The neighbourhood natural environment is associated with asthma in children: A birth cohort study

Effects of climate and environmental factors on childhood and adolescent asthma: A systematic review based on spatial and temporal analysis evidence

BACKGROUND

Asthma is a prevalent chronic respiratory disease among children, influenced by various climate and environmental factors. Despite its prevalence, the specific effects of these factors on asthma remain unclear. This study aims to systematically assess the epidemiological evidence using spatial and temporal methods on the impact of climate and environmental factors on childhood asthma.

METHODS

A systematic review was conducted to analyse the impact of climate and environmental factors on childhood asthma and wheezing, focusing on spatial and temporal trends. Searches were carried out in PubMed, Embase, and CINAHL databases for studies published from January 2000 to April 2024, using key search terms 'asthma/wheezing', 'extreme weather, 'green space', 'air pollution' and 'spatial or temporal analyses".

RESULTS

The systematic review analysed 28 studies, with six employing spatial and 22 using temporal analysis methods; however, none incorporated spatio-temporal analysis in their models. The findings reveal that extreme weather events, including heatwaves and heavy rainfall, elevate childhood asthma risks across various climates, with significant effects observed during summer and winter months. Dust storms in arid and subtropical regions are linked to immediate spikes in hospital admissions due to asthma exacerbations. The effects of green spaces on childhood asthma are mixed, with some studies indicating protective effects while others suggest increased risks, influenced by local environmental factors. Air pollutants such as PM2.5, NO2, and ozone can exacerbate asthma symptoms and along with other environmental factors, contribute to seasonal effects. High temperatures generally correlate with increased asthma risks, though the effects vary by age, sex, and climate.

CONCLUSION

Future research should integrate spatial and temporal methods to better understand the effects of environmental and climate changes on childhood asthma.

Association of antenatal and early childhood air pollution and greenspace exposures with respiratory pathogen upper airway acquisitions and respiratory health outcomes

The association of air pollution and greenspace with respiratory pathogen acquisition and respiratory health was investigated in a community-based birth-cohort of 158 Australian children. Weekly nasal swabs and daily symptom-diaries were collected for 2-years, with annual reviews from ages 3-7-years. Annual exposure to fine-particulate-matter (PM2.5), nitrogen-dioxide (NO2), and normalised-difference-vegetation-index (NDVI) was estimated for pregnancy and the first 2-years-of-life. We examined rhinovirus, any respiratory virus, Streptococcus pneumoniae, Moraxella catarrhalis, and Haemophilus influenzae detections in the first 3-months-of-life, age at initial pathogen detection, wheezing in the first 2-years, and asthma at ages 5-7-years. Our findings suggest that higher NDVI was associated with fewer viral and M. catarrhalis detections in the first 3-months, while increased PM2.5 and NO2 were linked to earlier symptomatic rhinovirus and H. influenzae detections, respectively. However, no associations were observed with wheezing or asthma. Early-life exposure to air pollution and greenspace may influence early-life respiratory pathogen acquisition and illness.  .

Associations of the planetary health diet index (PHDI) with asthma: the mediating role of body mass index

BACKGROUND

Given the global shifts in environmental conditions and dietary habits, understanding the potential impact of dietary factors and body mass index (BMI) on respiratory diseases, including asthma, is paramount. Investigating these relationships can contribute to the formulation of more effective prevention strategies. The Planetary Health Diet Index (PHDI), a dietary scoring system that balances human health with environmental sustainability, underscores the importance of increasing the consumption of plant-based foods while reducing the intake of red meat, sugar, and highly processed foods. The objective of this study was to assess the association between PHDI and the prevalence of asthma and the mediation effect of BMI in a US general population.

METHODS

This study utilized data from 32,388 participants in the National Health and Nutrition Examination Survey (NHANES) spanning from 2005 to 2018. Multivariate logistic regression and weighted quantile sum (WQS) regressions were employed to investigate the association between PHDI, individual nutrients, and asthma. Restricted cubic spline (RCS) analysis explored the linear or non-linear relationship between PHDI and asthma. Interaction analyses were conducted on subgroups to validate the findings. Mediation analysis was performed to examine the effect of BMI on the relationship between PHDI and asthma.

RESULTS

There was a significant negative association between PHDI and asthma. After adjusting for covariates, for every 10-point increase in PHDI, there was a 4% decrease in the prevalence of asthma (P = 0.025). Moreover, as PHDI increased, there was a trend towards lower asthma prevalence (P for trend < 0.05). WQS analyses showed consistent associations (OR = 0.93, 95%CI: 0.88, 0.98), with Fiber, Vitamin C, and Protein significant factors. The dose-response curve indicated a linear association between PHDI and asthma, with higher PHDI associated with lower asthma prevalence. Additionally, BMI is significantly positively associated with asthma (P < 0.001), and BMI decreases as the PHDI increases (β = -0.64, P < 0.001). Mediation analysis indicates that BMI significantly mediates the relationship between PHDI and asthma, with a mediation proportion of 33.85% (P < 0.001).

CONCLUSION

The results of this study show a strong negative correlation between PHDI and the prevalence of asthma. In addition, BMI mediated this negative relationship.

EAACI guidelines on environmental science for allergy and asthma: The impact of short-term exposure to outdoor air pollutants on asthma-related outcomes and recommendations for mitigation measures

The EAACI Guidelines on the impact of short-term exposure to outdoor pollutants on asthma-related outcomes provide recommendations for prevention, patient care and mitigation in a framework supporting rational decisions for healthcare professionals and patients to individualize and improve asthma management and for policymakers and regulators as an evidence-informed reference to help setting legally binding standards and goals for outdoor air quality at international, national and local levels. The Guideline was developed using the GRADE approach and evaluated outdoor pollutants referenced in the current Air Quality Guideline of the World Health Organization as single or mixed pollutants and outdoor pesticides. Short-term exposure to all pollutants evaluated increases the risk of asthma-related adverse outcomes, especially hospital admissions and emergency department visits (moderate certainty of evidence at specific lag days). There is limited evidence for the impact of traffic-related air pollution and outdoor pesticides exposure as well as for the interventions to reduce emissions. Due to the quality of evidence, conditional recommendations were formulated for all pollutants and for the interventions reducing outdoor air pollution. Asthma management counselled by the current EAACI guidelines can improve asthma-related outcomes but global measures for clean air are needed to achieve significant impact.

