Areas with tree cover may provide greater mitigation of air pollution, noise and heat than more open green spaces

April 21, 2022

Science Daily/Barcelona Institute for Global Health (ISGlobal)

A study recently published in Environment International has found that living in a tree-filled environment is associated with better early childhood development than living in an environment where vegetation takes the form of grass cover. The analysis -- led by Matilda van den Bosch, senior researcher at the Barcelona Institute for Global Health (ISGlobal), a centre supported by the "la Caixa" Foundation -- also found that both varieties of green space are associated with better child development outcomes than areas dominated by paved surfaces.

The study reinforces the notion -- supported by a growing body of research -- that green spaces are associated with better attention and memory in early childhood, higher academic achievement, and fewer emotional and behavioural problems. However, the research team wanted to go further and explore whether the type of vegetation makes a difference in these positive associations. All green spaces appear to promote health, but tree-filled areas may mitigate air pollution, noise and heat better than more open green spaces, while also doing more to support restoration from mental fatigue and the capacity for directed attention. Grassy spaces, in contrast, may do more to encourage group activities and therefore foster social well-being. Paved surfaces, meanwhile, are associated with more heat exposure and traffic-related air and noise pollution.

How the Study Was Conducted

The analysis was carried out in the Vancouver metropolitan area (Canada) and was based on a large birth cohort containing data on 27,539 children. These data were collected between 2000 and 2005 by various government bodies, including the British Columbia Ministry of Health. The children were followed from birth to age five years, at which time their kindergarten teachers rated their physical health and well-being, social competence, emotional maturity, language and cognitive development, communication skills and general knowledge. The teachers performed this assessment using a tool known as the Early Development Instrument (EDI).

The researchers used a high-spatial-resolution land cover map to determine whether the areas where the children lived were vegetated or non-vegetated and whether the vegetated land consisted of grass or trees (predominantly deciduous). The mean percentage of total vegetation exposure was found to be 36%, while the mean percentage of paved surfaces exposure was slightly lower at 32.2%.

Conclusion

Children with the greatest exposure to vegetation (either trees or grass) had the highest developmental scores. This positive association was especially notable for exposure to tree-filled areas. In contrast, early-life exposure to paved surfaces was associated with poorer child development.

"Because we assessed different types of vegetation, our findings contribute to an improved understanding of associations between exposure to green spaces and early childhood development," commented Ingrid Jarvis, researcher at the University of British Columbia (Canada) and first author of the study.

Although more research is needed, these findings may be useful to urban planners. "Taken together, our findings suggest that converting paved surfaces to green spaces and, in particular, increasing the amount of trees in neighbourhoods may have positive effects on early childhood health and development," noted ISGlobal researcher Matilda van den Bosch who led the research. Such efforts would not only reap the benefits associated with green spaces, but potentially also "reduce the adverse effects associated with urbanisation and impervious environments," she added. Although the observed associations between environmental exposure and childhood development were relatively small, "even minor individual gains in childhood could lead to important public health benefits across the life course," she concluded.

https://www.sciencedaily.com/releases/2022/04/220421141608.htm