Trees, parks, and gardens are not just simply considered beauty in the city but as a matter of improving public health. There is a link between an individual’s socio-economic position and their health is well-established. Epidemiological studies show a positive relationship between longevity and proximity to green space. Fewer people die of asthma and heart disease in Chicago, Los Angeles, and other U.S. cities when trees and other greenery are present. A single tree cleans the air because of a tree’s ability to absorb tiny smog and soot particulates. Trees also provide shade which block ultraviolet rays that contribute to skin cancers. Another health benefit of evergreen trees can be found by patients in hospitals with views of trees and gardens outside their window who recovered faster after surgery.
Brief encounters with nature make people happier, reduce chronic stress that leads to ill health and help both adults and children (including kids with ADD) focus better on mentally taxing tasks. Exposure to green surroundings reduces mental fatigue and irritability. The ability to concentrate is increased by green views, along with the ability and willingness to deal with problems thoughtfully and less aggressively.
A 2011 study in the Amercian Journal of Epidemiology found that vandalism and gun assaults and stress levels decreased in greener environments. In a study conducted in a Chicago public housing development, people who lived in apartment buildings with trees and greenery immediately outside reported fewer aggressive and violent acts than those living in barren but otherwise identical buildings. In addition, the people in greener surroundings reported a smaller range of aggressive tactics during their lifetime.