Stress in School. Some Empirical Hints on the Circadian Cortisol Rhythm of Children in Outdoor and Indoor Classes

Promoting adolescent sleep and circadian function: A narrative review on the importance of daylight access in schools

Adolescent sleep disturbances and circadian delays pose significant challenges to mood and daytime functioning. In this narrative review, we explore the impact of light on sleep and highlight the importance of monitoring and managing light exposure in adolescents throughout the day and night. The benefits of daylight exposure in mitigating sleep and circadian disruptions are well-established; however, interventions targeting access to daylight in adolescents remain understudied and underutilized. The primary aim of this narrative review is to bring attention to this gap in the literature and propose the need for institutional-level interventions that promote access to daylight, especially considering adolescents' early school start times and substantial time spent indoors on weekdays. School-led interventions, such as active commuting to school and outdoor curriculums, have promising effects on sleep and circadian rhythms. Additionally, practical measures to optimize natural light in classrooms, including managing blinds and designing conducive environments, should also be considered. While future studies are necessary to facilitate the implementation of interventions, the potential for these school-level interventions to support adolescent sleep health is evident. Aiming for integration of individual-level regulation and institutional-level intervention of light exposure is necessary for optimal outcomes.

Biodiversity and human health: A scoping review and examples of underrepresented linkages

Mounting evidence supports the connections between exposure to environmental typologies(such as green and blue spaces)and human health. However, the mechanistic links that connect biodiversity (the variety of life) and human health, and the extent of supporting evidence remain less clear. Here, we undertook a scoping review to map the links between biodiversity and human health and summarise the levels of associated evidence using an established weight of evidence framework. Distinct from other reviews, we provide additional context regarding the environment-microbiome-health axis, evaluate the environmental buffering pathway (e.g., biodiversity impacts on air pollution), and provide examples of three under- or minimally-represented linkages. The examples are (1) biodiversity and Indigenous Peoples' health, (2) biodiversity and urban social equity, and (3) biodiversity and COVID-19. We observed a moderate level of evidence to support the environmental microbiota-human health pathway and a moderate-high level of evidence to support broader nature pathways (e.g., greenspace) to various health outcomes, from stress reduction to enhanced wellbeing and improved social cohesion. However, studies of broader nature pathways did not typically include specific biodiversity metrics, indicating clear research gaps. Further research is required to understand the connections and causative pathways between biodiversity (e.g., using metrics such as taxonomy, diversity/richness, structure, and function) and health outcomes. There are well-established frameworks to assess the effects of broad classifications of nature on human health. These can assist future research in linking biodiversity metrics to human health outcomes. Our examples of underrepresented linkages highlight the roles of biodiversity and its loss on urban lived experiences, infectious diseases, and Indigenous Peoples' sovereignty and livelihoods. More research and awareness of these socioecological interconnections are needed.

The influence of screen time on behaviour and emotional problems among adolescents: A comparison study of the pre-, peak, and post-peak periods of COVID-19

The coronavirus disease 2019 (COVID-19) pandemic has brought drastic changes globally in the past three years, one of which is an increase in the use of digital media or electronic devices. Previous studies have shown that long screen time may stimulate the neurobiological system, resulting in various behavioural and emotional problems; however, there is insufficient population-based evidence. This study aimed to investigate the influence of screen time on behavioural and emotional problems in Indonesian adolescents at three time points: the pre-, peak, and post-peak periods of COVID-19. Data were collected using an online community mental health survey. This survey incorporated the Youth Screen Time Survey to gauge screen time and the adolescent version of the Strengths and Difficulties Questionnaire to assess emotional, conduct, and prosocial behaviour problems. The participants were adolescents in secondary and senior high schools, with 337, 423, and 1,096 participants from the pre-, peak-, and post-pandemic periods, respectively, included in the analysis. Daily average screen time was compared, followed by the calculation of odds ratios for screen time and mental health problems during the different periods. The results demonstrated significant differences in adolescents' total daily average screen time between the different pandemic periods. Decreased screen time was associated with reduced emotional, conduct, and prosocial behaviour problems, especially during the peak period. Thus, psychoeducation on screen time in adolescents should be considered as a point of interest for mental well-being interventions.

Communication, Cognition and Competency Development in Healthcare: A Model for Integrating Cognitive Ethnography and Communication Skills Training in Clinical Interventions

OBJECTIVES

The aim of this study was to conduct and evaluate the Blended Learning communication skills training program. The key objective was to investigate (i) how clinical intervention studies can be designed to include cognitive, organizational, and interactive processes, and (ii) how researchers and practitioners could work with integrated methods to support the desired change.

