About Green Heart Louisville

About Green Heart Louisville

Green Heart Louisville is a unique, first of its kind study to rigorously and scientifically assess the impact of green space on air quality and health in urban communities.

(video transcript)

Green Heart Louisville will examine, for the first time, if increasing greenness in an urban community will reduce the levels of air pollution in the neighborhood, decrease the risk of heart disease, and increase outdoor activity and relationships between neighbors.Green Heart will help us to discover:

  • How to plant trees in urban communities to maximize the removal of air pollution,
  • If increasing green space affects the risk of developing obesity, diabetes, and heart disease,
  • If increasing urban green space reduces mental stress, enhances social cohesion, increases physical activity, and
  • If urban green space affects crime rates, property values, storm water runoff, energy use, and heat island effect.

Green Heart Neighborhoods

To find the ideal place for Green Heart we evaluated existing tree cover, major roadways, population density, plantable space, and neighborhood characteristics of all the neighborhoods in Louisville. From this assessment, we chose a three-square mile area in South Louisville encompassing six communities, Oakdale-Wyandotte, Wilder Park, Taylor-Berry, Beechmont, and Hazelwood.


  • Baseline measurements in 2018 and 2019
    • Monitor levels of air pollution around roadways and residential areas.
    • Recruit hundreds of people for the HEAL Health Study to see baseline health, stress levels, lifestyle and relationships, and disease risk.
  • Greening in 2019 and 2020
    • Plant thousands of trees, shrubs, and grasses to create a robust and sustainable ecosystem maximized to remove air pollution.
  • Monitoring in 2020 and 2021
    • Track changes in pollution, physical and mental health, and social change.
  • Comparison in 2022
    • Compare observed changes before planting and two years after planting

    Green for Good Pilot Project

    Before there was Green Heart, there was Green For Good. Green For Good was a smaller, pilot project from 2015 until 2017 that led to Green Heart. In 2015, we searched all over Louisville for a place where people needed to be protected from roadway air pollution. We identified St. Margret Mary Catholic Elementary School, across 8 lanes of traffic from one of Louisville's busiest shopping malls. When we approached the Principal of the School and the Father of the Parish, they were very open to protecting their students from air pollution through nature. Over the course of two years, our team established health and air pollution baselines, planted the intervention buffer, and conducted the follow-up health assessment. Our findings from the Green For Good pilot project established our initial proof-of-concept needed to grow the idea into the larger Green Heart project. Read the press release for the greening intervention and about our initial observations

    Louisville's Tree Canopy

    Research shows that people living in neighborhoods with busy streets and high levels of roadway air pollution have a higher risk of heart disease than people living in neighborhoods with more green space. Louisville's trees currently remove over 4 million pounds of ground level ozone and over 1 million pounds of particulate matter from the air we breathe each year. The health value of removing that much air pollution is estimated at more than $10 million every year.

    However, Louisville's urban tree canopy is 37%, lower than the 44% recommended canopy for a healthy city. Each year Louisville loses an average of 54,000 trees per year and Louisville has lost more than 6,500 acres of trees since 2004. At the same time, impervious surfaces like roads, buildings, parking lots, and sidewalks have increased by 9%. If this trend continues, our tree canopy may decrease to 31% over the next ten years.

    Through Green Heart Louisville, our researchers will assess the health and social benefits of increasing green space and tree canopy by:

    • Discovering new relationships between nature and health,
    • Discovering new ways to prevent heart disease, diabetes, and obesity without medications or changing personal behavior,
    • Developing of a scientifically-validated blueprint for greening urban spaces to reduce air pollution that could be replicated in cities around the world, and
    • Creating a new model for healthy urban development.


    Participate in Green Heart's HEAL Health Study

    The Health Environment, and Action in Louisville (HEAL) community study is a part of Green Heart and the University of Louisville School of Medicine. HEAL will measure the health of hundreds of people living in the Green Heart study area in 2019 and again in 2021. Participation in the HEAL study will help us find new ways to prevent heart disease, diabetes, and obesity without the use of medication or changing personal behaviors. See if you are eligible to participate in the HEAL study!

    Volunteer with Green Heart's Greening Team

    In 2019 Green Heart will plant thousands of trees, shrubs, grasses, vines, and flowers to create a robust and sustainable ecosystem maximized to remove air pollution. If you're interested in working with our Greening Team, please email us at for more information!

    Collaborative Partners

    Green Heart is a collaborative project at the University of Louisville's Envirome Institute in partnership with Louisville Metro Government, Washington University in St. Louis, US Forest Service, Cornell University, and Hyphae Design Lab with funding from The Nature Conservancy and the National Institutes for Health.