Greenspace, physical activity, and BMI in children from two cities in northern Mexico

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.

Association of greenspaces exposure with cardiometabolic risk factors: a systematic review and meta-analysis

BACKGROUND

Cardiometabolic conditions are major contributors to the global burden of disease. An emerging body of evidence has associated access to and surrounding public open spaces (POS) and greenspace with cardiometabolic risk factors, including obesity, body mass index (BMI), hypertension (HTN), blood glucose (BG), and lipid profiles. This systematic review aimed to synthesize this evidence.

METHODS

This systematic review was conducted based on the PRISMA guidelines. Four electronic databases including Web of Science, PubMed, Scopus, and Google Scholar were searched for eligible articles published until July 2023. All observational studies which assessed the association of greenspace and POS with cardiometabolic risk factors including obesity, BMI, HTN, BG, and lipid profiles were included and reviewed by two authors independently. Heterogeneity between studies was assessed using the I2 index and Cochrane's Q test. Random/fixed effect meta-analyses were used to combine the association between greenspace exposure with cardiometabolic risk factors.

RESULTS

Overall, 118 relevant articles were included in our review. The majority of the articles were conducted in North America or Europe. In qualitative synthesis, access or proximity to greenspaces or POS impacts BMI and blood pressure or HTN, BG, and lipid profiles via various mechanisms. According to the random effect meta-analysis, more access to greenspace was significantly associated with lower odds of HTN (odds ratio (OR): 0.81, 95% confidence intervals (CIs): 0.61-0.99), obesity (OR: 0.83, 95% CIs: 0.77-0.90), and diabetes (OR:0.79, 95% CI: 0.67,0.90).

CONCLUSIONS

Findings of this systematic review and meta-analysis suggested that greenspace accessibility is associated with some cardiometabolic risk factors. Improving greenspace accessibility could be considered as one of the main strategies to reduce cardiometabolic risk factors at population level.

Long-term ambient air pollution exposure and prospective change in sedentary behaviour and physical activity in individuals at risk of type 2 diabetes in the UK

BACKGROUND

Air pollution may be a risk factor for physical inactivity and sedentary behaviour (SED) through discouraging active lifestyles, impairing fitness and contributing to chronic diseases with potentially important consequences for population health.

METHODS

Using generalized estimating equations, we examined the associations between long-term particulate matter with diameter ≤2.5 μm (PM2.5), ≤10 μm (PM10) and nitrogen dioxide (NO2) and annual change in accelerometer-measured SED, moderate-to-vigorous physical activity (MVPA) and steps in adults at risk of type 2 diabetes within the Walking Away from Type 2 Diabetes trial. We adjusted for important confounders including social deprivation and measures of the built environment.

RESULTS

From 808 participants, 644 had complete data (1605 observations; 64.7% men; mean age 63.86 years). PM2.5, NO2 and PM10 were not associated with change in MVPA/steps but were associated with change in SED, with a 1 ugm-3 increase associated with 6.38 (95% confidence interval: 0.77, 12.00), 1.52 (0.49, 2.54) and 4.48 (0.63, 8.34) adjusted annual change in daily minutes, respectively.

CONCLUSIONS

Long-term PM2.5, NO2 and PM10 exposures were associated with an annual increase in SED: ~11-22 min/day per year across the sample range of exposure (three standard deviations). Future research should investigate whether interventions to reduce pollution may influence SED.

Interventions to prevent obesity in Latinx children birth to 6 years globally: a systematic review

OBJECTIVE

To conduct a systematic review of obesity prevention interventions in Latinx children ages birth to 6 years published in any language from 2010-2020.

DESIGN

We used PubMed, ERIC, PsycINFO, Scopus, Scientific Electronic Library Online (SciELO) and Google Scholar databases to conduct a search on May 1 2020, January 1 2021 and November 1 2022. We included randomised controlled trials, quasi-experimental studies and non-randomised interventions with a control or comparison group that reported measures of adiposity.

SETTING

Interventions taking place in the United States, Latin America or the Caribbean.

PARTICIPANTS

Latinx children ages birth to 6 years.