METHODS

The method combined design and implementation of a 12-week Blended Learning communication skills training program based on the Calgary-Cambridge Guide. The training was implemented in a patient clinic at a Danish university hospital and targeted all healthcare professionals at the clinic. Cognitive ethnography was used to document and evaluate healthcare professionals' implementation and individual competency development, and support the design of in-situ simulation training scenarios.

RESULTS

Thirteen participants completed the program. The synergy within the teams, as well as the opportunities for participants to coordinate, share, discuss, and reflect on the received knowledge with a colleague or on-site researcher, affected learning positively. The knowledge transfer process was affected by negative feedback loops, such as time shortages, issues with concept development and transfer, disjuncture between the expectations of participants and instructors of the overall course structure, as well as participant insecurity and a gradual loss of motivation and compliance.

CONCLUSION

We propose a novel 3-step model for clinical interventions based on our findings and literature review. This model will effectively support the implementation of educational interventions in health care by narrowing the theory-practice gap. It will also stimulate desired change in individual behavior and organizational culture over time. Furthermore, it will work for the benefit of the clinic and may be more suitable for the implementation of communication projects than, for example, randomized setups.

Spending time in the forest or the field: qualitative semi-structured interviews in a randomized controlled cross-over trial with highly sensitive persons

Introduction

The effects of spending time in forests have been subject to investigations in various countries around the world. Qualitative comparisons have been rarely done so far.

Methods

Sixteen healthy highly sensitive persons (SV12 score ≥ 18) aged between 18 and 70 years were randomly assigned to groups spending 1 h in the forest and in the field at intervals of one week. Semi-structured interviews were conducted after each intervention and analyzed using a mixed-methods approach of content analysis and grounded theory.

Results

Both natural environments induced feelings of inner calmness, inner cleansing, joy, freedom, connectedness, strengthening qualities, and heightened body awareness. The forest environment additionally offered emotional shelter, and showed advantages in promoting inner strength and self-concentration.

Discussion

People with previous negative experiences in the forest may feel safer in fields because of the wider view and better overview. Important preconditions are enough time and the absence of a judgmental authority. The two environments induced in part different but also similar emotions which might be useful to promote psychological well-being differentially.

Choice matters: Pupils' stress regulation, brain development and brain function in an outdoor education project

BACKGROUND

Education outside the classroom (EOtC) is considered beneficial to children's physical and mental health. Especially, stress resilience has been linked to nature experience.

AIMS

This study experimentally explored the effects of pupils' autonomy support (AUT) and physical activity (PA) on their biological stress responses and brain development in EOtC.

SAMPLE

The study comprised 48 fifth and sixth graders.

METHODS

The intervention consisted of one day/week taught in a forest over one school year. Structural magnetic resonance imaging (MRI) was conducted at the beginning and the end of the school year, functional MRI under a stress condition at the end. Regions of interest were amygdala, hippocampus and the anterior cingulate cortex (ACC). All other measures were obtained at the beginning, at mid-term and at the end of the school year. PA was measured using accelerometry. Cortisol levels were obtained three times during the examined school days. AUT was measured with a paper-based survey. Data were analysed using Bayesian multivariate models.

RESULTS

EOtC students exhibit more efficient regulation of biological stress-reactivity and show a reduction of cortisol over the day associated with light PA in the forest. Cortisol is further associated with amygdala activation in the stress condition. Cerebral structural change is best explained by age; however, AUT has a positive direct effect on the maturation of the ACC, which is stronger in EOtC.

CONCLUSIONS

Our results support the idea that autonomy supportive teaching fosters cerebral maturation and that EOtC can have a positive effect on biological stress regulation.

Lessons in a Green School Environment and in the Classroom: Effects on Students' Cognitive Functioning and Affect

The positive impact of short-term exposure to nature during a green recess in a school day is documented in the literature. In this study we investigated cognitive, academic, and affective effects of a single contact with nature during a regular school lesson in the greenness, compared to an usual classroom lesson, on young students in second and third grades (N = 65). In a within-subjects design, for the cognitive effects we examined children's (a) selective and sustained attention and (b) math calculation performance in common school tasks. For affective effects we considered (c) their positive and negative mood and (d) the perception of environmental restorativeness. Findings revealed that after a single lesson taught in the green school garden, children had greater selective attention and math calculation performance in two tasks than after a similar lesson in the classroom environment. Moreover, children with higher self-reported emotional difficulties showed greater selective attention and reported a statistically significant increase in positive affect and a tendency to a significant decrease in negative affect after the lesson in the greenness than in the classroom. Students also perceived the green space as more restorative than the classroom environment. Results are discussed against theories on the benefits of exposure to natural environments, highlighting the theoretical and practical significance of the study.

