“The Greenprint Project is an exciting collaboration with several partners committed to making Louisville a healthier, greener city. This initiative offers a unique opportunity to reimagine and revitalize downtown Louisville,” said Aruni Bhatnagar, director, Christina Lee Brown Envirome Institute. “Using an evidence-based approach, the project will create a ‘greenprint’ designed to enhance both environmental quality and public health. The model we develop could serve as a scientific framework for greening downtowns around the world.”

This is the latest in the institute’s growing efforts to understand how the environment impacts human health and chronic disease. UofL’s New Vision of Health Campus and Trager Microforest also are participating partners.

“Downtown is the heart of our city and revitalizing our downtown benefits every Louisvillian. The Greenprint initiative shows what’s possible when government, nonprofits, businesses and community partners come together around a shared vision,” said Louisville Mayor Craig Greenberg. “By using nature as a tool to strengthen our neighborhoods and create welcoming spaces, we are making downtown safer, healthier and stronger for everyone – and setting an example that other cities across the country can follow.”

Seed funding of $1.5 million from the James Graham Brown Foundation helped catalyze the partnership, which includes leaders from city government, higher education, nonprofits and grassroots groups. The charter signing represents the formal beginning of this collective effort and signals Louisville’s intent to become a national model for revitalizing cities through nature-based solutions.

“The Greenprint initiative reflects the kind of bold, collaborative vision the James Graham Brown Foundation is proud to support,” said Mason Rummel, president and CEO of the James Graham Brown Foundation. “By aligning science and community input, this effort has the potential to transform downtown Louisville into a national model for place-based investment in public health and urban vitality.”

Greenprint projects will span beyond traditional parks to include tree canopy enhancements, pollinator-friendly landscaping, green corridors, microforests and nature-based health interventions. Together, these efforts aim to improve air quality, reduce heat islands, support biodiversity and enhance mental and physical health. Monitoring technology will be used to track environmental and health impacts of greening over time. These tools will help measure progress, inform future investments and increase transparency and public engagement.

The partnership, built on a collective impact model, focuses on measurable outcomes and long-term sustainability. While each participating project maintains its own identity, Greenprint ensures alignment through shared data and strategy that can assist with tracking impact across the downtown footprint.

Other partners include: Belvedere, LouMed, Louisville Downtown Partnership, Louisville Metro Government, Louisville Parks and Recreation, Office of Sustainability – Whole City Nature Vision, Broadway All the Way, East Market Streetscape Improvements, Reimagine 9th Street, Louisville Sports & Entertainment District/Slugger Field, Olmsted Conservancy, Parks Alliance of Louisville, TreesLouisville, VOA Care Campus and Waterfront Park.

View pictures on  from the Aug. 20, 2025, charter signing event.

To learn more about the Greenprint initiative and explore the portfolio of projects, visit .

After more than two years of baseline research, construction and planting, the 0.65-acre Founders Square, located at Fifth Street and Muhammad Ali Boulevard, is now an inviting public space for everyone to enjoy. However, the Trager MicroForest is more than a refreshed urban park. It is a space for scientific inquiry into the impact of intense urban greening on human health and the wider urban environment.

“The vitality of downtown Louisville is inextricably linked to the vitality of the University of Louisville and the entire metropolitan community,” said UofL President Gerry Bradley. “This beautifully renewed green space will benefit not only residents and visitors to the downtown area, it also will serve as a research site for groundbreaking investigations into the connection between trees and health by UofL researchers.”

A 30-year lease with Louisville Metro Government allows the Envirome Institute to use Founders Square as an outdoor public laboratory. In the park, UofL researchers test the physiological effects of dense planting on human health and to what extent the forest  affects temperature and humidity in the area. For Phase One of the project, the central area of the park has been densely planted with trees, shrubs and ground cover to optimize cooling and reduce urban heat.

The Trager MicroForest Project builds on the Envirome Institute’s groundbreaking Green Heart Project, which found that adding trees to a neighborhood lowered residents’ inflammation levels.

Prior to planting and construction, UofL researchers collected baseline data on how spending time in the space affects stress levels and physiological responses compared with spending time in nearby downtown areas that lack greening. In addition to human studies, the researchers are monitoring air and surface temperatures, air quality and other measures to assess the impact of densely planted trees on the environment in and around the park.

