed a reverse J-shaped exposure-response curve for the total population and females and a U-shaped association for males. In all cases examined, the minimum mortality temperature was identified around the 80th percentile of each distribution. It is noteworthy that despite the fact that the highest risks of cardiovascular mortality were estimated for exposure to extreme temperatures, moderate temperatures were found to cause the highest burden of mortality. On the whole, our estimations demonstrated that the population in Thessaloniki is more susceptible to cold effects and in regard with gender, females seem to be more vulnerable to ambient thermal conditions.

Modification of temperature-related human mortality by area-level socioeconomic and demographic characteristics in Latin American cities

BACKGROUND

In Latin America, where climate change and rapid urbanization converge, non-optimal ambient temperatures contribute to excess mortality. However, little is known about area-level characteristics that confer vulnerability to temperature-related mortality.

OBJECTIVES

Explore city-level socioeconomic and demographic characteristics associated with temperature-related mortality in Latin American cities.

METHODS

The dependent variables quantify city-specific associations between temperature and mortality: heat- and cold-related excess death fractions (EDF, or percentages of total deaths attributed to cold/hot temperatures), and the relative mortality risk (RR) associated with 1 °C difference in temperature in 325 cities during 2002-2015. Random effects meta-regressions were used to investigate whether EDFs and RRs associated with heat and cold varied by city-level characteristics, including population size, population density, built-up area, age-standardized mortality rate, poverty, living conditions, educational attainment, income inequality, and residential segregation by education level.

RESULTS

We find limited effect modification of cold-related mortality by city-level demographic and socioeconomic characteristics and several unexpected associations for heat-related mortality. For example, cities in the highest compared to the lowest tertile of income inequality have all-age cold-related excess mortality that is, on average, 3.45 percentage points higher (95% CI: 0.33, 6.56). Higher poverty and higher segregation were also associated with higher cold EDF among those 65 and older. Large, densely populated cities, and cities with high levels of poverty and income inequality experience smaller heat EDFs compared to smaller and less densely populated cities, and cities with little poverty and income inequality.

DISCUSSION

Evidence of effect modification of cold-related mortality in Latin American cities was limited, and unexpected patterns of modification of heat-related mortality were observed. Socioeconomic deprivation may impact cold-related mortality, particularly among the elderly. The findings of higher levels of poverty and income inequality associated with lower heat-related mortality deserve further investigation given the increasing importance of urban adaptation to climate change.

Climate change and the prevention of cardiovascular disease

Climate change is a worsening global crisis that will continue negatively impacting population health and well-being unless adaptation and mitigation interventions are rapidly implemented. Climate change-related cardiovascular disease is mediated by air pollution, increased ambient temperatures, vector-borne disease and mental health disorders. Climate change-related cardiovascular disease can be modulated by climate change adaptation; however, this process could result in significant health inequity because persons and populations of lower socioeconomic status have fewer adaptation options. Clear scientific evidence for climate change and its impact on human health have not yet resulted in the national and international impetus and policies necessary to slow climate change. As respected members of society who regularly communicate scientific evidence to patients, clinicians are well-positioned to advocate on the importance of addressing climate change. This narrative review summarizes the links between climate change and cardiovascular health, proposes actionable items clinicians and other healthcare providers can execute both in their personal life and as an advocate of climate policies, and encourages communication of the health impacts of climate change when counseling patients. Our aim is to inspire the reader to invest more time in communicating the most crucial public health issue of the 21st century to their patients.

The impact of greenspace or nature-based interventions on cardiovascular health or cancer-related outcomes: A systematic review of experimental studies

SIGNIFICANCE

Globally, cardiovascular disease (CVD) and cancer are leading causes of morbidity and mortality. While having different etiologies, CVD and cancer are linked by multiple shared risk factors, the presence of which exacerbate adverse outcomes for individuals with either disease. For both pathologies, factors such as poverty, lack of physical activity (PA), poor dietary intake, and climate change increase risk of adverse outcomes. Prior research has shown that greenspaces and other nature-based interventions (NBIs) contribute to improved health outcomes and climate change resilience.

OBJECTIVE

To summarize evidence on the impact of greenspaces or NBIs on cardiovascular health and/or cancer-related outcomes and identify knowledge gaps to inform future research.

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 and Peer Review of Electronic Search Strategies (PRESS) guidelines, we searched five databases: Web of Science, Scopus, Medline, PsycINFO and GreenFile. Two blinded reviewers used Rayyan AI and a predefined criteria for article inclusion and exclusion. The risk of bias was assessed using a modified version of the Newcastle-Ottawa Scale (NOS). This review is registered with PROSPERO, ID # CRD42021231619.

