A life course approach to understanding associations between natural environments and mental well-being for the Danish blood donor cohort

The association between green space around schools, screen time for entertainment, and adolescent depressive symptoms: a nationwide study from China

BACKGROUND

Natural green environments are beneficial to people's mental health, while too much screen time may be harmful to adolescents' mental health. However, it is not clear how green spaces and screen time affect mental health together in adolescents. MethodsA total of 22,868 adolescents were recruited from October to December 2021 in eight cities in China, through multistage cluster sampling. The Patient Health Questionnaire (PHQ-9) was used to investigate adolescents' depressive symptoms, and the Normalised Vegetation Index for the 200m, 500m and 1000m buffer zones around the school represents the green cover around the school. We used binary logistic regression to analyse the association between green space, screen time and depressive symptoms.

RESULTS

In fully adjusted models, the highest quartile of NDVI in the 200m, 500m and 1000m buffer zones around the school was a protective factor for depressive symptoms. For less than 2 hours of recreational screen time, the highest quartiles of the NDVI and the association with depressive symptoms were negatively correlated for the 200m, 500m and 1000m buffer zones (NDVI200: 0.904(0.848-0.964)), NDVI500: 0.863(0.808-0.921), NDVI1000: 0.862(0.808-0.920)). The highest quartiles of NDVI in all buffers were not associated with depressive symptoms when the screen time was >2 hours. The association between green space and depressive symptoms at lower recreational screen time was observed to be stronger in the group of adolescents with a lower family economic status (NDVI200: 0.780(0.695-0.876), NDVI500: 0.838(0.748-0.938), NDVI1000: 0.783(0.698-0.879)). No potential gender differences were observed.

CONCLUSIONS

For adolescents with less than two hours of recreational screen time per day, the greenery around the school had a protective effect on their mental health, especially for adolescents from economically disadvantaged families. Green spaces around schools are significant in improving health inequities.

Perspectives on environment and health research in Denmark

AIMS

We provide an overview of nationwide environmental data available for Denmark and its linkage potentials to individual-level records with the aim of promoting research on the potential impact of the local surrounding environment on human health.

BACKGROUND

Researchers in Denmark have unique opportunities for conducting large population-based studies treating the entire Danish population as one big, open and dynamic cohort based on nationally complete population and health registries. So far, most research in this area has utilised individual- and family-level information to study the clustering of disease in families, comorbidities, risk of, and prognosis after, disease onset, and social gradients in disease risk. Linking environmental data in time and space to individuals enables novel possibilities for studying the health effects of the social, built and physical environment.

METHODS

We describe the possible linkage between individuals and their local surrounding environment to establish the exposome - that is, the total environmental exposure of an individual over their life course.

CONCLUSIONS

The currently available nationwide longitudinal environmental data in Denmark constitutes a valuable and globally rare asset that can help explore the impact of the exposome on human health.

A Review of the Role of Built Environment and Temperature in the Development of Childhood Obesity

The burden of obesity is rising globally and is studied widely, yet the evidence for the association of environmental factors (both built and natural) with childhood obesity remains inconsistent. A relation with temperature as a proxy for natural environmental factors for obesity has not been reviewed previously. The purpose of this review was to assimilate updated evidence on environmental factors of childhood obesity. Three databases, MEDLINE (Medical Literature Analysis and Retrieval System Online), Web of Science, and Cochrane, were searched for articles related to the effect of built environment and temperature on childhood obesity in 6-12-year-olds published in the last five years. Twelve studies were identified: four longitudinal and eight cross-sectional. The studies were appraised using the National Institute of Health Quality (NIH) Assessment Tool. A review of included studies showed that built environmental features like higher residential and population density, higher intersection density, more playgrounds, and all park features like the presence or availability of parks, high number of parks, proximity to parks, and an increased park land area, showed a protective association against childhood obesity while land use mix showed a promoting association for the development of childhood obesity. Inconclusive evidence was observed for other built environmental features. The search strategy did not retrieve any literature published in the past five years studying the association between temperature and the development of childhood obesity. Standardization of definitions of exposure and outcome measures is recommended. Further research studying the relationship between environmental temperature and the development of childhood obesity is recommended.

