Green space in health research : An overview of common indicators of greenness

Human environments influence human health in both positive and negative ways. Green space is considered an environmental exposure that confers benefits to human health and has attracted a high level of interest from researchers, policy makers, and increasingly clinicians. Green space has been associated with a range of health benefits, such as improvements in physical, mental, and social wellbeing. There are different sources, metrics and indicators of green space used in research, all of which measure different aspects of the environment. It is important that readers of green space research understand the terminology used in this field, and what the green space indicators used in the studies represent in the real world. This paper provides an overview of the major definitions of green space and the indicators used to assess exposure for health practitioners, public health researchers, and health policy experts who may be interested in understanding this field more clearly, either in the provision of public health-promoting services or to undertake research

Novel green space measures and birthweight in Queensland, Australia

IntroductionEnvironmental exposures can contribute both benefits and risks to human health. Green space\ua0represents an environmental exposure that may confer benefits to human health. There are several\ua0proposed benefits to green space exposure, such as improving mental wellbeing, increasing physical\ua0activity, improving the social cohesion of local neighbourhoods, reducing the negative effect of\ua0environmental risk factors, and improving exposure to beneficial microbiota. One of the proposed\ua0health benefits is an improvement in the health outcomes of neonates. Maternal exposure to green\ua0space has been associated with improvements in birthweight, among other birth outcomes. The\ua0developmental origins of health and disease hypothesis suggests that investing in healthy foetal\ua0development in Utero confers benefits across the life span. This makes an assessment of the\ua0potential impacts of environmental exposures on foetal development an important undertaking in\ua0population health. The current body of evidence on birthweight and maternal green space exposure\ua0is limited to a handful of exposure measures and coarse allocation of exposure. Newer measures of\ua0green space have been developed, which allows for an exploration of the effect of different ground\ua0covers (green, dry and bare earth), as well as measures of biodiversity, on health. This thesis\ua0explores the association of these novel green space measures with birthweight in a large birth cohort\ua0in Queensland, Australia.ObjectivesThis study has several objectives: 1) to examine the maternal and socio-demographic characteristics\ua0associated with birthweight; 2) to test for an association between green space, dry cover and bare\ua0earth and birthweight outcomes, controlling for the maternal and social factors; 3) to test whether\ua0foliage projective cover, a measure of crown canopy shading, is associated with birthweight\ua0outcomes; 4) to explore whether effects of green space differ between rural and urban communities;\ua05) to explore the interaction of green space with other environmental variables, namely air pollution\ua0and ambient temperature; and 6) to explore whether biodiversity is associated with birthweight\ua0outcomes.MethodsSeveral data sets were acquired and merged to create the data set used in this study. The outcome\ua0was birthweight (in grams and age-standardised), and this was acquired along with maternal\ua0covariates from the routine health records available for all births in Queensland, Australia. Social\ua0and neighbourhood variables were acquired from the Australian Bureau of Statistics. The exposures\ua0of interest to this study were green space (fractional cover, biodiversity and foliage projective\ua0cover), ambient temperature and air pollution. Directed acyclic graphs were developed to guide\ua0variable selection in all analyses. Mixed-effects linear regression and generalised linear mixed-effects\ua0models were developed, with random intercepts for maternal residential locality and year of\ua0birth. Results are presented as standardised beta coefficients or odds ratios, with 95% confidence\ua0intervals.ResultsMaternal characteristics such as smoking, maternal pre-pregnancy BMI, migration status,\ua0hypertension and diabetes remain important predictors of low birthweight. Analysis ofenvironmental factors showed that in urban areas, each percentage increase of green cover (0.59g,\ua095% CI 0.28 – 0.91) and foliage projective cover (0.52g, 95% CI 0.22 – 0.83) are associated with\ua0increases in estimated birthweight. Each increasing percentage of dry cover (-0.69g, 95% CI -1.21 –\ua0-0.17) and bare earth (-0.35g, 95% CI -0.66 – -0.05) are associated with an estimated decrease in\ua0birthweight. Mothers living in rural areas had similar results, with each percentage increase in green\ua0cover (0.36g, 95% CI 0.06 – 0.65), but not foliage projective cover, associated with an estimated\ua0increase in birthweight, while bare earth (-0.55g, 95% CI -0.91 – -0.19) was associated with a\ua0decrease in birthweight. The biodiversity measure used in this study was not associated with any\ua0birthweight outcomes.ConclusionThis study finds that the types of ground cover within the maternal residential locality are\ua0associated with small, but significant, changes in estimated birthweight. Higher levels of greencover were associated with small increases in birthweight for women residing in both urban and\ua0rural locations. The current study finds that the beneficial effects of green space, and the potentially\ua0negative effects of other ground cover types, is not limited to urban areas. The difference in effect\ua0across the rural-urban divide suggests that rural areas should be considered in future research of\ua0environmental factors. While this study finds highly significant changes in birthweight with\ua0increasing green space, the change is very small, and the current evidence base is lacking on\ua0whether these small changes are important to long-term health of the individual. In the context of\ua0what is currently known, this study concludes that the changes in birthweight found in this\ua0population associated with green space are unlikely to be of biological importance to the individual,\ua0but may be of importance in population health

Environmental risk factors associated with child stunting: a systematic review of the literature

