Non-smoking hotel rooms generally contained more third-hand smoke when they were part of hotels that allowed smoking in other, designated rooms. They had, on average, twice the amount of nicotine on surfaces and seven times as much 3EP (another cigarette byproduct) in the air. In smoking-permitted rooms, of course, the presence of these contaminants was much higher.
The women, after spending the night in a hotel that permitted smoking, even after requesting a non-smoking room, the next morning had significantly more nicotine on their fingers, and five to six times the amount of cotinine -- a biomarker of second-hand smoke exposure -- in their urine.
Lindsay Abrams of The Atlantic summarizes the study: Link | The paper over at Tobacco Control