RESULTS & DISCUSSION

Of 2565 articles retrieved, 31 articles met the inclusion criteria, and overall had a low risk of bias. 26 articles studied cardiovascular related outcomes and 5 studied cancer-related outcomes. Interventions were coded into 4 categories: forest bathing, green exercise, gardening, and nature viewing. Outcomes included blood pressure (BP), cancer-related quality of life (QoL) and (more infrequently) biomarkers of CVD risk. Descriptions of findings are presented as well as visual presentations of trends across the findings using RAW graphs. Overall studies included have a low risk of bias; and alluvial chart trends indicated that NBIs may have beneficial effects on CVD and cancer-related outcomes.

CONCLUSIONS & IMPLICATIONS

(1) Clinical implication: Healthcare providers should consider the promotion of nature-based programs to improve health outcomes. (2) Policy implication: There is a need for investment in equitable greenspaces to improve health outcomes and build climate resilient neighborhoods. (3) Research or academic implication: Research partnerships with community-based organizations for a comprehensive study of benefits associated with NBIs should be encouraged to reduce health disparities and ensure intergenerational health equity. There is a need for investigation of the mechanisms by which NBIs impact CVD and exploration of the role of CVD biological markers of inflammation among cancer survivors.

Urban heat vulnerability: A dynamic assessment using multi-source data in coastal metropolis of Southeast China

Extreme heat caused by global climate change has become a serious threat to the sustainable development of urban areas. Scientific assessment of the impacts of extreme heat on urban areas and in-depth knowledge of the cross-scale mechanisms of heat vulnerability forming in urban systems are expected to support policymakers and stakeholders in developing effective policies to mitigate the economic, social, and health risks. Based on the perspective of the human-environment system, this study constructed a conceptual framework and index system of "exposure-susceptibility-adaptive capacity" for urban heat vulnerability (UHV) and proposed its assessment methods. Taking Xiamen City, a coastal metropolis, as an example, spatial analysis and Geodetector were used to explore the spatial and temporal changes, spatial characteristics, and patterns of UHV under multiple external disturbances from natural to anthropological factors, and to reveal the main factors influencing UHV forming and spatial differentiation. Results showed that the exposure, susceptibility, adaptive capacity, and UHV in Xiamen City had a spatial structure of "coastal-offshore-inland". On the hot day, both the exposure and UHV showed a temporal pattern of "rising and then falling, peaking at 14:00" and a spatial pattern of "monsoonal-like" movement between coast and inland. Coastal zoning with favorable socioeconomic conditions had less magnitude of changes in UHV, where the stability of the urban system was more likely to be maintained. During the hot months, the high UHV areas were mainly distributed in the inland, while coastal areas showed low UHV levels. Further, coastal UHV was mainly dominated by "heat exposure", offshore by "comprehensive factors", and inland in the northern mountainous areas by "lack of adaptive capacity". Multi-scale urban adaptive capacity was confirmed to alter spatial distribution of exposure and reshape the spatial pattern of UHV. This study promotes the application of multi-scale vulnerability framework to disaster impact assessment, enriches the scientific knowledge of the urban system vulnerability, and provides scientific references for local targeted cooling policy development and extreme heat resilience building programs.

The Effect of High and Low Ambient Temperature on Infant Health: A Systematic Review

Children, and particularly infants, have physiological, anatomic, and social factors that increase vulnerability to temperature extremes. We performed a systematic review to explore the association between acute adverse infant outcomes (children 0-1 years) and exposure to high and low ambient temperatures. MEDLINE (Pubmed), Embase, CINAHL Plus, and Global Health were searched alongside the reference lists of key papers. We included published journal papers in English that assessed adverse infant outcomes related to short-term weather-related temperature exposure. Twenty-six studies met our inclusion criteria. Outcomes assessed included: infant mortality (n = 9), sudden infant death syndrome (n = 5), hospital visits or admissions (n = 5), infectious disease outcomes (n = 5), and neonatal conditions such as jaundice (n = 2). Higher temperatures were associated with increased risk of acute infant mortality, hospital admissions, and hand, foot, and mouth disease. Several studies identified low temperature impacts on infant mortality and episodes of respiratory disease. Findings on temperature risks for sudden infant death syndrome were inconsistent. Only five studies were conducted in low- or middle-income countries, and evidence on subpopulations and temperature-sensitive infectious diseases was limited. Public health measures are required to reduce the impacts of heat and cold on infant health.

Ambient temperature and risk of urinary tract infection in California: A time-stratified case-crossover study using electronic health records

BACKGROUND

In the United States (US), urinary tract infections (UTI) lead to more than 10 million office visits each year. Temperature and season are potentially important risk factors for UTI, particularly in the context of climate change.