Background: Stunting, a form of malnutrition characterized by impaired linear growth in the first two years of life, affects one quarter of children globally. While nutritional status remains the key cause of stunting, there is evidence that environmental risk factors are associated with stunting.Objective: The objective of this review is to explore the current literature and compile the environmental risk factors that have been associated with stunting. Further, we seek to discover which risk factors act independently of nutritional intake.Methods: A systematic search of the literature was performed using PubMed, EMBASE, Scopus, TOXNET, and CINAHL. A search of the grey literature was conducted. Papers were included in this review if they examined an association between childhood stunting and exposure to environmental risk factors.Findings: We included 71 reports in the final analysis. The included studies showed that foodborne mycotoxins, a lack of adequate sanitation, dirt floors in the home, poor quality cooking fuels, and inadequate local waste disposal are associated with an increased risk of childhood stunting. Access to safe water sources was studied in a large number of studies, but the results remain inconclusive due to inconsistent study findings. Limited studies were available for arsenic, mercury, and environmental tobacco, and thus their role in stunting remains inconclusive. The identified research did not control for nutritional intake. A causal model identified solid fuel use and foodborne mycotoxins as being environmental risk factors with the potential to have direct effects on childhood growth.Conclusions: A diverse range of environmental risk factors are, to varying degrees, associated with stunting, demonstrating the importance of considering how the environment interacts with nutrition. Health promotion activities may be more effective if they consider environmental factors alongside nutritional interventions

Early environmental exposures and life-long risk of chronic non-respiratory disease

Exposure to environmental hazards occurs from the earliest stages of development. There are a broad range of environmental hazards, and virtually all children are exposed to these hazards during the critical period of growth and development. The burden of many chronic diseases continues to rise, and life course studies have shown that early exposure to environmental hazards is associated with non-communicable disease in later years. This review will discuss the environmental exposures associated with four non-respiratory chronic diseases: obesity, diabetes, cardiovascular disease and neurodevelopmental /neurodegenerative conditions.</p

Relationships between women's and men's modifiable preconception risks and health behaviors and maternal and offspring health outcomes: an umbrella review

Parental health before conception effects maternal and offspring health outcomes. Preconception care provides healthcare to prospective parents addressing modifiable preconception risks and health behaviors. This umbrella review aimed to consolidate evidence on women's and men's modifiable preconception risks or health behaviors associated with maternal and offspring health outcomes. MEDLINE, EMBASE, Maternity and Infant Care, CINAHL, and PsycINFO were searched from March 4, 2010, to March 4, 2020. Eligible studies were systematic reviews or meta-analyses of observational studies examining associations between modifiable preconception risks or health behaviors and maternal and offspring health outcomes. Screening, data extraction, and methodological quality assessment (AMSTAR 2) occurred independently by two reviewers. Degree of overlap was examined. Findings were summarized for evidence synthesis. Twenty-seven systematic reviews were included. Modifiable preconception risks and health behaviors were identified across categories: body composition (e.g., overweight, obesity), lifestyle behaviors (e.g., caffeine, smoking), nutrition (e.g., micronutrients), environmental exposures (e.g., radiation), and birth spacing (e.g., short interpregnancy intervals). Outcomes associated with exposures affected embryo (e.g., embryonic growth), maternal (e.g., gestational diabetes mellitus), fetal/neonate (e.g., preterm birth), and child (e.g., neurocognitive disorders) health. For real-world practice and policy relevance, evidence-based indicators for preconception care should include body composition, lifestyle, nutrition, environmental, and birth spacing.</p

Urban environmental exposures during the first 2000 days of life as a foundation for health across the life-course: a scoping review

Objectives: By 2030, 60% of the global population is expected to live in urban areas. Exposure to urban environments during the first 2000 days of life can have positive or negative health outcomes across the life course. Understanding the types of urban exposures that influence health outcomes is needed to guide research priorities for public health and urban planning. This review aims to summarise the published research examining the health outcomes of all urban environmental exposures during the first 2000 days of life, identify the quantity and characteristics of research in this area, methods used, and knowledge gaps. Methods: We conducted a scoping review using the JBI methodology for scoping reviews. Eight databases were searched for peer-reviewed primary studies. Inclusion criteria were studies that measured maternal, infant and child exposure to everyday urban environment features and conditions in cities/metropolitan areas during the first 2000 days of life and reported offspring health outcomes across the life course, including embryo, fetal/newborn, infant, child, adolescent, and adult outcomes. We used Covidence software for data screening and extraction. Study characteristics and findings were summarised using tables and narrative synthesis. Results: We reviewed 235 articles, which included studies conducted across 41 countries, the majority in the US (n = 63). A broad range of environmental exposures were studied, spanning seven categories: air pollution; energy-based pollution; atmosphere, chemical and metal exposure; neighbourhood-built and natural environment features; neighbourhood community conditions; and residential living conditions. Air pollution was the most studied exposure type (n = 153 studies). Health outcomes were reported for all life stages except adults, with fetal/newborn outcomes the most studied life stage (n = 137). Conclusions: We found that most research investigating urban environmental exposures in the first 2000 days and health outcomes across the life course focused on air pollution exposures and fetal/newborn health outcomes, using correlational retrospective cohort designs. Few studies included multiple environmental exposures. There is a clear need for more longitudinal research to determine the health impacts of multiple urban environmental exposures across the life course. This will assist in developing urban design and planning strategies and population health to mitigate health risks across the life course

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.  </p