Well: Safety: Smoke in Nonsmoking Hotel Rooms

Staying in a nonsmoking room in a hotel that allows smoking elsewhere does not prevent exposure to tobacco smoke, a new study reports.

Source: http://well.blogs.nytimes.com/2013/05/17/smoke-permeates-nonsmoking-hotel-rooms/?partner=rss&emc=rss

example here as example as an example explained here