METHODS

We examined the relationship between ambient temperature and outpatient UTI diagnoses among patients followed from 2015 to 2017 in two California healthcare systems: Kaiser Permanente Southern California (KPSC) and Sutter Health in Northern California. We identified UTI diagnoses in adult patients using diagnostic codes and laboratory records from electronic health records. We abstracted patient age, sex, season of diagnosis, and linked community-level Index of Concentration at the Extremes (ICE-I, a measure of wealth and poverty concentration) based on residential address. Daily county-level average ambient temperature was assembled from the Parameter-elevation Regressions on Independent Slopes Model (PRISM). We implemented distributed lag nonlinear models (DLNM) to assess the association between UTI and lagged daily temperatures. Main analyses were confined to women. In secondary analyses, we stratified by season, healthcare system, and community-level ICE-I.

RESULTS

We observed 787,186 UTI cases (89% among women). We observed a threshold association between ambient temperature and UTI among women: an increase in daily temperature from the 5th percentile (6.0 ˚C) to the mean (16.2 ˚C) was associated with a 3.2% (95% CI: 2.4, 3.9%) increase in same-day UTI diagnosis rate, whereas an increase from the mean to 95th percentile was associated with no change in UTI risk (0.0%, 95% CI: -0.7, 0.6%). In secondary analyses, we observed the clearest monotonic increase in the rate of UTI diagnosis with higher temperatures in the fall. Associations did not differ meaningfully by healthcare system or community-level ICE-I. Results were robust to alternate model specifications.

DISCUSSION

Increasing temperature was related to higher rate of outpatient UTI, particularly in the shoulder seasons (spring, autumn).

Global Health Impacts for Economic Models of Climate Change: A Systematic Review and Meta-Analysis

Rationale: Avoiding excess health damages attributable to climate change is a primary motivator for policy interventions to reduce greenhouse gas emissions. However, the health benefits of climate mitigation, as included in the policy assessment process, have been estimated without much input from health experts. Objectives: In accordance with recommendations from the National Academies in a 2017 report on approaches to update the social cost of greenhouse gases (SC-GHG), an expert panel of 26 health researchers and climate economists gathered for a virtual technical workshop in May 2021 to conduct a systematic review and meta-analysis and recommend improvements to the estimation of health impacts in economic-climate models. Methods: Regionally resolved effect estimates of unit increases in temperature on net all-cause mortality risk were generated through random-effects pooling of studies identified through a systematic review. Results: Effect estimates and associated uncertainties varied by global region, but net increases in mortality risk associated with increased average annual temperatures (ranging from 0.1% to 1.1% per 1°C) were estimated for all global regions. Key recommendations for the development and utilization of health damage modules were provided by the expert panel and included the following: not relying on individual methodologies in estimating health damages; incorporating a broader range of cause-specific mortality impacts; improving the climate parameters available in economic models; accounting for socioeconomic trajectories and adaptation factors when estimating health damages; and carefully considering how air pollution impacts should be incorporated in economic-climate models. Conclusions: This work provides an example of how subject-matter experts can work alongside climate economists in making continued improvements to SC-GHG estimates.

The effect of absolute versus relative temperature on health and the role of social care

We investigate the effect of extreme temperatures on mortality and emergency hospital admissions, and whether local social care allows to mitigate their adverse effects. We merge monthly administrative data on mortality and hospital discharge from Italian municipalities for the period 2001-2015 with daily data on local weather conditions, and yearly data on disaggregated municipal expenditure. We compare two different measures of temperature shocks, one using the conventional approach based on absolute levels (without accounting for regional heterogeneity) and the other based on deviations from local mean temperatures. The former approach shows noisy evidence of an increase in mortality due to extremely hot days while the latter approach shows a large increase in mortality and hospital admissions for cardiovascular and respiratory diseases due to both cold and hot days. These effects are mostly driven by the oldest age group and partially by young children. Then, we report evidence of a mitigating effect of social expenditure on the impact of extremely hot and cold days on both emergency hospital admission and mortality rates. A back of the envelope calculation suggests that the additional social care expenditure is fully compensated by the benefits arising from the lower impact of temperature shocks.

The effect of ambient temperature on in-hospital mortality: a study in Nanjing, China

To reduce the inpatient mortality and improve the quality of hospital management, we explore the relationship between temperatures and in-hospital mortality in a large sample across 10 years in Nanjing, Jiangsu. We collected 10 years’ data on patient deaths from a large research hospital. Distributed lag non-linear model (DLNM) was used to find the association between daily mean temperatures and in-hospital mortality. A total of 6160 in-hospital deaths were documented. Overall, peak RR appeared at 8 °C, with the range of 1 to 20 °C having a significantly high mortality risk. In the elderly (age ≥ 65 years), peak RR appeared at 5 °C, with range − 3 to 21 °C having a significantly high mortality risk. In males, peak RR appeared at 8 °C, with the range 0 to 24 °C having a significantly high mortality risk. Moderate cold (define as 2.5th percentile of daily mean temperatures to the MT), not extreme temperatures (≤ 2.5th percentile or ≥ 97.5th percentile of daily mean temperatures), increased the risk of death in hospital patients, especially in elderly and male in-hospital patients.