Residential greenness during pregnancy and early life and development of asthma up to 27 years of age: The Espoo Cohort Study

Previous studies have suggested that living close to green spaces has protective health effects, but potential effects on asthma are contradictory. We investigated the association between the amount of greenness in the residential area during pregnancy and early life and development of asthma in the first 27 years of life. The study population included all 2568 members of the Espoo Cohort Study, Finland. We calculated individual-level exposure to green space measured as cumulative Normalized Difference Vegetation Index (cumNDVI in unit-months) within 300 m of the participant's residence during pregnancy and the first two years of life in both spring and summer seasons. The onset of asthma was assessed using information from the baseline and follow-up surveys. Exposure to residential greenness in the spring season during pregnancy was associated with an increased risk of asthma up to 6 years of age, with an adjusted hazard ratio (aHR) of 3.72 (95% confidence interval (CI): 1.11, 12.47) per 1 unit increase in cumNDVI. Increased greenness in the summer during pregnancy associated with asthma up to 6 years, with an aHR of 1.41 (95% CI: 0.85, 2.32). The effect was found to be related to increased greenness particularly during the third trimester of pregnancy, with an aHR of 2.37 (95% CI: 1.36, 4.14) per 1 unit increase of cumNDVI. These associations were weaker at the ages of 12 and 27 years. No association was found between NDVI in the first two years of life and the development of asthma. Our findings provide novel evidence that exposure to greenness during pregnancy increases the risk of developing asthma. The adverse effects were strongest for the prenatal greenness in the spring season and in the third trimester of pregnancy. Both the season and trimester of exposure to greenness are critical in the development of asthma.

Obesity and Asthma: Implementing a Treatable Trait Care Model

Recognition of obesity as a treatable trait of asthma, impacting its development, clinical presentation and management, is gaining widespread acceptance. Obesity is a significant risk factor and disease modifier for asthma, complicating treatment. Epidemiological evidence highlights that obese asthma correlates with poorer disease control, increased severity and persistence, compromised lung function and reduced quality of life. Various mechanisms contribute to the physiological and clinical complexities observed in individuals with obesity and asthma. These encompass different immune responses, including Type IVb, where T helper 2 cells are pivotal and driven by cytokines like interleukins 4, 5, 9 and 13, and Type IVc, characterised by T helper 17 cells and Type 3 innate lymphoid cells producing interleukin 17, which recruits neutrophils. Additionally, Type V involves immune response dysregulation with significant activation of T helper 1, 2 and 17 responses. Finally, Type VI is recognised as metabolic-induced immune dysregulation associated with obesity. Body mass index (BMI) stands out as a biomarker of a treatable trait in asthma, readily identifiable and targetable, with significant implications for disease management. There exists a notable gap in treatment options for individuals with obese asthma, where asthma management guidelines lack specificity. For example, there is currently no evidence supporting the use of incretin mimetics to improve asthma outcomes in asthmatic individuals without Type 2 diabetes mellitus (T2DM). In this review, we advocate for integrating BMI into asthma care models by establishing clear target BMI goals, promoting sustainable weight loss via healthy dietary choices and physical activity and implementing regular reassessment and referral as necessary.

The Role of Biodiversity in the Development of Asthma and Allergic Sensitization: A State-of-the-Science Review

BACKGROUND

Changes in land use and climate change have been reported to reduce biodiversity of both the environment and human microbiota. These reductions in biodiversity may lead to inadequate and unbalanced stimulation of immunoregulatory circuits and, ultimately, to clinical diseases, such as asthma and allergies.

OBJECTIVE

We summarized available empirical evidence on the role of inner (gut, skin, and airways) and outer (air, soil, natural waters, plants, and animals) layers of biodiversity in the development of asthma, wheezing, and allergic sensitization.

METHODS

We conducted a systematic search in SciVerse Scopus, PubMed MEDLINE, and Web of Science up to 5 March 2024 to identify relevant human studies assessing the relationships between inner and outer layers of biodiversity and the risk of asthma, wheezing, or allergic sensitization. The protocol was registered in PROSPERO (CRD42022381725).

RESULTS

A total of 2,419 studies were screened and, after exclusions and a full-text review of 447 studies, 82 studies were included in the comprehensive, final review. Twenty-nine studies reported a protective effect of outer layer biodiversity in the development of asthma, wheezing, or allergic sensitization. There were also 16 studies suggesting an effect of outer layer biodiversity on increasing asthma, wheezing, or allergic sensitization. However, there was no clear evidence on the role of inner layer biodiversity in the development of asthma, wheezing, and allergic sensitization (13 studies reported a protective effect and 15 reported evidence of an increased risk).

CONCLUSIONS

Based on the reviewed literature, a future systematic review could focus more specifically on outer layer biodiversity and asthma. It is unlikely that association with inner layer biodiversity would have enough evidence for systematic review. Based on this comprehensive review, there is a need for population-based longitudinal studies to identify critical periods of exposure in the life course into adulthood and to better understand mechanisms linking environmental exposures and changes in microbiome composition, diversity, and/or function to development of asthma and allergic sensitization. https://doi.org/10.1289/EHP13948.

Residential surrounding greenness and the incidence of childhood asthma: Findings from a population-based cohort in Ontario, Canada

Several epidemiological studies have investigated the possible role that living in areas with greater amounts of greenspace has on the incidence of childhood asthma. These findings have been inconsistent, and few studies explored the relevance of timing of exposure. We investigated the role of residential surrounding greenness on the risk of incident asthma using a population-based retrospective cohort study. We included 982,131 singleton births in Ontario, Canada between 2006 and 2013. Two measures of greenness, the Normalized Difference Vegetation Index (NDVI) and the Green View Index (GVI), were assigned to the residential histories of these infants from pregnancy through to 12 years of age. Longitudinally-based diagnoses of asthma were determined by using provincial administrative health data. The extended Cox hazards model was used to characterize associations between greenness measures and asthma (up to age 12 years) while adjusting for several risk factors. In a fully adjusted model, that included a term for traffic-related air pollution (NO2), we found no association between an interquartile range increase (0.08) of the NDVI during childhood and asthma incidence (HR = 0.99; 95 % CI = 0.99-1.01). In contrast, we found that an 0.08 increase in NDVI during childhood reduced the risk of asthma in children 7-12 years of age by 14 % (HR = 0.86, 95 % CI:0.79-0.95). Seasonal differences in the association between greenness and asthma were noted. Our findings suggest that residential proximity to greenness reduces the risk of asthma in children aged 7-12.

