There are a number of threats to the Smoky Mountains. From smoke at local power plants, to non-native species changing the look of the park. This is a great article published a couple of weeks ago that looks at threats to the park in detail.
http://www.charlotteobserver.com/local/story/817043.html
******If you want to stay between Pigeon Forge and Gatlinburg on your next visit to the Smokies, check out www.smokymountaintower.com , that’s where we stay when in the Smokies!****