“The Trager MicroForest is part of the wider mission of the Envirome Institute to pursue knowledge about health,” said Aruni Bhatnagar, director of the Christina Lee Brown Institute. “This little forest will not only provide a pleasant space to spend time in downtown Louisville, but it will also help us test how dense urban planting can improve human health. The results of this experiment could inspire and inform the planting of microforests in cities worldwide.”

The microforest is considered part of UofL’s New Vision of Health Campus, located just across Fifth Street, which will include specially designed laboratory space to study sleep, nutrition and exercise, as well as offices and public spaces to investigate how environmental factors impact human health. The development of this innovative campus affirms UofL’s commitment to the vitality of Louisville’s urban core.

“We are excited for this project and hope to see further growth in the greening of downtown Louisville,” Michael Trager-Kusman said. “We believe having public spaces like these will only contribute to the growth of downtown Louisville.”

The park’s opening marks the completion of Phase One of the project. Planning and design for Phase Two of the Trager MicroForest will begin in late 2025. Learn more about .��

• 0.65-acre site
• 119 new trees
• 242 new shrubs
• 750 tons of new top soil
• 220 linear feet of new pathways
• 178 linear feet of retaining wall

of the official opening on May 13, 2025. View the .��

A new discovery at the University of Louisville may help scientists test the effects of exposure to green plants “greenness” on health. Pawel Lorkiewicz, associate professor of chemistry and environmental medicine at , measured a person’s exposure to trees and plants by testing their urine.

Limonene is a nontoxic substance emitted into the air by many trees and plants. Concentrated limonene has a lemony smell and is used in perfumes, foods, cleaning and other household products. When a person breathes concentrated limonene, the body breaks it down into metabolites which can be measured in their urine.

These metabolites also are in a person’s urine after they spend time in a forest, . This means the metabolites can be used to measure a person’s exposure to trees and plants. Comparing this exposure with health information may help researchers more accurately determine whether time spent in nature is beneficial for an individual’s health.

“Even though we may not smell limonene exactly, usually we can tell that we are surrounded by trees and greenness because of the smell. Parks and forests, or even meadows or larger green spaces have a characteristic smell because of plant volatile organic compounds such as limonene,” Lorkiewicz said.

For several years, Envirome Institute researchers have been studying the health effects of living near trees and greenness. As part of the , they planted trees and shrubs in specific neighborhoods, measuring changes in the residents’ health compared with those living in areas with fewer trees. But the researchers found it challenging to accurately measure an individual’s actual exposure to trees. There may be many trees where they live, but they spend much of their time working in tree-sparse locations or indoors, insulated from trees and plants.

So the team searched for a way to measure how much time an individual spent around greenness. Because many trees and plants release significant amounts of limonene into the air, they developed a method to test for limonene exposure using urine, which is easy to collect.

After testing the urine of people who smelled pure limonene from a vial, they compared those results with urine from people who spent time walking in a forest. They found the same metabolites in the urine of both groups, tagging three of them as reliable biomarkers of exposure to greenness.

“It was very exciting. That’s what constitutes a biomarker, something was released by trees in real life, metabolized by our bodies and found in our urine, not just the result of smelling a pure chemical in a lab,” Lorkiewicz said. “So, we objectively can tell when someone is not working in an office at a desk, but they actually go outside and are surrounded by greenness.”

Keith said the biomarker for greenness exposure is a breakthrough for the Green Heart Project, the Trager MicroForest project in downtown Louisville and other studies.

“We have been working with the overall premise that trees affect health in a positive way. Our mission in the Green Heart Project is to understand in some ways how they do that,” she said. “We have turned to the idea of using the human as the biomonitor of greenness in the human. We hope to use this to see changes in people’s overall exposure to greenness as we plant trees and determine whether those changes correlate to changes in health.”

To assess people’s exposure to trees and plants, Keith combines the limonene biomarker test with satellite images showing tree density where people live and surveys of their time spent outdoors and compares the exposure information with health data such as blood pressure and heart rate.

In additional research, Keith and her team are using the biomarker to compare the health effects of limonene and other compounds emitted by plants on the body.