Different greenness exposure in Europe and respiratory outcomes in youths. A systematic review and meta-analysis

The existing evidence on the association between greenness and respiratory outcomes remains inconclusive. We aimed at systematically summarizing existing literature on greenness exposure and respiratory outcomes in European children and adolescents, with a preliminary attempt to qualify the distribution of dominant tree species across different geographical areas and bioclimatic regions. Overall, 4049 studies were firstly identified by searching PubMed/MEDLINE, EMBASE, Scopus, Web of Science, GreenFile and CAB direct, up to 29 August 2023. Eighteen primary studies were included in the systematic review and six were meta-analyzed. No overall significant association was observed between the Normalized Difference Vegetation Index, assessed within 500-m buffers (i.e. NDVI-500), and the odds of asthma for 0.3-increase in the exposure (OR: 0.97, 95% CI from 0.53 to 1.78). Similarly, an overall exposure to the NDVI-300 highest tertile, as compared to the lowest tertile, was not significantly associated with asthma (OR: 0.65, 95% CI from 0.22 to 1.91): heterogeneity among studies was significant (p = 0.021). We delineated some key elements that might have mostly contributed to the lack of scientific consensus on this topic, starting from the urgent need of harmonized approaches for the operational definition of greenness. Additionally, the complex interplay between greenness and respiratory health may vary across different geographical regions and climatic conditions. At last, the inconsistent findings may reflect the heterogeneity and complexity of this relationship, rather than a lack of scientific consensus itself. Future research should compare geographical areas with similar bioclimatic parameters and dominant or potentially present vegetation species, in order to achieve a higher inter-study comparability.

Associations between combined urban and lifestyle factors and respiratory health in European children

INTRODUCTION

Previous studies identified some environmental and lifestyle factors independently associated with children respiratory health, but few focused on exposure mixture effects. This study aimed at identifying, in pregnancy and in childhood, combined urban and lifestyle environment profiles associated with respiratory health in children.

METHODS

This study is based on the European Human Early-Life Exposome (HELIX) project, combining six birth cohorts. Associations between profiles of pregnancy (38 exposures) and childhood (84 exposures) urban and lifestyle factors, identified by clustering analysis, and respiratory health were estimated by regression models adjusted for confounders.

RESULTS

Among the 1033 included children (mean ± standard-deviation (SD) age: 8.2 ± 1.6 years old, 47% girls) the mean ± SD forced expiratory volume in 1s (FEV1) and forced vital capacity (FVC) were 99 ± 13% and 101 ± 14%, respectively, and 12%, 12% and 24% reported ever-asthma, wheezing and rhinitis, respectively. Four profiles of pregnancy exposures and four profiles of childhood exposures were identified. Compared to the reference childhood exposure profile (low exposures), two exposure profiles were associated with lower levels of FEV1. One profile was characterized by few natural spaces in the surroundings and high exposure to the built environment and road traffic. The second profile was characterized by high exposure to meteorological factors and low levels of all other exposures and was also associated with an increased risk of ever-asthma and wheezing. A pregnancy exposure profile characterized by high exposure levels to all risk factors, but a healthy maternal lifestyle, was associated with a lower risk of wheezing and rhinitis in children, compared to the reference pregnancy profile (low exposures).

CONCLUSION

This comprehensive approach revealed pregnancy and childhood profiles of urban and lifestyle exposures associated with lung function and/or respiratory conditions in children. Our findings highlight the need to pursue the study of combined exposures to improve prevention strategies for multifactorial diseases such as asthma.

In vivo biological analysis of cold plasma on allergenicity reduction of tropomyosin in shrimp

In vivo biological regulations of the allergenicity of tropomyosin (TM) treated by cold plasma (CP) were investigated by in vivo mouse model. The sensitization models of Balb/c mice were successfully established. CP treatment reduced the allergic symptoms of mice and regulated the Th1/Th2 balance to prevent allergy by activating Treg cells, which was deduced by serum and cytokines analysis. For intestinal flora analysis, allergy occurrence was accompanied by the decreased species abundance and the increased species diversity of intestinal flora. The significant species composition difference between the TM group and the PBS group showed a possible connection between bacterial diversity and allergy. Furthermore, Firmicutes, Bacteroidetes, Parabacteroides, Alloprevotella, Bacteroides, and Lachnospiraceae could relate to allergy occurrence. Intestinal section analysis suggested that allergy occurrence was accompanied by the damaged intestinal structure, and CP treatment could relieve the damage caused by an allergy.

Mapping wild vascular plant species diversity in urban areas in California using crowdsourcing data by regression kriging: Examining socioeconomic disparities

Biodiversity is crucial for human health, but previous methods of measuring biodiversity require intensive resources and have other limitations. Crowdsourced datasets from citizen scientists offer a cost-effective solution for characterizing biodiversity on a large spatial scale. This study has two aims: 1) to generate fine-resolution plant species diversity maps in California urban areas using crowdsourced data and extrapolation methods; and 2) to examine their associations with sociodemographic factors and identify subpopulations with low biodiversity exposure. We used iNaturalist observations from 2019 to 2022 to calculate species diversity metrics by exploring the sampling completeness in a 5 × 5-km2 grid and then computing species diversity metrics for grid cells with at least 80 % sample completeness (841 out of 4755 grid cells). A generalized additive model with ordinary kriging (GAM OK) provided moderately reliable estimates, with correlations of 0.64-0.66 between observed and extrapolated metrics, relative mean absolute errors of 21 %-23 %, and relative root mean squared errors of 27 %-30 % for grid cells with ≥80 % sample completeness from 10-fold cross-validation. GAM OK was further applied to extrapolate species diversity metrics from saturated grid cells (N = 841) to the remaining grid cells with <80 % sample completeness (N = 3914) and generate diversity maps that cover the grid. Further, generalized linear mixed models were used to examine the associations between species diversity and sociodemographic indicators at census tract level. The wild vascular plant species diversity metrics were inversely associated with neighborhood socioeconomic status (i.e., unemployment, linguistic isolation, educational attainment, and poverty rate). Minority populations (i.e., African American, Asian American, and Hispanic) and children had significantly lower diversity exposure in their neighborhoods. Crowdsourcing data offers a cost-effective solution for characterizing large-scale biodiversity in urban areas.

Greenness and chronic respiratory health issues: a systematic review and meta-analysis

Introduction

The number of chronic respiratory disease (CRD) individuals worldwide has been continuously increasing. Numerous studies have shown that greenness can improve chronic respiratory health issues through different mechanisms, with inconsistent evidence. By quantitatively summarizing existing studies, our purpose is to determine the connection between greenness exposure and various chronic respiratory health.