Children's Attentional Processes in Outdoor and Indoor Environments: The Role of Physiological Self-Regulation

Previous research has documented that exposure to green spaces has the beneficial effects of attention restoration and stress reduction. This study investigated the effects of indoor (classroom) and outdoor (green school garden) environments on attentional processes in interaction with emotion and physiological self-regulation. Children in third and fourth grades (n = 42) completed a school-related emotional Stroop task assessing the effects of outdoor and indoor classroom backgrounds when facing positive and negative stimuli. Children's attentional patterns in a task completed in both environments were also assessed. Heart rate variability was registered at rest as an index of physiological self-regulation. The results revealed that children were less distracted from negative emotional materials when presented with outdoor compared with indoor background stimuli. Greater selective attention and sustained attention were shown in the green than in the classroom environment. Moreover, sustained attention varied in relation to physiological self-regulation but only when performing the task indoor.

Dynamics of Erythroferrone Response to Erythropoietin in Rats

Background: Erythroferrone (ERFE) is a hormone identified recently as a master regulator connecting iron homeostasis and erythropoiesis. Serum ERFE concentrations significantly increase in animals and humans with normal or impaired kidney function after receiving exogenous erythropoiesis-stimulating agents (ESAs), which suggests it might be a predictive factor for erythropoiesis. To evaluate whether ERFE is an early, sensitive biomarker for long-term erythropoietic effects of ESAs, we investigated the relationship between ERFE dynamics and time courses of major erythropoietic responses to ESA treatment. Methods: Healthy rats received single dose and multiple doses (thrice a week for 2 weeks) of recombinant human erythropoietin (rHuEPO) at three dose levels (100, 450, and 1350 IU/kg) intravenously. The rHuEPO and ERFE concentrations in plasma were determined at a series of time points after dosing. Erythropoietic effects including red blood cell count and hemoglobin concentrations were continuously monitored for 24 days (single dose) or 60 days (multiple doses). The expansion of erythroblasts in bone marrow was quantified by flow cytometry analysis. Results: ERFE significantly increased within a few hours and return to baseline at 24 h after rHuEPO treatment. The ERFE response was enhanced after repeated treatment, which was consistent with the observed expansion of erythroblasts in the bone marrow. In addition, the dynamics of ERFE showed double peaks at approximately 2 and 10 h after rHuEPO stimulation, and the ERFE baseline displayed a significant circadian rhythm. There was a strong positive correlation between peak values of short-term ERFE responses and the long-term hemoglobin responses. Conclusion: The stimulated release of ERFE is a rapid process within 24 h. The second peak in the ERFE response to rHuEPO suggests the presence of a feedback mechanism counterregulating the ESA stimulation. The early increase of ERFE at 2 h appears to be a predictor of the hemoglobin response at 14 days after single dose of rHuEPO. Under multiple-dose regimen, the enhanced ERFE responses still correlate with the peak hemoglobin responses. The ERFE baseline also exhibits a circadian rhythm.

The Potential for Outdoor Nature-Based Interventions in the Treatment and Prevention of Depression

There is growing interest in nature-based interventions (NBI) to improve human health and wellbeing. An important nascent area is exploring the potential of outdoor therapies to treat and prevent common mental health problems like depression. In this conceptual analysis on the nature-depression nexus, we distil some of the main issues for consideration when NBIs for depression are being developed. We argue that understanding the mechanisms, or 'active ingredients' in NBIs is crucial to understand what works and for whom. Successfully identifying modifiable mediating intervention targets will pave the way for interventions with increased efficacy. We highlight a non-exhaustive list of five clinically relevant putative, candidate mechanisms which may underly the beneficial effects of NBIs on depression: stress, rumination, mindfulness, sleep and exercise. We also make the case that when developing NBIs it is important to not neglect young people, explore personalised approaches and focus on both treatment and prevention approaches. To achieve these aims methodologically rigorous programmes of clinical research are needed that include well-powered and controlled experimental designs including randomised controlled trials, qualitative research, longitudinal studies and large prospective cohorts.

Effects of Nature (Greenspace) on Cognitive Functioning in School Children and Adolescents: a Systematic Review

There is growing interest in understanding the extent to which natural environments can influence learning particularly in school contexts. Nature has the potential to relieve cognitive overload, reduce stress and increase wellbeing—all factors that are conducive to learning. This paper provides a PRISMA-guided systematic review of the literature examining the effects of nature interventions on the cognitive functioning of young people aged 5 to 18 years. Examples of nature interventions include outdoor learning, green playgrounds, walks in nature, plants in classrooms and nature views from classroom windows. These can vary in duration and level of interaction (passive or active). Experimental and quasi-experimental studies with comparison groups that employed standardized cognitive measures were selected, yielding 12 studies from 11 papers. Included studies were rated as being of high (n = 10) or moderate quality (n = 2) and most involved short-term nature interventions. Results provide substantial support for cognitive benefits of nature interventions regarding selective attention, sustained attention and working memory. Underlying mechanisms for the benefits were also explored, including enhanced wellbeing, cognitive restoration and stress reduction—all likely to be contributors to the nature-cognition relationship. The cognitive effects of nature interventions were also examined according to age and school level with some differences evident. Findings from this systematic review show promise that providing young people with opportunities to connect with nature, particularly in educational settings, can be conducive to enhanced cognitive functioning. Schools are well placed to provide much needed ‘green’ educational settings and experiences to assist with relieving cognitive overload and stress and to optimize wellbeing and learning.

