A new study reinforces the belief that exposure to a natural environment with lots of trees keeps a person healthy.
A study conducted by Geoffrey Donovan, a research forester at the Forest Service's Pacific Northwest Research Station, and his colleagues found how the presence of tress affects a person's health in a good way.
The loss of 100 million trees in the eastern and mid-western parts of the United States provided a good opportunity to study the impact of a major change in the natural environment on human health. After collecting and analyzing data from 15 countries of 18 years, it was found that Americans who live in areas that were infected by insects that kills trees saw 15,000 deaths from cardiovascular diseases and 6,000 more from respiratory illness compared to people who lived in places that had trees.
"There's a natural tendency to see our findings and conclude that, surely, the higher mortality rates are because of some confounding variable, like income or education, and not the loss of trees," said Donovan in a report published by Science Daily. "But we saw the same pattern repeated over and over in counties with very different demographic makeups."
Through the study a direct link between human mortality and loss of trees were found. It has also been determined that loss of trees cause cardiovascular diseases and respiratory illness. However, the reason and mechanism behind this link is yet to be discovered.
The study was conducted in collaboration with David Butry, with the National Institute of Standards and Technology; Yvonne Michael, with Drexel University; and Jeffrey Prestemon, Andrew Liebhold, Demetrios Gatziolis, and Megan Mao, with the Forest Service's Southern, Northern, and Pacific Northwest Research Stations.