Effects of Urban Landscape and Sociodemographic Characteristics on Heat-Related Health Using Emergency Medical Service Incidents

It is well known that extremely hot weather causes heat-related health issues. Health problems, especially in urban areas, are becoming increasingly important due to urban heat island effect. Understanding the impact of neighborhood characteristics is important for research into the relationship between thermal environment and human health. The objectives of this study were to explore the urban landscape and sociodemographic characteristics affecting heat-related health and identify spatial inequalities for vulnerable groups. A total of 27,807 heat-related EMS incidents were used at the census block group level (N = 285). We used land cover database and Landsat satellite images for urban landscape variables and used 2019 U.S. Census data for sociodemographic variables. Negative binomial regression was used to identify the neighborhood variables associated with the heat-related EMS incidents in each block group. Heat-related health has been alleviated in block groups with high green areas. However, the negative effects of thermal environments on human health were higher in areas with a high percentage of impervious surface, over 65 years, non-white people, no high school diploma, or unemployment. The results indicate that heat-related health problems can be addressed through prevention strategies for block group variables. Local intervention efforts to solve health issues should be targeted at more vulnerable areas and groups.

Warm Season and Emergency Department Visits to U.S. Children's Hospitals

BACKGROUND

Extreme heat exposures are increasing with climate change. Health effects are well documented in adults, but the risks to children are not well characterized.

OBJECTIVES

We estimated the association between warm season (May to September) temperatures and cause-specific emergency department (ED) visits among U.S. children and adolescents.

METHODS

This multicenter time-series study leveraged administrative data on 3.8  million ED visits by children and adolescents ≤ 18  years of age to the EDs of 47 U.S. children's hospitals from May to September from 2016 to 2018. Daily maximum ambient temperature was estimated in the county of the hospital using a spatiotemporal model. We used distributed-lag nonlinear models with a quasi-Poisson distribution to estimate the association between daily maximum temperature and the relative risk (RR) of ED visits, adjusting for temporal trends. We then used a random-effects meta-analytic model to estimate the overall cumulative association.

RESULTS

Extreme heat was associated with an RR of all-cause ED visits of 1.17 (95% CI: 1.12, 1.21) relative to hospital-specific minimum morbidity temperature. Associations were more pronounced for ED visits due to heat-related illness including dehydration and electrolyte disorders (RR = 1.83; 95% CI: 1.31, 2.57), bacterial enteritis (1.35; 95% CI: 1.02, 1.79), and otitis media and externa (1.30; 95% CI: 1.11, 1.52). Taken together, temperatures above the minimum morbidity temperature accounted for an estimated 11.8% [95% empirical 95% confidence interval (eCI): 9.9%, 13.3%] of warm season ED visits for any cause and 31.0% (95% eCI: 17.9%, 36.5%) of ED visits for heat-related illnesses.

CONCLUSION

During the warm season, days with higher temperatures were associated with higher rates of visits to children's hospital EDs. Higher ambient temperatures may contribute to a significant proportion of ED visits among U.S. children and adolescents. https://doi.org/10.1289/EHP8083.

Time trends in cardiovascular disease mortality attributable to non-optimal temperatures in China: An age-period-cohort analysis using the Global Burden of Disease Study 2019

Background

Associations between non-optimal temperatures and cardiovascular disease (CVD) mortality risk have been previously reported, yet the trends of CVD mortality attributable to non-optimal temperatures remain unclear in China. We analyzed trends in CVD mortality attributable to non-optimal temperatures and associations with age, period, and birth cohort.

Methods

Data were obtained from the Global Burden of Disease Study (GBD) 2019. Joinpoint regression analysis was used to calculate annual percent change (APC) and average annual percent change (AAPC) from 1990 to 2019. We used the age-period-cohort model to analyze age, period, and cohort effects in CVD mortality attributable to non-optimal temperatures between 1990 and 2019.

Results

The age-standardized mortality rate (ASMR) of CVD attributable to non-optimal temperature generally declined in China from 1990 to 2019, whereas ischemic heart disease (IHD) increased slightly. Low temperatures have a greater death burden than high temperatures, but the death burden from high temperatures showed steady increases. Joinpoint regression analysis showed that CVD mortality decreased in all age groups except for IHD, and the decreases were greater in females than in males. The mortality of CVD attributable to non-optimal temperatures of males was higher than females. The mortality rate showed an upwards trend with age across all CVD categories. Period risks were generally found in unfavorable trends. The cohort effects showed a progressive downward trend during the entire period.

