What Do You Value?

By: Jeremy Kranowitz

For almost 50 years, Keep Indianapolis Beautiful has been working with tens of thousands of volunteers to make our city a “beautiful” place to live. But what does that mean? It may be surprising to learn that we care about – and are working to address – many of the same issues that matter to you.

Do you care about reducing violent crime? 

Many people are rightly worried about the level of violence in Indy, and would be eager to pursue solutions that can help. Here’s how KIB’s work makes a difference:

Over the years, KIB has transformed over 65 vacant or abandoned lots into vibrant community greenspaces that are actively maintained and sustained by volunteer community members. Research by the University of Michigan School of Public Health in Flint, Michigan found that community-engaged mowing of vacant lots reported a 40% reduction in assaults compared to street segments with no maintenance.¹

KIB greenspaces were the subject of recent analysis by the same team at the University of Michigan.  Comparing three dozen KIB GreenSpaces with comparable untreated vacant lots, and using extensive data from IMPD, researchers found that KIB GreenSpaces were associated with a statistically significant decrease of 12% in the expected number of gun assaults. The social science behind this decrease is that a higher level of community engagement in the space makes it less enticing for vice.

Similarly, there is research to suggest that public art can also have a positive influence on reducing violent crime. A recent study in Cincinnati, Ohio found murals result in better neighborhood vitality and also observed a notable decrease in violent crime when murals coexist near commercial clusters.² Smithsonian Magazine printed an article about research on the effects of human eyes on posters or billboards on human behavior. People tend to behave better when they feel they are being watched – even from a poster.³  

Some of KIB’s greenspaces have large murals. Some of those murals are of graphic designs or butterflies. However, a few have murals of local residents who made a difference in that community. KIB plans to study this more in the future, and perhaps create more murals going forward to determine the extent of the impact on crime reduction.

Do you care about clean air to breathe?

Multiple studies demonstrate the benefits to air quality from having a more robust tree canopy. A recent study that examined 744 cities across Europe concluded that each 5 percent increase in tree canopy would prevent 4727 premature deaths related to air pollution.⁴

Here’s how KIB’s work makes a difference:  KIB plants thousands of trees every year, mostly through our long-term contracts with the City of Indianapolis, and more recently with a new contract with the US Forest Service. We use satellite and aerial imagery to identify the neighborhoods that have the lowest overall percentage of tree canopy and intentionally go to those places to make sure everyone can breathe healthier air.

Do you care about reducing street flooding after heavy rains? 

Weather patterns are shifting, with more frequent heavy precipitation events, which can often overwhelm old sewer systems. Here’s how KIB’s work makes a difference:

Flooding occurs when too much water enters the system too quickly, such as during a heavy rainstorm. A report by hydrologists at Citizens Energy Group noted that a single mature tree can keep 100 gallons from rushing into the sewer system during a rainstorm by capturing water with its leaves, helping water soak into the soil, and absorbing water through its roots.⁵ That is why KIB partnered with Citizens to plant 10,000 trees in specific locations where sewer overflows are most likely to occur. We planted the 10,000^th tree in 2024 and are now making sure that they continue to grow and thrive to make a bigger difference every year. Soon they will collectively reduce 1 million gallons of stormwater surges.

Do you care about staying cool in the summer? 

More than half of the world’s population lives in cities. The concentration of buildings, streets, parking lots and sidewalks come at the expense of a healthy tree canopy, and also retain heat, creating what is known as the “Heat Island Effect,” where cities are much warmer than nearby natural areas. It is well documented that trees reduce heat by providing shade.⁶ A study in Korea determined that the number of trees is important, and so is the density of the tree canopy (leaf area density). By increasing from 4% to 60% tree canopy, the daily average temperature was reduced by 5.4 degrees! (3⁰ C).⁷

Keep Indianapolis Beautiful has partnered with the City of Indianapolis Department of Public Works and with Citizens Energy Group to plant tens of thousands of trees across the city. Our particular focus is in neighborhoods with fewer trees and lower tree canopy. Some parts of Marion County have over 60% tree canopy, and others have less than 10%, so we have focused intentionally on places where those trees can make a big difference. 

Do you care about reducing children’s exposure to toxic lead and heavy metals? 

It is well-documented that exposure to lead can have significant detrimental effects on brain development, especially in young children. What may be surprising is that one of the main ways in which children come in contact with lead and other heavy metals is in the soil. Research by University of Indiana-Indianapolis shows that the distribution of toxic lead and other heavy metals is widespread; but not evenly distributed—one block (or even a single lot) can have high levels of lead, while the next one does not.⁸ Here’s how KIB’s work makes a difference?

When KIB builds a community greenspace, there is often the addition of new walking paths, new soil, new mulch, or installation of children’s play areas or raised vegetable gardens. Each of these additions helps provide a protective layer of clean ground material. Preliminary research by Indiana University at a KIB GreenSpace showed a 50% reduction in surface soil lead levels.

Do you care about property values?

A number of studies around the world show consistently higher residential property values with proximity to urban parks, community gardens, or other urban green infrastructure efforts. Studies across the world have found consistent positive relationships between proximity to greenspace and higher property values.⁹ The National Recreation and Park Association reprinted findings from Dr. John Crompton, who conducted a review of 33 peer-reviewed publications.¹⁰ The consensus is that a range of 8 to 10% premium can be felt for properties within 500 to 600 feet of the park. The magnitude changes based on whether it is a “passive” park or an “active” one (i.e., one with lighted ball fields, concession stands, and associated traffic and congestion). It also is dependent on size – larger parks have a bigger impact. Overall, it is clear that proximity to a park, especially the kind of “passive” community-engaged greenspaces that KIB co-creates with neighborhoods, will have a positive impact on property values.