RESULTS

Of 8601 unique records identified, forty manuscripts about thirty-nine unique studies describing thirty distinct interventions in the United States and nine interventions in Latin America and the Caribbean met our inclusion criteria. Interventions were primarily based in early care and education centres (n 13) or combined home settings, for example home and community (n 7). Randomised interventions taking place in community or home settings were more likely to report significant reductions in adiposity or weight-related outcomes compared to other settings. Using the Cochrane risk of bias tools for randomised and non-randomised studies, we judged thirty-eight randomised trials and nine non-randomised interventions to have a high or unclear risk of bias.

CONCLUSIONS

The results highlight a need for more rigorous designs and more effective intervention strategies in Latinx children at risk for having overweight and obesity. Registered with the PROSPERO database for systematic reviews under registration number CRD42020161339.

Low prevalence of ideal levels in cardiovascular behavior metrics among Mexican adolescents

BACKGROUND

Lifestyle changes when transitioning from high-school to college expose students to unhealthy behaviors associated with high cardiovascular risk. The study aimed to assess the cardiovascular behavior metrics according to the AHA criteria, in freshman college adolescents from Northwest Mexico.

METHODS

The study was cross-sectional. Demographics and health history were collected by questionnaires. Four behaviors were evaluated: diet quality using a duplicated FFQ, physical activity (PA) using the IPAQ, smoking, and body mass index (BMI) percentile; blood pressure was measured as a biological metric. Intakes were averaged and summed for each food group; sodium and saturated fat were calculated using the Mexican System of Food Equivalents or the USDA Database. Metrics were categorized into ideal, intermediate or poor level according to the AHA criteria. Diet outliers (± 3 SD) were trimmed and data was tested for normality. Mean±SD were calculated for continuous and percentages for categorical variables. Chi-square test compared the prevalence of demographic variables and levels of each cardiovascular metric by sex. Independent T-test evaluated differences in anthropometrics, dietary, and PA by sex, and the prevalence of ideal vs. non-ideal dietary intakes.

RESULTS

Participants were n = 228, 55.6% men, age = 18.5±0.4 y. A higher prevalence of men indicated working, playing sports, and family history hypertriglyceridemia (p < 0.05). Men showed higher weight, height, BMI, waist, blood pressure, and lower PA and body fat (p < 0.05). Concerning diet quality, significant differences by sex were observed in nuts and seeds (1.1±0.6 and 0.9±0.6 oz/week, p = 0.042) and processed meats (749.8±639 and 503.6±300.3 g/week, p = 0.002); only fish and shellfish group reached AHA recommendations (513.1 ± 450.7 vs. 501.7 ± 428 g/week, p = 0.671) for men and women, respectively. Ideal level was reached by 70.9% participants for BMI percentile, 87% for smoking, 67.2% for blood pressure, 25.9% for PA, and 12.2% for diet score. Regarding food groups and nutrients, the lower prevalence in the ideal level was for sugar-sweetened beverages (10%, p = 0.013) and processed meats (4.8%, p = 0.208), and the highest for fish and shellfish (87.8%, p = 0.281) .

CONCLUSIONS

The diet and PA patterns of Northwest Mexican freshman adolescents make them a high-risk group for developing long-term unhealthy habits and cardiovascular complications early in adulthood.

Incorporating interactions into structured life course modelling approaches: A simulation study and applied example of the role of access to green space and socioeconomic position on cardiometabolic health

Background

Structured life course modelling approaches (SLCMA) have been developed to understand how exposures across the lifespan relate to later health, but have primarily been restricted to single exposures. As multiple exposures can jointly impact health, here we: i) demonstrate how to extend SLCMA to include exposure interactions; ii) conduct a simulation study investigating the performance of these methods; and iii) apply these methods to explore associations of access to green space, and its interaction with socioeconomic position, with child cardiometabolic health.

Methods

We used three methods, all based on lasso regression, to select the most plausible life course model: visual inspection, information criteria and cross-validation. The simulation study assessed the ability of these approaches to detect the correct interaction term, while varying parameters which may impact power (e.g., interaction magnitude, sample size, exposure collinearity). Methods were then applied to data from a UK birth cohort.

Results

There were trade-offs between false negatives and false positives in detecting the true interaction term for different model selection methods. Larger sample size, lower exposure collinearity, centering exposures, continuous outcomes and a larger interaction effect all increased power. In our applied example we found little-to-no association between access to green space, or its interaction with socioeconomic position, and child cardiometabolic outcomes.