Methods

We conducted a comprehensive search on PubMed, EMBASE, and Web of Science core databases to identify relevant studies on the correlation between greenness exposure and chronic respiratory health issues. Studies published up to January 2023 were included in the search. The study used the most frequent indicator (normalized difference vegetation index [NDVI]) as the definition of greenness exposure.

Results

We finally identified 35 studies for meta-analysis. We calculated pooled effects across studies using a random-effects model and conducted a subgroup analysis by age and buffer zones to discuss the effects on chronic respiratory health issues. This study showed that 0.1 increments in NDVI were significantly related to lower rates of asthma incidence, lung cancer incidence, and chronic obstructive pulmonary disease (COPD) mortality risk; the pooled RRs were 0.92 (95% CI: 0.85-0.98), 0.62 (95% CI: 0.40-0.95), and 0.95 (95% CI: 0.92- 0.99), respectively. For the age subgroup, the higher greenness exposure level was related to the incidence rate of asthma among teenagers aged 13-18years (RR: 0.91; 95% CI: 0.83-0.99). For the buffer subgroup, a positive relationship with greenness exposure and asthma incidence/prevalence at 200-300m and 800- 1000m buffers, as well as the COPD mortality at 800-1000m buffer, the pooled RRs were 0.92 (95% CI: 0.86-0.98), 0.87 (95% CI: 0.81-0.93), and 0.93 (95% CI: 0.88- 0.98), respectively. Evidence of publication bias was not detected in this study.

Discussion

Our study is the first global meta-analysis between greenness and various CRDs to report an inverse association. Further research is needed in order to determine the effect of greenness exposure on different CRDs. Therefore, when planning for green development, more consideration must be given to public health and green management as intervention measures.

https://www.crd.york.ac.uk/PROSPEROFILES/384029_STRATEGY_20230116.pdf.

Factors by which global warming worsens allergic disease

Increased use of fossil fuels has led to global warming with concomitant increases in the severity and frequency of extreme weather events such as wildfires and sand and dust storms. These changes have led to increases in air pollutants such as particulate matter and greenhouse gases. Global warming is also associated with increases in pollen season length and pollen concentration. Particulate matter, greenhouse gases, and pollen synergistically increase the incidence and severity of allergic diseases. Other indirect factors such as droughts, flooding, thunderstorms, heat waves, water pollution, human migration, deforestation, loss of green space, and decreasing biodiversity (including microbial diversity) also affect the incidence and severity of allergic disease. Global warming and extreme weather events are expected to increase in the coming decades, and further increases in allergic diseases are expected, exacerbating the already high health care burden associated with these diseases. There is an urgent need to mitigate and adapt to the effects of climate change to improve human health. Human health and planetary health are connected and the concept of One Health, which is an integrated, unifying approach to balance and optimize the health of people, animals, and the environment needs to be emphasized. Clinicians are trusted members of the community, and they need to take a strong leadership role in educating patients on climate change and its adverse effects on human health. They also need to advocate for policy changes that decrease the use of fossil fuels and increase biodiversity and green space to enable a healthier and more sustainable future.

Villeneuve P, Kaiser DJ, Smargiassi A. The influence of urban trees and total vegetation on asthma development in children

Objective

We aimed to assess whether the influence of urban vegetation on asthma development in children (<13 years) varies by type (e.g., total vegetation, tree type, and grass) and season.

Methods

We used a cohort of all children born in Montreal, Canada, between 2000 and 2015. Children and cases were identified from linked medico-administrative databases. Exposure to residential vegetation was estimated using the Normalized Difference Vegetation Index (NDVI) for total vegetation and using the total area covered by deciduous and evergreen crowns for trees in 250 m buffers centered on residential postal codes. Seasonal variations in vegetation were modeled by setting values to zero on days outside of pollen and leaf-on seasons. Cox models with vegetation exposures, age as a time axis, and adjusted for sex, material deprivation, and health region were used to estimate hazard ratios (HR) for asthma development.

Results

We followed 352,946 children for a total of 1,732,064 person-years and identified 30,816 incident cases of asthma. While annual vegetation (total and trees) measures did not appear to be associated with asthma development, models for pollen and leaf-on seasons yielded significant nonlinear associations. The risk of developing asthma was lower in children exposed to high levels (>33,300 m2) of deciduous crown area for the leaf-on season (HR = 0.69; 95% confidence interval [CI] = 0.67, 0.72) and increased for the pollen season (HR = 1.07; 95% CI =1.02, 1.12), compared with unexposed children. Similar results were found with the Normalized Difference Vegetation Index.

Conclusion

The relationship between urban vegetation and childhood asthma development is nonlinear and influenced by vegetation characteristics, from protective during the leaf-on season to harmful during the pollen season.

The epithelial barrier: The gateway to allergic, autoimmune, and metabolic diseases and chronic neuropsychiatric conditions

Since the 1960 s, our health has been compromised by exposure to over 350,000 newly introduced toxic substances, contributing to the current pandemic in allergic, autoimmune and metabolic diseases. The "Epithelial Barrier Theory" postulates that these diseases are exacerbated by persistent periepithelial inflammation (epithelitis) triggered by exposure to a wide range of epithelial barrier-damaging substances as well as genetic susceptibility. The epithelial barrier serves as the body's primary physical, chemical, and immunological barrier against external stimuli. A leaky epithelial barrier facilitates the translocation of the microbiome from the surface of the afflicted tissues to interepithelial and even deeper subepithelial locations. In turn, opportunistic bacterial colonization, microbiota dysbiosis, local inflammation and impaired tissue regeneration and remodelling follow. Migration of inflammatory cells to susceptible tissues contributes to damage and inflammation, initiating and aggravating many chronic inflammatory diseases. The objective of this review is to highlight and evaluate recent studies on epithelial physiology and its role in the pathogenesis of chronic diseases in light of the epithelial barrier theory.

