PROBLEM: When rooms are continually smoked in, they become “reservoirs of tobacco smoke toxicants that accumulate in carpets, dust, upholstery, mattresses, curtains and furniture, penetrate wallpaper and paint, and are even stored in drywall.” It’s what some experts refer to as “third-hand smoke,” and no one’s quite sure how to clean it up. And while it’s easy enough to keep smokers confined to designated rooms, smoke itself is harder to contain.

METHODOLOGY: Two non-smoking women were recruited by researchers at San Diego State University to spend their weekends at low to mid-budget local hotels. Overall, they sampled 30 non-smoking and 29 smoking rooms in hotels that allow smoking, and 10 rooms in hotels that ban it altogether.

Before they arrived for each 12 to 14-hour stay, a research assistant would set up equipment to measure the air quality and presence of surface contaminants in the room. The women would then spend the night (they were allowed one pre-approved, non-smoking visitor), being sure to touch everything a typical hotel guest would touch, from the drapes to the TV remote, for at least 30 seconds. The women’s fingers and urine were tested for traces of nicotine and other byproducts of cigarette smoke before and after their stay.

RESULTS: 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.

IMPLICATIONS: It’s unclear exactly how cigarette byproducts ended up in places they didn’t belong. It could, write the authors, be the result of smoke migration, or from other patrons ignoring the ban, or from hotels not being entirely upfront about honoring people’s requests for non-smoking rooms. Research budgets didn’t allow for a proper analysis of luxury hotels, but the same principle probably applies across the board: Like most things that may have happened in a hotel room before you got there, and that may or may not have left some residue, you’re probably best not thinking too much about it.

As published on http://www.theatlantic.com/health/archive/2013/05/study-people-test-positive-for-smoke-exposure-after-staying-in-non-smoking-hotel-rooms/275808/