Does green space matter? Exploring relationships between green space type and health indicators

•We examined all different types together, but we also measured them separately.•Aggregated green space was not related to mental and general health.•Forest was associated with fewer days of mental health complaints.•Urban green space was related to fewer days of mental health complaints in stratified analyses.•Types and size seem important factors in the relationship between green space and mental health.

This study explores whether general specification or specific types of green spaces are associated with mental and general health. A sample of 5,148 respondents from the Behavioral Risk Factor Surveillance System, conducted in 2006 in Washington State across 98 zip-codes, was analyzed. Measures included mental health complaints (last 30 days), anxiety-depression complaints (last 14 days), and general health status. Percentage of green spaces was derived from the National Land Cover Dataset. The associations were examined in both total and subsamples (urban vs. rural zip-codes). Bivariate correlations and multilevel regression analysis controlling for age, sex, race, income, education level, size of green space, and zip-code population and socio-economic situation indicated 'aggregated green space' was not associated with mental and general health. On the other hand, respondents in areas that have more forests report fewer days of mental health complaints in total sample. Results also revealed that more urban green space was associated with fewer days of mental health complaints in urban zip-codes. In addition, size of forest in urban areas was associated with fewer days of mental health complaints. Our findings suggest that types of green space should be considered individually rather than aggregated as 'simply green' and 'size' of forest in urban areas seems an important factor to affect the relationship between green space and mental health.