Mental health and air temperature: Attributable risk analysis for schizophrenia hospital admissions in arid urban climates

Park cool island modifications to assess radiative cooling of a tropical urban park

Many cities experience urban overheating from climate change and the urban heat island phenomenon. Previous studies demonstrate that parks are a potential nature-based solution to mitigate urban overheating through the 'Park Cool Island' (PCI) effect. PCI intensity can be measured through field measurements (FM) or remote sensing. This FM study used a network of meteorological sensors within a park and in its surrounding urban area to ascertain its PCI intensity in Singapore from January to December 2022. Consistently cooler air temperatures were found throughout a 24-h period in the park area, with mean daytime (nighttime) PCI intensity measured ~ 2.21 °C (~ 1.69 °C). A modified version of PCI (PCImodified) was developed to highlight the radiative cooling differences between the urban and park areas. PCImodified leverages on the network of sensors to preserve the spatial granularity of data, allowing for the interpolation of point data across the study area. By employing Geographical Information Science concepts, the model visualises the diurnal changes in PCImodified intensities with respect to tree height, tree density, and building height; significant cooling is positively (negatively) correlated with tree height and density (building height). This study demonstrates a comprehensive analysis of PCI and cooling intensities of parks using FM in understudied tropical urban environments.

Urban heat island impacts on mental health in middle-aged and older adults

BACKGROUND

Urban heat island (UHI), attributed to rapid urbanization, might be a latent modifiable risk factor for human health, yet little is known about whether UHI puts a strain on public mental health. This study aimed to assess the effect of the summer UHI on mental health.

METHODS

Leveraging 338,363 urban residents from the UK Biobank, this study estimated the associations of summer UHI effect with incidence risks of mental disorders, substance use disorder, depressive disorder, and anxiety disorder using both time-independent and time-dependent Cox regression models with full adjustment for possible confounders. Furthermore, the effect of UHI on related psychiatric symptoms and brain microstructure were explored through logistic regression models and multiple linear regression models, respectively.

RESULTS

In this study, summer UHI was significantly associated with the elevated risks of psychiatric disorders. The hazard ratio with a 95% confidence interval (CI) from the time-dependent Cox model was 1.04 (95% CI, 1.03-1.05) for mental disorders, 1.12 (1.11-1.14) for substance use disorder, 1.08 (1.06-1.10) for depressive disorder, and 1.06 (1.04-1.08) for anxiety disorder per standard deviation of UHI intensity, respectively. Subgroup analyses showed that females and individuals with hypertension or coronary artery disease were more vulnerable to the UHI effect on mental health. The detrimental effects on psychiatric symptoms and white matter microstructure were also observed.

CONCLUSION

The study suggested UHI could be an environmental stressor and induce a heavier burden on mental health. The effective mitigation of urban heat stress could benefit both public health and sustainable development.

A small area analysis of acute exposure to temperatures and mental health in North Carolina

Increasing evidence suggests that temperatures adversely impact mental and behavioral disorders (MBD). This study explores the effects of temperatures on mental health outcomes using over 5.9 million MBD-related emergency department (ED) visits across three geographical regions of North Carolina (i.e., Mountains, Piedmont, and Coast) from 2016 to 2019. A distributed lag non-linear model (DLNM) with a generalized linear model and quasi-Poisson distribution adjusted for humidity, long-term seasonal time trends, and day of the week examined the acute impact (i.e., 7-day) of temperature on daily MBD-related ED visits at zip code tabulation area (ZCTA) locations. Results were pooled at the region and state levels and reported in reference to the median temperature using a case-time series design for the analysis of small-area data. Stratified analyses were conducted for age, sex, and specific mental-health related ED visits (substance use, mood disorders, anxiety disorders). At the state level, we found significant positive associations between high temperatures (97.5th percentile) and an increase in relative risk (RR) for total MBDs (RR:1.04, 95% CI,1.03-1.05) and psychoactive substance use (RR:1.04, 95% CI, 1.02-1.06). Low air temperatures (2.5th percentile) only increased risk for the elderly (i.e., 65 and older) and predominantly white communities (RR: 1.03, CI: 1.03-1.05). During high temperatures (97.5th percentile), majority-white communities (RR:1.06, CI: 1.01-1.10) and low-income communities had the highest risk for MBDs (RR: 1.05, CI: 1.03-1.07). Our findings suggest there is a positive association between exposure to high temperatures and increased MBD-related ED visits, modified by patient age and place-based sociodemographic (ie., race and income) context.

