Effects Of Heat Waves Research Articles

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

ImportanceExtensive 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.ObjectiveTo assess the association between heat waves and adverse health events among dually eligible individuals 65 years and older.Design, Setting, and ParticipantsThis 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.ExposureHeat 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 MeasuresDaily counts of heat-related emergency department visits and heat-related hospitalizations for each ZCTA.ResultsThe 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 RelevanceIn 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.

Response of native and invasive grazers to global warming: marine heatwaves vs. gradual trends

Ecological responses to global warming are likely driven by a combination of gradual warming trends and extreme climate events, which are increasing in frequency and intensity. Specifically, heatwaves may amplify the impact of ongoing warming, and thus affect species’ physiological responses, behaviour and eventually survival. Here, we tested the hypothesis that a tropical invasive grazer snail, Cerithium scabridum, will be more resilient to the effects of future gradual warming and marine heatwaves (MHWs) than its native congener C. lividulum, co-occurring in rocky intertidal pools along the Levantine coast. Survival and faecal production (as a proxy for feeding rate) of the 2 species were measured under 4 experimental temperature conditions: ambient summer mean (31°C), predicted warming scenario (ambient +3°C), and short-term MHWs (+5°C) added to either ambient or warming treatments, followed by a recovery period. No effect of warming alone was detected on either species, whereas MHW reduced faecal production only in the native C. lividulum. During the recovery period, C. lividulum survival dropped, but the few surviving individuals recovered from the heat stress as indicated by the increase in faecal production. Neither snail species survived under the combination of warming and MHW. These results suggest that both species, living in a thermally fluctuating and often extreme environment, can tolerate a +3°C gradual warming, but only the invasive snail can withstand a +5°C heatwave. However, neither species can endure a severe heatwave on top of predicted gradual warming, potentially leading to population collapse among both species in the region.

Effect of heatwaves on mortality of Alzheimer's disease and other dementias among elderly aged 60 years and above in China, 2013–2020: a population-based study

BackgroundChina has the largest number of dementia patients in the world, posing a significant health and economic burden. Alzheimer's disease (AD) and other dementia patients face a higher risk of mortality during heatwaves, but relevant studies on this topic have been limited so far. MethodsThe study extracted data from the China Cause of Death Reporting System (CDRS) on deaths of AD and other dementia patients aged 60 years and above between 2013-2020. Using an individual-level, time-stratified, and case-crossover study design, the effects of heatwaves across nine scenarios on dementia mortality were quantified by conditional logistic regression combined with distributed lag non-linear model (DLNM). Additionally, the attributable fractions (AFs) of deaths due to heatwaves were calculated. FindingsA total of 399,036 death cases were reported caused by AD and other dementias during the study period. It was found that heatwaves significantly increased the risk of death among people with AD and other dementias. As the intensities and durations of the heatwaves increased, the lag0-7 cumulative odds ratios (CORs) of mortality increased progressively from 1·140 (95% CI: 1·118, 1·163) under the mildest heatwave to 1·459 (95% CI: 1·403, 1·518) under the most severe one, across nine heatwave scenarios examined. Additionally, under specific heatwave scenarios, sex and regions modified the mortality risk, but no significant age differences were observed. The AFs of AD and other dementia mortality due to milder heatwaves were lower compared to more severe heatwaves, ranging from 12·281% (95% CI: 10·555%, 14·015%) to 31·460% (95% CI: 28·724%, 34·124%). InterpretationThe study provided critical insights into the substantial increase in heatwave-related mortality among AD and other dementia patients during and after heatwave events. The results from our quantitative analyses will provide needed scientific evidence for policymakers and practitioners to develop relevant policies and guidelines to protect the health and well-beings of vulnerable populations in future in the context of both seasonal changes and long-term climate change. FundingThis work was supported by the Project of Prevention and Intervention on Major Diseases for Elderly in China, NCNCD [00240201307], the National Key Research and Development Program of China [2022YFC2602301, 2023YFC2308703] and the Science and Technology Fundamental Resources Investigation Program of China [2017FY101201].

