April 28 (UPI) -- In most cities in the United States, low-income blocks host fewer trees than blocks in more well-to-do neighborhoods, according to a new study.
The new data, detailed Wednesday in the journal PLOS One, also showed low-income blocks are a few degrees hotter on average.
Several studies have highlighted the lack of green space in low-income neighborhoods and the implications for human health.
Access to trees and green space, including parks and gardens, has been linked with better physical and mental health outcomes.
Residents living in close proximity to trees and greenery tend to enjoy lower stress levels and breathe cleaner air. Research has even shown greenspace correlates with lower crime rates and reduced Medicare expenditures.
The latest study is one of the first to take a block-by-block look at the links between income levels, tree cover and temperature patterns.
To quantify tree cover on city blocks, researchers analyzed aerial images from the National Agriculture Imagery Program.
Scientists measured tree cover in thousands of cities across the United States, averaging summertime temperature data for the same city blocks using Landsat imagery.
The analysis revealed a disparity between tree cover on low- and high-income blocks in 92 percent of urban communities.
On average, low-income blocks had 15 percent less tree cover. The same blocks experienced summertime temperatures 1.5 degrees Celsius higher on average.
In parts of the northeast, the tree cover and temperature disparities were even greater, with low-income blocks hosting 30 percent fewer trees than than wealthier blocks.
And in some East Coast cities, temperature disparities between low- and high-income blocks were as great as 4 degrees.
Across the 100 largest urban areas in U.S., researchers determined the tree difference between comparable low- and high-income blocks is roughly 62 million trees.
Scientists estimated the gap could be closed with a $17.6 billion investment in tree planting and regeneration.