Surviving the 2021 heat dome with schizophrenia: A qualitative, interview-based unpacking of risks and vulnerabilities

This study explores the multifaceted challenges experienced by individuals with schizophrenia during extreme heat, highlighting the interplay between individual factors, social dynamics, and environmental influences. Despite making up only 1% of the Canadian population, individuals diagnosed with schizophrenia comprised 16% (n = 97) of the deaths during the 2021 heat dome in Western Canada. However, to date, there exists scant qualitative research that explore the direct experiences and the intricacies of intersecting factors faced by individuals with schizophrenia during extreme heat events. This study aims to explore experiences of heat by those living with schizophrenia, including social, behavioural and physiological vulnerability factors that may exacerbate heat-related risks. Between October 2023 and February 2024, semi-structured interviews were conducted with 35 people with a clinical diagnosis of schizophrenia from in-patient and community settings. Participants had experienced the 2021 Heat Dome, or other extreme heat events, in a community setting within British Columbia, Canada. A descriptive form of thematic analysis that prioritizes participants' experiences was used to identify and explore patterns in the interview transcripts. Participants' narratives underscore how some symptoms of schizophrenia - such as paranoia and delusional thinking - may hinder participants' ability to seek relief from the heat and interpret bodily sensations accurately. Social isolation, compounded by societal stigma, acts as a significant barrier to accessing support networks and public resources for coping with extreme temperatures. Additionally, participants described feeling deterred from seeking medical care or public resources due to past negative experiences and social stigma. Findings illustrate various factors that contribute to the disproportionate impact of extreme heat on individuals diagnosed with schizophrenia, encapsulating both schizophrenia-specific biomedical factors as well as social vulnerability associated with their diagnosis. These findings can inform the development of a multidimensional approach that transcends individual responsibility and addresses the systemic and structural determinants of health.

The combined effects of sleep and extreme heat exposure on cognitive function among older adults

BACKGROUND

Extreme heat is linked to cognitive impairment. Normal sleep duration and good sleep quality can reduce cognitive impairment risks. However, the combined impact of sleep (duration and quality) and extreme heat on cognitive impairment is unclear. This study tests whether normal sleep duration and good sleep quality during a heatwave reduce cognitive impairment compared to poor sleep quality and long sleep duration in older adults.

METHODS

This study used cohort data from 9153 older adults. Extreme heat was defined as periods ≥ 3 days with daily minimum temperatures above the 92.5th percentile during the warm season. Cognitive function was assessed with the Mini-Mental State Examination (MMSE). Sleep duration was categorized as long, normal, or short, and sleep quality as good or poor. Six and four categories were used for combinations of heatwave exposure with sleep duration and quality, respectively. Cox regression models were applied for analysis.

RESULTS

Compared to those with long sleep duration during heatwaves, participants exposed to heatwaves with normal sleep duration had lower cognitive impairment risk (HR: 0.86, 95 %CI: 0.76-0.97). Those exposed to extreme heat with short sleep duration also showed lower cognitive risks (HR: 0.74, 95 %CI: 0.62-0.88). Compared to those with poor sleep quality during heatwave, participants with good sleep quality during heatwaves did not show significantly lower cognitive impairment risk (HR: 1.10, 95 %CI: 0.98-1.23).

CONCLUSION

Older adults with normal or short sleep duration during heatwaves may face lower cognitive impairment risks, highlighting the importance of sleep guidance to protect cognitive health during extreme heat.

Projecting the overall heat-related health burden and associated economic costs in a climate change context in Quebec, Canada