5.F. Scientific session: Staying cool: innovative solutions for an ageing population in a warming Europe

Abstract The EU is facing the dual challenge of climate change and rapid population ageing: temperatures in Europe are warming more rapidly than in the rest of the world and at the same time the number of those aged 85 years or more in the EU is projected to more than double by 2050. The increase of morbidity and mortality due to extreme heat is higher in older adults compared to the other age groups. During the workshop, we will first address the effect of heat waves and raising temperatures on older adults’ health and then present and discuss possible innovative tools and actions to minimise their impact on the EU ageing population. Objectives Emphasise the importance of addressing heat waves and raising temperatures including their impact on NCDs, with a focus on the implications for the ageing population; Present the reinforced activities of the Climate and Health Observatory, focusing on raising temperatures and heat waves; Discuss possible measures at EU level, multisectoral collaboration, the synergies and possible trade-offs between adaptation and mitigation measures; Discuss innovative solutions to minimise the impact of raising temperatures and heat waves on older adults. Speakers/Panelists • Projections of heat exposure of older adults and the consequences. • The European Climate & Health Observatory – presentation of reinforced & broadened activities. • Measures for adapting to and protecting against the effects of heat waves and warming. • Tackling the problem at the source: mitigating the contribution of the healthcare sector to GHG emissions/climate change.

Disentangling effects of droughts and heatwaves on alpine periphyton communities: A mesocosm experiment

AbstractThe accelerating rate of global climate change at higher elevations and latitudes is increasing the potential for extreme climatic events. Here, a knowledge gap exists in how the order of exposure to, and duration of droughts and heatwaves affect their cumulative impact on aquatic communities. We tested experimentally for the legacy effects of simultaneous vs. sequential exposures to drought and heatwave on sediment‐dwelling algal communities (epipelon) from small fishless alpine lakes. In both simultaneous, and sequential exposure treatments involving drought followed by a heatwave, the negative effect of drought masked the effects of warming on chlorophyll‐inferred algal biomass and taxonomic composition. Reversal of order of exposure (i.e., heatwave followed by drought) lowered their cumulative effect on community structure. These findings highlight the potential for drought events to dominate over heatwaves in altering shallow littoral ecosystems at high elevations under a rapidly warming climate.

The interactive effect of extreme weather events and PM2.5 on respiratory health among the elderly: a case-crossover study in a high-altitude city.

With climate change posing increasing threats and aging populations, understanding the complex relationship between extreme temperatures, PM2.5 pollution, and respiratory health among the elderly is crucial. While some research exists, there remains a significant gap in studying the combined effects of heat waves, cold spells, and PM2.5 on elderly respiratory health in high-altitude regions. We collected data from Xining (2016-2021), including respiratory disease outpatient visits, meteorological, and pollutant data. Employing a case-crossover design and conditional Poisson regression analysis, we investigated the individual and interactive impacts of heat wave, cold spell, and PM2.5 on outpatient visits for respiratory disease among the elderly. We used the relative excess odds due to interaction (REOI), proportion attributable to interaction (AP), and synergy index (S) as quantitative indicators of interaction. Our analysis revealed significant associations between heat wave, cold spell, PM2.5 exposure, and outpatient visits for respiratory disease among the elderly, with odds ratios of 1.10 (95%CI: 1.06, 1.15) and 1.16 (95%CI: 1.13, 1.20), respectively. Moreover, a synergistic effect between cold spell and PM2.5 was observed, particularly affecting vulnerable groups such as female and those aged ≥ 80. The combined exposure to cold spell and elevated PM2.5 levels was estimated to contribute to up to 0.18 (95%CI: 0.17, 0.27) of respiratory outpatient visits. This study underscores the need for urgent interventions, such as reducing PM2.5 exposure and enhancing extreme weather warning systems, to protect the respiratory health of the elderly, especially in high-altitude regions.

Youth suicidality risk relative to ambient temperature and heatwaves across climate zones: A time series analysis of emergency department presentations in New South Wales, Australia.