Conclusions

Incorporating interactions between multiple exposures is an important extension to SLCMA. The choice of method depends on the researchers' assessment of the risks of under- vs over-fitting. These results also provide guidance for improving power to detect interactions using these methods.

Family predictors of physical activity change during the COVID-19 lockdown in preschool children in Germany

The COVID-19 pandemic is associated with crucial changes in children's daily life including their physical activity (PA) and screen time (ST). Among preschool children, the family represents an important factor for sufficient PA levels by being the gatekeeper for PA. Thus, the aim of this study was to investigate the influence of the family environment, specifically SES, parental support, and having siblings on COVID-19-related changes of PA and ST behavior in 317 (170 boys, 147 girls) German preschool children using longitudinal data. Our results indicate a decline in total amount of sports-related PA, an increase in outdoor play, as well as an increase in leisure ST in preschool children. The changes in total amount of PA differed between children with different levels of parental support as well as in dependence on having siblings. Furthermore, levels of outdoor play and ST in preschool children were influenced by environmental factors like having access to their own garden. We conclude that the family environment (parental support as well as physical environment) is highly relevant for PA and ST levels in preschool children. To provide every child with PA opportunities during potential future lockdowns, restriction policies should be adapted and parents need sophisticated information about the importance of their support and thus the PA levels of their children.

What is the impact of nature on human health? A scoping review of the literature

Background

The burden of non-communicable diseases (including poor mental health) is increasing, and some practitioners are turning to nature to provide the solution. Nature-based interventions (NBIs) could offer cost-effective solutions by reconnecting individuals with nature, but the success of these interventions depends partially on the way in which people engage with blue and green spaces.

Methods

We conducted a scoping review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) and Cochrane guidelines to establish the evidence base for treating poor mental and physical health with NBIs. We searched five databases and the grey literature. Exposure was the active engagement with natural environments. The primary outcome was mental health and the secondary outcome was physical health defined using established metrics. All data were extracted to a charting table and reported as a narrative synthesis.

Results

952 studies were identified, of which 39 met the inclusion criteria. 92% demonstrated consistent improvements across any health outcome where individuals engaged with natural outdoor environments. Mental health outcomes improved across 98% of studies while physical and cognitive health outcomes showed improvement across 83% and 75% of studies respectively. Additionally, we identified 153 factors affecting engagement with nature, 78% of which facilitated engagement compared with 22% that reduced engagement. Aspects such as the sense of wilderness, accessibility, opportunities for physical activity and the absence of noise/ air pollution all increased engagement.

Conclusions

Further research (accompanied by a global improvement in study design) is needed to establish the magnitude and relative effect of nature-based interventions, and to quantify the compounding effect of factors that improve engagement with green and blue spaces. Nevertheless, this review has documented the increasing body of evidence in support of NBIs as effective tools to improve mental, physical, and cognitive health outcomes, and highlighted key factors that improve engagement with the natural world.

Registration

Open Science Framework: https://doi.org/10.17605/OSF.IO/8J5Q3.

Green Space Exposure and Obesity in the Mexican Adult Population

Green space or natural vegetation may reduce obesity risk by increasing opportunities for physical activity or reducing stress and exposure to other pollutants. Obesity prevalence in Mexico is ranked among the highest in the world. However, research on the association between green space and obesity in Mexico is lacking. We used data from the National Nutrition Survey in Mexico (2018-2019), a nationally representative sample of Mexican adults. The analytical sample included participants between 20-59 years of age (n = 12,631). We assessed exposure to green space using a 30 m resolution Landsat satellite Normalized Difference Vegetation Index (NDVI) from 2018. Linear regression models examined associations between NDVI and body mass index (BMI), adjusting for confounders. The mean age of the study sample was 38 (SD 0.19) years. Participants living in areas with the highest green space exposure had the lowest education level (53.51%) and socioeconomic status (28.38%) and were located in central (33.01%), south (30.37%), and rural areas (21.05%). Higher residential exposure to green space was associated with a mean decrease in BMI of -1.1 kg/m² (95% CI: -1.59, -0.68). This is one of the first studies in Latin America to suggest a protective association between green space and obesity among Mexican adults.

Association between built environments and weight status: evidence from longitudinal data of 9589 Australian children

Background

No studies appear to examine potential associations between changes in built environments across childhood and the developmental trajectories of child weight status.

