Westminster, Colo. (August 26, 2010) – Second-hand smoke is associated with a number of diseases and conditions, including cancer, heart disease, and emphysema. It is an irritant to lung tissue and blood vessels, but the processes through which the body reacts to second-hand smoke comprise a mystery scientists are only beginning to unravel. Researchers at the University of Colorado–Denver are currently studying how second-hand smoke affects the lungs of rats, and so far it appears that second-hand smoke triggers a complex inflammatory response.