The following is a summary by the U.S. Forest Service’s Pacific Northwest Research Station on work they conducted to explore the connections between trees and human health. You can read the full article by clicking here: http://www.fs.fed.us/pnw/sciencef/scifi158.pdf
The spread of the emerald ash borer, which poses no direct threat to humans but has killed more than 100 million trees in the United States, was associated with an additional 15,000 human deaths from cardiovascular disease and an additional 6,000 deaths from lower respiratory disease.
Human mortality increased the longer the emerald ash borer was present in a county, consistent with the progression of the insect infestation. Infected trees typically die within 2 to 7 years.
More human deaths occurred in wealthier counties, where trees usually are more abundant.
The association between human health and trees is quantifiable, as demonstrated by examining the effect of tree death on human health. Entities such as public health agencies, urban forestry departments, and city planners can use this information in their decision making.
Trees are widely available, inexpensive, and offer many benefits including human health. Trees as such may be a cost-effective way of improving a city’s public health infrastructure.
All urban residents need to be well informed about the many benefits trees provide.