Extreme heat represents a major health risk for the world's population, that is amplified by climate change. However, the health costs associated with these heat events have only been little studied. To stimulate the implementation of effective interventions against extreme heat, a more comprehensive economic valuation of these health impacts is crucial. In this study, a general framework for assessing historical and projected heat-related health costs is presented and then applied to the province of Quebec (Canada). First, heat-related mortality and morbidity, as well as the number of extreme heatwaves, were computed for a historical (∼2000) and projected (∼2050) period under two shared socioeconomic pathways (SSP). Then, these heat-related numbers were converted into 1) direct healthcare costs, 2) indirect productivity costs and 3) intangible societal costs, using the best available cost information. Results showed that historical heat-related health costs were respectively 15M$, 5M$ and 3.6G$ (in 2019 Canadian dollars) annually for the direct, indirect and intangible components in Quebec, Canada. Under a middle-of-the-road scenario (SSP2-4.5), there was a 3-fold increase in total costs due to climate and population change (10.9G$ annually), while under a pessimistic scenario (SSP5-8.5), the increase was 5-fold (17.4G$). Total costs were mostly driven by intangible impacts, such as loss of life (∼90-95%) and of well-being during heatwaves (∼5-10%). Given that heat-related health costs are already significant, and likely to increase substantially in the future, this study has demonstrated the vital need to reduce its burden now and in the future by adopting more measures to mitigate climate change and adapt to heat.

The risk of hospitalization associated with hot nights and excess nighttime heat in a subtropical metropolis: a time-series study in Hong Kong, 2000-2019

Background

Recent studies showed increased mortality risks after hot nights, but their effect on hospitalizations, especially in vulnerable populations, remains under-studied.

Methods

Daily hospitalization, meteorological (including hourly), and air pollution data were collected for the hot seasons (May-October) of 2000-19 in Hong Kong. We derived three hot-night metrics: HNday28 °C, daily minimum temperature ≥28 °C, the governmental definition of hot nights; HNe, hot night excess calculated by summing heat excess of hourly temperatures above 28 °C at night; and HNday90th, hot nights classified using the 90th percentile HNe (17.7 °C⋅h) as a cutoff. We fitted time-series regression with distributed lag nonlinear models to examine the associations of hot-night metrics with various hospitalizations.

Findings

During the 3680 study days, 5,002,114 non-cancer non-external (NCNE) hospitalizations were recorded. Half (1874) of the days experienced excess nighttime heat (HNe>0) with a mean (SD) of 8.0 (6.8) °C⋅h; 499 and 187 hot nights were identified by HNday28 °C and HNday90th, respectively. Extreme HNe (99th percentile vs 0 °C⋅h) was significantly associated with increased NCNE hospitalizations over lag 0-4 days by 3.1% [95% confidence interval: 1.5%, 4.8%] overall, with enhanced effects in elderly (5.3% [3.2%, 7.4%]), low-SES individuals (5.3% [2.8%, 8.0%]), and circulatory admissions (3.4% [0.2%, 6.8%]). HNday90th, reflecting extreme HNe, better identified hazardous hot nights than the official HNday28 °C.

Interpretation

Excessive nighttime heat is significantly associated with increased hospitalizations, particularly affecting the elderly and socioeconomically disadvantaged individuals. Nighttime heat intensity should be incorporated in defining hot nights with public health relevance.

Funding

British Heart Foundation.

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 4 days). Using quasi-Poisson generalized linear models (GLMs), we estimated the risks (at lag 0 day) and cumulative effects (lag 0-10 days) 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 0 day and during lag 0-10 days. The impact of heatwave was significant at lag 0 day for schizophrenia, mood and neurotic disorders visits, it remained significant for neurotic and mood disorders visits during lag 0-10 days. Heatwave durations lasting more than 4 days were associated with higher relative risks of mental disorders at lag 0 day. Older adults had relatively higher effect estimations than younger individuals. This research highlights the effects of extreme heat on mental health.

Responding to the Heat and Planning for the Future: An Interview-Based Inquiry of People with Schizophrenia Who Experienced the 2021 Heat Dome in Canada

People with schizophrenia have died at disproportionately higher rates during recent extreme heat events (EHEs) in Canada, including the deadly 2021 Heat Dome in British Columbia (B.C.). However, to date, little research has qualitatively focused on how people with schizophrenia experience and respond to EHEs. This study aimed to (i) explore how people with schizophrenia experienced and were impacted by the 2021 Heat Dome physically, cognitively, and emotionally and (ii) understand their level of awareness and health-protective actions taken in response to the EHE. Between October 2023 and February 2024, interviews were conducted with 35 people with schizophrenia who experienced the 2021 Heat Dome in a community setting within B.C., Canada. The semi-structured interviews were guided by pre-defined questions to explore the participant's background, living situation, social network, awareness and access to heat-mitigation measures. The transcripts were analyzed using a descriptive form of thematic analysis. Participants shared critical insights on how the EHE impacted them, including descriptions of mild to severe physical manifestations of heat stress (e.g., fainting, heat rashes), the triggering of schizophrenia-related symptoms (e.g., paranoia, hallucinations), and the detrimental effects on their energy levels and emotional stability, which further caused disruptions to their everyday life. Participants also illustrated gaps in knowledge and challenges experienced with accessing information, which hindered their ability to manage the heat exposure effectively and, for some, resulted in no actions (or counter-intuitive actions) being taken to mitigate the heat. These findings demonstrate the complex ways that individuals with schizophrenia experienced and responded to the 2021 Heat Dome and revealed various situational and contextual factors that further compounded the challenge of heat mitigation. These findings can support the development of tailored individual and community-level heat response and communication initiatives and strategies for people with schizophrenia.

