Trees Save More than 800 Lives Per Year

Trees prevent 670,000 incidences of acute respiratory symptoms and save 850 human lives a year, a new study has found.

The study, conducted by researchers at U.S. Forest Service's Northern Research Station, found that trees lower air pollution levels and so, help reduce respiratory problems. Although, trees' bring about one percent improvement in air quality levels, researchers said that its effect on human health was substantial. The team valued the reduction in air pollution at $7 billion every year in terms of health care cost savings.

"With more than 80 percent of Americans living in urban area, this research underscores how truly essential urban forests are to people across the nation," said Michael T. Rains, Director of the Forest Service's Northern Research Station and the Forest Products Laboratory, according to a news release. "Information and tools developed by Forest Service research are contributing to communities valuing and managing the 138 million acres of trees and forests that grace the nation's cities, towns and communities."

The current study is important because it shows that trees are directly contributing to human health. Researchers found that the effect of air pollution reduction was seen both in urban and rural population.

An estimated 34.2 percent land in the U.S. has tree cover. However, tree cover varies between states with 2.6 percent in North Dakota to 88.9 percent in New Hampshire.

In the study, researchers assessed reductions in four air pollutant levels. these pollutants; nitrogen dioxide, ozone, sulfur dioxide, and particulate matter less than 2.5 microns (PM2.5) in diameter, are known to be associated with health problems. In the U.S., around 130,000 deaths are linked to PM2.5 exposure while 4,700 deaths were tied to high ozone levels in the atmosphere. (2005 data).

 "In terms of impacts on human health, trees in urban areas are substantially more important than rural trees due to their proximity to people," Nowak said in a news release. "We found that in general, the greater the tree cover, the greater the pollution removal, and the greater the removal and population density, the greater the value of human health benefits."