Basis of preventive and non-pharmacological interventions in asthma

Asthma is one of the most common atopic disorders in all stages of life. Its etiology is likely due to a complex interaction between genetic, environmental, and lifestyle factors. Due to this, different non-pharmacological interventions can be implemented to reduce or alleviate the symptoms caused by this disease. Thus, the present narrative review aimed to analyze the preventive and non-pharmacological interventions such as physical exercise, physiotherapy, nutritional, ergonutritional, and psychological strategies in asthma treatment. To reach these aims, an extensive narrative review was conducted. The databases used were MedLine (PubMed), Cochrane (Wiley), Embase, PsychINFO, and CinAhl. Asthma is an immune-mediated inflammatory condition characterized by increased responsiveness to bronchoconstrictor stimuli. Different factors have been shown to play an important role in the pathogenesis of asthma, however, the treatments used to reduce its incidence are more controversial. Physical activity is focused on the benefits that aerobic training can provide, while physiotherapy interventions recommend breathing exercises to improve the quality of life of patients. Nutritional interventions are targeted on implement diets that prioritize the consumption of fruits and vegetables and supplementation with antioxidants. Psychological interventions have been proposed as an essential non-pharmacological tool to reduce the emotional problems associated with asthma.

Effect of altered human exposome on the skin and mucosal epithelial barrier integrity

Pollution in the world and exposure of humans and nature to toxic substances is continuously worsening at a rapid pace. In the last 60 years, human and domestic animal health has been challenged by continuous exposure to toxic substances and pollutants because of uncontrolled growth, modernization, and industrialization. More than 350,000 new chemicals have been introduced to our lives, mostly without any reasonable control of their health effects and toxicity. A plethora of studies show exposure to these harmful substances during this period with their implications on the skin and mucosal epithelial barrier and increasing prevalence of allergic and autoimmune diseases in the context of the "epithelial barrier hypothesis". Exposure to these substances causes an epithelial injury with peri-epithelial inflammation, microbial dysbiosis and bacterial translocation to sub-epithelial areas, and immune response to dysbiotic bacteria. Here, we provide scientific evidence on the altered human exposome and its impact on epithelial barriers.

Higher greenspace exposure is associated with a decreased risk of childhood asthma in Shanghai - A megacity in China

Inconsistent evidence exists about whether exposure to greenspace benefits childhood asthma. Previous studies have only focused on residential or school greenspace, and no research has combined greenspace exposures at both homes and schools to determine their link with childhood asthma. A population-based cross-sectional study was conducted among 16,605 children during 2019 in Shanghai, China. Self-reported questionnaires were used to collect information on childhood asthma and demographic, socioeconomic and behavioural factors. Environmental data including ambient temperature, particulate matter with aerodynamic diameter less than 1 µm (PM₁), enhanced vegetation index (EVI), and normalized difference vegetation index (NDVI) were collected from satellite data. Binomial generalized linear models with a logit link were carried out to evaluate the association between greenspace exposure and children's asthma, as well as the effect modifiers. An interquartile range increment of whole greenspace (NDVI₅₀₀, NDVI₂₅₀, EVI₅₀₀, and EVI₂₅₀) exposure was associated with a reduced odds ratio of children's asthma (0.88, 95% CI: 0.78, 0.99; 0.89, 95% CI: 0.79, 1.01; 0.87, 95% CI: 0.77, 0.99; and 0.88, 95% CI: 0.78, 0.99, respectively) after controlling potential confounders. Low temperature, low PM₁, males, vaginal delivery, suburban/rural area, and without family history of allergy appeared to enhance the greenspace-asthma association. Increased greenspace exposure was associated with a lower risk of childhood asthma, and the association was modified by a range of socio-environmental factors. These findings add to the body of evidence on the benefits of biodiversity and supporting the promotion of urban greenspace to protect children's health.

Covid-19 and outdoor recreation - Lessons learned? Introduction to the special issue on "Outdoor recreation and Covid-19: Its effects on people, parks and landscapes"

The special issue presents international experiences with COVID-19 in the years 2020 and 2021 on outdoor recreation and nature-based tourism. To set the scene, a bibliometric and qualitative analysis illustrates and clusters recent publications on COVID-19. Against this background contributions from Japan, China, Brazil, Indonesia, Austria, Croatia, the United States, New Zealand, Taiwan, Australia, Sweden, Poland and Ireland draw a truly international picture of the pandemic crisis, the effects, coping behavior and related strategies. The papers contribute to the COVID-19 related research by documenting the shock in the field of outdoor recreation and tourism, by understanding the immediate consequences on behavior and the required managerial consequences and finally, by analyzing the possible follow up effects including long term effects, discussing resilient solutions and proposing new strategies. In the discussion section we try to answer the questions whether the high visitation rate in recreation facilities, forests, parks and protected areas will remain, and whether adapted visitor management concepts will be required. In addition, we discuss possible implications for urban planning and management. Finally, based on a changing connectedness to nature also possible positive effects by the pandemic are discussed which may lead to a new target group in outdoor recreation and nature-based tourism.

Management implications

The overview on the Covid-19 related literature suggests improvements in planning and management, such as-new concepts for destination and visitor management, considering an ongoing risk-management,-proactive urban planning and management considering short-term effects in the existing built environment as well as a long-term perspective with strategically planned green infrastructure, including not only the supply of green infrastructure, but also its accessibility, its amenities, and aspects of environmental justice,-the consideration of new target groups in tourism and outdoor recreation.

The effect of greenness on allergic rhinitis outcomes in children and adolescents: A systematic review and meta-analysis

BACKGROUND

The relationship between greenness and health emerges as new public health concern. More published studies from multiple areas have explored the relationship between greenness and allergic rhinitis (AR) in children and adolescents. This study aims to determine the association between greenness and allergic rhinitis by systematic review and meta-analysis, in order to provide a more comprehensive assessment of the impact of greenness on AR in children and adolescents.

METHODS

The relative literature was systematically searched in PubMed, Embase, and Web of science lastly on September 25, 2022. Terms related to greenness and allergic rhinitis were used for searching. Summary effect estimates of greenness on AR in children and adolescents were calculated for per 10 % increase of greenness exposure with different buffer sizes by random-effects model.

RESULTS

A total of 579 studies were screened, and fourteen studies from Europe, Asia and North America were finally included. Most greenness exposure were measured by normalized difference vegetation index (NDVI). Enhanced vegetation index, outdoor-green environmental score and existed to measuring different greenness types. Greenness surrounding residences and schools were assessed. The overall effect of greenness on primary outcome was 1.00 (95%CI = 0.99-1.00). Most effect estimates of greenness were included in the NDVI-500 m group, and the pooled OR was 0.99 (95%CI = 0.97-1.01). No significant pooled estimates were found in analyses with study locations.

