Does Switching to Nicotine Containing Electronic Cigarettes Reduce Health Risk Markers

The overall goal of this project is to understand the likely health effects of cigarette smokers switching to a Standardized Research Electronic Cigarette (SREC) and to assess the role of nicotine delivery on switching and acceptability as well as markers of health outcomes. Current smokers who meet all eligibility criteria will completely switch from their combustible (regular) cigarettes to an electronic cigarette (SREC) that either contains 58 mg/ml of nicotine or 0 mg/ml of nicotine in the liquid. The investigators' hypothesis is that attempting to switch to a SREC will result in a reduction in markers of harms to health, as compared with the baseline (smoking) measures. The investigators also hypothesize that nicotine-containing SRECs will facilitate switching from smoking more efficiently than zero nicotine SRECs and will result in a significantly greater improvement in markers of health risk, but will result in higher ratings of dependence on the SREC (as compared to the zero nicotine SREC).