Methodological Considerations for Movement Education Interventions in Natural Environments for Primary School Children: A Scoping Review

Background: Education is the ideal setting for carrying out projects to improve primary students’ capacities. In recent years, interventions in natural environments have been more frequently proposed, but there is still a lack of standardization, making deeper study of the topic necessary. This review aims to report on what previous scientific research has been carried out, and eventually, to propose standard operating procedures for future interventions. Methods: This is a scoping review that adopted the PRISMA guidelines. Primary school children have been included, and the interventions had to be proposed adopting nature as the primary element of the learning process. Results: A total of 19 studies have been included, and a wide range of methodological differences has been detected regarding the included intervention protocols. Conclusions: Learning in nature is a feasible intervention that, despite the high heterogeneity of interventions, demonstrates positive outcomes in the learning sphere of children.

Impact of Thermal Dissipation on the Lighting Performance and Useful Life of LED Luminaires Applied to Urban Lighting: A Case Study

Currently, LED technology is an established form of lighting in our cities and homes. Its lighting performance, durability, energy efficiency and light, together with the economic savings that its use implies, are displacing other classic forms of lighting. However, some problems associated with the durability of the equipment related to the problems of thermal dissipation and high temperature have begun to be detected, which end up affecting their luminous intensity and the useful life. There are many studies that show a direct relationship between the low quality of LED lighting and the aging of the equipment or its overheating, observing the depreciation of the intensity of the light and the visual chromaticity performance that can affect the health of users by altering circadian rhythms. On the other hand, the shortened useful life of the luminaires due to thermal stress has a direct impact on the LCA (Life Cycle Analysis) and its environmental impact, which indirectly affects human health. The purpose of this article is to compare the results previously obtained, at different contour temperatures, by theoretical thermal simulation of the 3D model of LED street lighting luminaires through the ANSYS Fluent simulation software. Contrasting these results with the practical results obtained with a thermal imaging camera, the study shows how the phenomenon of thermal dissipation plays a fundamental role in the lighting performance of LED technology. The parameter studied in this work is junction temperature (T_j), and how it can be used to predict the luminous properties in the design phase of luminaires in order to increase their useful life.

Get Outside! Promoting Adolescent Health through Outdoor After-School Activity

BACKGROUND

The Get Outside: After School Activity Program (GO-ASAP) exemplifies how a rural community can utilize its natural resources and community partnerships to promote adolescent health.

METHODS

A qualitative descriptive inquiry was conducted using convenience sampling. Data were collected from students (n = 13/2018; n = 13/2019) via focus group and art-based method (2018 only) and parent (n = 6/2018) focus group. Data were analyzed via qualitative content analysis using the applied theoretical frameworks of Social Cognitive Theory and Social Determination Theory.

RESULTS

(1) Increasing Health-Related Competencies. Students increased their physical activity, improved their sleep, perceived less stress, and reported changes in dietary habits and electronic use. (2) Increasing Social Relatedness. Students made new friends, felt more connected, and spent less time home alone after school. (3) Increasing Autonomy and Intrinsic Motivation. Students recognized their emerging capabilities, and their increased confidence stimulated more action-oriented behavior. Parent-perceived changes support and mirror student reports.

CONCLUSION

Outdoor, nature-based, activity programs are a novel upstream approach to promote adolescent health, especially in rural communities where natural resources often exceed health-service resources and community partnerships are a way of life.

Nature’s Services and Contributions: The Relational Value of Childhood Nature Experience and the Importance of Reciprocity

People depend on functioning ecosystems to meet human needs and support well-being across the life span. This article considers the interest in ecosystem service valuation, the growing interest in the benefits of nature experience for children, and ways to bridge these perspectives. We focus on embodied childhood nature experiences: the physical and multisensory experiences that intertwine child and nature. Additionally, we highlight the reciprocal quality of nature and child experience relationship as an example of how this relationship goes beyond the instrumental and demonstrates relational value. Underlying this perspective is the belief that children need to be better represented in the perception and action of ecosystem valuation in environmental policy.