CONCLUSION

This study indicates no significant association between greenness exposure and AR in children and adolescents. Various exposure measures and conversion of data may affect the results of this meta-analysis. More precise assessment of personal greenness exposure in well-designed prospective studies are vital for drawing a definite association in future. Furthermore, greenness exposure surrounding schools should be paid considerable attention for its effect on AR in school-aged children and adolescents.

Residential greenspace and childhood asthma: An intra-city study

Interest in assessing the effects of exposure to greenspace on human health has been increasing due to rapid urbanization, and rising trends of physical inactivity and air pollution. However, findings on the link between greenspace and child respiratory health, especially asthma, are inconsistent. We investigated the association between greenspace surrounding residential addresses and asthma in children. A city-wide cross-sectional study was conducted, involving 16,605 children aged 3-12 years, in Shanghai, China. Data on asthma symptoms and covariates were collected from validated self-reported questionnaires. Residential greenspace was measured using satellite-derived normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI). Information on ambient temperature and particulate matter with dynamic diameter <1 μm (PM₁) and 2.5 μm (PM_2.5) was also collected from satellite data. Logistic regression models were performed to assess the associations of greenspace exposure with childhood asthma as well as the effect modification by covariates. The prevalence of current asthma in children was 4.8 % in this study. An interquartile range increase in mean NDVI from 2016 to 2018 was associated with decreased odds of asthma in 2019 at 500 m, and 250 m resolutions (0.82, 95 % confidence interval (CI): 0.74 to 0.93; and 0.82, 95 % CI: 0.72 to 0.94, respectively) after adjustment for covariates. The greenspace-asthma association was modified by ambient temperature and residential area. Sensitivity analyses using various models and EVI exposure showed the robustness of the results. In conclusion, higher individual-level exposure to greenspace was associated with decreased odds of asthma in children, and the association appeared to be modified by different environmental and socio-demographic factors. These findings provide additional evidence for promoting urban greenness to protect children's health and well-being.

Association between exposure to greenness and atopic march in children and adults-A systematic review and meta-analysis

Introduction

Allergic diseases are a global public health problem. Food allergy, atopic dermatitis (AD), allergic rhinoconjunctivitis, allergic rhinitis (AR) and asthma represent the natural course of allergic diseases, also known as the "atopic march". In recent years, a large number of studies have been published on the association between greenness exposure and allergic diseases. However, systematic reviews on the association between greenness exposure and multiple allergic diseases or atopic march are lacking.

Methods

In this study, PubMed, EMBASE, ISI Web of Science, and Scopus were systematically searched. Meta-analyses were performed if at least three studies reported risk estimates for the same outcome and exposure measures.

Results

Of 2355 records, 48 studies were included for qualitative review. Five birth cohort studies, five cross-sectional studies, and one case-control study were included for asthma meta-analysis, respectively. Four birth cohort studies were included for AR meta-analysis. Our results support that exposure to a greener environment at birth reduces the risk of asthma and AR in childhood. In addition, higher greenness exposure was associated with decreased odds of current asthma in children.

Discussion

There was a large heterogeneity among the included studies and most of them did not specify the vegetation type and causative allergens. Therefore the study results need to be further validated. In addition, a small number of studies evaluated the association between greenness and food allergy, AD and allergic rhinoconjunctivitis. More research is needed to strengthen our understanding of the association between greenness and allergic diseases.

Greenspace and health outcomes in children and adolescents: A systematic review

An increasing body of evidence has linked greenspace and various health outcomes in children and adolescents, but the conclusions were inconsistent. For this review, we comprehensively summarized the measurement methods of greenspace, resultant health outcomes, and potential mechanisms from epidemiological studies in children and adolescents (aged ≤19 years). We searched for studies published and indexed in MEDLINE and EMBASE (via Ovid) up to April 11, 2022. There were a total of 9,291 studies identified with 140 articles from 28 countries finally assessed and included in this systematic review. Over 70% of the studies were conducted in highly urbanised countries/regions, but very limited research has been done in low-and middle-income countries and none in Africa. Measures of greenspace varied. Various health outcomes were reported, including protective effects of greenspace exposure on aspects of obesity/overweight, myopia, lung health, circulatory health, cognitive function, and general health in children and adolescents. The associations between greenspace exposure and other health outcomes were inconsistent, especially for respiratory health studies. We pooled odds ratios (OR) using random-effects meta-analysis for health outcomes of asthma (OR = 0.94, 95%CI: 0.84 to 1.06), allergic rhinitis (OR = 0.95; 95% CI: 0.73 to 1.25), and obesity/overweight (OR = 0.91, 95%CI: 0.84 to 0.98) with per 0.1 unit increase in normalized difference in vegetation index (NDVI). These associations have important implications for the assessment and management of urban environment and health in children and adolescents.

Association of individual green space exposure with the incidence of asthma and allergic rhinitis: a systematic review and meta-analysis

The association between allergic respiratory diseases, such as asthma and allergic rhinitis (AR), and green space (GS) remains controversial. Our study aimed to summarize and synthesize the association between individual GS exposure and the incidence of asthma/AR. We systematically summarized the qualitative relationship between GS exposure and asthma and AR. The pooled odds ratio (OR) with 95% confidence intervals (CIs) was used to estimate the effect of the Normalized Difference Vegetation Index (NDVI) on asthma and AR. A total of 21 studies were included for systematic review, and 8 of them underwent meta-analysis. In the meta-analysis of current asthma, the 0 < radius ≤ 100 m group, 100 < radius ≤ 300 m group, and 500 < radius ≤ 1000 m group presented weak negative associations between the NDVI and current asthma. For ever asthma, slight positive associations existed in the 0 < radius ≤ 100 m group and 300 < radius ≤ 500 m group. In addition, the NDVI might slightly reduce the risk of AR in radius of 100 m and 500 m. Our findings suggest that the effects of GS exposure on asthma and AR were not significant. Differences in GS measurements, disease diagnoses and adjusted confounders across studies may have an impact on the results. Subsequent studies should consider potential confounding factors and use more accurate GS exposure measurements to better understand the impact of GS exposure on respiratory disease in the population.

The associations between residential greenness and allergic diseases in Chinese toddlers: A birth cohort study

BACKGROUND

Green space in the living environment has been linked to the development of allergic diseases. However, evidence regarding early-onset allergy in toddlers was limited, and the critical exposure window remained unclear. We aimed to investigate associations between residential greenness with allergic diseases in early life.