Youth suicidality prevalence continues to rise alongside hot weather severity. Links between these two variables are underexplored. We examined associations between daily temperature and emergency department suicidality presentations by young people. We assessed these associations for five regions covering New South Wales as determined by 'climate zone' and analysed for heatwave effects as well as based on demographic subgroups. Daily emergency department presentations for suicidality by people aged 12-24 years across New South Wales, Australia, during warmer months (November to March) from 2012 to 2019 were examined in relation to daily mean temperature and heatwaves (⩾3 consecutive days ⩾ 95th percentile of long-term daily mean temperature) and by climate zone, using a generalised additive model with negative binomial distribution. Risks for age- and sex-based subgroups were also calculated. New South Wales youth suicidality presentation rates were significantly higher on hotter days. For every 1°C rise above average daily mean temperature, youth suicidality presentations to New South Wales emergency departments increased by 1.3%. Heatwaves did not increase presentation rates beyond single-day daily mean temperature effects. These findings were predominantly replicated across climate zones and demographic subgroups, though the association between suicidality and ambient temperature was weaker in coastal regions including Eastern Sydney. There is a positive linear association between ambient temperature and youth suicidality presentations to emergency departments. Risks are increased on single hot days, not only during heatwaves. Public health, broader societal approaches to heat and health system planning should consider impacts on youth suicidality of predicted increases in hot weather severity and frequency.

The combined effects of heatwaves, air pollution and greenery on the risk of frailty: a national cohort study

The associations between heatwaves and frailty, as well as the joint effects of heatwaves with air pollution and greenery, are currently unknown. This study leverages data from the China Health and Retirement Longitudinal Study (CHARLS), which collected information from 6,400 older adults between 2011 and 2018. Our outcome variable was frailty, as measured by the frailty index (FI > 0.21). Heatwaves were defined based on maximum temperature, incorporating four thresholds (≥ 97.5%, 97.5%, 92.5%, and 90%) and three durations (≥ 2, 3, and 4 days). These variables were considered as time-varying variables, representing the one-year exposure preceding survival events. Fine particulate matter (PM2.5) and greenery (normalized difference vegetation index (NDVI)) were utilized as indicators of air pollution and greenery exposure, respectively, and were treated as time-varying indicators concurrent with heatwaves.Time-varying Cox proportional hazards models were employed to assess the independent effects, as well as the multiplicative and additive interactions of heatwaves, air pollution, and greenery on the risk of frailty. These effects were quantified using hazard ratios (HRs), a traditional product term representing the ratio of HRs, and the relative excess risk due to interaction (RERI). Our findings indicate that heatwaves are associated with an increased risk of frailty, with HRs ranging from 1.035 (95% CI: 1.006–1.064) to 1.063 (95% CI: 1.028–1.101). We observed both a positive multiplicative interaction (HRs > 1) and an additive interaction (RERI > 0) between high level PM2.5 concentration, lack of greenery, and heatwaves. This study reveals that the combined effects exacerbate the adverse impact of heatwaves on the risk of frailty. Moreover, the combined effects of heatwaves, air pollution, and greenery exposure on frailty risk vary across age, gender, and educational attainment.

Association of heat and cold waves with cause-specific mortality in Iran: a systematic review and meta-analysis

Despite the frequent occurrence of heat waves in the Middle East, there is a lack of evidence regarding the overall estimates for the effect of heat waves on mortality in this region. This study aimed to review the effect of exposure to heat and cold waves and daily cause-specific mortality. Four electronic databases were searched. The titles, abstracts, and full-texts of the articles were carefully reviewed by two researchers. Once eligible studies were identified, the required data were extracted. Separate meta-analyses were conducted based on gender, age group, and health endpoint combinations. According to the meta-analysis, heat waves had a statistically significant effect on all-cause mortality with an RR of 1.23 (CI 95%: 1.08, 1.39). Cardiovascular mortality significantly increased in heat waves with an RR of 1.08 (CI 95%: 1.05, 1.10). However, the increase in respiratory mortality was not statistically significant. Compared to young people (age < 65 years old) and women, elderly and men were more vulnerable to heat waves with RRs of 1.31 (95% CI: 1.05, 1.57) and 1.33 (95% CI: 1.08, 1.58), respectively. This study can be beneficial in developing response or adaptation plans for heat waves. Future studies should focus on other specific health endpoints like ischemic heart disease, chronic obstructive pulmonary diseases, etc., and other outcomes such as hospitalization and emergency visits.

