Caregivers’ perceptions of green space may be an important indicator of children’s green space exposure Existing research indicates that exposure to green space is linked to improved mental health and cognitive function outcomes in children; however, studies commonly rely on different assessment methods to quantify green space exposure. Studies also often quantify green space based on a fixed point that does not account for individual movement or actual green space utilization. Additionally, green space assessments generally fail to incorporate perceptions of green space quality, safety, or accessibility that are likely to influence children’s exposure. This study aimed to clarify how different measures of green space exposure, based on both subjective and objective assessments, are related to children’s mental health and cognitive function outcomes. In the study, objective green space referred to actual time spent in green areas, measured using spatial and environmental data collected via GPS to track individual movement, while subjective green space was defined as caregiver-reported time spent in green space and their perceptions of neighborhood green space.
Children and their primary caregivers were recruited to participate in the research as part of the ongoing Project Green Space, Sleep, and Mental Health (G-SPACE) study. Eligible participants included caregivers over 18 who spoke English or Spanish, and whose child was enrolled in first, second, or third grade at a school in Rhode Island, U.S. Data collection occurred over one week and included both subjective (caregiver-reported) and objective (device-measured) assessments. Children’s mental health and cognitive function during the previous week were evaluated using the Patient Reported Outcome Measurement Information System (PROMIS) survey, completed by their caregivers. This survey included subscales to assess cognitive functioning, psychological stress experiences, anger, and positive affect. Caregivers completed a green space questionnaire to determine children’s park or green space usage over the past week as a subjective measure of green space exposure. Caregivers also reported their perceptions of their neighborhood parks and green space. Completed surveys were obtained from 104 caregivers. To obtain an objective assessment of green space exposure, children wore a Global Positioning System (GPS) unit for one week. Green space exposure was quantified using the Normalized Difference Vegetation Index (NDVI) and a tree canopy cover dataset based on children’s GPS location data. Complete GPS/green space exposure data was collected from 61 children. The study also collected participants’ socioeconomic information. Data analysis employed statistical methods.
A majority of caregivers reported positive perceptions of the green spaces in their neighborhoods: 89% indicated that green spaces were accessible, 74% considered them sufficient, and 84% regarded them as well-maintained. Overall, caregivers indicated that children visited green spaces 3.7 times a week, for a total of 6.7 hours. Statistical comparison of caregiver-reported green space exposure with NDVI and tree canopy cover data revealed significant associations, suggesting consistency between subjective and objective green space measures. Interestingly, significant relationships were found between caregivers’ perceptions of green space and objective measures of children’s green space exposure. Children’s NDVI and tree canopy exposure were higher when caregivers perceived neighborhood green space to be sufficient or well-kept. However, caregivers’ perception of green space accessibility was not related to objective green space measures. Overall results regarding the relationship between green space, mental health, and cognition revealed that children with higher green space exposure or better perceptions of neighborhood green space generally had better mental health and cognitive function outcomes. In particular, children with above-normal psychological stress experiences were significantly more likely to live in neighborhoods where caregivers perceived green space as not well-kept. This relationship remained significant even after adjusting for socioeconomic status. Importantly, analysis determined that “the odds of increased psychological stress experiences were 96% lower for children living in neighborhoods with well-kept green space compared to children living in neighborhoods without well-kept green space.” Additionally, after adjusting for socioeconomic status, higher NDVI exposure was significantly linked to reduced odds of below normal cognitive function. Other relationships were also identified; however, they were not statistically significant. Overall, the non-significant findings provided some indication that children with higher green space exposure tended to have mental health and cognitive function scores within the normal limits.
The study is one of the first to compare objective measures of green space exposure, caregiver-reported green space exposure, and caregiver perceptions of neighborhood green space to children’s mental health and cognitive function. As such, “this study makes meaningful contributions to the limited literature exploring how objective and subjective green space measures are related.” The researchers conclude that “caregiver green space perception and caregiver-reported green space are important indicators of objective green space exposure in children and highlight the differential green space needs of pediatric populations.” Although the study identified links between increased green space and improved mental health and cognition outcomes, surprisingly, few of the relationships were statistically significant. Researchers should continue to examine the links between green space and children’s mental health and cognitive function and explore the mechanisms that underlie these relationships. Findings also call attention to the distinct green space needs of children, especially the significance of adequate and well-maintained areas to enhance children's exposure.
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