
Trees are
nature's answer to diminishing air pollution, as well as reducing
respiratory problems for the human population, according to US Forest
Service scientists and collaborators behind a new study.
Their
broad-scale estimates concluded that trees are saving more than 850
human lives a year and preventing 670,000 incidents of acute respiratory
symptoms - and that's just by improving air quality less than one
percent.
Not to mention that trees can help save $7 billion a year in health costs by reducing respiratory illness.
The study,
published in the journal Environmental Pollution, was led by Dave Nowak
and Eric Greenfield of the US Forest Service's Northern Research Station
(NRS) and Satoshi Hirabayashi and Allison Bodine of the Davey
Institute. It is the first to directly link air pollution to improved
healthy effects.
Researchers came to these staggering conclusions
by investigating four pollutants in particular: nitrogen dioxide,
ozone, sulfur dioxide, and particulate matter less than 2.5 microns
(PM2.5) in aerodynamic diameter. The Environmental Protection Agency
(EPA) currently has air quality standards established for these four
pollutants.
The NRS team
found that pollution removal is substantially higher in rural areas
compared to urban areas, however the effects on human health are
considerably greater in urban areas than rural areas.
"With more
than 80 percent of Americans living in urban areas, this research
underscores how truly essential urban forests are to people across the
nation," Michael T. Rains, Director of the Forest Service's Northern
Research Station, said in a news release.
Health effects related
to air pollution include impacts on pulmonary, cardiac, vascular, and
neurological systems. In the United States, approximately 130,000
PM2.5-related deaths and 4,700 ozone-related deaths in 2005 were because
of air pollution.
It may seem simple that trees are the answer
to reducing air pollution and all its associated health effects, but
tree cover is not created equal in the United States. For example, trees
cover 2.6 percent of North Dakota compared to 88.9 percent in New
Hampshire.
"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. "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."
For more details about Onuesoke Foundation Tree Planting Projects and donation.