Current summer heat waves impair rainbow trout (Oncorhynchus mykiss) spermatogenesis: Implications for future fish farming management practices in South Europe

Freshwater environments provide different ecosystem services for human well-being, and are one of the most important natural sources of healthy animal protein. Climate change and extreme temperature events, among other factors, represent a growing concern for their sustainable use. In contrast to the research effort to elucidate how global warming affects these aquatic environments, few studies pay attention to the potential effects of heat waves, a current phenomenon with direct effects on contemporaneous organisms. Here, the potential effects of a single heat wave event on rainbow trout (Oncorhynchus mykiss) males, mimicking a recorded environmental event, have been evaluated by means of biometric, redox and stress response, plasma testosterone, histopathology and transcriptomic analyses. Environmental monitoring showed how, during the last 4 years, mean water temperature increased (2–4 °C; from April to October), heat wave duration progressively increased (from 15 to 100 days), and mean intensities ranged 1.7–3.8 °C with a maximum of 8.0 °C. An experimentally recreated heat wave lasting only 16 days, with mean and maximum intensities of 2.7 and 6.7 °C, induced a decrease in body weight and total antioxidant status, but increased blood plasma cortisol levels and redox enzyme activity. The induced heat wave decreased testosterone plasma levels and sperm quality, arrested spermatocyte type I and II differentiation and increased spermatozoa apoptosis. These effects were correlated with a differential expression of 1156 genes (116 up- and 1040 down-regulated genes) in exposed fish when compared to Control fish, reflecting an alteration in cell apoptosis and spermatozoa maturation processes. These results not only increase concern about current heat wave events, recreating a real scenario, but also unveil for the first time the particular molecular mechanisms of subsequent spermatogenesis disruption, opening new avenues for designing urgent and necessary strategies to mitigate the effects of extreme climate change conditions on freshwater aquaculture.

Exceptional heatwaves and mortality in Europe: Greater impacts since the coronavirus disease 2019 outbreak

Record-breaking hot weather (exceptional heatwaves) has been increasingly common worldwide, posing a significant threat to human health. However, little is known about the effect of these exceptional heatwaves on mortality in Europe, especially since the coronavirus disease 2019 (COVID-19) outbreak, which converges with climate change to affect healthcare systems and human lives. We collected mortality data of 967 regions in 30 European countries over the last decade (2014–2023) from the Eurostat. A standard time-series analysis was used to estimate the effect of exceptional heatwaves by quasi-Poisson regression model, including the main effect (effect from heatwave intensity) and the added effect (effect from heatwave duration), on mortality for each region during two periods (before and since the COVID-19 outbreak). We used random effects meta-analysis to pool the mortality risk (i.e., relative risk [RR]) and burden (i.e., attributable fraction [AF]) associated with exceptional heatwaves, at the country level and for Europe as a whole. In Europe, the mortality burden attributable to main and added effects increased from 0.492% (95% CI: 0.488%–0.496%) to 1.276% (95% CI: 1.266%–1.285%) and from 0.307% (95% CI: 0.294%–0.318%) to 0.428% (95% CI: 0.407%–0.448%), respectively. Furthermore, substantial variations across countries were observed, with some countries such as France and Spain experiencing a large increase in the mortality burden attributable to exceptional heatwaves since the COVID-19 outbreak. Our findings underscore the urgent need for heat-health actions to consider the multi-effects of exceptional heatwaves amidst a warming climate.

