Researchers quantify the impact of urban vegetation on mortality rates

A nationwide study on urban greenery found that increased green vegetation in large, metropolitan areas could have prevented more than 30,000 deaths over two decades. Researchers examined publicly available data to model and quantify the impact of urban greenery on the longevity of senior citizens.

The Boston University-based team, supported in part by a grant from the U.S. National Science Foundation, used publicly available data from the U.S. Census, the Centers for Disease Control and Prevention, and NASA satellites to survey the health impact of increased green vegetation on senior citizens living in urban areas across the nation during three specific time periods.

The team used a widely accepted index to estimate how many deaths could have been avoided with an 0.1 increase in the index across the urban areas in the cohort and found about 15 to 20 deaths per 10,000 seniors could have been prevented.

"We've known that living in greener areas can have a positive impact on our physical and mental health, but there is a lack of data on how changes in greenness distribution can affect death rates across the country," said lead author of the study Paige Brochu. "Our study quantifies the impact of greenness expansion in urban areas and shows that increasing green vegetation could potentially add to life expectancy."

Greening varies by area due to climate, water sources, urbanization and terrain. The findings from the study can inform urban planning and policy that develop effective greening and climate action plans.

"Increasing greenness in an arid climate in the Southwest is different than increasing greenness in an urban area in the Pacific Northwest," said Brochu. "If an area's climate makes it difficult to plant lush trees, urban planners can use this greenness data as a starting point and consider other types of vegetation that may be more realistic."

Added study co-author Marcia Pescador Jimenez, "A next step is to evaluate whether the effect of greenness on mortality is the same across race/ethnicity groups.”