Physical Properties of Waterpipe Shisha Smoke
The use of waterpipe in the United States is increasing in a largely unregulated market. Little is known about the particulate matter size distributions of waterpipe smoke, though much of this particulate matter is able to penetrate into the lungs. Particulate matter distributions were characterized for trials in which the head contained various components of hookah shisha to determine their contribution to the size and concentration of hookah smoke. Data suggest that glycerol particles peak between 200 and 300 nm in diameter, while flavorants contribute particles peaking between 100 and 200 nm in diameter. Tobacco leaves appear to produce particulate matter in a bimodal distribution peaking below 5 nm in diameter and at about 225 nm in diameter. Further research needs to be conducted to determine the concentration of particles produced below 5.6 nm and above 560 nm in diameter.