Residential Green Space Provides Behavioral Benefits During Early Childhood

Multiple studies around the world have found associations between access to green space and mental health in adults, particularly those living in metropolitan areas. The impact of green space on the mental health of younger children has not been as widely studied. A recent paper appearing in JAMA Psychiatry tackles this topic and finds that exposure to green space may be particularly beneficial during early childhood.

“The positive influence of green space on the wellbeing of children is an old idea in the traditional understanding of childhood,” said lead investigator Nissa Towe-Goodman, Ph.D., a research scientist at Frank Porter Graham Child Development Institute at The University of North Carolina at Chapel Hill. However, it has seldom been considered when pressing issues such as domestic violence, substance abuse disorders in the family, food insecurity, and neighborhood safety command the attention of researchers, she continued.

Towe-Goodman led a diverse team in analyzing whether exposure to green space is associated with internalizing (e.g. anxiety and depression) or externalizing (e.g. aggression and rule-breaking) symptoms during early (ages 2-5) or middle (6-11) childhood. The study group included over two thousand children whose families were participating in the Environmental Influences on Child Health Outcomes (ECHO) cohort. ECHO is an NIH-funded program examining how the environment contributes to child health.

The participants were divided equally by gender and lived primarily in the eastern U.S. and metropolitan areas. Green space around each child’s home address was calculated using the Normalized Difference Vegetation Index (NDVI), which uses satellite image data to calculate vegetation density.

The results were adjusted for sex, prematurity, birthing parent educational level and age at delivery, and neighborhood socioeconomic vulnerability. This last is important as research has highlighted the marked inequality of green space between neighborhoods of higher and lower socioeconomic (SES) status.

The data showed that proximity to more residential green space was associated with fewer internalizing symptoms among younger children within the ECHO cohort, even accounting for neighborhood socioeconomic vulnerability. The study did not find the same association in the older cohort, but Towe-Goodman feels that this may be a case where absence of evidence does not equal evidence of absence.

“The difficulty lies in teasing apart the entangled elements [influencing behavior],” Towe-Goodman said. She stressed the need for a big-picture approach that includes assessing not only access to green space but the quality of that space and how children use it.

Children ages 6-11 have started school and experience an increase in screen time and decrease in physical activity in any environment as they are in class and their unstructured play time decreases, even if their structured outdoor time, such as team sports, increases. Playing soccer is not the same kind of exposure to nature as a walk in a wooded area, she said. The study did not include green space levels near daycares or school, though others have studied the positive benefits of green schoolyards, especially for low-income neighborhoods.

Towe-Goodman suggested a good follow-up study would make use of cell phone tracking and accelerometer data to track children’s proximity to green space across the day and quantify the type and duration of their physical activities. This approach could tease out distinctions between free play where nature itself is a significant part of the activity, and organized sports, where the green is a backdrop and other activity holds the child’s attention.

Towe-Goodman acknowledged the limitations of using the NDVI to measure green space. While it detects the presence of vegetation, it cannot assess the quality, accessibility, or safety of nearby natural areas. Green space present near neighborhoods might be agricultural, vegetation growing on brownfields, unsafe derelict areas, or private natural areas not available to the public. There was also limited data for arid parts of the country, where green space is scare, or rural areas where abundant green space is combined with lower SES –topics Towe-Goodman intends to pursue next.

She also hopes to identify what it is about natural spaces that benefits young children, including the possibility that it is not the “green” per se, but rather engagement with biodiversity, including insects, animals, and even soil microbes. If exposure to biodiversity proves important, this would influence intervention efforts.

Overall, Towe-Goodman said this study supports the idea that funding access to healthy green space, particularly for vulnerable SES neighborhoods, has value in offsetting the mental health stresses on children and fostering healthier adolescents.

This study and the ECHO program were supported by multiple grants and awards from the NIH. ■