Public perceptions of the health risks of extreme heat across US states, counties, and neighborhoods

Interactive effects of atmospheric oxidising pollutants and heat waves on the risk of residential mortality

BACKGROUND

The impact of heat waves and atmospheric oxidising pollutants on residential mortality within the framework of global climate change has become increasingly important.

OBJECTIVE

In this research, the interactive effects of heat waves and oxidising pollutants on the risk of residential mortality in Fuzhou were examined. Methods We collected environmental, meteorological, and residential mortality data in Fuzhou from 1 January 2016, to 31 December 2021. We then applied a generalised additive model, distributed lagged nonlinear model, and bivariate three-dimensional model to investigate the effects and interactions of various atmospheric oxidising pollutants and heat waves on the risk of residential mortality.

RESULTS

Atmospheric oxidising pollutants increased the risk of residential mortality at lower concentrations, and O3 and Ox were positively associated with a maximum risk of 2.19% (95% CI: 0.74-3.66) and 1.29% (95% CI: 0.51-2.08). The risk of residential mortality increased with increasing temperature, with a strong and long-lasting effect and a maximum cumulative lagged effect of 1.11% (95% CI: 1.01, 1.23). Furthermore, an interaction between atmospheric oxidising pollutants and heat waves may have occurred: the larger effects in the longest cumulative lag time on residential mortality per 10 µg/m3 increase in O3, NO2 and Ox during heat waves compared to non-heat waves were [-3.81% (95% CI: -14.82, 8.63)]; [-0.45% (95% CI: -2.67, 1.81)]; [67.90% (95% CI: 11.55, 152.71)]; 16.37% (95% CI: 2.43, 32.20)]; [-3.00% (95% CI: -20.80, 18.79)]; [-0.30% (95% CI: -3.53, 3.04)]. The risk on heat wave days was significantly higher than that on non-heat wave days and higher than the separate effects of oxidising pollutants and heat waves.

CONCLUSIONS

Overall, we found some evidence suggesting that heat waves increase the impact of oxidising atmospheric pollutants on residential mortality to some extent.

Exposure to heat wave risks across time and places: Seasonal variations and predictors of feelings of threat across heat wave geographical susceptibility locations

Vulnerability to heat waves and their negative effects on health vary not only due to individual factors but also due to situational factors, such as time and geography. Hence, we explored seasonal variations and predictors of heat wave feelings of threat across different heat wave geographical susceptibility locations in Portugal. A total of 238 Portuguese residents responded to a web-based longitudinal survey: before the summer, during a heat wave in the summer, during the summer, and after the summer. Geographical location was used as an indicator of risk exposure, operationalized as heat wave occurrence susceptibility (low, moderate, high). Heat wave demands and resources perceptions were assessed to compute an indicator of heat wave feelings of threat. During the heat wave, feelings of threat were higher among participants in high-susceptibility locations, with demands outweighing resources perceptions, suggesting greater distress and coping difficulty. Regression analysis suggested that older participants and female participants living in moderate-high-susceptibility locations had greater difficulty in recovering. Heat wave risk perception and positive affect about heat were identified as the most consistent predictors of heat wave feelings of threat, with risk perception increasing and positive affect decreasing such feelings. Participants with (individual and geographical) vulnerability profiles, who had greater difficulty in coping and recovering from heat waves, could benefit from resource-building/enhancing interventions. In a climatic crisis context, monitoring psychological responses to heat waves (e.g., threat) may enable anticipated action to build resilience before, rather than after, the effects become damaging to physical and psychological health.

Main factors influencing the perceived health risk of endocrine-disrupting chemicals: A systematic literature review

Endocrine-disrupting chemicals (EDCs) are linked to rising health issues such as infertility, childhood obesity, and asthma. While some research exists on health risk perceptions of EDCs, a comprehensive understanding across different populations and contexts is needed. We performed a systematic literature review, examining 45 articles published between 1985 and 2023, focusing on both the risk perception of EDCs as a whole as well as individual EDCs found in the environment (e.g., pesticides, bisphenol A, and phthalates). We identified four major categories of factors influencing EDC risk perception: sociodemographic factors (with age, gender, race, and education as significant determinants), family-related factors (highlighting increased concerns in households with children), cognitive factors (indicating that increased EDC knowledge generally led to increased risk perception), and psychosocial factors (with trust in institutions, worldviews, and health-related concerns as primary determinants). This review highlights the complex nature of EDC risk perception, shaped by sociodemographic, family, cognitive, and psychosocial factors, essential for policymakers in crafting educational and communication strategies. Future research should expand to cover more EDCs, use representative samples, and explore the influence of psychosocial factors on risk perception more deeply.

Measuring climate change perception in China using mental images: A nationwide open-ended survey

Current knowledge about public climate change perception mainly covers belief, concern, and attitudes. However, how this discourse is interpreted using individuals' own frame of reference remains largely unknown, particularly in many large emitters from non-Annex I countries such as China. This study, for the first time, performs a nationwide open-ended survey covering 4,037 respondents and collected 12,100 textual answers. Using a semiautomated coding method, we find seven mental images that exclusively represent the Chinese interpretation of the climate change issue, including global warming, distant icons, natural disasters, environmental degradation, cause, solution, and weather. Analysis of influencing factors shows that females, those with lower education levels, lower income, and older individuals tend to connect climate change with natural weather phenomena. Younger and well-educated residents in developed cities are more aware of various consequences and anthropogenic causes of climate change. People with stronger climate change beliefs, policy support, and personal experience of extreme weather are more likely to mention disastrous impacts, carbon emission as causes, and potential solutions. Employing the multilevel regression and post-stratification technique, we map the prevalence of mental images in China at the prefecture-city level. The results reveal significant geographical heterogeneity, with estimated national means ranging from a high of 55% (weather) to a low of 11% (solution). Our findings reveal diverse perspectives and a widespread misconception of climate change in China, suggesting the need for tailored clarification strategies to gain public consent.