METHODS

This prospective birth cohort study included 522 mother-child pairs in Guangzhou, China. We quantified prenatal, postnatal, and early-life (i.e., the first 1000 days of life) residential greenness, estimated from remote satellite data using normalized difference vegetation index (NDVI), enhanced vegetation index (EVI), and tree cover. We identified physician-diagnosed allergic diseases (eczema, atopic dermatitis, urticaria, allergic rhinitis, allergic conjunctivitis, food allergy, and asthma) based on medical records at age 2 years. Generalized linear regression was conducted to examine the associations of greenness with allergic outcomes.

RESULTS

The ranges of residential NDVI and EVI values in 500-m buffer during early life were 0.06-0.70 and 0.03-0.46, respectively. We found a 0.1 unit increase of NDVI in 500-m buffer throughout early life was associated with higher odds of any allergic diseases (prenatal: OR [odds ratio], 1.25; 95%CI, 1.02-1.53; postnatal: OR, 1.24; 95%CI, 1.02-1.52; early-life: OR, 1.25, 95%CI: 1.02-1.53) and higher odds of eczema (prenatal: OR, 1.28; 95%CI, 1.04-1.59; postnatal: OR, 1.24; 95%CI, 1.01-1.54; early-life: OR, 1.26, 95%CI: 1.02-1.56). The results were consistent when using EVI as a proxy for greenness. We only observed that prenatal exposure to the highest tertile of NDVI-500 was adversely associated with any allergic diseases (OR, 1.63; 95%CI, 1.03-2.58) and eczema (OR, 1.70; 95%CI: 1.04-2.78) compared with the lowest tertile.

CONCLUSIONS

This study identified detrimental associations of residential greenness with allergic diseases especially eczema among toddlers, and pregnancy appears to be the critical exposure window. Our findings highlighted the importance of urban planning to develop friendly-green neighborhood to improve maternal and child health.

Growing up green: a systematic review of the influence of greenspace on youth development and health outcomes

Youth growing up in places with more greenspaces have better developmental outcomes. The literature on greenspace and youth development is largely cross-sectional, thus limited in terms of measuring development and establishing causal inference. We conducted a systematic review of prospective, longitudinal studies measuring the association between greenspace exposure and youth development outcomes measured between ages two and eighteen. We searched Cochrane, PubMed, CINAHL, Scopus, and Environment Complete, and included prospective cohort, quasi-experimental, and experimental studies on greenspace and youth development. Study quality was assessed using a 10-item checklist adapted from a previously published review on greenspace and health. Twenty-eight studies met criteria for review and were grouped into five thematic categories based on reported outcomes: cognitive and brain development, mental health and wellbeing, attention and behavior, allergy and respiratory, and obesity and weight. Seventy-nine percent of studies suggest an association between greenspace and improved youth development. Most studies were concentrated in wealthy, Western European countries, limiting generalizability of findings. Key opportunities for future research include: (1) improved uniformity of standards in measuring greenspace, (2) improved measures to account for large latency periods between greenspace exposure and developmental outcomes, and (3) more diverse study settings and populations.

Exposure to urban greenspace and pathways to respiratory health: An exploratory systematic review

BACKGROUND/OBJECTIVE

Urban greenspace may have a beneficial or adverse effect on respiratory health. Our objective was to perform an exploratory systematic review to synthesise the evidence and identify the potential causal pathways relating urban greenspace and respiratory health.

METHODS

We followed PRISMA guidelines on systematic reviews and searched five databases for eligible studies during 2000-2021. We incorporated a broad range of urban greenspace and respiratory health search terms, including both observational and experimental studies. Screening, data extraction, and risk of bias, assessed using the Navigation Guide criteria, were performed independently by two authors. We performed a narrative synthesis and discuss suggested pathways to respiratory health.

RESULTS

We identified 108 eligible papers (n = 104 observational, n = 4 experimental). The most common greenspace indicators were the overall greenery or vegetation (also known as greenness), green land use/land cover of physical area classes (e.g., parks, forests), and tree canopy cover. A wide range of respiratory health indicators were studied, with asthma prevalence being the most common. Two thirds (n = 195) of the associations in these studies were positive (i.e., beneficial) with health, with 31% (n = 91) statistically significant; only 9% (n = 25) of reported associations were negative (i.e., adverse) with health and statistically significant. The most consistent positive evidence was apparent for respiratory mortality. There were n = 35 (32%) 'probably low' and n = 73 (68%) 'probably high' overall ratings of bias. Hypothesised causal pathways for health benefits included lower air pollution, more physically active populations, and exposure to microbial diversity; suggested mechanisms with poorer health included exposure to pollen and other aeroallergens.

CONCLUSION

Many studies showed positive association between urban greenspace and respiratory health, especially lower respiratory mortality; this is suggestive, but not conclusive, of causal effects. Results underscore the importance of contextual factors, greenspace metric employed, and the potential bias of subtle selection factors, which should be explored further.

Climate change and global health: A call to more research and more action

There is increasing understanding, globally, that climate change and increased pollution will have a profound and mostly harmful effect on human health. This review brings together international experts to describe both the direct (such as heat waves) and indirect (such as vector-borne disease incidence) health impacts of climate change. These impacts vary depending on vulnerability (i.e., existing diseases) and the international, economic, political, and environmental context. This unique review also expands on these issues to address a third category of potential longer-term impacts on global health: famine, population dislocation, and environmental justice and education. This scholarly resource explores these issues fully, linking them to global health in urban and rural settings in developed and developing countries. The review finishes with a practical discussion of action that health professionals around the world in our field can yet take.

Association between Land Use Mix and Respiratory Symptoms and Asthma in Children from the Generation XXI Birth Cohort

Land use mix (LUM) in the neighbourhoods has been associated with healthier lifestyles. However, less is known about the association between LUM and health outcomes, namely during childhood. The objective of this study was to evaluate the association between different LUM indexes for Porto Metropolitan Area and asthma and respiratory symptoms in children. A cross-sectional analysis was performed involving 6260 children enrolled in Generation XXI. Land use around the child's residence was assessed with the Portuguese official map of land cover using a GIS. Generalized linear mixed-effects models were fitted to estimate the association between LUM and respiratory symptoms and asthma at 7 years of age. Adjusted associations were quantified using odds ratio (OR) and 95% confidence interval (95% CI). After adjustment, LUM was associated with a lower odds of wheezing in the last 12 months [OR (95% CI) = 0.37 (0.15; 0.93) using Shannon's Evenness Index within 500 m; and OR = 0.93 (0.89; 0.98) using the number of different land use types within 250 m]. Living in neighbourhoods with high LUM has a protective effect on current wheezing symptoms. Our results highlight the association between LUM and respiratory symptoms among children, suggesting that public health considerations should be incorporated in land use decision-making.