Greenspace Interventions, Stress and Cortisol: A Scoping Review

Background: Engaging with nature can profoundly impact psychological and physiological health of persons across the lifespan. Greenspace interventions (GSI) encompass a broad range of strategic, nature-based activities for overall health and wellbeing. Within the past 20 years there has been a growing interest in the access to and management of greenspace to mediate the deleterious impact of acute and chronic stress, particularly, physiologic biomarkers of stress such as cortisol. Objective: This review aims to describe the impact of greenspace interventions on cortisol, to present the current state of the science on GSIs as they impact cortisol, and to uncover any limitations of current research strategies to best inform future research. Methods: A scoping methodology was conducted to systematically study this emerging field and inform future research by mapping the literature based on the GSI category, interventional design, cortisol metrics, and subsequent analysis of cortisol. Conclusion: Considerable heterogeneity in research design, aim(s), interventional strategy, and cortisol metrics were identified from a total of 18 studies on GSIs and cortisol outcomes. While studies demonstrated a potential for the positive association between GSIs and stress relief, more rigorous research is needed to represent GSIs as an intervention to mitigate risks of stress.

Landscapes of becoming social: A systematic review of evidence for associations and pathways between interactions with nature and socioemotional development in children

BACKGROUND

Existing research indicates that spending time in nature is associated with diverse aspects of children's health and wellbeing. Although fundamental to later life chances and health, no systematic reviews, to our knowledge, have focused specifically on the effects of interaction with nature on socioemotional functioning in childhood.

OBJECTIVES

Amongst children, what is the consistency of associations between the availability of or spending time in nature on socioemotional function and development? Furthermore, which child behaviours and states independently associate with socioemotional function and availability of or spending time in nature, and what is the consistency of associations between these behaviours and states and contact with nature?

DATA SOURCES

Embase, Environment Complete, MEDLINE, and APA PsycINFO. Eligible studies were backward and forward snowball-searched.

STUDY ELIGIBILITY CRITERIA

Studies investigating effects of, or associations between, availability of or interaction with nature on socioemotional or proximal outcomes in children under the age of 12 years were included in this review.

STUDY APPRAISAL AND SYNTHESIS METHODS

The internal validity of studies investigating socioemotional outcomes were based on assessments of elements of study design, conduct, and reporting to identify potential issues related to confounding or other biases. The number of analyses indicating positive, negative, and non-significant associations between availability or interaction with green space and the outcomes were summed.

RESULTS

A total of 223 eligible full-texts, of which 43 pertained to socioemotional outcomes and 180 to proximal outcomes, met eligibility criteria. Positive associations between availability of and spending time in green space were found with children's intra- and interpersonal socioemotional function and development. Proportions of positive findings ranged from 13.9% to 55% across experimental and observational research, exposures, populations, and contexts. Modifying and mediating factors were identified. We found consistent evidence for improved aspects of cognition and, for children over six years, reduced risk of obesity and overweight in association with green space; consistent links between movement behaviours in the experimental, but not observational research; tentative trends suggesting associations with play, motor skills, language, screen time, and communication skills; little evidence for positive associations between green space and mood, physical wellbeing, and stress; some evidence for associations with healthy birth outcomes, and little evidence for direct associations between availability of green space and asthma and allergy prevalence, however, mediation via, for example, air pollution was likely.

LIMITATIONS

We identified few studies without either probable or severe risk of bias in at least one item. Improved study quality may therefore result in different results. Restricting analyses to include only studies considered at low risk of bias indicated similar or slightly lower proportions of positive findings. Risk of bias in proximal outcomes was not assessed.

CONCLUSIONS

The empirical evidence for benefits of availability of and interaction green space for child socioemotional function and development must currently be considered limited. A number of proximal indicators were identified. Systematic review registration number.

PROSPERO ID

CRD42019135016.

Adverse Childhood Experiences: The Protective and Therapeutic Potential of Nature

Adverse childhood experiences (ACEs) are prevalent in many western populations. Large studies have put the likelihood of having at least one ACE above 50% of the general population. ACEs and the associated experience of chronic stress, moreover, have been consistently linked with a variety of negative physical and psychological health outcomes across the lifespan from behavioral problems and cognitive difficulties early on, to greater chance of suffering from a mental health disorder and engaging in self destructing behaviors. The literature puts forward several protective factors, such as mother-child relations, parental health, and community engagement. In this perspective paper we put forward the potential of regular nature engagement as a possible additional protective factor. Nature's therapeutic potential has been well documented, for many psychopathologies and mental health difficulties. Yet studies looking at the protective and therapeutic potential of nature with people with ACEs are remarkably limited in numbers. In this perspective piece we conduct a search of the literature to find previous applications of nature as a protective or therapeutic intervention for people with ACEs. We highlight the gap in the current literature, and put forward various mechanisms of action that justify a closer exploration of this area in further research.