Private vs. public emergency visits for mental health due to heat: An indirect socioeconomic assessment of heat vulnerability and healthcare access, in Curitiba, Brazil

Few studies have explored the influence of socioeconomic status (SES) on the heat vulnerability of mental health (MH) patients. As individual socioeconomic data was unavailable, we aimed to fill this gap by using the healthcare system type as a proxy for SES. Brazilian national statistics indicate that public patients have lower SES than private. Therefore, we compared the risk of emergency department visits (EDVs) for MH between patients from both healthcare types. EDVs for MH disorders from all nine public (101,452 visits) and one large private facility (154,954) in Curitiba were assessed (2017-2021). Daily mean temperature was gathered and weighed from 3 stations. Distributed-lag non-linear model with quasi-Poisson (maximum 10-lags) was used to assess the risk. We stratified by private and public, age, and gender under moderate and extreme heat. Additionally, we calculated the attributable fraction (AF), which translates individual risks into population-representative burdens - especially useful for public policies. Random-effects meta-regression pooled the risk estimates between healthcare systems. Public patients showed significant risks immediately as temperatures started to increase. Their cumulative relative risk (RR) of MH-EDV was 7.5 % higher than the private patients (Q-Test 26.2 %) under moderate heat, suggesting their particular heat vulnerability. Differently, private patients showed significant risks only under extreme heat, when their RR became 4.3 % higher than public (Q-Test 6.2 %). These findings suggest that private patients have a relatively greater adaptation capacity to heat. However, when faced with extreme heat, their current adaptation means were potentially insufficient, so they needed and could access healthcare freely, unlike their public counterparts. MH patients would benefit from measures to reduce heat vulnerability and access barriers, increasing equity between the healthcare systems in Brazil. AF of EDVs due to extreme heat was 0.33 % (95%CI 0.16;0.50) for the total sample (859 EDVs). This corroborates that such broad population-level policies are urgently needed as climate change progresses.

Climate change and disorders of the nervous system

Anthropogenic climate change is affecting people's health, including those with neurological and psychiatric diseases. Currently, making inferences about the effect of climate change on neurological and psychiatric diseases is challenging because of an overall sparsity of data, differing study methods, paucity of detail regarding disease subtypes, little consideration of the effect of individual and population genetics, and widely differing geographical locations with the potential for regional influences. However, evidence suggests that the incidence, prevalence, and severity of many nervous system conditions (eg, stroke, neurological infections, and some mental health disorders) can be affected by climate change. The data show broad and complex adverse effects, especially of temperature extremes to which people are unaccustomed and wide diurnal temperature fluctuations. Protective measures might be possible through local forecasting. Few studies project the future effects of climate change on brain health, hindering policy developments. Robust studies on the threats from changing climate for people who have, or are at risk of developing, disorders of the nervous system are urgently needed.

Immediate and delayed effects of environmental temperature on schizophrenia admissions in Liuzhou, China, 2013-2020: a time series analysis