Individual heat adaptation: Analyzing risk communication, warnings, heat risk perception, and protective behavior in three German cities

Extreme heat poses severe health threats, as the increased numbers of hospitalizations and fatalities during heat waves show, though little is known about adaptive behavior toward heat. We conducted a household survey on individual perceptions of heat stress and individual heat protection in the summer and autumn of 2019. In total, 1417 people from three medium-sized German cities participated via telephone or online. Based on the Protective Action Decision Model (PADM), which we adapted to heat stress, we analyzed links between risk perception, environmental and demographic factors, perceptions of stakeholders, different heat warning messages, as well as actual and intended adaptive behavior. Overall, the PADM constructs explained around 16% of the variance in protection motivation, 19% in protective response, and 23% in emotion-focused coping. Context factors (i.e., temperature, risk communication, gender, age, and homeownership) were significant predictors of the addressed outcome variables as were psychological factors (i.e., perceived personal vulnerability, response efficacy, response costs, preparedness, and perceived external responsibility). We further explored the effect of different warning messages on situational knowledge and intended behavioral adaptation in an experimental setting. Results showed that respondents felt significantly better informed after receiving a warning with action recommendations and reported more intended specific behaviors. Our research gives insights into individual protective action decision-making processes. Based on our findings, we recommend tailoring risk communication strategies and combining heat warnings with action recommendations whenever possible to increase understanding and individual adaptation.

Research to Confront Climate Change Complexity: Intersectionality, Integration, and Innovative Governance

Climate impacts increasingly unfold in interlinked systems of people, nature, and infrastructure. The cascading consequences are revealing sometimes surprising connections across sectors and regions, and prospects for climate responses also depend on complex, difficult-to-understand interactions. In this commentary, we build on the innovations of the United States Fifth National Climate Assessment to suggest a framework for understanding and responding to complex climate challenges. This approach involves: (a) integration of disciplines and expertise to understand how intersectionality shapes complex climate impacts and the wide-ranging effects of climate responses, (b) collaborations among diverse knowledge holders to improve responses and better encompass intersectionality, and (c) sustained experimentation with and learning about governance approaches capable of handling the complexity of climate change. Together, these three pillars underscore that usability of climate-relevant knowledge requires transdisciplinary coordination of research and practice. We outline actionable steps for climate research to incorporate intersectionality, integration, and innovative governance, as is increasingly necessary for confronting climate complexity and sustaining equitable, ideally vibrant climate futures.

The practices of heat adaptation among elderly in Dezful: A qualitative study

BACKGROUND

Useful experiences of the elderly in adapting to the environment may play an important role in formulating future policies. This study was conducted to explain the past experiences of the elderly in Dezful in adapting to heat.

MATERIALS AND METHODS

This study was conducted with a qualitative research approach and a qualitative content analysis method in 2020 and 2021. The experiences of 18 elderly in Dezful were collected through semi-structured interviews via recording, face-to-face interviews, and data observation. Sampling was performed by the purpose-based method, and the data of this stage were analyzed using a content analysis approach using the Zhang and Wildemuth method.

RESULTS

During the data analysis process, three main themes were extracted, including psychophysiological, socioeconomic, and environmental adaptation. Also, twelve subthemes including changes in physiological conditions, urban architecture, house architecture, diet, clothing, business conditions, mindset, life conditions, and the use of factors (spirituality, experience, and natural capacities) were extracted.

CONCLUSION

Explaining the experiences of the elderly in Dezful, who have lived with heat for many years, can provide better identification of solutions and more tangible experiences of adaptation to heat for other communities. These experiences can be used in urban, cultural, and social planning.

The Spread of Beliefs in Partially Modularized Communities

Many life-influencing social networks are characterized by considerable informational isolation. People within a community are far more likely to share beliefs than people who are part of different communities. The spread of useful information across communities is impeded by echo chambers (far greater connectivity within than between communities) and filter bubbles (more influence of beliefs by connected neighbors within than between communities). We apply the tools of network analysis to organize our understanding of the spread of beliefs across modularized communities and to predict the effect of individual and group parameters on the dynamics and distribution of beliefs. In our Spread of Beliefs in Modularized Communities (SBMC) framework, a stochastic block model generates social networks with variable degrees of modularity, beliefs have different observable utilities, individuals change their beliefs on the basis of summed or average evidence (or intermediate decision rules), and parameterized stochasticity introduces randomness into decisions. SBMC simulations show surprising patterns; for example, increasing out-group connectivity does not always improve group performance, adding randomness to decisions can promote performance, and decision rules that sum rather than average evidence can improve group performance, as measured by the average utility of beliefs that the agents adopt. Overall, the results suggest that intermediate degrees of belief exploration are beneficial for the spread of useful beliefs in a community, and so parameters that pull in opposite directions on an explore-exploit continuum are usefully paired.

Population Aging and Heat Exposure in the 21st Century: Which U.S. Regions Are at Greatest Risk and Why?

BACKGROUND AND OBJECTIVES

The co-occurring trends of population aging and climate change mean that rising numbers of U.S. older adults are at risk of intensifying heat exposure. We estimate county-level variations in older populations' heat exposure in the early (1995-2014) and mid (2050) 21st century. We identify the extent to which rising exposures are attributable to climate change versus population aging.

RESEARCH DESIGN AND METHODS

We estimate older adults' heat exposure in 3,109 counties in the 48 contiguous U.S. states. Analyses use NASA NEX Global Daily Downscaled Product (NEX-GDDP-CMIP6) climate data and county-level projections for the size and distribution of the U.S. age 69+ population.

RESULTS

Population aging and rising temperatures are documented throughout the United States, with particular "hotspots" in the Deep South, Florida, and parts of the rural Midwest. Increases in heat exposure by 2050 will be especially steep in historically colder regions with large older populations in New England, the upper Midwest, and rural Mountain regions. Rising temperatures are driving exposure in historically colder regions, whereas population aging is driving exposure in historically warm southern regions.