Conclusion

Although there have been reductions in CVD mortality attributable to non-optimum temperatures, the mortality of IHD has increased and the burden from non-optimal temperatures remains high in China. In the context of global climate change, our results call for more attention and strategies to address climate change that protect human health from non-optimal temperatures.

Heat and cold-related morbidity risk in north-east of Iran: a time-stratified case crossover design

This study aimed to estimate morbidity risk/number attributed to air extreme temperatures using time-stratified case crossover study and distributed lag non-linear model in a region of Iran during 2015-2019. A time-stratified case crossover design based on aggregated exposure data was used in this study. In order to have no overlap bias in the estimations, a fixed and disjointed window by using 1-month strata was used in the design. A conditional Poisson regression model allowing for over dispersion (Quasi-Poisson) was applied into Distributed Lag Non-linear Model (DLNM). Different approaches were applied to estimate Optimum Temperature (OT). In the model, the interaction effect between temperature and humidity was assessed to see if the impact of heat or cold on Hospital Admissions (HAs) are different between different levels of humidity. The cumulative effect of heat during 21 days was not significant and it was the cold that had significant cumulative adverse effect on all groups. While the number of HAs attributed to any ranges of heat, including medium, high, extreme, and even all values were negligible, but a large number was attributable to cold values; about 10000 HAs were attributable to all values of cold temperature, of which about 9000 were attributed to medium range and about 1000 and less than 500 were attributed to high and extreme values of cold, respectively. This study highlights the need for interventions in cold seasons by policymakers. The results inform researchers as well as policy makers to address both men and women and elderly when any plan or preventive program is developed in the area under study.

Global warming and neurological practice: systematic review

Background

Climate change, including global warming, will cause poorer global health and rising numbers of environmental refugees. As neurological disorders account for a major share of morbidity and mortality worldwide, global warming is also destined to alter neurological practice; however, to what extent and by which mechanisms is unknown. We aimed to collect information about the effects of ambient temperatures and human migration on the epidemiology and clinical manifestations of neurological disorders.

Methods

We searched PubMed and Scopus from 01/2000 to 12/2020 for human studies addressing the influence of ambient temperatures and human migration on Alzheimer’s and non-Alzheimer’s dementia, epilepsy, headache/migraine, multiple sclerosis, Parkinson’s disease, stroke, and tick-borne encephalitis (a model disease for neuroinfections). The protocol was pre-registered with PROSPERO (2020 CRD42020147543).

Results

Ninety-three studies met inclusion criteria, 84 of which reported on ambient temperatures and nine on migration. Overall, most temperature studies suggested a relationship between increasing temperatures and higher mortality and/or morbidity, whereas results were more ambiguous for migration studies. However, we were unable to identify a single adequately designed study addressing how global warming and human migration will change neurological practice. Still, extracted data indicated multiple ways by which these aspects might alter neurological morbidity and mortality soon.

Conclusion

Significant heterogeneity exists across studies with respect to methodology, outcome measures, confounders and study design, including lack of data from low-income countries, but the evidence so far suggests that climate change will affect the practice of all major neurological disorders in the near future. Adequately designed studies to address this issue are urgently needed, requiring concerted efforts from the entire neurological community.

Heat Perception and Coping Strategies: A Structured Interview-Based Study of Elderly People in Cologne, Germany

The transdisciplinary project “Heat-Health Action Plan for Elderly People in Cologne” addresses the most heat-vulnerable risk group, people over 65 years of age. A quantitative study aimed to better understand heat perception and coping strategies of elderly people during heat waves to inform heat-health action plans. We conducted a representative quantitative survey via structured interviews with 258 randomly chosen people over 65 years old, living in their own homes in four areas of Cologne, Germany. These areas varied, both in terms of social status and heat strain. Data regarding demographics, health status, coping strategies, and heat perception were collected in personal interviews from August to October 2019. The majority of the participants perceived heat strain as moderate to very challenging. Women, people with a lower monthly income, and those with a lower health status found the heat more challenging. We found that participants adapted to heat with a number of body-related, home-protective, and activity-related coping strategies. The number of coping strategies was associated with perceived personal heat strain. There is a definite underuse of water-related heat adaption strategies among the elderly. This is of increasing relevance, as rising heat impact will lead to more heat-related geriatric morbidity. Our results are seminal to inform elderly-specific, socio-adapted local heat-health action plans.