Psychological impacts of "screen time" and "green time" for children and adolescents: A systematic scoping review

Technological developments in recent decades have increased young people's engagement with screen-based technologies (screen time), and a reduction in young people's contact with nature (green time) has been observed concurrently. This combination of high screen time and low green time may affect mental health and well-being. The aim of this systematic scoping review was to collate evidence assessing associations between screen time, green time, and psychological outcomes (including mental health, cognitive functioning, and academic achievement) for young children (<5 years), schoolchildren (5-11 years), early adolescents (12-14 years), and older adolescents (15-18 years). Original quantitative studies were identified in four databases (PubMed, PsycInfo, Scopus, Embase), resulting in 186 eligible studies. A third of included studies were undertaken in Europe and almost as many in the United States. The majority of studies were cross-sectional (62%). In general, high levels of screen time appeared to be associated with unfavourable psychological outcomes while green time appeared to be associated with favourable psychological outcomes. The ways screen time and green time were conceptualised and measured were highly heterogeneous, limiting the ability to synthesise the literature. The preponderance of cross-sectional studies with broadly similar findings, despite heterogeneous exposure measures, suggested results were not artefacts. However, additional high-quality longitudinal studies and randomised controlled trials are needed to make a compelling case for causal relationships. Different developmental stages appeared to shape which exposures and outcomes were salient. Young people from low socioeconomic backgrounds may be disproportionately affected by high screen time and low green time. Future research should distinguish between passive and interactive screen activities, and incidental versus purposive exposure to nature. Few studies considered screen time and green time together, and possible reciprocal psychological effects. However, there is preliminary evidence that green time could buffer consequences of high screen time, therefore nature may be an under-utilised public health resource for youth psychological well-being in a high-tech era.

Sociodemographic and Environmental Determinants of Indoor Versus Outdoor Active Play Among Children Living in the Washington, DC Area

BACKGROUND

Sociodemographic and environmental factors play important roles in determining both indoor and outdoor play activities in children.

METHODS

The Built Environment and Active Play Study assessed neighborhood playability for children (7-12 y), based on parental report of their children's active play behaviors, neighborhood characteristics, and geographic locations. Simple logistic regression modeling tested the associations between sociodemographic characteristics and the frequency of and access to venues for indoor and outdoor play.

RESULTS

Children of higher socioeconomic status were almost 3 times more likely to live more than a 30-minute walk from indoor recreational facilities compared with their less affluent peers (odds ratio [OR] = 2.9; 95% confidence interval [CI], 1.2-6.8). Non-Hispanic black children were less likely to live more than 30 minutes from indoor facilities (OR = 0.21; 95% CI, 0.08-0.57) and more were likely to engage in indoor activity (OR = 3.40; 95% CI, 1.17-9.88) than were white children. Boys were substantially more likely to play outdoors at a playing fields compared with girls (OR = 5.37; 95% CI, 2.10-13.69).

CONCLUSIONS

Findings from this study could be used to enhance indoor and outdoor activity spaces for children and to reduce disparities in access to such spaces.

Effects of forest bathing (shinrin-yoku) on levels of cortisol as a stress biomarker: a systematic review and meta-analysis

Forest bathing is a traditional practice characterized by visiting a forest and breathing its air. This review aims to investigate the effects of forest bathing on levels of salivary or serum cortisol as a stress biomarker in order to understand whether forest bathing can reduce stress. Medline/PubMed, Embase, Scopus, Web of Science, Cochrane Library, and Google Scholar were systematically searched for relevant articles. The quality of included trials was assessed following the criteria of the NIH dedicated tools. Afterwards, a qualitative and quantitative synthesis of retrieved evidence was performed. A total of 971 articles were screened; 22 of them were included in the systematic review and 8 in the meta-analysis. In all but two included studies, cortisol levels were significantly lower after intervention in forest groups if compared with control/comparison groups, or a significant pre-post reduction of cortisol levels was reported in the forest groups. The main results of the meta-analysis showed that salivary cortisol levels were significantly lower in the forest groups compared with the urban groups both before (MD = - 0.08 μg/dl [95% CI - 0.11 to - 0.05 μg/dl]; p < 0.01; I² = 46%) and after intervention (MD = - 0.05 μg/dl [95% CI - 0.06 to - 0.04 μg/dl]; p < 0.01; I² = 88%). Overall, forest bathing can significantly influence cortisol levels on a short term in such a way as to reduce stress, and anticipated placebo effects can play an important role in it. Further research is advised because of the limited available data.

