Levels of Urine Cotinine from Hookah Smoking and Exposure to Hookah Tobacco Secondhand Smoke in Hookah Lounges and Homes.

Hookah tobacco smoke is a source of substantial nicotine exposure. Our results call for protecting hookah smokers' and non-smokers' health by requiring accurate hookah tobacco labels, raising taxes on hookah tobacco, reducing the spread of hookah lounges, and encouraging voluntary bans on smoking hookah tobacco in private homes.