Characteristics of Prehospital Heat Illness Cases During the Annual Heat Wave Period in Telangana, India

OBJECTIVES

Global warming and more intense heat wave periods impact health. Heat illness during heat waves has not been studied in the prehospital setting of a low- and middle-income country (LMIC). Early intervention in the community and in the prehospital setting can improve outcomes. Hence, this paper aims to describe the characteristics of heat illness patients utilizing the ambulance service in Telangana state, India with the aim of optimizing public prevention and first aid strategies and prehospital response to this growing problem.

METHODS

This retrospective observational study reviewed patients presenting to Telangana's prehospital emergency care system with heat illness symptoms during the heat wave period from March through June in 2018 and 2019. Descriptive analysis was done on the prehospital, dispatch, and environmental data looking at the patients' characteristics and prehospital intervention.

RESULTS

There were 295 cases in 2018 and 230 cases in 2019 from March-June. The overall incidence of calls with heat illness symptoms was 1.5 cases per 100,000 people. The Scheduled Tribes (ST) had the highest incidence of 4.5 per 100,000 people. Over 96% were from the white income group (below poverty line) while two percent were from the pink income group (above poverty line). From geospatial mapping of the cases, the highest incidence of calls came from the rural, tribal areas. However, the time to response in rural areas was longer than that in an urban area. Males with an average age of 47 were more likely to be affected. The three most common symptoms recorded by the first responders were vomiting (44.4%), general weakness (28.7%), and diarrhea (15.9%). The three most common medical interventions on scene were oxygen therapy (35.1%), oral rehydration salt (ORS) solution administration (26.9%), and intravenous fluid administration (27.0%), with cold sponging infrequently mentioned.

CONCLUSION

This descriptive study provides a snapshot of the regions and groups of people most affected by heat illness during heat waves and the heterogeneous symptom presentation and challenges with management in the prehospital setting. These data may aid planning of prehospital resources and preparation of community first responders during heat wave periods.

A pediatrician's guide to climate change-informed primary care

Despite the urgency of the climate crisis and mounting evidence linking climate change to child health harms, pediatricians do not routinely engage with climate change in the office. Each primary care visit offers opportunities to screen for and support children burdened with risks to health that are increasingly intense due to climate change. Routine promotion of healthy behaviors also aligns with some needed-and powerful-solutions to the climate crisis. For some patients, including those engaged in athletics, those with asthma and allergies, or those with complex healthcare needs, preparedness for environmental risks and disasters worsened by climate change is a critical component of disease prevention and management. For all patients, anticipatory guidance topics that are already mainstays of pediatric best practices are related closely to needed guidance to keep children safe and promote health in the setting of compounding risks due to climate change. By considering climate change in routine care, pediatricians will be updating practice to align with evidence-based literature and better serving patients. This article provides a framework for pediatricians to provide climate-informed primary care during the structure of pediatric well child and other visits.

Spatial variation in the joint effect of extreme heat events and ozone on respiratory hospitalizations in California

Extreme heat and ozone are co-occurring exposures that independently and synergistically increase the risk of respiratory disease. To our knowledge, no joint warning systems consider both risks; understanding their interactive effect can warrant use of comprehensive warning systems to reduce their burden. We examined heterogeneity in joint effects (on the additive scale) between heat and ozone at small geographical scales. A within-community matched design with a Bayesian hierarchical model was applied to study this association at the zip code level. Spatially varying relative risks due to interaction (RERI) were quantified to consider joint effects. Determinants of the spatial variability of effects were assessed using a random effects metaregression to consider the role of demographic/neighborhood characteristics that are known effect modifiers. A total of 817,354 unscheduled respiratory hospitalizations occurred in California from 2004 to 2013 in the May to September period. RERIs revealed no additive interaction when considering overall joint effects. However, when considering the zip code level, certain areas observed strong joint effects. A lower median income, higher percentage of unemployed residents, and exposure to other air pollutants within a zip code drove stronger joint effects; a higher percentage of commuters who walk/bicycle, a marker for neighborhood wealth, showed decreased effects. Results indicate the importance of going beyond average measures to consider spatial variation in the health burden of these exposures and predictors of joint effects. This information can be used to inform early warning systems that consider both heat and ozone to protect populations from these deleterious effects in identified areas.

The Mortality Effect of Apparent Temperature: A Multi-City Study in Asia

(1) Background: The health effect of temperature has become a rising public health topic. The objective of this study is to assess the association between apparent temperature and non-accidental deaths, and the mortality burden attributed to cold and heat temperature; (2) Methods: The daily data on temperature and deaths were collected from 10 cities in Thailand, Korea and China. We fitted a time-series regression with a distributed lag nonlinear model (DLNM) to derive the health risk of temperature for each city and then pooled them to get the overall cumulative risk by multivariate meta-analysis. Additionally, we calculated the attributable fraction of deaths for heat and cold, which was defined as temperatures above and below minimum-mortality temperature (MMT); (3) Results: There are regional heterogeneities in the minimum mortality percentiles (MMP) and attributable fractions for different countries. The MMP varied from about the 5-10th percentile in Thailand to 63-93rd percentile in China and Korea. The attributable fractions of the total deaths due to short-term exposure to temperature in Asia is 7.62%, of which the cold effect (6.44%) is much higher than the heat effect (1.18%); (4) Conclusions: Our study suggested that apparent temperature was associated with an increase in non-accidental mortality. Most of the temperature-related mortality burden was attributable to cold, except for Thailand.