Heatwave and upper urinary tract stones morbidity: effect modification by heatwave definitions, disease subtypes, and vulnerable populations.

As heatwave occurs with increased frequency and intensity, the disease burden for urolithiasis, a heat-specific disease, will increase. However, heatwave effect on urolithiasis subtypes morbidity and optimal heatwave definition for urolithiasis remain unclear. Distributed lagged linear models were used to assess the associations between 32 defined heatwave and upper urinary tract stones morbidity. Relative risk (RR) and attributable fraction (AF) of upper urinary tract stone morbidity associated with heatwave of different intensities (low, middle, and high) were pooled by meta-analysis. Optimal heatwave definition was selected based on the combined score of AF, RR, and quasi-Akaike Information Criterion (QAIC) value. Stratified analyses were conducted to investigate the modification effects of gender, age, and disease subtypes. Association between heatwave and upper urinary tract stones morbidity was mainly for ureteral calculus, and AF was highest for low-intensity heatwave. This study's optimal heatwave was defined as average temperature > 93rd percentile for ≥ 2 consecutive days, with AF of 7.40% (95% CI:2.02%, 11.27%). Heatwave was associated with ureteral calculus morbidity in males and middle-aged adults. While heatwave effect was statistically insignificant in females and other age groups. Managers should develop appropriate definitions to address heatwave based on regional characteristics and focus on heatwave effects on urolithiasis.

Characteristics and drivers of marine heatwaves in the western South Atlantic

Marine heatwaves are events of extreme warming in the ocean and have devastating consequences for marine life. Here we used a K-mean clustering analysis to detect different types of marine heatwaves along the South American coast from 10°S to 45°S and identify their remote drivers. In the central part of the domain, marine heatwaves are associated with atmospheric blocking caused by wave trains triggered by the Madden-Julian Oscillation. On the other hand, marine heatwaves occurring along the northern and southern coast of South America are associated with El Niño and La Niña events, respectively. The intensity and duration of these marine heatwaves are modulated by the development phase and intensity of the Niño and Niña events. By identifying the climatic modes of variability leading to each type of marine heatwaves, our study can help develop adaptation strategies, such as early warning systems, to prevent the devastating effects of marine heatwaves.

Clinical Spectrum of Heatstroke in a Tertiary Care Hospital during the 2024 Delhi Heat wave Peak

Abstract Background: Heat-related illnesses (HRIs) have a wide spectrum from relatively mild heat cramps to heatstroke in its severest form. The 2024 heat wave in Delhi, with temperatures consistently above 40°C, resulted in over 270 deaths due to heatstroke. This study examines nine cases of classical heatstroke admitted over a 24-h period to a tertiary care hospital in Delhi. Materials and Methods: This is a cross-sectional study of patients presenting to emergency with altered consciousness during the 24-h period just before the culmination of the 40-day long heat wave period. In the absence of alternative etiologies on the investigation, a diagnosis of classical heatstroke was entertained. The sociodemographic details, clinical features, investigations, treatment, and outcomes of nine such patients are being reported. Results: Common symptoms observed in the patients were hyperthermia (100%), dehydration (100%), altered sensorium (100%), vomiting (33%), and seizures (33%). Laboratory findings showed respiratory alkalosis (100%), hypokalemia (88.8%), thrombocytopenia (88.8%), and transaminitis (77.7%). Eight heatstroke patients required mechanical ventilation. Despite intensive treatment, three patients died, whereas six were discharged in stable condition. Conclusion: The 2024 heat wave in Delhi highlighted the severe impact of extreme heat on health. The spectrum of clinical features in classical heatstroke has been outlined. The impact of heat wave was such that even normal individuals accustomed to high-heat environments developed HRI. Early recognition and rapid cooling are crucial in managing heatstroke. Improved public awareness, healthcare infrastructure, and management protocols are essential to mitigate the effects of future heat waves.

