The Benefits of Green Space for Children
Photo by Juan Encalada on Unsplash
A UBC population-based cohort study investigated the association between lifetime residential exposure to greenspace and improved childhood development.
The population-based birth cohort study of nearly 30,000 children born in Metro Vancouver, BC, between April 1, 2000 and December 31, 2005, run by a UBC team led by Ingrid Jarvis, assessed early childhood development via teacher ratings on the Early Development Instrument (EDI) and used the EDI score as the primary outcome variable.
Lifetime residential exposure to greenspace was estimated as the mean of annual percentage vegetation values within 250 metres of participants’ residential postal codes. Eight covariates were used to investigate associations between greenspace exposure and EDI scores, including nitrogen oxide (NO2), fine particulate matter (PM2.5), and noise level.
The outcomes of the study support the growing evidence suggesting that exposure to greenspace, such as forest, street trees, parks and gardens, has a positive effect on early childhood development. Suggested reasons for this have included the ability of vegetation to reduce levels of air pollution and noise via means such as removal, distance buffering, or source emission reductions. It has been suggested that exposure to air pollution and noise may adversely affect childhood health and development through, for example, increased stress, sleep disturbance, inflammation and oxidative stress.
The study results give support for these theories, finding that higher levels of lifetime residential exposure to greenspace were associated with an increased ability to meet age-appropriate developmental expectations in kindergarten, as measured by the EDI. The use of a large population-based birth cohort gave access to data on the exposure period from birth to the time of outcome assessment, and the study was able to expand on previous work in the field by using postcode-linked vegetation values and exposure to noise (e.g. from street traffic/rail/aircraft volumes/topography as well as building heights and footprint).
The study notes: “Although our estimated effect of greenspace exposure on EDI scores is small, our findings agree with studies that indicate a positive influence of greenspace on child development outcomes. Previous research has shown that exposure to residential greenspace is associated with better intellectual, behavioral, and psychomotor development among children, and access to neighbourhood greenspace is associated with a reduced odds of childhood social vulnerability. Studies also indicate that access to greenness might reduce behavioural problems in children.”
In an October 25, 2021, article for CBC news, Ingrid Jarvis, the lead researcher on the study, noted, “The findings are important. Not only do they contribute to this broader body of literature suggesting that green space is beneficial for human health … but it’s also really important for application to urban planning policy.” She said that her team’s finding support increasing green space in cities through a large tree canopy, building more parks and community gardens, and increasing access to parks. The study noted that Vancouver has a greater volume of greenspace than many other urban areas, indicating that the outcomes of a similar study in other urban zones might lead to even stronger indications of correlation.
The CBC article also interviewed Stuart Smith, a board member at Abundant Housing Vancouver, who noted that more affluent areas of the city are greener than those with apartments and dense housing due to zoning laws and construction requirements, noting that apartments and dense housing have been used in the past as a “buffer” for more expensive single-family homes in Vancouver to escape noise and air pollution. He argues for upzoning in affluent areas to allow duplexes and denser buildings, to create more equitable access to green space, and move towards a greener Metro Vancouver that would replace large roads and built-up areas that lack vegetation, moving towards reduced overall car usage.