This study aimed to investigate the associations between environmental temperature and schizophrenia admissions in Liuzhou, China. A Poisson generalized linear model combined with a distributed lag nonlinear model was used to analyze the effects of daily mean temperature on schizophrenia admissions from 2013 to 2020 in Liuzhou. Additionally, subgroup analyses were conducted to investigate possible modifications stratified by gender, marital status, and age. In this study, 10,420 schizophrenia admissions were included. The relative risks of schizophrenia admissions increased as the temperature rose, and the lag effects of high temperature on schizophrenia admissions were observed when the daily mean temperature reached 21.65°C. The largest single effect was observed at lag0, while the largest cumulative effect was observed at lag6. The single effects of high temperatures on schizophrenia admissions were statistically significant in both males and females, but the cumulative effects were statistically significant only in males, with the greatest effect at lag0-7. The single effect of high temperatures on admissions for unmarried schizophrenics was greatest at lag5, while the maximum cumulative effect for unmarried schizophrenia was observed at lag0-7. The single effects of high temperatures on schizophrenia admissions were observed in those aged 0-20, 21-40, and 41-60. The cumulative effects for schizophrenics aged 21-40 were observed from lag0-3 to lag0-7, with the maximum effect at lag0-7. In conclusion, the risk of schizophrenia admissions increased as the environmental temperature increased. The schizophrenics who were unmarried appeared to be more vulnerable to the single and cumulative effects of high temperature.

Bane or boon regarding urbanicity and psychotic spectrum disorders: a scoping review of current evidence

PURPOSE OF REVIEW

This review aims to provide an update on the association between urbanization and psychotic spectrum disorders, focusing on specific aspects of the urban environment that could be a bane or boon for the risk of psychosis.

RECENT FINDINGS

Majority of the included studies support previous evidence suggesting that urbanization is linked to a higher risk of psychotic experiences and psychotic spectrum disorders. A small minority, however, have also found specific factors in the urban environment that could give rise to positive outcomes, such as better social functioning and lower mortality rates in psychotic spectrum disorders, or mitigate the risks associated with urbanization. The perception of the urban environment was also an important factor that increased or mitigated stress levels in patients with psychosis, which in turn affected their susceptibility to psychotic symptoms.

SUMMARY

Specific aspects of the urban environment such as the availability and density of greenspaces are crucial for mitigating the effect of urbanization on risk of psychotic spectrum disorders, and should be incorporated into urban planning. At the same time, there is a need to further explore how modifiable risk factors of the urban environment such as air and noise pollution can be minimized to allow for more liveable cities in the context of psychotic spectrum conditions.

The relationship between hot temperatures and hospital admissions for psychosis in adults diagnosed with schizophrenia: A case-crossover study in Quebec, Canada

INTRODUCTION

Some studies have found hot temperatures to be associated with exacerbations of schizophrenia, namely psychoses. As climate changes faster in Northern countries, our understanding of the association between temperature and hospital admissions (HA) for psychosis needs to be deepened.

OBJECTIVES

1) Among adults diagnosed with schizophrenia, measure the relationship between mean temperatures and HAs for psychosis during summer. 2) Determine the influence of individual and ecological characteristics on this relationship.

METHODS

A cohort of adults diagnosed with schizophrenia (n = 30,649) was assembled using Quebec's Integrated Chronic Disease Surveillance System (QICDSS). The follow-up spanned summers from 2001 to 2019, using hospital data from the QICDSS and meteorological data from the National Aeronautics and Space Administration's (NASA) Daymet database. In four geographic regions of the province of Quebec, a conditional logistic regression was used for the case-crossover analysis of the relationship between mean temperatures (at lags up to 6 days) and HAs for psychosis using a distributed lag non-linear model (DLNM). The analyses were adjusted for relative humidity, stratified according to individual (age, sex, and comorbidities) and ecological (material and social deprivation index and exposure to green space) factors, and then pooled through a meta-regression.

RESULTS

The statistical analyses revealed a statistically significant increase in HAs three days (lag 3) after elevated mean temperatures corresponding to the 90th percentile relative to a minimum morbidity temperature (MMT) (OR 1.040; 95% CI 1.008-1.074), while the cumulative effect over six days was not statistically significant (OR 1.052; 95% IC 0.993-1.114). Stratified analyses revealed non statistically significant gradients of increasing HAs relative to increasing material deprivation and decreasing green space levels.

CONCLUSIONS

The statistical analyses conducted in this project showed the pattern of admissions for psychosis after hot days. This finding could be useful to better plan health services in a rapidly changing climate.