Objective

Examine the developmental trajectories of child weight status with respect to changes in childhood exposure to the built environments.

Methods

This study used data of 9589 children with biennial follow-up (2004–2016), retrieved from the Longitudinal Study of Australian Children. Changes in objectively-measured child weight status (i.e., body mass index-BMI, waist circumference) were investigated in relation to changes in seven built environments (i.e., neighbourhood safety; green space quality; footpaths and street conditions; public transport; shopping facilities; basic services; and local traffic) subjectively reported by caregivers. Group-based discrete trajectory mixture models were used to classify children according to their developmental trajectories of built environments and weight status. Multilevel multinomial logistic regression was employed to examine associations between built environments and child weight status adjusted for confounding.

Results

Two, four, and six trajectory groups were developed for built environment variables. Three groups namely “moderate”, “high”, and “extreme increase” were generated for each BMI and waist circumference. Findings from multilevel analyses indicated that growing up in neighbourhoods that are considered highly safe, with better quality of green space nearby, and in areas with low local traffic over time are protective against unhealthy weight increase in childhood. Meanwhile, living with better access to shopping facilities and basic services was associated with an unhealthy increase in BMI and/or waist circumference. No clear associations appeared between the quality of footpath and street conditions, access to public transport, and child weight status.

Conclusions

Built environments might act either as a risk or protective factor of an unhealthy increase in child weight status. Enabling health-promoting neighbourhoods (i.e., highly safe, quality green space nearby, low local traffic) is important to support a healthy weight trajectory across childhood.

Factors associated with changes in movement behaviors in toddlers and preschoolers during the COVID-19 pandemic: A national cross-sectional study in Mexico

Little is known about physical activity, screen time and sleep among Mexican toddlers and preschoolers. The COVID-19 pandemic led to the closure of childcare education centers and restrictions to spend time outdoors. This study aimed to investigate the correlates of changes in movement behaviors from before to during the early stages of the COVID-19 lockdown in a national sample of toddlers and preschoolers in Mexico. A cross-sectional study was conducted using an open online survey completed by caretakers of children aged 1-5 years from April to July 2020. The questionnaire enquired about the time spent in each movement behavior during a regular week before and during lockdown, and family and household characteristics. Factors associated with changes in movement behaviors were explored using adjusted linear regression models. A total of 631 children (3.3y, 95% CI: 3.1, 3.4) were included in the study. During lockdown, physical activity decreased by 25%, screen time doubled, and sleep quality declined in 17% (p < 0.001). Toddlers and preschoolers of older age, attending a childcare education center before the lockdown, with a screen in their bedroom, higher access to electronic devices, and lower socioeconomic level experienced greater changes during this period. Those with limits on the use of electronic devices, who had someone available to play with them, and availability of toys experienced less pronounced changes. Pandemic restrictions have impacted movement behaviors of toddlers and preschoolers, with disproportionate effects among lower socioeconomic levels. Interventions with a multi-level equity-oriented approach are urgently needed to mitigate these effects.

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.

Home and Neighborhood Physical Activity Location Availability among African American Adolescent Girls Living in Low-Income, Urban Communities: Associations with Objectively Measured Physical Activity

Based on the ecological model of active living, the neighborhood environment may relate to individual physical activity (PA) behaviors. The purposes of this study were to (1) generate a replicable neighborhood-level physical activity location availability score (PALAS) from data variables associated with physical activity among adolescents and adults, and apply this score to Baltimore City, Maryland, and (2) determine if relationships exist between PA and PA location availability. Geographic information systems (GISs) were used to create the PALAS. Using linear regression models, we examined relations between objectively measured PA among low-income, urban, predominantly African American adolescent girls (n = 555, 2009-2012 data collection), and the PALAS rating of their neighborhood environment (neighborhood PALAS) and their home neighborhood area (PALAS variables/subcomponents within 0.25 miles of the home). A PALAS map of the study area was created, illustrating neighborhoods varying in availability and variety of PA locations. After adjusting for confounders, a higher neighborhood PALAS (β = 0.10, p = 0.041) and the presence of a recreation center in the home neighborhood area (β = 0.46, p = 0.011) were associated with more minutes per day spent in moderate to vigorous PA. Policy makers and stakeholders should consider increasing access to PA locations as a strategy to promote PA among adolescent girls.

