A 2010 report from the US Surgeon General says even secondhand smoke causes immediate damage to one's organs and poses risk of serious illness or death. 
"There is no risk-free level of exposure to tobacco smoke." 
I'm very glad to see the Parks and Open Space division take action to eliminate smoking in our parks, following suit of the UO's tobacco free initiative as well as regulations in effect in other local communities, to minimize public exposure to avoidable health risks. We all deserve the opportunity to recreate in areas without exposure to cigarette smoke, and if the public follows this policy it will also remove the threat of fire danger from persons choosing to smoke in the Ridgeline and other natural areas during fire season.