Marine or freshwater: the role of ornamental fish keeper's preferences in the conservation of aquatic organisms in Brazil

Background

The use of ornamental fish as pets has important implications for the conservation of the species used in fish keeping, particularly in relation to overexploitation. Understanding ornamental fish keepers' relationship with the hobby can provide important information for assessing the potential impacts of the activity. Here, we analyzed the profile of Brazilian ornamental fish keepers and evaluated their preferences and the implications of their choices.

Methods

Information was obtained by applying questionnaires to 906 ornamental fish keepers participating in fish keeping groups in a social network. The questionnaire contained questions about the species of fish kept (freshwater and marine), techniques used, socio-economic aspects, and associated conservation perspectives.

Results

Most ornamental fish keepers were young men (20-40 years old), with higher education and monthly income above US$ 530.00. Participants predominantly kept freshwater fish (86%), but marine fish only (5%) or both marine and freshwater hobbyists (9%) were also recorded. A total of 523 species of ornamental fish were kept, most of which comprised freshwater (76% of the total) and exotic species (73%). About a third of the fish species recorded were under national trade restrictions. In addition, about a third of ornamental fish keepers declared that they also had invertebrates. Marine aquariums require a greater financial investment, especially at the beginning, than freshwater aquariums and are also almost entirely based on exotic species. The aesthetic factor is the main motivation associated with practicing this hobby, being color and behavior key factors in choosing fish. A total of 10% of hobbyists have already released fish into the wild, highlighting concerns about potential biological invasions. There is an urgent need to enforce regulations towards restricting ornamental fish keepers' access to threatened native species and potentially invasive species, as well as measures aimed at informing and raising hobbyists' awareness of conservation measures related to the hobby.

Exposure to surrounding greenness and natural-cause and cause-specific mortality in the ELAPSE pooled cohort

BACKGROUND

The majority of studies have shown higher greenness exposure associated with reduced mortality risks, but few controlled for spatially correlated air pollution and traffic noise exposures. We aim to address this research gap in the ELAPSE pooled cohort.

METHODS

Mean Normalized Difference Vegetation Index (NDVI) in a 300-m grid cell and 1-km radius were assigned to participants' baseline home addresses as a measure of surrounding greenness exposure. We used Cox proportional hazards models to estimate the association of NDVI exposure with natural-cause and cause-specific mortality, adjusting for a number of potential confounders including socioeconomic status and lifestyle factors at individual and area-levels. We further assessed the associations between greenness exposure and mortality after adjusting for fine particulate matter (PM2.5), nitrogen dioxide (NO2) and road traffic noise.

RESULTS

The pooled study population comprised 327,388 individuals who experienced 47,179 natural-cause deaths during 6,374,370 person-years of follow-up. The mean NDVI in the pooled cohort was 0.33 (SD 0.1) and 0.34 (SD 0.1) in the 300-m grid and 1-km buffer. In the main fully adjusted model, 0.1 unit increment of NDVI inside 300-m grid was associated with 5% lower risk of natural-cause mortality (Hazard Ratio (HR) 0.95 (95% CI: 0.94, 0.96)). The associations attenuated after adjustment for air pollution [HR (95% CI): 0.97 (0.96, 0.98) adjusted for PM2.5; 0.98 (0.96, 0.99) adjusted for NO2]. Additional adjustment for traffic noise hardly affected the associations. Consistent results were observed for NDVI within 1-km buffer. After adjustment for air pollution, NDVI was inversely associated with diabetes, respiratory and lung cancer mortality, yet with wider 95% confidence intervals. No association with cardiovascular mortality was found.

CONCLUSIONS

We found a significant inverse association between surrounding greenness and natural-cause mortality, which remained after adjusting for spatially correlated air pollution and traffic noise.