Spending Time in Nature Promotes Early Childhood Development

Summary: Children who live in areas with easy access to greenspaces and natural vegetation showed better overall development than their peers who lived closer to fewer greenspaces.

Source: University of British Columbia

Want to ensure your child hits their expected developmental milestones? New UBC research suggests living in areas with high exposure to greenspace can help set them up for success.

For the study, researchers at the UBC faculty of forestry and faculty of medicine analyzed the developmental scores of 27,372 children in Metro Vancouver who attended kindergarten between 2005 and 2011. They estimated the amount of greenspace around each child’s residence from birth to age five. They also assessed levels of traffic-related air pollution and community noise.

The results highlight the fundamental importance of natural green spaces like street trees, parks and community gardens, authors say.

“Most of the children were doing well in their development, in terms of language skills, cognitive capacity, socialization and other outcomes,” says study author Ingrid Jarvis, a PhD candidate in the department of forest and conservation sciences at UBC.

“But what’s interesting is that those children living in a residential location with more vegetation and richer natural environments showed better overall development than their peers with less greenspace.”

According to the researchers, the reason for this is partly greenspaces’ ability to reduce the harmful effects of air pollution and noise—environmental challenges that have been shown to adversely affect children’s health and development through increased stress, sleep disturbances and central nervous system damage.

“Few studies have investigated this pathway linking greenspace and developmental outcomes among children, and we believe this is the first Canadian study to do so,” adds Jarvis.

The researchers assessed early childhood development using the Early Development Instrument (EDI), a survey completed by kindergarten teachers for each child. The tool measures a child’s ability to meet age-appropriate developmental expectations.

“More research is needed, but our findings suggest that urban planning efforts to increase greenspace in residential neighbourhoods and around schools are beneficial for early childhood development, with potential health benefits throughout life,” says the study’s senior author and UBC research associate, Matilda van den Bosch (she/her).

“Time in nature can benefit everyone, but if we want our children to have a good head start, it’s important to provide an enriching environment through nature contact. Access to greenspace from a very young age can help ensure good social, emotional and mental development among children.”

The study, published recently in The Lancet Planetary Health, includes contributions by researchers at the University of California Berkeley, University of California Los Angeles, Barcelona Institute for Global Health, BC Children’s Hospital and BC Centre for Disease Control.

Abstract

Assessing the association between lifetime exposure to greenspace and early childhood development and the mediation effects of air pollution and noise in Canada: a population-based birth cohort study

Background

Exposure to greenspace is associated with improved childhood development, but the pathways behind this relationship are insufficiently understood. Therefore, we aimed to investigate the association between lifetime residential exposure to greenspace and early childhood development and evaluate the extent to which this association is mediated by reductions in traffic-related air pollution and noise.

Methods

This population-based birth cohort study comprised singleton births in Metro Vancouver, BC, Canada, between April 1, 2000, and Dec 31, 2005. Children and mothers had to be registered with the mandatory provincial health insurance programme, Medical Services Plan, and have lived within the study area from the child’s birth to the time of outcome assessment. Early childhood development was assessed via teacher ratings on the Early Development Instrument (EDI), and we used the total EDI score as the primary outcome variable.

We estimated greenspace using percentage vegetation derived from spectral unmixing of annual Landsat satellite image composites. Lifetime residential exposure to greenspace was estimated as the mean of annual percentage vegetation values within 250 m of participants’ residential postal codes. Multilevel modelling, adjusted for eight covariates, was used to investigate associations between greenspace exposure and EDI scores. We estimated the mediation effects of nitrogen dioxide (NO₂), fine particulate matter (PM_2·5), and noise levels using causal mediation analyses.

Findings

Of the 37 745 children born in Metro Vancouver between April 1, 2000, and Dec 31, 2005, 27 372 were included in our final study sample. In the adjusted model, 1 IQR increase in percentage vegetation was associated with a 0·16 (95% CI 0·04–0·28; p=0·0073) increase in total EDI score, indicating small improvements in early childhood development. We estimated that 97·1% (95% CI 43·0–396·0), 29·5% (12·0–117·0), and 35·2% (17·9–139·0) of the association was mediated through reductions in NO₂, PM_2·5, and noise, respectively.

Interpretation

Increased exposure to residential greenspace might improve childhood development by reducing the adverse developmental effects of traffic-related exposures, especially NO₂ air pollution. Our study supports the implementation of healthy urban planning and green infrastructure interventions.