Physical
Trees care for your lungs
Trees help keep our world clean and healthy by filtering particles out of the air we breathe, decreasing the risk of respiratory illnesses.
Lovasi, G.S., J.W. Quinn, K.M. Neckermann, M.S. Perzanowski, and A. Rundle. 2008. "Children Living in Areas with More Street Trees Have Lower Prevalence of Asthma." Journal of Epidemiology and Community Health 62 (2008): 647-649. JECH online. Web. 16 February 2016.
Donovan, Geoffrey H., David T. Butry, Yvonne L. Michael, Jeffrey P. Prestemon, Andrew M. Liebhold, Demetrios Gatziolis, and Megan Y. Mao. 2013."The Relationship Between Trees and Human Health: Evidence from the Spread of the Emerald Ash Borer." American Journal of Preventive Medicine 44.2 (2013): 139-45. Elsevier. Web. 13 January 2016.