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Reduced Risk of Autism Spectrum Disorder in Babies Born to Individuals Living Close to Parks

A recent study conducted by researchers from Health Canada, BORN Ontario, and the Ottawa Hospital Research Institute (OHRI) found that proximity to parks was associated with a reduced risk of Autism Spectrum Disorder (ASD) in babies born to individuals living in such areas at birth (even after accounting for ambient air pollution exposure and other covariates).

As the first known study to show a reduced risk of ASD with park proximity, this research adds to our understanding of environmental influences on neurodevelopmental outcomes and underscores how greenspaces can positively impact public health.

What’s Next?

The authors call for further research to explore the mechanisms behind these associations and to identify the most effective types of greenspaces. In addition, they hope this work will inform urban planning (i.e. prioritizing accessible park areas) and policy decisions (i.e. city planning and public health initiatives for creating healthier living environments).

Study Details

The researchers explored prenatal exposure to greenspace and active living environments using the following measures:

  • Green View Index (GVI) 
  • Normalized Difference Vegetation Index (NDVI)
  • tree canopy
  • park proximity
  • Active Living Environments index (ALE)

The study used population-based data from the Ontario Ministry of Children and Youth Services' Child and Adolescent Needs and Strengths – Autism Spectrum Profile (CANS-ASP), the BORN Information System, and the Canadian Urban Environmental Health Research Consortium from 2012 to 2017.

The researchers analyzed 8643 mother-child pairs, including 1,554 children with ASD (children aged 2-6 diagnosed by a health professional).  Although they did not find an association between ASD and NDVI, GVI, tree canopy, or various ALE categories, they found a protective effect of park proximity on the risk ASD. Park proximity measured at birth (i.e., living closer to a park) decreased a child's risk of ASD regardless of the level of urbanicity and adjustment for air pollution, although protective effects appeared to be more pronounced in neighborhoods with a lower population density. 

Study Limitations

Data constraints led to several limitations:

  • Only children accessing publicly-funded services in Ontario were presented in the CANS-ASP dataset.
  • Approximately 40% of ASD cases could not be linked to provincial birth records.
  • Information on the severity of ASD cases was unavailable.
  • Potential residential relocations during pregnancy were not accounted for.
  • Temporal changes in greenspace exposure throughout pregnancy were not accounted for.

 

Learn more about this study: 

Associations of neighborhood greenspace, and active living environments with autism spectrum disorders: A matched case-control study in Ontario, Canada