Assessing the impact of climatic variability on acute respiratory diseases across diverse climatic zones in South Africa

Acute respiratory diseases are a significant public health concern in South Africa, with climatic variables such as temperature and rainfall being key influencers. This study investigates the associations between these variables and the prevalence of acute respiratory diseases in Johannesburg, Cape Town, and Gqeberha (Port Elizabeth), representing distinct climatic zones. Spearman's correlation analyses showed negative correlations in Johannesburg for respiratory disease claims with maximum temperature (r = -0.12, p < 0.0001) and mean temperature (r = -0.13, p < 0.0001), and a negative correlation with daily rainfall (r = -0.12, p < 0.0001). Cape Town demonstrated a negative correlation with maximum temperature (r = -0.18, p < 0.0001) and a positive correlation with rainfall (r = 0.08, p < 0.0001). Utilizing Distributed Lag Non-linear Models (DLNM), the study revealed that in Johannesburg, the relative risk (RR) of respiratory claims increases notably at temperatures below 12 °C, and again at a Tmax between 16 and 23 °C. The risk escalates further at >30 °C, although with a considerable error margin. For Cape Town, a stable level of moderate RR is seen from Tmax 15-24 °C, with a significant increase in RR and error margin above 30 °C. In Gqeberha, the DLNM results are less definitive, reflecting the city's moderate climate and year-round rainfall. The RR of acute respiratory diseases did not show clear patterns with temperature changes, with increasing error margins outside the 22 °C threshold. These findings emphasize the imperative for region-specific public health strategies that account for the complex, non-linear influences of climate on respiratory health. This detailed understanding of the climate-health nexus provides a robust basis for enhancing public health interventions and future research directed at reducing the impacts of climate factors.

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.

Association between greenspace exposure and suicide-related outcomes across the lifespan: A systematic review

A growing number of studies have linked greenspace exposure to suicide, but findings are inconsistent. We conducted a systematic review on the associations between greenspace exposure and suicide-related outcomes (namely, suicide mortality, self-harm, and suicidal ideation) up until January 6, 2023. We used the Mixed Methods Appraisal Tool (or MMAT) to assess the quality of the included studies. In total, 23 studies met our inclusion criteria, consisting of 14 ecological, four cross-sectional, three longitudinal, and two experimental studies. Most studies were published in 2022 and conducted in Europe (n = 10), Asia (n = 7), and North America (n = 5), with one worldwide analysis. Various indicators were used to assess greenspace exposure including objective measures (e.g., level of surrounding greenness, quantity, structural features, tree canopy coverage), and greenspace use (e.g., duration and frequency). Suicide mortality was the most studied outcome (n = 14). Quality assessment showed that most (87 %) of the included observational studies used representative samples. Protective associations of exposure to greenspace were reported for suicide mortality (9/14 or 64 %), self-harm (n = 3/5 or 60 %) and suicidal ideation (n = 4/6 or 67 %), with nine or 36 % studies reporting no association. Most of the included studies adjusted for key covariates such as age, sex, and socioeconomic status at various aggregate levels (e.g., household, city). For greenspace exposure and suicide mortality, studies stratified by sex (n = 10) showed larger protective associations for females (n = 7) than for males (n = 4). However, the included studies showed high heterogeneity in terms of exposure indicators and greenspace definitions. Experimental studies and studies using youth samples were rare. While more research is warranted, preliminary findings suggest protective associations between greenspace exposure and suicide-related outcomes.

Hospital admission tendencies caused by day-to-day temperature changes during summer: a case study for the city of Novi Sad (Serbia)

Increased temperature risk in cities threatens the health and well-being of urban population and is fueled by climate change and intensive urbanization. Consequently, further steps must be taken for assessing temperature conditions in cities and their association with public health, in order to improve public health prevention at local or regional level. This study contributes to solving the problems by analyzing the connection between extreme temperatures and the tendencies of all-cause hospital admissions. The analyses used (a) 1-h air temperature data, and (b) daily data of all-cause hospital admissions. The datasets include the summer period (June, July, August) for the years 2016 and 2017. We tested the effects of two temperature indices, day-to-day change in maximum temperature - T_max,c and daily temperature range - T_r, with all-cause hospital admission subgroups, such as all-cause cases - H_a, hospital admissions in the population below 65 - H_a<65, and hospital admissions in the population aged 65 and over - H_a≥65. The results show the highest values of H_a when T_max,c is between 6 and 10 °C. Therefore, more intensive hospital admissions can be expected when T_max increases from day-to-day (positive values of T_max,c), and it is more visible for H_a and H_a<65 (1 °C = 1% increase in hospital admissions). Also, T_r values between 10 °C and 14 °C cause an increase in the number of hospital admissions, and it is more noticeable for H_a≥65.