Climate Justice Approaches In “Sand” And “On Darwin Tides”

Fiction has always addressed climate change, but since the last century, writers have emphasized the theme through several genres, including climate fiction, which encompasses works focused on climate change and its impacts on the planet. Among the multiple aspects these narratives address, climate justice plays a crucial role. Studies show that developing countries, mainly located in the Global South, are the ones that suffer the most the devastating effects of floods, extreme weather, heat waves, and species extinction caused by anthropogenic climate change. Such impacts bring to the debate the issue of climate justice since it underscores its inequality. Climate fiction plays a significant role in presenting possible scenarios caused by climate change, implicitly or explicitly pointing out who and what is impacted by its adverse effects. Perspectives on climate justice are analyzed in the short stories “Sand” by Conor Corderoy and “On Darwin Tides” by Shauna O’Meara. These short stories portray how the characters deal with climate effects and how physical spaces, natural or urban, are affected. Their narratives emphasize issues related to climate justice, including the difficulties people face in surviving in deeply transformed realities and the discrepancy in the perception of the impacts of the climate crisis according to economic and social conditions. These stories stress the need to reflect on how the most vulnerable populations and ecosystems are affected and how climate justice can prevail to change this unfair scenario.

Fouling community shows high resistance and metabolic resilience towards experimental high intensity heatwave

Climate change is predicted to increase the prevalence of marine heatwaves with an increase in heatwave frequency and intensity. While some studies have shown the effect of marine heatwaves in warm temperate climates and the effect of overall higher temperature in warm and cold temperate climates, it is yet not entirely understood how heatwaves impact marine urban communities in cold temperate climates. As thermal resistance might be related to selective pressures and acclimation, it seems reasonable to assume that they may have a strong impact on local fauna and flora. In the present study, we simulated an in situ high amplitude heatwave and observed the community structure and the metabolism of Bugula neritina at two time-steps after the heatwave and compared them to control communities and individuals. Contrary to our expectations, the community structure remained vastly unaffected, as did the total metabolome of B. neritina. This shows that the community was able to resist the disturbance of the heatwave. Bugula neritina additionally showed a certain metabolic resilience as the already minor differences in the metabolome between control and the heatwave treatment diminished even further between the tested time steps.

"Groundbreaking study: Combined effect of marine heatwaves and polyethylene microplastics on Pacific oysters, Crassostrea gigas"

Microplastics (MPs) and rising marine seawater temperatures are one of the major environmental problems threatening the survival of marine organisms and biodiversity. However, interactions between such multiple stressors are virtually unexplored. This study aimed to assess the combined effect of two temperatures and polyethylene MPs on the Pacific oyster Crassostrea gigas, one of the most globalized mollusc species for aquaculture. Our work highlights the potential ecological risk posed by these two factors on marine bivalve molluscs. The experimental design was carried out following a 14-day exposure of oysters to environmental concentrations of polyethylene MPs (0.01 mg.L-1), and to two temperatures (15 °C and 22 °C). Sampling was performed on days 0, 7, and 14. The μ-FTIR analysis was applied to quantify MPs of interest and to check a potential environmental contamination. Tissue samples of digestive glands were collected from the oysters to evaluate the activity of biomarkers including superoxide dismutase, glutathione-s-transferase, malondialdehyde and laccase through protein levels. We note that the combination of MPs and high water temperature (HWT, 22 °C) had a significant impact both on the survival of animals and on stress markers, by modifying lipid peroxidation and immune responses. This original study gave the first innovative results on this topic and provides us with knowledge of the combined effects of MPs pollution and HWT (simulating marine heatwaves situation) on C. gigas. There remains a lack of information on the toxicity and the potential environmental hazard of plastics in the marine environment.

