INMA: “Social inequalities, green and blue spaces and mental health in 6–12 years old children participating in the INMA cohort”

14/02/2024

An exciting new study has used the INMA cohort to investigate how living near to green and blue spaces affects people’s mental health. While there is existing evidence to suggest that access to the natural environment is beneficial for mental health, this new study went further by investigating the potential impact of socio-economic status (SES) on this relationship. This is an important consideration because there is evidence that people from lower socio-economic backgrounds have less access to natural environment features, which may exacerbate existing inequalities.

Specifically, this study used validated questionnaires to determine the extent to which children from Asturias, Gipuzkoa, Sabadell and Valencia in Spain, internalize or externalize their perceived psychological problems, and also looked at four distinct symptom groups: emotional problems, conduct problems, hyperactivity and inattention, and peer problems. The authors used two quantitative measures of proximity to natural environment features, namely, the normalised difference in vegetation index (NDVI) and whether or not the person has green space (such as a park) within 5km of their home. The SES for the specific areas in which people live was calculated using a validated index that is based on unemployment, the proportion of manual workers, people in temporary work, low-levels of educational attainment, and low-levels of educational attainment in young people.

The study found no clear difference in the relationship between mental health conditions and natural environment features between levels of SES, although children whose mothers graduated from secondary school consistently had lower internalizing and externalizing scores than children whose mothers had a highest educational level of primary school.

This new study did not identify an association between green and blue space and internalizing and externalizing problems. This finding is consistent with a recent systematic review on the subject. The authors of the new study hypothesised that this may be due differences in the association between subgroups of the population, hence the investigation by different levels of SES. Analysing subgroups according to SES, however, did not show a statistically significant association between green and blue space and internalizing and externalizing problems.

While the study didn’t find associations between SES and the relationship between mental health and access to the natural environment, it found some evidence to suggest that proximity to natural environment features alone was influenced by SES. These were not always in the expected direction though, for example while children in the lowest SES band had lower levels of vegetation than those in the highest SES band according to the NDVI score, they actually had higher levels of access to major green space. Other studies have reported that there may be a difference in the quality of these green spaces, but this was outside the scope of the current study.

The authors concluded that while this study did not identify statistically significant associations between mental health and the natural environment by levels of SES, there are grounds for further investigation. They suggested that future investigations may benefit from measuring the amount of time individuals spend in natural areas, rather than just their access to them, and also the quality of the natural spaces. All in all this study contributed to the existing literature by providing additional evidence of the factors that may or may not influence mental health in children

Reference: Subiza-Pérez M, García-Baquero G, Fernández-Somoano A, Riaño I, González L, Delgado-Saborit JM, Guxens M, Fossati S, Vrijheid M, Fernandes A, Ibarluzea J, Lertxundi N. Social inequalities, green and blue spaces and mental health in 6-12 years old children participating in the INMA cohort. Health Place. 2023 Sep;83:103104.

Link to scientific article: https://doi.org/10.1371/journal.pone.0283799