Short-term exposure to extreme temperature and risk of hospital admission due to cardiovascular diseases

Objective: Numerous epidemiological studies have reported relevance of morbidity and mortality from cardiovascular diseases with short-term exposure to environmental temperature. In this study, we examined the hypothesis between temperature indices and hospital admission because of cardiovascular diseases. Methods: The daily number of CVDs was obtained from all hospitals of the Sabzevar city. A semi-parametric generalized additive model (GAM) following a quasi-Poisson distribution with distributed lag non-linear model (dlnm) was selected as a modeling framework for time-series analysis. Results: The overall CVD risk comparing the 1st percentile and the 99th percentile relative to the mean temperature (at lag 0) was 1.33 (95% CI, 1.11: 1.61), and 1.34 (95% CI, 1.10: 1.64), respectively. For all indicators, the extremely cold effects persisted for the initial 7 days. Conclusions: Our results suggest that extremely cold and extremely hot temperatures increase the relative risk of cardiovascular diseases.

Compounding Effects of Social Vulnerability and Recurring Natural Disasters on Mental and Physical Health

OBJECTIVE

This study evaluated the relationships between the occurrence of recent and recurring natural disasters on the incidence of acute and chronic health outcomes at the census tract level in 500 cities across the United States between 2001 and 2015.

METHODS

Using the Centers for Disease Control and Prevention (CDC) 500 cities data set, the CDC Social Vulnerability Index, and the US Small Business Administration (SBA) Disaster Loan Database, we modeled the incidence of self-reported, poor mental and physical health, or a clinical diagnosis of high blood pressure or asthma in census tracts (N = 27 204 tracts in 500 cities) that had experienced recent or recurring natural disasters while controlling for social and environmental risk factors.

RESULTS

Communities that experienced a natural disaster in the previous 5 years compared to those that had not had a higher incidence of poor mental health (RR: 1.02, 95% CI: 1.01-1.02), poor physical health (RR: 1.03, 95% CI: 1.02-1.04), high blood pressure (RR: 1.04, 95% CI: 1.02-1.05), and asthma (RR: 1.01, 95% CI: 1.01-1.02). The incidence of these poor health outcomes increased 1-2% with each additional year that a community experienced a disaster.

CONCLUSIONS

Prevention and preparedness plans that work to build resilience in communities before disasters should focus on closing the gap in environmental and social determinants that have been linked with disproportionate health burdens and slow recovery post-disaster.

Burden of cause-specific mortality attributable to heat and cold: A multicity time-series study in Jiangsu Province, China

Previous epidemiological studies primarily examined the temperature-related mortality burden of all-cause or cardiovascular diseases (CVD) and respiratory diseases. However, evidence on the heat- and cold-attributable mortality burden from other specific causes is limited. This paper aimed to systematically examine the association of heat and cold with a comprehensive spectrum of plausible temperature-related diseases, and to estimate the mortality burdens attributable to heat and cold. In the time-series study of 11 cities in Jiangsu, China, distributed lag non-linear models were applied to estimate city-specific temperature-mortality associations, and then meta-analysis was conducted to pool the estimates. A total of 1,368,648 cases of death were included in this study. Both extreme heat and cold were associated with increased mortality risks from all-cause, CVD, respiratory diseases, nervous diseases, and external causes. Short-term exposures to heat and cold were associated with excess burden of mortality for several specific diseases, accounting for 16.38% (95% eCI, 7.27-22.31%) for myocardial infarction (MI), 12.41% (95% eCI, 8.81-15.07%) for stroke, 27.97% (95% eCI, 18.42-33.35%) for hypertensive heart disease, 25.18% (95% eCI, 18.42-29.63%) for chronic obstructive pulmonary disease, and 28.46% (95% eCI: 4.93-33.57%) for Alzheimer's and dementia. Diabetes was only associated with extreme heat, with 4.61% (95% eCI, 0.13-7.13%) of diabetes mortality attributable to heat. In total, 11.98% (95% eCI, 10.46-13.08%) of mortality was attributable to heat and cold, with 3.49% (95% eCI, 2.87-4.00%) attributable to heat and 8.48% (95% eCI, 7.31-9.49%) attributable to cold, and about 64% of this overall temperature-related mortality burden was found in 6 aforementioned specific causes and about 10% of mortality burden in external causes. Extreme heat and/or cold are associated with increased risks of mortality from a wide range of causes, including previously identified causes in cardiorespiratory diseases and under-studied causes such as diabetes and Alzheimer's and dementia. Future research is needed to confirm the substantial mortality burden of heat and cold.