DISCUSSION AND IMPLICATIONS

Interventions to address the impacts of temperature extremes on older adult well-being should consider the geographic distribution and drivers of this exposure. In historically cooler areas where climate change is driving exposures, investments in warning systems may be productive, whereas investments in health care and social services infrastructures are essential in historically hot regions where exposures are driven by population aging.

Climate change: Attitudes and concerns of, and learnings from, people with neurological conditions, carers, and health care professionals

OBJECTIVE

Concern about climate change among the general public is acknowledged by surveys. The health care sector must play its part in reducing greenhouse gas emissions and adapting to a changing climate, which will require the support of its stakeholders including those with epilepsy, who may be especially vulnerable. It is important to understand this community's attitudes and concerns about climate change and societal responses.

METHODS

A survey was made available to more than 100 000 people among a section of the neurological community (patients, carers, and clinicians), focused on epilepsy. We applied quantitative analysis of Likert scale responses supported by qualitative analyses of free-text questions with crossover analyses to identify consonance and dissonance between the two approaches.

RESULTS

A small proportion of potential respondents completed the survey; of 126 respondents, 52 had epilepsy and 56 explicitly declared no illness. The survey indicated concern about the impact of climate change on health within this neurological community focused on epilepsy. More than half of respondents considered climate change to have been bad for their health, rising to 68% in a subgroup with a neurological condition; over 80% expected climate change to harm their health in future. Most (>75%) believed that action to reduce greenhouse gas emissions will lead to improved health and well-being. The crossover analysis identified cost and accessibility as significant barriers.

SIGNIFICANCE

The high level of concern about climate change impacts and positive attitudes toward policies to reduce greenhouse gas emissions provide support for climate action from the epilepsy community. However, if policies are implemented without considering the needs of patients, they risk being exclusionary, worsening inequalities, and further threatening neurological health and well-being.

Concurrent Heat and Air Pollution Exposures among People Experiencing Homelessness

BACKGROUND

Extreme heat and air pollution are important human health concerns; exposure can affect mental and physical well-being, particularly during periods of co-occurrence. Yet, the impacts on people are largely determined by underlying health conditions, coupled with the length and intensity of exposure. Preexisting adverse health conditions and prolonged exposure times are more common for people experiencing homelessness, particularly those with intersectional identity characteristics (e.g., disease, ability, age, etc.). Partially due to methodological limitations, such as data scarcity, there is a lack of research at the intersection of this at-risk population within the climate-health domain.

OBJECTIVES

We have three distinct objectives throughout this article: a) to advance critical discussions around the state of concurrent high heat and air pollution exposure research as it relates to people experiencing homelessness; b) to assert the importance of heat and air pollution exposure research among a highly vulnerable, too-often homogenized population-people experiencing homelessness; and c) to underline challenges in this area of study while presenting potential ways to address such shortcomings.

DISCUSSION

The health insights from concurrent air pollution and heat exposure studies are consequential when studying unhoused communities who are already overexposed to harmful environmental conditions. Without holistic data sets and more advanced methods to study concurrent exposures, appropriate and targeted prevention and intervention strategies cannot be developed to protect this at-risk population. We highlight that a) concurrent high heat and air pollution exposure research among people experiencing homelessness is significantly underdeveloped considering the pressing human health implications; b) the severity of physiological responses elicited by high heat and air pollution are predicated on exposure intensity and time, and thus people without means of seeking climate-controlled shelter are most at risk; and c) collaboration among transdisciplinary teams is needed to resolve data resolution issues and enable targeted prevention and intervention strategies. https://doi.org/10.1289/EHP13402.

Predicting climate-change induced heat-related illness risk in Grand Canyon National Park visitors

BACKGROUND

The climate crisis is the greatest public health threat of the 21st century. Excessive heat is responsible for more deaths than any other extreme weather event, and the frequency, intensity, and duration of extreme heat events are increasing globally due to climate change. Exposure to excessive heat can result in heat related illnesses (HRIs) and long-term poor health outcomes. Physical exertion, sudden exposure to excessive heat, and the lack of physical or behavioral adaptation resources are all associated with greater HRI risk, which is expected to increase for visitors to Grand Canyon National Park (GCNP) and other public lands as climate change worsens.

OBJECTIVES

Our objectives were to understand 1) the relationship between weather and HRI in GCNP visitors, 2) how future HRI rates may change, and 3) how land management agencies can update risk mitigation strategies to match changing risk and better manage an increased HRI burden.

METHODS

We utilized previously published data on HRI in GCNP visitors, and records of daily visitation, temperatures, and maximum and minimum daily humidity from the same study period to develop a model estimate for HRI risk. We then used future climate projections from the World Climate Research Programme's Coupled Model Intercomparison Project phase 5 multi-model dataset to model future HRI risk under different climate scenarios.

RESULTS

The incidence of HRI was significantly associated with maximum daily temperature and minimum relative humidity, and was more common in the shoulder season months. We estimated that HRI will increase 29%-137% over 2004-2009 levels through 2100, assuming no change in visitation.

DISCUSSION

Climate change will continue to increase HRI risk for GCNP visitors and poses risks to public land managers' mission to provide for safe recreation experiences for the benefit of this and future generations in places like GCNP. Excessive risk during the shoulder season months presents an opportunity to increase preventative search and rescue and education efforts to mitigate increased risk.

Higher Temperatures in Socially Vulnerable US Communities Increasingly Limit Safe Use of Electric Fans for Cooling

As the globe warms, people will increasingly need affordable, safe methods to stay cool and minimize the worst health impacts of heat exposure. One of the cheapest cooling methods is electric fans. Recent research has recommended ambient air temperature thresholds for safe fan use in adults. Here we use hourly weather reanalysis data (1950-2021) to examine the temporal and spatial evolution of ambient climate conditions in the continental United States (CONUS) considered safe for fan use, focusing on high social vulnerability index (SVI) regions. We find that although most hours in the day are safe for fan use, there are regions that experience hundreds to thousands of hours per year that are too hot for safe fan use. Over the last several decades, the number of hours considered unsafe for fan use has increased across most of the CONUS (on average by ∼70%), with hotspots across the US West and South, suggesting that many individuals will increasingly need alternative cooling strategies. People living in high-SVI locations are 1.5-2 times more likely to experience hotter climate conditions than the overall US population. High-SVI locations also experience higher rates of warming that are approaching and exceeding important safety thresholds that relate to climate adaptation. These results highlight the need to direct additional resources to these communities for heat adaptive strategies.

