Trees saving lives
ECOLOGY & ENVIRONMENT
In a study published by the International Society of Arbiculture back in 2007 it was noted that "The Urban forests in the United States were estimated to produce ≈61 million metric tons (67 million tons) of oxygen annually, enough oxygen to offset the annual oxygen consumption of approximately two-thirds of the U.S. population" .
In spite of the very same study, the effects of this oxygen production were quoted as "relatively insignificant and negligible value", another study published this year contradicts slightly this statement.
In the publication Tree and forest effects on air quality and human health in the United States (available on-line here), in the first broad-scale estimate of air pollution removal by trees nationwide, U.S. Forest Service scientists and collaborators calculated that trees are saving more than 850 human lives a year and preventing 670,000 incidences of acute respiratory symptoms .
GLOBAL IMPACT OF DEFORESTATION
But deforestation may have other impacts on human health as well. With less than 2 percent of the Earth's total surface, the rain forest hosts more than 50 percent of the Earth's plants.
The US National Cancer Institute (NCI) calculated in approximately 70 percent the anti-cancer plants identified in the rain forest, and certainly many more waiting to be discovered, but with the current levels of deforestation rain forest will probably not be there anymore in one or two generations let alone some of the plants that may have helped us to find cures to already existing and future illnesses and ailments.