Here, they find a correlation between e-cigarette use and higher and more sustained levels of smoking. But because this is a cross-sectional study, they cannot determine which came first. In other words, what is the direction of the causal relationship? Does the e-cigarette use precede, and cause, the smoking? Or does the smoking precede, and cause, the e-cigarette use?

G. Zero.

The study finds that e-cigarette use is associated with smoking status. In addition, e-cigarette use is associated with heavier smoking and with fewer periods of smoking abstinence.

"It'll seem to be cool," he said.

LAST：2014 new innovative products health&medical iGo2 e cigarette dual tank e-cig |NEXT：TizeTech electronic cigarette dry herb vaporizer,best wickless atomizer ecig, ego ce4 ce5 ce6 atomizer