Government is expected to lead the payment of heat-resilient infrastructure

Urban heat is severe in numerous cities, but the urgency of heat action and support for the development of heat-resilient infrastructure is unclear. To address these research gaps, this study investigated the perceived urgency of developing heat-resilient infrastructure and associated payment issues in eight megacities, in China using a questionnaire survey of 3758 respondents in August 2020. Overall, the respondents thought it was moderately urgent to take actions to address heat-related challenges. The development of mitigation and adaptation infrastructure is urgent. About 86.4% of the 3758 respondents expected the government to be involved in paying for heat-resilient infrastructure, but 41.2% supported cost-sharing among the government, developers, and owners. There were 1299 respondents willing to pay, resulting in an average annual payment of 44.06 RMB in a conservative scenario. This study is important for decision-makers to formulate plans on heat-resilient infrastructure and to release financial strategies for collecting investments and funds.

Geographic and demographic variation in worry about extreme heat and COVID-19 risk in summer 2020

Extreme heat is a major health hazard that is exacerbated by ongoing human-caused climate change. However, how populations perceive the risks of heat in the context of other hazards like COVID-19, and how perceptions vary geographically, are not well understood. Here we present spatially explicit estimates of worry among the U.S. public about the risks of heat and COVID-19 during the summer of 2020, using nationally representative survey data and a multilevel regression and poststratification (MRP) model. Worry about extreme heat and COVID-19 varies both across states and across demographic groups, in ways that reflect disparities in the impact of each risk. Black or African American and Hispanic or Latino populations, who face greater health impacts from both COVID-19 and extreme heat due to institutional and societal inequalities, also tend to be much more worried about both risks than white, non-Hispanic populations. Worry about heat and COVID-19 were correlated at the individual and population level, and patterns tended to be related to underlying external factors associated with the risk environment. In the face of a changing climate there is an urgent need to address disparities in heat risk and develop responses that ensure the most at-risk populations are protected.

Variations of Urban Thermal Risk with Local Climate Zones

Due to the differences in land cover and natural surroundings within cities, residents in various regions face different thermal risks. Therefore, this study combined multi-source data to analyze the relationship between urban heat risk and local climate zones (LCZ). We found that in downtown Shenyang, the building-type LCZ was mainly found in urban centers, while the natural- type LCZ was mainly found in suburbs. Heat risk was highest in urban centers, gradually decreasing along the suburban direction. The thermal risk indices of the building-type LCZs were significantly higher than those of the natural types. Among the building types of LCZs, LCZ 8 (open middle high-rise) had the highest average thermal risk index (0.48), followed by LCZ 3 (0.46). Among the natural types of LCZs, LCZ E (bare rock and paved) and LCZ F (bare soil and sand) had the highest thermal risk indices, reaching 0.31 and 0.29, respectively. This study evaluated the thermal risk of the Shenyang central urban area from the perspective of LCZs and combined it with high-resolution remote sensing data to provide a reference for thermal risk mitigation in future urban planning.

How Thermal Perceptual Schema Mediates Landscape Quality Evaluation and Activity Willingness

The use of outdoor space is closely related to local microclimate conditions. Some studies have shown that people form perceptual schemata based on their perceptual experience of microclimate conditions, which leads to perceptual bias, so it is necessary to further investigate how the thermal schemata formed by the accumulation of thermal experience affect the willingness to engage in activities, which will be beneficial to improve the use of urban space. Studies have not explored the relationship between the thermal perceptual schema (TPS), landscape quality evaluation (LQE), and activity willingness. Therefore, it is necessary to further investigate how thermal schemas formed by the accumulation of thermal experience affect activity willingness. A total of 3435 volunteers were surveyed online and divided into two groups, the first group for comfortable weather (N = 1773) and the second group for hot weather (N = 1662), and voted for each of the four dimensions of the five scenarios according to the TPS. This study found that socioeconomic status (SES) and age were the main factors contributing to TPS bias when perceiving the same destination according to TPS, and this difference was consistent in both groups, which affects the willingness to be active at the destination. The study also found that LQE may be a major factor in residents' willingness to be active in more pleasant weather, while TPS plays a more important role in hot weather conditions. In addition, we investigated the relationship between TPS and residents' activity willingness mediated by different landscape features and parameter configurations. These results indicate that the TPS formed by thermal experience accumulation affects people's LQE and activity willingness, and that landscape configuration parameters play an important role.

Vulnerable, Resilient, or Both? A Qualitative Study of Adaptation Resources and Behaviors to Heat Waves and Health Outcomes of Low-Income Residents of Urban Heat Islands

Little is known of how low-income residents of urban heat islands engage their knowledge, attitudes, behaviors, and resources to mitigate the health impacts of heat waves. In this qualitative study, we conducted semi-structured interviews with 40 adults in two such neighborhoods in Los Angeles California to explore their adaptation resources and behaviors, the impacts of heat waves on physical and mental health, and threat assessments of future heat waves. Eighty percent of participants received advanced warning of heat waves from television news and social media. The most common resource was air conditioning (AC) units or fans. However, one-third of participants lacked AC, and many of those with AC engaged in limited use due primarily to the high cost of electricity. Adaptation behaviors include staying hydrated, remaining indoors or going to cooler locations, reducing energy usage, and consuming certain foods and drinks. Most of the participants reported some physical or mental health problem or symptom during heat waves, suggesting vulnerability to heat waves. Almost all participants asserted that heat waves were likely to increase in frequency and intensity with adverse health effects for vulnerable populations. Despite limited resources, low-income residents of urban heat islands utilize a wide range of behaviors to minimize the severity of health impacts, suggesting they are both vulnerable and resilient to heat waves.

