Does reducing exposure mean the same thing as reducing risk?
Cigarette smoke contains numerous carcinogens, mutagens and other toxins that are inhaled into the lungs. Smokeless tobacco products deliver carcinogens, mutagens and other toxins into the mouth and throat. A PREP may reduce exposure to these toxins. However, the amount of reduction in exposure needs to be tested in people with biomarkers (a biochemical feature that can be used to measure the progress of disease or treatment) to determine if the reduced exposure is meaningful. Reduction in exposure may be small and so the risk of tobacco-related disease might not change. PREPs that change delivery of one or a few of their many toxins might not lower risk. This means that reducing exposure does not mean the same thing as reducing risk.