Immersive Nature-Experiences as Health Promotion Interventions for Healthy, Vulnerable, and Sick Populations? A Systematic Review and Appraisal of Controlled Studies

In this systematic review, we summarized and evaluated the evidence for effects of, and associations between, immersive nature-experience on mental, physical, and social health promotion outcomes. Immersive nature-experience was operationalized as non-competitive activities, both sedentary and active, occurring in natural environments removed from everyday environments. We defined health according to the World Health Organization's holistic and positive definition of health and included steady-state, intermediate, and health promotion outcomes. An electronic search was performed for Danish, English, German, Norwegian, and Swedish articles published between January 2004 and May 2017. Manual approaches, e.g., bibliographies from experts, supplemented the literature search. Data were extracted from 461 publications that met the inclusion criteria. To assess the status and quality of the evidence for health promotion effects of immersive nature-experience, we focused on the subset of studies based on controlled designs (n = 133). Outcome level quality of the evidence was assessed narratively. Interventions most often involved adventure-based activities, short-termed walking, and seated relaxation in natural environments. We found positive effects on a range of health promotion outcomes grouped under psychological wellbeing (n = 97; ≈55% positive; ≈13% mixed; ≈29% non-significant; 2% negative); psychosocial function (n = 67; ≈61% positive; ≈9% mixed; ≈30% non-significant); psychophysiological stress response (n = 50; ≈58% positive; ≈18% mixed; ≈24% non-significant), and cognitive performance (n = 36; ≈58% positive; ≈6% mixed; ≈33% non-significant; 3% negative); and social skills and relationships (n = 34; ≈70% positive; ≈7% mixed; ≈22% non-significant). Findings related to outcomes categorized under physical health, e.g., risk of cardiovascular disease, were less consistent (n = 51; ≈37% positive; ≈28% mixed; ≈35% non-significant). Across the types of interventions and outcomes, the quality of the evidence was deemed low and occasionally moderate. In the review, we identify, discuss, and present possible solutions to four core methodological challenges associated with investigating immersive nature-experience and health outcomes: (1) intervention and program complexity; (2) feasibility and desirability of randomization; (3) blinding of participants and researchers; and (4) transferability and generalizability. The results of the review have been published as a popular-scientific report and a scientific research overview, both in Danish language.

Children's Cortisol and Cell-Free DNA Trajectories in Relation to Sedentary Behavior and Physical Activity in School: A Pilot Study

The worldwide prevalence of mental disorders in children and adolescents increased constantly. Additionally, the recommended amount of physical activity (PA) is not achieved by this age group. These circumstances are associated with negative impacts on their health status in later life and can lead to public health issues. The exposure to natural green environments (NGE) seems to be beneficial for human health. The compulsory school system offers great opportunities to reach every child with suitable health-related contents and interventions at an early stage. The concept of Education Outside the Classroom (EOtC) uses NGE and sets focus on PA. Therefore, EOtC might be a beneficial educational intervention to promote students health. The association between biological stress markers and sedentary behavior (SB) plus PA is insufficiently evaluated in school settings. This exploratory study aims to evaluate the association between students' cortisol, plus circulating cell-free deoxyribonucleic acid (cfDNA) levels, and their SB, light PA (LPA), and moderate-to-vigorous PA (MVPA). We assessed data from an EOtC program (intervention group [IG], n = 37; control group [CG], n = 11) in three seasons (fall/spring/summer) in outdoor lessons (IG) in a NGE and normal indoor lessons (CG). SB and PA were evaluated by accelerometry, and cortisol and cfDNA levels by saliva samples. Fitted Bayesian hierarchical linear models evaluated the association between cortisol and cfDNA, and compositional SB/LPA/MVPA. A steady decline of cortisol in the IG is associated with relatively high levels of LPA (posterior mean = −0.728; credible interval [CRI 95%]: −1.268; −0.190). SB and MVPA tended to exhibit a similar effect in the CG. A high amount of cfDNA is positively associated with a relatively high amount of SB in the IG (posterior mean, 1.285; CRI: 0.390; 2.191), the same association is likely for LPA and MVPA in both groups. To conclude, LPA seems to support a healthy cortisol decrease in children during outdoor lessons in NGEs. Associations between cfDNA and SB/PA need to be evaluated in further research. This study facilitates the formulation of straightforward and directed hypotheses for further research with a focus on the potential health promotion of EOtC.

Do Experiences With Nature Promote Learning? Converging Evidence of a Cause-and-Effect Relationship

Do experiences with nature - from wilderness backpacking to plants in a preschool, to a wetland lesson on frogs-promote learning? Until recently, claims outstripped evidence on this question. But the field has matured, not only substantiating previously unwarranted claims but deepening our understanding of the cause-and-effect relationship between nature and learning. Hundreds of studies now bear on this question, and converging evidence strongly suggests that experiences of nature boost academic learning, personal development, and environmental stewardship. This brief integrative review summarizes recent advances and the current state of our understanding. The research on personal development and environmental stewardship is compelling although not quantitative. Report after report - from independent observers as well as participants themselves - indicate shifts in perseverance, problem solving, critical thinking, leadership, teamwork, and resilience. Similarly, over fifty studies point to nature playing a key role in the development of pro-environmental behavior, particularly by fostering an emotional connection to nature. In academic contexts, nature-based instruction outperforms traditional instruction. The evidence here is particularly strong, including experimental evidence; evidence across a wide range of samples and instructional approaches; outcomes such as standardized test scores and graduation rates; and evidence for specific explanatory mechanisms and active ingredients. Nature may promote learning by improving learners' attention, levels of stress, self-discipline, interest and enjoyment in learning, and physical activity and fitness. Nature also appears to provide a calmer, quieter, safer context for learning; a warmer, more cooperative context for learning; and a combination of "loose parts" and autonomy that fosters developmentally beneficial forms of play. It is time to take nature seriously as a resource for learning - particularly for students not effectively reached by traditional instruction.

