Thank you for your letter to the FDA. I have done a lot of research into the ingredients in the e-cigarettes cartridges, and found that they could be a healthy choice for non smokers also. Nicotine does repair stress damage to the brain, and has it's place in preventing Alzheimer's and Parkinson's disease. Propylene glycol has been, as is currently used as a germicide. Although it can csuse problems for pregnant women and people with heart problems, the e-cig venders warn buyers about these problems and discourages the use of e-cigarettes in those cases. I truely believe that the e-cigarette could make a big dent in the cost of health care all over the world. Keep up the good work!