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.

Residential and school green and blue spaces and intelligence in children: The Generation XXI birth cohort

Green and blue spaces have numerous health benefits. It has been hypothesized that contact with these spaces can have an important role in cognitive development, because it provides children with unique stimuli that can help develop curiosity, creativity, awareness, and control. This study aimed to estimate the association between exposure to green and blue spaces and the various measures of intelligence quotient (IQ) among children from Porto Metropolitan Area (Portugal). This investigation used data from the Generation XXI birth cohort. Exposure was assessed by Geographic Information Systems using vegetation indexes and measures of accessibility to urban green spaces and blue spaces in the surroundings of the residence and school, measured at 0, 4, 7 and 10 years. The outcome was the verbal, performance, and global IQ, measured using the Wechsler Intelligence Scale for Children (WISC-III), administered at age 10. Associations were estimated using crude and adjusted multilevel models. The mediation role of air pollution and physical activity was quantified. This study included 3827 children. The adjusted models showed that having green spaces up to 800 m of the residence was positively associated with performance IQ (1.30 95%CI [0.26; 2.35]) and global IQ (1.27 [0.18; 2.36]). No clear associations were observed regarding accessibility to blue spaces. Physical activity appeared to have a minor mediation role. Children with urban green spaces around their residences had higher performance and global IQ. Local actors in the sectors of public health and urban planning should promote the creation of green spaces close to residential areas.

Association between Asthma Control and Exposure to Greenness and Other Outdoor and Indoor Environmental Factors: A Longitudinal Study on a Cohort of Asthmatic Children

Achieving and maintaining asthma control (AC) is the main goal of asthma management. Indoor and outdoor environmental factors may play an important role on AC. The aim of this longitudinal study was to evaluate the association between AC and exposure to greenness and other outdoor or indoor environmental factors in a cohort of asthmatic children. This study involved 179 asthmatic children (5-16 years). Parents were interviewed through a modified version of the SIDRIA questionnaire. AC was assessed at each visit. Exposure to greenness was measured using the normalized difference vegetation index (NDVI). A logistic regression model was applied for assessing risk factors for uncontrolled asthma (UA). Low NDVI exposure was a risk factor for UA (OR: 2.662, 95% CI (1.043-6.799)); children exposed to passive smoke during pregnancy had a higher risk of UA than those non-exposed to passive smoke during pregnancy (OR: 3.816, 95% CI (1.114-13.064)); and a unit increase in the crowding index was associated with an increased risk of UA (OR: 3.376, 95% CI (1.294-8.808)). In conclusion, the current study provided a comprehensive assessment of urban-related environmental exposures on asthma control in children, using multiple indicators of greenness and other outdoor or indoor environmental factors.

Advances and highlights in asthma in 2021

Last year brought a significant advance in asthma management, unyielding to the pressure of the pandemics. Novel key findings in asthma pathogenesis focus on the resident cell compartment, epigenetics and the innate immune system. The precision immunology unbiased approach was supplemented with novel tools and greatly facilitated by the use of artificial intelligence. Several randomised clinical trials and good quality real-world evidence shed new light on asthma treatment and supported the revision of several asthma guidelines (GINA, Expert Panel Report 3, ERS/ATS guidelines on severe asthma) and the conception of new ones (EAACI Guidelines for the use of biologicals in severe asthma). Integrating asthma management within the broader context of Planetary Health has been put forward. In this review, recently published articles and clinical trials are summarised and discussed with the goal to provide clinicians and researchers with a concise update on asthma research from a translational perspective.

Nature and Children's Health: A Systematic Review

CONTEXT

Daily outdoor play is encouraged by the American Academy of Pediatrics. Existing evidence is unclear on the independent effect of nature exposures on child health.

OBJECTIVE

We systematically evaluated evidence regarding the relationship between nature contact and children's health.

DATA SOURCES

The database search was conducted by using PubMed, Cumulative Index to Nursing and Allied Health Literature, PsychInfo, ERIC, Scopus, and Web of Science in February 2021.

STUDY SELECTION

We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. In all searches, the first element included nature terms; the second included child health outcome terms.

DATA EXTRACTION

Of the 10 940 studies identified, 296 were included. Study quality and risk of bias were assessed.

RESULTS

The strongest evidence for type of nature exposure was residential green space studies (n = 147, 50%). The strongest evidence for the beneficial health effects of nature was for physical activity (n = 108, 32%) and cognitive, behavioral, or mental health (n = 85, 25%). Physical activity was objectively measured in 55% of studies, and 41% of the cognitive, behavioral, or mental health studies were experimental in design.

LIMITATIONS

Types of nature exposures and health outcomes and behaviors were heterogenous. Risk of selection bias was moderate to high for all studies. Most studies were cross-sectional (n = 204, 69%), limiting our ability to assess causality.

CONCLUSIONS

Current literature supports a positive relationship between nature contact and children's health, especially for physical activity and mental health, both public health priorities. The evidence supports pediatricians in advocating for equitable nature contact for children in places where they live, play, and learn.

Urban Green Spaces, Greenness Exposure and Species Richness in Residential Environments and Relations with Physical Activity and BMI in Portuguese Adolescents

Environmental factors play an important role in obesity-related behaviors. Evidence indicates significant associations between weight and urban green spaces in adults, but it is not clear whether this relationship applies to adolescents. Therefore, our aim was to determine the associations between urban green spaces, greenness exposure and species richness in residential environments with physical activity and body mass index. Sixty-two adolescents between 12 and 18 years of age answered a self-administered questionnaire, providing information on height, weight, age, sex and home address. Data on socioeconomic deprivation were obtained from the European Index of Deprivation for Small Portuguese Areas. Physical activity levels were assessed using accelerometers. Urban green space counts and the normalized difference vegetation index values were measured using buffers along the roads with distances of 300, 500, 1000 and 1500 m from each participant's residence. To quantify the species richness, the species richness index was used. Linear regression models were fitted to analyze whether urban green spaces, exposure to green spaces and species richness counts for each distance were associated with physical activity and self-reported body mass index. We did not find significant associations between the independent variables and the probability of overweight or obesity. The relationship between environmental variables, adolescents' physical activity and body weight seems to be complex and further studies may contribute to better understanding of the topic.