March 9, 2022

Green spaces can provide a wide variety of environmental, health and equity benefits for urban residents. Environmental benefits of green space include negating urban heat, minimizing air pollution, and regulating flooding. Health benefits of green space include positive health outcomes for mental health, physical activity, stress, pregnancy outcomes and cardiovascular health. Equity benefits of green space include a phenomenon known as the equigenesis hypothesis. Equigenesis is a term that refers to when something in the environment narrows a health inequity, making health outcomes more equitably distributed. According to this hypothesis, green spaces promote health equity by supporting the health of residents in less advantage neighborhoods and reducing socioeconomic status-based disparities in cardiovascular mortality and mental health outcomes.

Celina Koh, MPH Epidemiology and Biostatistics ‘21, became interested in this research topic after completing her applied practical experience with the Environmental Protection Agency (EPA)’s Region 3 Office of Communities, Tribes, and Environmental Assessment (OCTEA) and the Urban Health Collaborative (UHC). She also worked as a research assistant at the UHC with Usama Bilal, MD, PhD, MPH, assistant professor, on the Big Cities Health Coalition’s COVID-19 Health Inequities Dashboard.

Her study analyzed adults residing in Philadelphia and found a very wide socioeconomic disparity in hypertension after adjusting for age, sex, and race and ethnicity. Individuals with lower educational attainment or living in areas of low income had a higher prevalence of hypertension. However, the study did not find support for the equigenic hypothesis, as they found that the educational and income disparities in hypertension were similar across all levels of green space availability. Green space is a relatively new tool for addressing health equity and outcomes for population health. This present study contributes to the current body of evidence by providing additional insight on association between green space and educational disparities in hypertension prevalence.

This study also includes Heather Rollins, data analyst, UHC, and Michelle Kondo, PhD, scientist, USDA Forest Service.

Read the full study here.