Relationship Between the Physical Environment and Physical Activity Levels in Preschool Children: A Systematic Review

PURPOSE OF REVIEW

The aim of this study was to understand the influence of the physical environment on the physical activity (PA) behavior of preschool children (aged 2 to 6 years), in order to provide an overview of these influences from the perspective of the ecological model.

RECENT FINDINGS

PA is of great importance for the prevention of obesity and cardiovascular diseases since childhood. The physical environment has a direct relationship with the different domains, where people can spend their time being physically active. Nonetheless, despite the importance of the physical environment to engagement in PA, very few reviews have focused on this relationship in the context of the growing problem of physical inactivity among preschool children. Studies that had analyzed the school domain had found that greater availability of a wider variety of portable play equipment, presence of certain fixed playground equipment, and presence of open spaces had favored PA levels. Furthermore, different studies had shown that the natural environment and the presence of hills were important for children's PA. Thus, despite the associations with PA we were able to identify in this review, new studies will still be needed to link the physical environment with PA levels, especially regarding transportation and leisure time. In conclusion, promoting studies on this subject from an early age will allow us to obtain information that could allow the adaptation, design, and construction of healthier homes, neighborhoods, and schools that promote children's health.

Are school-based measures of walkability and greenness associated with modes of commuting to school? Findings from a student survey in Ontario, Canada

OBJECTIVES

In Canada, students are increasingly reliant on motorized vehicles to commute to school, and few meet the recommended overall physical activity guidelines. Infrastructure and built environments around schools may promote active commuting to and from school, thereby increasing physical activity. To date, few Canadian studies have examined this research question.

METHODS

This study is a cross-sectional analysis of 11,006 students, aged 11-20, who participated in the 2016/2017 Ontario Student Drug Use and Health Survey. The remote sensing-derived Normalized Difference Vegetation Index (NDVI), at a buffer of 500 m from the schools' locations, was used to characterize greenness, while the 2016 Canadian Active Living Environments (Can-ALE) measure was used for walkability. Students were asked about their mode of regular commuting to school, and to provide information on several socio-demographic variables. Multivariable logistic regression models were used to quantify associations between active commuting and greenness and the Can-ALE. The resulting odds ratios, and their 95% confidence intervals, were adjusted for a series of risk factors that were collected from the survey.

RESULTS

Overall, 21% of students reported active commuting (biking or walking) to school, and this prevalence decreased with increasing age. Students whose schools had higher Can-ALE scores were more likely to be active commuters. Specifically, the adjusted odds ratio (OR) of being an active commuter for schools in the highest quartile of the Can-ALE was 2.11 (95% CI = 1.64, 2.72) when compared with those in the lowest. For children, aged 11-14 years, who attended schools in high dwelling density areas, a higher odds of active commuting was observed among those in the upper quartile of greenness relative to the lowest (OR = 1.41; 95% CI = 0.92, 2.15). In contrast, for lower dwelling density areas, greenness was inversely associated with active commuting across all ages.

CONCLUSION

Our findings suggest that students attending schools with higher Can-ALE scores are more likely to actively commute to school, and that positive impacts of greenness on active commuting are evident only in younger children in more densely populated areas. Future studies should collect more detailed data on residential measures of the built environment, safety, distance between home and school, and mixed modes of commuting behaviours.

Greenspace with overweight and obesity: A systematic review and meta-analysis of epidemiological studies up to 2020

Several reviews have been conducted to assess the association between greenspace and overweight or obesity, but the conclusions were inconsistent. However, an updated comprehensive review and meta-analysis is warranted, because several high-quality papers have been published more recently. The objectives of this study are to systematically and quantitatively assess the evidence for a link between greenspace with overweight/obesity and to make specific recommendations for further research. We searched three English language databases, four Chinese language databases and the reference lists of previously published reviews for epidemiological studies on greenspace and overweight/obesity published before January 2020. We developed inclusion criteria, screened the literature and extracted key data from selected papers. We assessed methodological quality and risk of bias, and we graded the credibility of the pooled evidence. We also performed sensitivity analyses. Fifty-seven records met our inclusion criteria and were included in the study. Most studies were cross-sectional designs (81%) and were from developed nations (88%). More than half (55%) of the included studies found beneficial associations between greenspace and overweight/obesity in overall or subpopulations. Our meta-analytical results showed that greater normalized difference vegetation index was associated with lower odds of overweight/obesity in a statistically significant fashion (odds ratio [OR]: 0.88; 95% CI: 0.84, 0.91) but not residential proximity to greenspace (OR: 0.99; 95% CI: 0.99, 1.00), proportion of greenspace (OR: 0.96; 95% CI: 0.85, 1.08) or number of parks in an area (OR: 0.99; 95% CI: 0.97, 1.01). However, we detected high between-study heterogeneity in two of the four meta-analyses, which reduced the credibility of the pooled evidence. Current evidence indicates that there might be an association between greater access to greenspace and lower odds of overweight/obesity. However, additional high-quality studies are needed to more definitively assess the evidence for a causal association.