The Mortality Risk and Socioeconomic Vulnerability Associated with High and Low Temperature in Hong Kong

(1) Background: The adverse health effect associated with extreme temperature has been extensively reported in the current literature. Some also found that temperature effect may vary among the population with different socioeconomic status (SES), but found inconsistent results. Previous studies on the socioeconomic vulnerability of temperature effect were mainly achieved by multi-city or country analysis, but the large heterogeneity between cities may introduce additional bias to the estimation. The linkage between death registry and census in Hong Kong allows us to perform a city-wide analysis in which the study population shares virtually the same cultural, lifestyle and policy environment. This study aims to examine and compare the high and low temperature on morality in Hong Kong, a city with a subtropical climate and address a key research question of whether the extreme high and low temperature disproportionally affects population with lower SES. (2) Methods: Poisson-generalized additive models and distributed-lagged nonlinear models were used to examine the association between daily mortality and daily mean temperature between 2007–2015 with other meteorological and confounding factors controlled. Death registry was linked with small area census and area-level median household income was used as the proxy for socioeconomic status. (3) Results: 362,957 deaths during the study period were included in the analysis. The minimum mortality temperature was found to be 28.9 °C (82nd percentile). With a subtropical climate, the low temperature has a stronger effect than the high temperature on non-accidental, cardiovascular, respiratory and cancer deaths in Hong Kong. The hot effect was more pronounced in the first few days, while cold effect tended to last up to three weeks. Significant heat effect was only observed in the lower SES groups, whilst the extreme low temperature was associated with significantly higher mortality risk across all SES groups. The older population were susceptible to extreme temperature, especially for cold. (4) Conclusions: This study raised the concern of cold-related health impact in the subtropical region. Compared with high temperature, low temperature may be considered a universal hazard to the entire population in Hong Kong rather than only disproportionally affecting people with lower SES. Future public health policy should reconsider the strategy at both individual and community levels to reduce temperature-related mortality.

Mitigating heat-related mortality risk in Shanghai, China: system dynamics modeling simulations

Numerous studies in epidemiology, meteorology, and climate change research have demonstrated a significant association between abnormal ambient temperature and mortality. However, there is a shortage of research attention to a systematic assessment of potential mitigation measures which could effectively reduce the heat-related morbidity and mortality risks. This study first illustrates a conceptualization of a systems analysis version of urban framework for climate service (UFCS). It then constructs a system dynamics (SD) model for the UFCS and employs this model to quantify the impacts of heat waves on public health system in Shanghai and to evaluate the performances of two mitigation measures in the context of a real heat wave event in July 2013 in the city. Simulation results show that in comparison with the baseline without mitigation measures, if the hospital system could prepare 20% of beds available for emergency response to heat waves once receiving the warning in advance, the number of daily deaths could be reduced by 40-60 (15.8-19.5%) on the 2 days of day 7 and day 8; if increasing the minimum living allowance of 790 RMB/month in 2013 by 20%, the number of daily deaths could be reduced by 50-70 (17.7-21.9%) on the 2 days of day 8 and day 12. This tool can help policy makers systematically evaluate adaptation and mitigation options based on performance assessment, thus strengthening urban resilience to changing climate.

Social isolation and vulnerability to heatwave-related mortality in the urban elderly population: A time-series multi-community study in Korea

Although several studies have reported that social isolation is one of the important health risk factors in the elderly population living in urban areas, its effects on vulnerability to heatwaves have been studied relatively less than climatic and other socio-economic factors. Thus, we investigated the association between social isolation levels and heatwave-related mortality risk in the elderly population in 119 urban administrative districts in Korea, using a time-series multi-city dataset (2008-2017). We used a two-stage analysis. In the first stage, we estimated the heatwave-related mortality risk in the elderly population (age ≥ 65) for each district using a time-series regression with a distributed lag model. Subsequently, in the second stage, we applied meta-regressions to pool the estimates across all the districts and estimate the association between social isolation variables and heatwave-related mortality risk. Our findings showed that higher social gathering and mutual aid levels were associated with lower heatwave-related mortality risk. Further, the lower percentage of single elderly households living in detached houses was also related to higher heatwave-related mortality risk. The associations were generally more evident in males compared to females. Our findings suggest that vulnerability to heatwave-related mortality among the urban, city-dwelling, elderly population may be amplified by higher isolation indicators.