Heatwaves and its impact on the depressive symptoms among Chinese community-dwelling older adults: examining the role of social participation

ObjectivesBased on the Environment-Person Fit Perspective, this study explores the relationship between heatwaves and subsequent depressive symptoms among older Chinese community dwellers. Additionally, the study investigates if this association varies among older adults with different levels of social participation. MethodsHeatwaves were defined as the frequency of occurrences where daily maximum temperature exceeded 35°C for 3 consecutive days. A sample including 7124 older adults aged 55 and above was selected from the 2018 China Health and Retirement Longitudinal Study. Depressive symptoms were measured by the 10-item Centre for Epidemiological Studies Depression Scale. Social participation was measured by volunteer participation and leisure participation. Multilevel fixed effect model was employed to investigate the temporal association between heatwaves and depressive symptoms, as well as the moderating effect of social participation. ResultsThis study found that older adults who had experienced a greater number of heatwaves presented more severe depressive symptoms (b = 0.66, p < 0.001). However, a high level of leisure participation buffered the effect of heatwaves on depressive symptoms (b = ̶ 0.52, p < 0.05). ConclusionsThis study highlighted the differential impact of heatwaves on mental health outcomes among older adults depending on their levels of social participation. Our findings provide valuable insights into designing an integrative heatwave adaption scheme that simultaneously focuses on temperature adjustment and social participation enhancement.

Ocean conditions influence the quality of recruiting benthic marine invertebrate larvae—Insights from fatty acids

AbstractMany marine benthic invertebrates have a pelagic life stage, during which larvae need to accumulate enough reserves to complete metamorphosis to a settled benthic juvenile. Currently, very little is known about how ocean conditions affect quality of the larvae. We studied this for three settlement seasons (2017–2019) by collecting returning Dungeness crab (Metacarcinus magister) megalopae at the Oregon coast and analyzing them for fatty acid biomarkers. We found that the larvae are omnivorous and have versatile diets. The daily larval abundance was positively correlated with larval quality. Despite the relatively high day‐to‐day variation, we found pronounced seasonal and inter‐annual differences in the body condition (size and total fatty acid content) and biomarker composition of megalopae. Especially, the early season recruits of 2017 had lower content of lipids and polyunsaturated fatty acids known to be beneficial to crustaceans. This is likely related to lingering effects of the eastern Pacific marine heat wave (2014–2016) on pelagic communities. The larvae were rich in docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) with lower levels in benthic juveniles, indicating an ontogenetic diet shift and likely lower availability of DHA and EPA in the benthic environment. The pulsed megalopa recruitment may provide substantial carbon and lipid inputs to the nearshore ecosystem as a form of pelagic subsidy. Our results reveal that ocean conditions may have an effect on the quality of returning larvae, which likely influence their recruitment performance and early juvenile success, and thus potentially also the population size and commercial catch 4 yr later.

Association Between Extreme Heat and Outpatient Visits for Mental Disorders: A Time-Series Analysis in Guangzhou, China.

Previous evidence on heatwaves' impact on mental health outpatient visits is limited, especially uncertainty on how different heatwave definitions affect this relationship. In this time-series study, we assessed the association between heatwaves and outpatient visits for mental disorders in Guangzhou, China. Daily outpatient visits for mental disorders and its specific categories (schizophrenia, mood, and neurotic disorders) were sourced from the Urban Resident-based Basic Medical Insurance (URBMI) and the Urban Employee-based Basic Medical Insurance (UEBMI) claims databases in Guangzhou from 2010 to 2014. The study employed nine heatwave definitions, based on combinations of three daily mean temperature thresholds (90th, 92.5th, and 95th percentiles) and durations (2, 3, and 4days). Using quasi-Poisson generalized linear models (GLMs), we estimated the risks (at lag 0day) and cumulative effects (lag 0-10days) of heatwaves on mental disorder outpatient visits. Age, gender, types of medical insurance were considered as potential effect modifiers. We observed a positive association between heatwaves and increased total outpatient visits for mental disorders, both at lag 0day and during lag 0-10days. The impact of heatwave was significant at lag 0day for schizophrenia, mood and neurotic disorders visits, it remained significant for neurotic and mood disorders visits during lag 0-10days. Heatwave durations lasting more than 4days were associated with higher relative risks of mental disorders at lag 0day. Older adults had relatively higher effect estimations than younger individuals. This research highlights the effects of extreme heat on mental health.