Effect of an Additional 30 Minutes Spent Outdoors during Summer on Daily Steps and Individually Experienced Heat Index

Spending time outdoors is associated with increased physical activity; however, high ambient temperature/humidity, together with built environment features in urban versus rural environments, may influence physical activity. We conducted an intervention trial with 89 urban and 88 rural participants performing normal activities on Days 1-2 (baseline) and spending an additional 30 min outdoors on Days 3-7 (intervention) in the summer. Participants wore a pedometer with real-time visual feedback to track daily steps taken and a thermometer clipped to their shoe to track temperatures experienced individually. Hygrometer-thermometers were deployed in participants' neighborhoods to collect finer resolution ambient heat indexes in addition to regional weather station measurements. Using linear mixed effects models and adjusting for ambient conditions and individual-level factors, participants on average walked 637 (95%CI (83, 1192)) more steps and had a 0.59 °C (95%CI (0.30, 0.88)) lower daily mean individually experienced heat index during intervention days compared to baseline days. The intervention benefit of increased physical activity was greater in rural residents who were less active at baseline, compared to urban residents. Our results suggest adding a small amount of additional time outdoors may improve physical activity without increasing participants' heat exposure, even during summer in a humid subtropical climate.

Do Spatial Boundaries Matter for Exploring the Impact of Community Green Spaces on Health?

Green space exposure is thought to have a positive influence on physical activity behavior and overall health. However, the literature remains equivocal, and green space measurement methods remain complicated. Using data from the Illinois Behavioral Risk Factor Surveillance System, this study examines the influence of green space on health-related factors, such as exercise, physical health, and mental health. Moreover, we explore the methods for measuring community green space via various spatial boundaries and green space resources. The results show that combining two contextually designated census boundaries and a measure of green space with seasonality were the best spatial conceptualizations for capturing community green space. Moreover, the findings showed a positive influence of green space exposure on health outcomes. These findings highlight the importance of considering geographic contexts of daily human behaviors and green space seasonality in providing a better understanding of the influence of community activity space on environmental exposure measurement. Further, this work contributes to community planning for encouraging health-promoting behaviors.

Maternal exposure to ambient particulate matter and green spaces and fetal renal function

Exposure to air pollution has been associated with different harmful effects and exposure to greenspace has been related to improved human health. However, the available evidence on the impact of these exposures on renal function is still scarce. The aim of this study was to determine the relationship between exposure to ambient levels of PM₁, PM_2.5, PM₁₀ and indicators of exposure to traffic as well as greenspace during pregnancy and fetal renal function based on the umbilical cord blood. This study was based on 150 pregnant women residing in Sabzevar, Iran (2018). Multiple linear regression models were developed to estimate the association of glomerular filtration rate (GFR), creatinine (Cr) and blood urea nitrogen (BUN) with exposure to air pollution, traffic, and greenspace (one at a time) controlled for relevant covariates. There was an inverse significant association between exposure to PM₁, PM_2.5, PM₁₀ and total street length in a 100 m buffer around the home and eGFR. Increase in distance to major road and residential surrounding greenness (100 m buffer) was associated with increase in eGFR. We observed a significant direct association between exposure to PMs as well as street length in 100 m buffer and serum level of Cr. There was also an inverse association between distance to major road and NDVI in 100 m buffer and Cr. The associations for blood urea nitrogen (BUN) were not statistically significant. Our results suggest that exposure to air pollution during pregnancy could have negative impact and exposure to greenspace could have positive impact on renal function of fetal.