The effects of pictorial health warning label on waterpipe (low- and high-frequency) smokers' experiences, toxicant exposures, and puffing behavior

This crossover study evaluated the effects of pictorial health warning labels on puffing behavior, subjective experiences, and toxicant exposures in 60 low- and high-frequency waterpipe smokers in the United States. As part of the study, smokers completed two ad libitum waterpipe smoking sessions, with expired-breath carbon monoxide measured before and after each session using the Vitalograph BreathCO device.