Global Warming’s Six MTurks: A Secondary Analysis of a US-Based Online Crowdsourcing Market

Using a global warming audience segmentation tool (Six Americas Super Short Survey (SASSY)) as a case study, we consider how public health can use consumer panels and online crowdsourcing markets (OCMs) in research. Through a secondary analysis, we aim to understand how consumer panels and OCMs are similar to or different from each other on demographics and global warming beliefs through SASSY, and how they compare to US Census estimates. With this information, researchers will understand public opinion of global warming in their sample, which is useful for many climate change initiatives. Neither the consumer panel (Ipsos) or OCM sample (MTurk) matched US estimates of population demographics. Both panels achieved similar SASSY segments, showing that even with diverse sampling frames, SASSY is a useful tool for understanding global warming sentiment. Compared to Ipsos, MTurk was younger (more Millennials and Generation X), had higher educational attainment, and lower income. Both panels were majority White, but Ipsos was more diverse than the unweighted MTurk. Ipsos had more respondents from the South whereas MTurk had more respondents from the West. Across the MTurk SASSY segment, there were no significant differences for the majority of demographic characteristics except for age; younger generations were more Alarmed or Concerned, and older generations were more Doubtful and Dismissive. Researchers interested in understanding their sample’s opinions of global warming should use SASSY and consider oversampling in key demographic variables if they intend to achieve a nationally representative and diverse sample.

No Country for Old Men. Assessing Socio-Spatial Relationships Between Air Quality Perceptions and Exposures in Southern Chile

An extensive body of research has been noted that many socially deprived communities tend to live in areas characterized by higher levels of outdoor air pollution. Whilst there is an expanding literature documenting this disproportionate distribution, most previous studies have taken place in the Global North, have focused with industrial or vehicle air pollution sources and have tend to ignore the complex interactions between exposures, public perceptions and social factors. In this paper, we investigate the social vulnerability to and risk perceptions of air pollution sourced from domestic heating in two Chilean cities with particularly high levels of PM_2.5 during winter months. To this end, we integrate primary survey data, with geographically detailed estimates of air pollution exposures and area-level characteristics obtained from the Chilean Census. We first examine the spatial distribution of PM_2.5 exposures and air quality perceptions, and subsequently explore relationships between socio-demographic characteristics, air pollution exposure, and health concerns. Our results revel evident spatial patterns of dispersion, with some neighborhoods being more polluted than others. Age and percentage of roofs in poor condition in the participant's census tract are the best predictors of PM_2.5 exposure. We find no correlation between perceived and real levels of contamination. Our multivariate analysis indicates that personal perceptions of air quality are significantly associated with age, gender, family structure, and heating behaviors. Such detailed depictions provide insights into potential meaningful strategies to improve air quality and highlight the need to incorporate measures to better protect older adults.

The Malay-Version Knowledge, Risk Perception, Attitude and Practice Questionnaire on Heatwaves: Development and Construct Validation

Background: Heatwaves have long been recognised as a serious public health concern. This study was aimed at developing and validating a Malay-version of a questionnaire for evaluating knowledge, risk perception, attitudes, and practices regarding heatwaves. Method: The knowledge construct was evaluated with item analysis and internal reliability. The psychometric characteristics, construct and discriminant validity, and internal consistency of the risk perception, attitude and practice constructs were evaluated with exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). Results: The 16 items in the knowledge construct had a good difficulty, discrimination, and reliability index of 0.81. A total of 16 items were maintained in EFA with Cronbach’s alpha of 0.84 and 0.82, 0.78 and 0.84 obtained for total items and risk perception, attitude, and practice constructs, respectively. A total of 15 items were retained after CFA. The finalised model met the fitness indices threshold. The convergent and discriminant validity were good. Conclusion: This newly developed Malay-version KRPAP questionnaire is reliable and valid for assessing Malaysians’ knowledge, risk perception, attitudes, and practices regarding heatwaves.

COVID-19 pandemic modifies temperature and heat-related illness ambulance transport association in Japan: a nationwide observational study

BACKGROUND

During the COVID-19 pandemic, several illnesses were reduced. In Japan, heat-related illnesses were reduced by 22% compared to pre-pandemic period. However, it is uncertain as to what has led to this reduction. Here, we model the association of maximum temperature and heat-related illnesses in the 47 Japanese prefectures. We specifically examined how the exposure and lag associations varied before and during the pandemic.

METHODS

We obtained the summer-specific, daily heat-related illness ambulance transport (HIAT), exposure variable (maximum temperature) and covariate data from relevant data sources. We utilized a stratified (pre-pandemic and pandemic), two-stage approach. In each stratified group, we estimated the 1) prefecture-level association using a quasi-Poisson regression coupled with a distributed lag non-linear model, which was 2) pooled using a random-effects meta-analysis. The difference between pooled pre-pandemic and pandemic associations was examined across the exposure and the lag dimensions.

RESULTS

A total of 321,655 HIAT cases was recorded in Japan from 2016 to 2020. We found an overall reduction of heat-related risks for HIAT during the pandemic, with a wide range of reduction (10.85 to 57.47%) in the HIAT risk, across exposure levels ranging from 21.69 °C to 36.31 °C. On the contrary, we found an increment in the delayed heat-related risks during the pandemic at Lag 2 (16.33%; 95% CI: 1.00, 33.98%).

CONCLUSION

This study provides evidence of the impact of COVID-19, particularly on the possible roles of physical interventions and behavioral changes, in modifying the temperature-health association. These findings would have implications on subsequent policies or heat-related warning strategies in light of ongoing or future pandemics.

Contribution of urban ventilation to the thermal environment and urban energy demand: Different climate background perspectives

Urbanization can lead to changes in urban morphology that alter the urban thermal environment and energy demand. Improving urban ventilation can alleviate the urban heat island effect and reduce urban energy demand. We categorized the ventilation conditions of 31 major cities in China into four levels based on the frontal area index and presented the natural ventilation effects for cities in five different climate zones. We found that the land surface temperature varies between 0.029 and 5.357 °C in areas under the same climate background. Improving ventilation can directly or indirectly contribute to reductions in urban energy consumption. The energy demand in well-ventilated areas can be reduced by up to 6.704%. The largest reduction in urban energy demand was achieved by improving ventilation within the temperate continental climate zone.

