A man uses an E-cigarette, an electronic substitute in the form of a rod, slightly longer than a normal cigarette, in this illustration picture taken in Paris, March 5, 2013. REUTERS/Christian Hartmann
For the past two years, an average of 10 new e-cigarette brands enter the market every month, and more than 7,700 total flavors, according to a new online survey.
"The product has caught on fire," said Shu-Hong Zhu, a public health researcher at the University of California-San Diego who helped lead the research.
And in related news, a group of 129 physicians, epidemiologists and other professionals from 31 countries around the world sent an open letter to the World Health Organization this week urging the United Nations agency to impose strict regulations on electronic cigarettes.
The letter was a response to one sent last month by 53 other experts who urged the WHO to go easy on e-cigarettes, which the advocates called "part of the solution" in the fight against smoking.