Do you care about heart and lung health, and reducing the chance of having a stroke?

Hundreds of scientific studies demonstrate that air pollution can directly increase the risk of heart disease, and trigger heart attacks and strokes. Recent scientific evidence shows that exposure to greenspaces and vegetation may be a significant factor affecting cardiovascular health.¹¹ In any city, a spike in air pollution is followed 6 hours later with a spike in heart attacks.  Dr. Aruni Bhatnagar is conducting research in Louisville, Kentucky, planting over 8,000 fully mature trees over four square miles in low-income, low-tree canopy neighborhoods. The trees were planted in 2019, and participating neighbors provided blood samples to measure their levels of C-reactive protein, which is an indicator of inflammation. In 2024, the research team at the University of Louisville reported their first results – a 13-20% reduction in C-reactive protein, which correlates to a similar reduction in the chance of a heart attack or stroke!

Do you care about mental health?

Access to nature and overall mental health are highly correlated. While cities provide concentrated job opportunities, access to education and health services, and cultural activities, they also decrease access to nature. Controlled laboratory studies show that just seeing images and listening to sounds of nature have mental health benefits, including reduced stress.¹²

A number of fieldwork experiments also show a high level of correlation between access to nature and overall happiness and sense of well-being.^{13 14 15 16}  Experiencing nature  – whether that is green space, blue space (water), street trees or private gardens – all have an array of positive impacts. KIB is making that difference with each of our projects – installing more greenspace, more trees, and more native habitats throughout the City. 

Sources

1. Heinze, J.E., et al. “Busy Streets Theory: The Effects of Community-Engaged Greening on Violence,” American Journal of Community Psychology. Vol. 62, Issue 1-2, pp. 101-109, 9/2018. https://onlinelibrary.wiley.com/doi/10.1002/ajcp.12270
2. Jeong, H. and Hu, Y. “The Role of Public Murals in Street Vitality,” Cities, Vol. 165, May 2025, 106085.
3. Lewis, D. “Putting Eyeballs on Billboards Might Help Stop Crime.” Smithsonian Magazine, Aug. 26, 2015.
4. Sicard, P. et al. “Effect of Tree Canopy Cover on Air Pollution-Related Mortality in European Cities: An Integrated Approach.” The Lancet, Vol. 9, #6, E527-537, June 2025.
5. https://info.citizensenergygroup.com/digindy/related-projects/10-thousand-trees
6. Esfehankalateh, A.T., et al., “Influence of Tree Canopy Coverage and leaf Area Density on Urban Heat Island Mitigation” “Sustainability, 13(13), 7496. July 5, 2021.
7. Ziter, C.D., et al. “Scale-Dependent Interactions Between Tree Canopy Cover and Impervious Surfaces Reduce Daytime Urban Heat During Summer,” Proceedings of the National Academy of Sciences (PNAS)., 116 (15) 7575-7580, Mar. 25, 2019. https://www.pnas.org/doi/10.1073/pnas.1817561116
8. Filippelli, G.M., et al. “One in Four US Households Likely Exceed New Soil Lead Guidance Levels,” GeoHealth. Vol 8, Iss. 6, June 2024. https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024GH001045.
9. How Much Impact Do Parks Have on Property Values?” Parks & Recreation magazine, National Recreation and Park Association. https://www.nrpa.org/parks-recreation-magazine/2020/april/how-much-impact-do-parks-have-on-property-values/
10. Crompton, J.L. “The Impact of Parks on Property Values: Empirical Evidence from the Past Two Decades in the United States,” Managing Leisure, Vol. 10, Issue 4, pp. 203-218, 2005. https://www.tandfonline.com/doi/abs/10.1080/13606710500348060
11. Keith, R.J., Hart, J.L., Bhatnagar, A. “Greenspaces and Cardiovascular Health,” Circulation Research. Vol. 134, #9, 26 Apr. 2024, pp. 1179-1196. American Heart Association, Inc. https://www.ahajournals.org/doi/10.1161/CIRCRESAHA.124.323583
12. R. Ulrich, et al., “Stress recovery during exposure to natural and urban environments,” Journal of Environmental Psychology, 11, 201-230 (1991).
13. Memory and attention (Berman, M.G., et al., “Interacting with nature improves cognition and affect for individuals with depression.” Journal of Affective Disorders. 140, 300-305 (2012). https://www.science.org/doi/full/10.1126/sciadv.aax0903
14. Impulse control (Tayor, A.F., Kuo, F.E., et al., “Views of Nature and Self-Discipline: Evidence from inner city Children.” Journal of Environmental Psychology. 22, 49-63 (2002). https://www.science.org/doi/full/10.1126/sciadv.aax0903
15. ADHD (Kuo, F.E., Taylor, A.F. “A Potential natural Treatment for Attention-Deficit/Hyperactivity Disorder: Evidence from a National Study” American Journal of Public Health 94(9), 1580-1586 (2004). https://pmc.ncbi.nlm.nih.gov/articles/PMC1448497
16. Children’s school performance. Dadvand, P., et al. “Green spaces and cognitive development in primary schoolchildren. Proceedings of the National Academy of Sciences, 112, 7937-7942 (2015) https://www.science.org/doi/full/10.1126/sciadv.aax0903
    
    
    
    

Categories: Air quality & health, Children, Climate, Community health, Green infrastructure, Neighborhood & economy, Public safety, Research & Data