Growing up in Washington, D.C.'s Columbia Heights neighborhood, Rebecca Lemos-Otero says her first experience with nature came in her late teens when her mother started a community garden.
"I was really surprised and quickly fell in love," she recalls. The garden was peaceful, and a "respite" from the neighborhood, which had high crime rates, abandoned lots and buildings, she says.
Inspired by that experience, years later, Lemos-Otero, 39, started City Blossoms, a local nonprofit that has about 15 children-focused community green spaces across Washington, D.C. She wanted to give kids from minority and low-income communities easy access to some greenery.
Kids love the gardens, she says. It gives them a way to briefly forget their worries.
"Having access to a bit of nature, having a tree to read under, or, having a safe space like one of our gardens, definitely makes a huge difference on their stress levels," says Lemos-Otero. "The feedback that we've gotten from a lot of young people is that it makes them feel a little lighter."
Now a group of researchers from Philadelphia has published research that supports her experience. The study, published Friday in JAMA Network Open, found that having access to even small green spaces can reduce symptoms of depression for people who live near them, especially in low-income neighborhoods.
Previous research has shown that green spaces are associated with better mental health, but this study is "innovative," says Rachel Morello-Frosch, a professor at the department of environmental science, policy and management at the University of California, Berkeley, who wasn't involved in the research.
"To my knowledge, this is the first intervention to test — like you would in a drug trial — by randomly allocating a treatment to see what you see," adds Morello-Frosch. Most previous studies to look into this have been mostly observational.
Philadelphia was a good laboratory for exploring the impact of green space on mental health because it has many abandoned buildings and vacant lots, often cluttered with trash, says Eugenia South, an assistant professor at the Perelman School of Medicine at the University of Pennsylvania and an author of the study.
"There's probably over 40,000 of them in the city, but they're concentrated in certain sections of the city," she says. "And those areas tend to be poorer neighborhoods."
South and her colleagues wanted to see if the simple task of cleaning and greening these empty lots could have an impact on residents' mental health and well-being. So, they randomly selected 541 vacant lots and divided them into three groups.
They collaborated with the Pennsylvania Horticultural Society for the cleanup work.
The lots in one group were left untouched — this was the control group. The Pennsylvania Horticultural Society cleaned up the lots in a second group, removing the trash. And for a third group, they cleaned up the trash and existing vegetation, and planted new grass and trees. The researchers called this third set the "vacant lot greening" intervention.
The team surveyed residents living near the lots before and after their trial to assess their mental health and wellbeing. "We used a psychological distress scale that asked people how often they felt nervous, hopeless, depressed, restless, worthless and that everything was an effort," explains South.
The scale alone doesn't diagnose people with mental illness, but a score of 13 or higher suggests a higher prevalence of mental illness in the community, she says.
People living near the newly greened lots felt better. "We found a significant reduction in the amount of people who were feeling depressed," says South.
The impact was strongest for residents of poorer neighborhoods — they showed at least a 27.5 percent reduction in the prevalence of depression.
"It's very much in line with a lot of research in this area," says Mike Rogerson, a professor at the University of Essex in the United Kingdom, who wasn't involved in the new study.
Rogerson, who works on the physical and mental health impacts of green spaces and activities in outdoor spaces, says studies show that green spaces are "equigenic," or equalizers of socioeconomic disparities in health.
People from lower socioeconomic backgrounds tend to have worse mental and physical health outcomes. But when exposed to green spaces, "people who start out worse have more improvement," says Rogerson. "It's a leveler across society."
There could be several mechanisms at play here, he says, including a biological effect of exposure to nature. "Our bodies physically respond well to environment and nature because of our species' historical past," says Rogerson.
South's own previous work demonstrates this, at least for one measure of acute stress — heart rate. Using a similar experiment as this new study, she monitored the heart rate of residents walking past the vacant lots before and after the greening experiment.
"In the areas that had been greened I found that people had reduced heart rates when they walked past those spaces," she says.
She and her colleagues have also shown that the greening experiment reduces crime, which might make residents feel safer, and feeling safer in your own neighborhood might also explain in part the improvement in mental health.
And Rogerson's earlier research has shown that when people exercise outdoors, they're more likely to interact with each other for longer. And social cohesion is known to improve mental health and well being.
The new study found that the greening intervention in Philadelphia cost as little as $1,600 and an additional $180 per year per lot for maintenance.
"Vacant lot greening is a very simple, low cost improvement to neighborhoods that can improve mental health," says South.
Morello-Frosch agrees. "It's a piece of low-hanging fruit," when it comes to improving the mental health in poor communities, she says.
NOEL KING, HOST:
It's summer. It's a great time to get outdoors and enjoy nature. But a new study shows that even small green spaces in urban environments can improve our mental health. NPR's Rhitu Chatterjee has the story.
RHITU CHATTERJEE, BYLINE: Tucked between a parking lot and a busy playground in Washington, D.C.'s Columbia Heights neighborhood is a small community garden.
REBECCA LEMOS-OTERO: Welcome to the Girard Children's Community Garden.
CHATTERJEE: Rebecca Lemos-Otero started this garden about 10 years ago. She runs an organization called City Blossoms, which has 15 gardens like this across the city.
LEMOS-OTERO: All of our gardens are a mix of edibles, like herbs...
CHATTERJEE: There's eggplants and beans; also a couple of apple trees and grape vines. Lemos-Otero, who grew up in this neighborhood, says the space used to be vacant with an empty lot and abandoned buildings. People avoided the area. Now, kids love the garden. Many of them, she says, are from lower income communities of color, and the garden gives them a way to forget about their worries.
LEMOS-OTERO: Having access to a bit of nature - having a tree to read under definitely makes a huge difference on their stress levels, and the feedback that we've gotten from a lot of young people is that it makes them feel a little lighter.
CHATTERJEE: And now there's more evidence that supports what Lemos-Otero is saying. This new study is published in JAMA Network Open and was done in Philadelphia.
EUGENIA SOUTH: Philadelphia, in general, has a lot of vacant lots and abandoned buildings. There's probably about 40,000 of them across the city.
CHATTERJEE: That's Eugenia South, an assistant professor at the University of Pennsylvania.
SOUTH: The vacant lots are often trashy. We find condoms and needles in them. They're often overgrown with vegetation, and people dump large objects like a refrigerator or tires in them.
CHATTERJEE: She and her colleagues decided to test if turning these empty lots into green spaces could affect people's mental health. They randomly selected over 500 vacant lots. To about one-third of them, they did what they called a greening intervention, which involved...
LEMOS-OTERO: Removing the trash, old vegetation, planting new grass and new trees.
CHATTERJEE: For another third of the lots, they only cleaned up the trash, and the rest were kept untouched. When they surveyed residents for their mental health before and after their experiment, they found that those living next to the green spaces reported feeling better.
SOUTH: We found significant reduction in the amount of people who were feeling depressed.
CHATTERJEE: The impact was strongest in poorer neighborhoods. South says turning empty lots into green spaces is an easy, inexpensive way to improve mental health. It can't treat mental illness, but it can improve wellbeing in poor communities across the country. Rhitu Chatterjee, NPR News. Transcript provided by NPR, Copyright NPR.