The relationship between population heat vulnerability and urbanization levels: A county-level modeling study across China

The purpose of this work was to assess population vulnerability to heat-related health risks and its relationship with urbanization levels to provide essential information for the future development and policy-making for climate change adaptation. We constructed a heat vulnerability index (HVI), quantified the population heat vulnerability in each county across China by a principal component analysis (PCA) of multiple factors, and assessed urbanization levels in each county using multisource data. Then, the HVI was validated using the heat-attributable fraction (heat-AF) of nonaccidental mortality based on death monitoring data and meteorological data from 95 counties across China. The results showed that our HVI was significantly positively associated with the heat AF of nonaccidental mortality. A negative correlation was observed between the urbanization level and the HVI. The HVI was generally higher in less urbanized western China and lower in the more urbanized eastern regions. The baseline mortality occupies the top position in the importance ranking of the heat-vulnerability indicators at all three urbanization levels, but the other indicators, including the aging rate, agricultural population rate, education, ethnic structure, economic status, air conditioner ownership rate, and number of hospitals, ranked differently among different urbanization levels. This finding indicates that to reduce population heat vulnerability, the most important approach is to improve the health status of the whole population and reduce baseline mortality; additionally, regional-specific measures and emphasis should be adjusted reasonably along with the process of urbanization according to the characteristics and key factors of local heat vulnerability.

Evolution of the minimum mortality temperature (1983-2018): Is Spain adapting to heat?

The objective of this study was to analyze at the level of Spain's 52 provinces province level the temporal evolution of minimum mortality temperatures (MMT) from 1983 to 2018, in order to determine whether the increase in MMT would be sufficient to compensate for the increase in environmental temperatures in Spain for the period. It also aimed to analyze whether the rate of evolution of MMT would be sufficient, were it to remain constant, to compensate for the predicted increase in temperatures in an unfavorable (RCP 8.5) emissions scenario for the time horizon 2051-2100. The independent variable was made up of maximum daily temperature data (Tmax) for the summer months in the reference observatories of each province for the 1983-2018 period. The dependent variable was daily mortality rate due to natural causes (ICD 10: A00-R99). For each year and province, MMT was determined using a quadratic or cubic fit (p < 0.05). Based on the annual MMT values, a linear fit was carried out that allowed for determining the time evolution of MMT. These values were compared with the evolution of Tmax registered in each observatory during the 1983-2018 analyzed period and with the predicted values of Tmax obtained for an RCP8.5 scenario for the period 2051-2100. The rate of global variance in Tmax in the summer months in Spain during the 1983-2018 period was 0.41 °C/decade, while MMT across the whole country increased at a rate of 0.64 °C/decade. Variations in the provinces were heterogeneous. For the 2051-2100 time horizon, there was predicted increase in Tmax values of 0.66 °C/decade, with marked geographical differences. Although at the global level it is possible to speak of adaptation, the heterogeneities among the provinces suggest that the local level measures are needed in order to facilitate adaptation in those areas where it is not occurring.

Modelling of Temperature-Attributable Mortality among the Elderly in Lisbon Metropolitan Area, Portugal: A Contribution to Local Strategy for Effective Prevention Plans

Epidemiological studies on the impact of determining environmental factors on human health have proved that temperature extremes and variability constitute mortality risk factors. However, few studies focus specifically on susceptible individuals living in Portuguese urban areas. This study aimed to estimate and assess the health burden of temperature-attributable mortality among age groups (0-64 years; 65-74 years; 75-84 years; and 85+ years) in Lisbon Metropolitan Area, from 1986-2015. Non-linear and delayed exposure-lag-response relationships between temperature and mortality were fitted with a distributed lag non-linear model (DLNM). In general, the adverse effects of cold and hot temperatures on mortality were greater in the older age groups, presenting a higher risk during the winter season. We found that, for all ages, 10.7% (95% CI: 9.3-12.1%) deaths were attributed to cold temperatures in the winter, and mostly due to moderately cold temperatures, 7.0% (95% CI: 6.2-7.8%), against extremely cold temperatures, 1.4% (95% CI: 0.9-1.8%). When stratified by age, people aged 85+ years were more burdened by cold temperatures (13.8%, 95% CI: 11.5-16.0%). However, for all ages, 5.6% of deaths (95% CI: 2.7-8.4%) can be attributed to hot temperatures. It was observed that the proportion of deaths attributed to exposure to extreme heat is higher than moderate heat. As with cold temperatures, people aged 85+ years are the most vulnerable age group to heat, 8.4% (95% CI: 3.9%, 2.7%), and mostly due to extreme heat, 1.3% (95% CI: 0.8-1.8%). These results provide new evidence on the health burdens associated with alert thresholds, and they can be used in early warning systems and adaptation plans.

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.

The driving influences of human perception to extreme heat: A scoping review

Prior research demonstrates a link between heat risk perception and population response to a heat warning. Communicating a precise and understandable definition of "heat" or "heatwaves" can affect how a population perceives and responds to extreme heat. Still, little is known about how heat perception affects behavior changes to heat and heat communication across diverse populations. This scoping review aims to identify and describe the main themes and findings of recent heat perception research globally and map critical research gaps and priorities for future studies. Results revealed risk perception influences a person's exposure to and behavioral response to excessive heat. Risk perception varied geographically along the rural-urban continuum and was typically higher among vulnerable subgroups, including populations who were low-income, minority, and in poor health. A more integrated approach to refining risk communication strategies that result in a behavioral change and incorporates the individual, social, and cultural components of impactful group-based or community-wide interventions is needed. Research employing longitudinal or quasi-experimental designs and advanced statistical techniques are required to tease apart the independent and interacting factors that causally influence risk communication, heat perception, and adaptive behaviors. We advance a framework to conceptualize the structural, environmental, personal, and social drivers of population heat risk perception and how they interact to influence heat perception and adaptive behaviors. Our findings map future research priorities needed for heat perception and a framework to drive future research design.

