Search

Global urbanization has sparked substantial environmental, public health, and social science research on the importance of conserving and propagating natural environments. A large subset of this work focuses on the benefits of green space for health. An often-overlooked methodological concern when examining relations between green space and health, however, involves residential self-selection. The selective movement of individuals into greener neighborhoods on the basis of preexisting health and correlated social factors may bias associations, particularly in cross-sectional studies, which predominate existing green space/health research. To quantify the extent of residential self-selection bias, this study used a longitudinal sibling comparison design with repeated individual and neighborhood measures to estimate associations between pre-move health factors, including maternal body mass index (BMI) and infant birthweight, and post-move neighborhood green space in a residentially mobile sample of mothers in California, 2007 to 2015 (n = 288,333). Results show that better health before moving predicted higher levels of neighborhood green space after moving, providing evidence of health selection. Findings also indicate some support for differential health selection into neighborhood green space by race/ethnicity, including that evidence of selection emerges for white and Hispanic, but not Black, mothers. However, weak relations between pre-move individual factors and post-move neighborhood green space across analyses suggest that potential bias due to residential self-selection appears relatively minimal in a large, diverse, and highly mobile sample of families in California. Findings support calls to increase green space in historically marginalized neighborhoods as a means to promote environmental and health equity. • Greenspace-health research relies on cross-sectional designs susceptible to bias. • Study examines role of pre-move health on post-move greenspace among mothers. • Finds evidence of health selection into greenspace, stronger for White mothers. • Weak associations indicate minimal bias due to health selection in study population. • Suggest contextual and selection effects involved in greenspace-health associations. [ABSTRACT FROM AUTHOR]

Previous work reports an inverse association between neighborhood greenness and obesity. Limitations of this work, which relies largely on cross-sectional data, include that studies often lack control for unmeasured genetic and sociodemographic factors that may confound associations, and cannot disentangle temporal order between neighborhood greenness and obesity. We move beyond a cross-sectional approach and leverage a longitudinal sibling-linked dataset with health, residential, and demographic information on women with two births in California between 2007 and 2015 (N = 552,929). We used a sibling comparison design to control for unmeasured stable characteristics of women and tested whether a positive change in neighborhood greenness (i.e., "upward green mobility") precedes a reduction in obesity risk. Models also adjusted for baseline obesity risk and time-varying individual- and neighborhood-level socioeconomic factors. As hypothesized, we find that upward green mobility varies inversely with the odds of obesity. Results indicate that small decreases in neighborhood greenness may also show protective associations with obesity risk. Our findings, if replicated, suggest that changing levels (particularly increases) of greenness in the residential environment may combat the rise of obesity. [ABSTRACT FROM AUTHOR]