Stress Response and Cognitive Performance Modulation in Classroom versus Natural Environments: A Quasi-Experimental Pilot Study with Children

Stress during childhood can have mental and somatic health influences that track throughout life. Previous research attributes stress-reducing effects to natural environments, but has mainly focused on adults and often following leisurely relaxation in natural environments. This pilot study explores the impact of natural environments on stress response during rest and mental load and cognitive performance in 47 children aged 10–12 years in a school context. Heart rate variability measures indexing tonic, event, and phasic vagal tone and attention scores were compared across classroom and natural environments. Tonic vagal tone was higher in the natural environment than the classrooms, but no differences were found in event or phasic vagal tone or cognitive performance measures. These findings suggest a situational aspect of the conditions under which natural environments may give rise to stress-buffering influences. Further research is warranted to understand the potential benefits in a real-life context, in particular with respect to the underpinning mechanisms and effects of accumulated exposure over time in settings where children spend large proportions of time in natural environments.

Do Lessons in Nature Boost Subsequent Classroom Engagement? Refueling Students in Flight

Teachers wishing to offer lessons in nature may hold back for fear of leaving students keyed up and unable to concentrate in subsequent, indoor lessons. This study tested the hypothesis that lessons in nature have positive—not negative—aftereffects on subsequent classroom engagement. Using carefully matched pairs of lessons (one in a relatively natural outdoor setting and one indoors), we observed subsequent classroom engagement during an indoor instructional period, replicating these comparisons over 10 different topics and weeks in the school year, in each of two third grade classrooms. Pairs were roughly balanced in how often the outdoor lesson preceded or followed the classroom lesson. Classroom engagement was significantly better after lessons in nature than after their matched counterparts for four of the five measures developed for this study: teacher ratings; third-party tallies of “redirects” (the number of times the teacher stopped instruction to direct student attention back onto the task at hand); independent, photo-based ratings made blind to condition; and a composite index each showed a nature advantage; student ratings did not. This nature advantage held across different teachers and held equally over the initial and final 5 weeks of lessons. And the magnitude of the advantage was large. In 48 out of 100 paired comparisons, the nature lesson was a full standard deviation better than its classroom counterpart; in 20 of the 48, the nature lesson was over two standard deviations better. The rate of “redirects” was cut almost in half after a lesson in nature, allowing teachers to teach for longer periods uninterrupted. Because the pairs of lessons were matched on teacher, class (students and classroom), topic, teaching style, week of the semester, and time of day, the advantage of the nature-based lessons could not be attributed to any of these factors. It appears that, far from leaving students too keyed up to concentrate afterward, lessons in nature may actually leave students more able to engage in the next lesson, even as students are also learning the material at hand. Such “refueling in flight” argues for including more lessons in nature in formal education.

Diurnal Changes in Distribution Characteristics of Salivary Cortisol and Immunoglobulin A Concentrations

Salivary cortisol and secretory immunoglobulin A (S-IgA) are important biomarkers for environmental and public health research. The present study investigated the diurnal variations of these salivary biomarkers, with a focus on the change of distribution characteristics (i.e., skewness and kurtosis) of the concentrations. The participants in this study were 113 healthy young males. Salivary samples were collected in the morning (6:30–7:30 a.m.) and afternoon (1:00–4:00 p.m.). The skewness and kurtosis of salivary cortisol concentrations in afternoon samples (skewness = 1.06, kurtosis = 4.78) were significantly higher than those in morning samples (skewness = 0.49, kurtosis = 2.80). The differences in skewness and kurtosis of S-IgA concentrations were non-significant; however, the standard deviation and interquartile ranges for afternoon S-IgA concentrations were significantly smaller than those for morning S-IgA concentrations. Logarithmic transformation improved the distribution of afternoon cortisol values, making it an almost normal distribution, but the transformation showed no improvement in the distribution of morning cortisol or S-IgA values. The present study explored diurnal changes in the distribution characteristics of salivary cortisol and S-IgA. Consideration of a possible diurnal change in the distribution characteristics is needed when we compare the difference in these salivary biomarkers between different times of day.