Social Sensing of Heatwaves

Heatwaves cause thousands of deaths every year, yet the social impacts of heat are poorly measured. Temperature alone is not sufficient to measure impacts and “heatwaves” are defined differently in different cities/countries. This study used data from the microblogging platform Twitter to detect different scales of response and varying attitudes to heatwaves within the United Kingdom (UK), the United States of America (US) and Australia. At the country scale, the volume of heat-related Twitter activity increased exponentially as temperature increased. The initial social reaction differed between countries, with a larger response to heatwaves elicited from the UK than from Australia, despite the comparatively milder conditions in the UK. Language analysis reveals that the UK user population typically responds with concern for individual wellbeing and discomfort, whereas Australian and US users typically focus on the environmental consequences. At the city scale, differing responses are seen in London, Sydney and New York on governmentally defined heatwave days; sentiment changes predictably in London and New York over a 24-h period, while sentiment is more constant in Sydney. This study shows that social media data can provide robust observations of public response to heat, suggesting that social sensing of heatwaves might be useful for preparedness and mitigation.

Analysis of the impact of heat waves on daily mortality in urban and rural areas in Madrid

The objective of this study was to analyze and compare the effect of high temperatures on daily mortality in the urban and rural populations in Madrid. Data were analyzed from municipalities in Madrid with a population of over 10,000 inhabitants during the period from January 1, 2000 to December 31, 2020. Four groups were generated: Urban Metropolitan Center, Rural Northern Mountains, Rural Center, and Southern Rural. The dependent variable used was the rate of daily mortality due to natural causes per million inhabitants (CIE-X: A00-R99) between the months of June and September for the period. The primary independent variable was maximum daily temperature. Social and demographic "context variables" were included: population >64 years of age (%), deprivation index and housing indicators. The analysis was carried out in three phases: 1) determination of the threshold definition temperature of a heat wave (Tumbral) for each study group; 2) determination of relative risks (RR) attributable to heat for each group using Poisson linear regression (GLM), and 3) calculation of odds ratios (OR) using binomial family GLM for the frequency of the appearance of heat waves associated with context variables. The resulting percentiles (for the series of maximum daily temperatures for the summer months) corresponding to Tthreshold were: 74th percentile for Urban Metropolitan Center, 76th percentile for Southern Rural, 83rd for Rural Northern Mountains and 98th percentile for Center Rural (98). Greater vulnerability was found for the first two. In terms of context variables that explained the appearance of heat waves, deprivation index level, population >64 years of age and living in the metropolitan area were found to be risk factors. Rural and urban areas behaved differently, and socioeconomic inequality and the composition of the population over age 64 were found to best explain the vulnerability of the Rural Center and Southern Rural zones.

Using Twitter for Nursing Research: A Tweet Analysis on Heat Illness and Health

AIM

To provide an example of a tweet analysis for nurse researchers using Twitter in their research.

DESIGN

A content analysis using tweets about "heat illness + health."

METHODS

Tweets were pulled from Twitter's application programming interface with premium access using Postman and the key words "heat illness + health." All data cleaning and analysis was performed in R Version 3.5.2, and the tweet set was analyzed for term frequency, sentiment, and topic modeling. Principal R packages included LDAvis, tidytext, tm, and zyuzhet.

RESULTS

6,317 tweets were analyzed with a date range of April 6, 2009, to December 30, 2019. The most common terms in the tweets were heat (n = 4,532), illness (n = 4,085), and health (n = 2,257). Sentiment analysis showed that the majority of tweets (55%) had a negative sentiment. Topic modeling showed that there were three topics within the tweet set: increasing impact, prevention and safety, and symptoms.

CONCLUSIONS

Twitter can be a useful tool for nursing researchers, serving as a viable adjunct to current research methodologies. This practical example has facilitated a deeper understanding of the social media representation of heat illness and health that can be applied to other research.

CLINICAL RELEVANCE

Twitter serves as a tool for collecting health information for multiple groups, ranging from clinicians and researchers to patients. By utilizing the plethora of data that comes from the platform, we can work towards developing theories and interventions related to numerous health conditions and phenomena.

Geographic Distributions of Extreme Weather Risk Perceptions in the United States

Weather and climate disasters pose an increasing risk to life and property in the United States. Managing this risk requires objective information about the nature of the threat and subjective information about how people perceive it. Meteorologists and climatologists have a relatively firm grasp of the historical objective risk. For example, we know which parts of the United States are most likely to experience drought, heat waves, flooding, snow or ice storms, tornadoes, and hurricanes. We know less about the geographic distribution of the perceived risks of meteorological events and trends. Do subjective perceptions align with exposure to weather risks? This question is difficult to answer because analysts have yet to develop a comprehensive and spatially consistent methodology for measuring risk perceptions across geographic areas in the United States. In this project, we propose a methodology that uses multilevel regression and poststratification to estimate extreme weather and climate risk perceptions by geographic area (i.e., region, state, forecast area, and county). Then we apply the methodology using data from three national surveys (n = 9,542). This enables us to measure, map, and compare perceptions of risk from multiple weather hazards in geographic areas across the country.

Strategies for Delivering Mental Health Services in Response to Global Climate Change: A Narrative Review

This narrative review examined strategies for preparedness and response to mental health impacts of three forms of climate change from a services perspective: (1) acute and extreme weather events such as hurricanes, floods, and wildfires, (2) sub-acute or long-term events such as droughts and heatwaves; and (3) the prospect of long-term and permanent changes, including higher temperatures, rising sea levels, and an uninhabitable physical environment. Strategies for acute events included development and implementation of programs and practices for monitoring and treating mental health problems and strengthening individual and community resilience, training of community health workers to deliver services, and conducting inventories of available resources and assessments of at-risk populations. Additional strategies for sub-acute changes included advocacy for mitigation policies and programs and adaptation of guidelines and interventions to address the secondary impacts of sub-acute events, such as threats to livelihood, health and well-being, population displacement, environmental degradation, and civil conflict. Strategies for long-lasting changes included the implementation of evidence-based risk communication interventions that address the existing and potential threat of climate change, promoting the mental health benefits of environmental conservation, and promoting psychological growth and resilience.

Spatial Variability of Heat-Related Mortality in Barcelona from 1992-2015: A Case Crossover Study Design

Numerous studies have demonstrated the relationship between summer temperatures and increased heat-related deaths. Epidemiological analyses of the health effects of climate exposures usually rely on observations from the nearest weather station to assess exposure-response associations for geographically diverse populations. Urban climate models provide high-resolution spatial data that may potentially improve exposure estimates, but to date, they have not been extensively applied in epidemiological research. We investigated temperature-mortality relationships in the city of Barcelona, and whether estimates vary among districts. We considered georeferenced individual (natural) mortality data during the summer months (June–September) for the period 1992–2015. We extracted daily summer mean temperatures from a 100-m resolution simulation of the urban climate model (UrbClim). Summer hot days (above percentile 70) and reference (below percentile 30) temperatures were compared by using a conditional logistic regression model in a case crossover study design applied to all districts of Barcelona. Relative Risks (RR), and 95% Confidence Intervals (CI), of all-cause (natural) mortality and summer temperature were calculated for several population subgroups (age, sex and education level by districts). Hot days were associated with an increased risk of death (RR = 1.13; 95% CI = 1.10–1.16) and were significant in all population subgroups compared to the non-hot days. The risk ratio was higher among women (RR = 1.16; 95% CI= 1.12–1.21) and the elderly (RR = 1.18; 95% CI = 1.13–1.22). Individuals with primary education had similar risk (RR = 1.13; 95% CI = 1.08–1.18) than those without education (RR = 1.10; 95% CI= 1.05–1.15). Moreover, 6 out of 10 districts showed statistically significant associations, varying the risk ratio between 1.12 (95% CI = 1.03–1.21) in Sants-Montjuïc and 1.25 (95% CI = 1.14–1.38) in Sant Andreu. Findings identified vulnerable districts and suggested new insights to public health policy makers on how to develop district-specific strategies to reduce risks.

Influence of Atlantic and Pacific Sea Surface Temperatures on Heat-Related Mortality in the United States

The frequency and magnitude of extreme summer temperature events in the United States have increased in the past few decades. Long-term exposure to extreme summer temperatures can be detrimental to human health, due to potential risks of dehydration and thermoregulation strains on the cardiovascular system, which may often lead to heat-related mortality (HRM). The summer climate of the United States is influenced by variability in Atlantic and Pacific sea surface temperatures, driven in part by Atlantic Multidecadal Oscillation (AMO) and El-Nino Southern Oscillation (ENSO), respectively. However, the influence of AMO and ENSO on HRM in the United States has not been investigated. Here the longest time series of HRM spanning the past five decades is analyzed in relation with AMO and ENSO. We find that HRM doubled in the early-1990s, coinciding with the positive phase of the AMO. Furthermore, we note a positive association between the variability in HRM and summer temperatures across all regions of the United States, with the strongest association found over the Southern United States. Therefore, this research suggests that variability in Atlantic and Pacific sea surface temperatures has both a nationwide and regional impact on HRM in the United States. Hence, by understanding variability in sea surface temperatures, the future burden of heat-attributed emergencies during extreme summer temperature events can be reduced not only for the United States, but also worldwide.

Development of the Adjusted Wind Chill Equivalent Temperature (AWCET) for cold mortality assessment across a subtropical city: validation and comparison with a spatially-controlled time-stratified approach

Background

Global warming has reduced the adaptability of the people living in subtropical regions to cope up with cold stress due to lengthening of hot days and shortening of transition period from hot to cold weather. However, existing studies on measuring cold stress are based on biometeorological indices designed for temperate regions. This may overestimate the impact of wind chill on mortality risk in subtropical cities.

Methods

This study developed an Adjusted Wind Chill Equivalent Temperature (AWCET) index. A spatially-controlled time-stratified approach was applied to evaluate the ability of AWCET for estimating cold mortality in subtropical cities, based on a mortality dataset (2008–2012) in Hong Kong.

Results

The use of AWCET could indicate increase in all-cause, cardiovascular, respiratory, and cancer-related mortality risk during the days with average temperature < = 1st [11.0 °C], <= 3rd [12.6 °C] and < = 5th [13.4 °C] percentiles. The results were stable and consistent based on both log-linear and curve-linear relationships between AWCET and mortality risk. AWCET was also compared with the New Wind Chill Equivalent Temperature (NWCET) designed for temperate regions, and has found that higher magnitude of mortality risk would be found when using AWCET for assessing all-cause and cause-specific mortality in Hong Kong, for days with average temperature < = 1st, <= 3rd and < = 5th percentiles.

Conclusions

AWCET is validated to be effective to access cold mortality in the context of subtropical cities. The use of AWCET may enhance the cold weather warning system in subtropical cities, as a supplementary tool to help demonstrating small administrative-level perceived temperature with volunteered geographic information.

Heat-health action plans in Europe: Challenges ahead and how to tackle them

High temperatures have periodically affected large areas in Europe and urban settings. In particular, the deadly 2003 summer heat waves precipitated a multitude of national and subnational health prevention and research efforts. Building on these and other international experiences the WHO Regional Office for Europe developed and published in 2008 a comprehensive framework for prevention, the heat-health action plans (HHAPs). This provided a blueprint used by several national and subnational authorities to design their prevention efforts. A decade after the publication of the WHO guidance, a wealth of new evidence and acquired implementation experience has emerged around HHAP effectiveness; heat exposure; acclimatization and adaptation; heat-health governance and stakeholder involvement; and the role of urban design and greening interventions in prevention. This evidence and experience can guide the strategies to tackle current and upcoming challenges in protecting health from heat under a warming climate.