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電子菸會釋出致癌物質( 聯合新聞網 )

發佈日期: 2014-05-29

E-Cigarettes Deliver a Puff of Carcinogens
Electronic cigarettes appear to be safer than cigarettes for one simple reason: People don’t light up and smoke them.
With the e-cigarettes, there is no burning tobacco to produce myriad new chemicals, including some 60 carcinogens.
But new research suggests some popular e-cigarettes get so hot they can produce a handful of the carcinogens found in cigarettes and at similar levels.
A study to be published this month in the journal Nicotine and Tobacco Research found the high-power e-cigarettes known as tank systems produce formaldehyde, a known carcinogen, along with the nicotine-laced vapor that their users inhale. The toxin is formed when liquid nicotine and other e-cigarette ingredients are subjected to high temperatures. A second study points to similar findings.
The long-term effects of inhaling nicotine vapor are unclear, but there is no evidence it causes cancer or heart disease. Many researchers say e-cigarettes will turn out to be much safer than cigarettes.
Both studies focused on tank systems, fast-growing members of the e-cigarette family. Unlike disposable e-cigarettes, which tend to mimic the look and feel of conventional smokes, tank systems tend to be larger devices heated with batteries that can vary in voltage . Users fill them with liquid nicotine, or e-liquid, and the devices vaporize that fluid quickly, producing thick plumes and a big nicotine kick. Maciej L.
Goniewicz of the Roswell Park Cancer Institute in Buffalo, New York, who led the first study, said people using the systems “want more nicotine, but the problem is they’re also getting more toxicants.”
The second study focus ed on how people use the devices to create more potent vapor by dripping fluid onto the heating element . The e-liquid heats with such intensity that formaldehyde and related toxins “approach the concentration in cigarettes,” said Dr. Alan Shihadeh of American University in Beirut, who led the research.
Both studies show intense heat can change the composition of e-liquids, creating new chemicals. The researchers said the chemical reactions apply not only to the liquid nicotine, but also to two other crucial ingredients in most e-liquids: vegetable glycerin and propylene glycol.
The Roswell study found that when battery voltage increased to 4.8 volts from 3.2 volts, toxin levels increased markedly.
“This finding suggests that in certain conditions, E.C.s might expose their users to the same or even higher levels of carcinogenic formaldehyde as tobacco smoke,” the Roswell study says.
Traditional cigarettes create dozens of carcinogens, said Prue Talbot of the University of California, Riverside . E-cigarettes do not tend to generate enough heat to create combustion, a big reason health officials predict they will prove less harmful than cigarettes.
Dr. Shihadeh said, “If I was in a torture chamber and you said I had to puff on something, I’d choose an e-cigarette over a regular cigarette.”
The new tank systems are exploding in popularity and reshaping the market , said Bonnie Herzog, an industry analyst . She expects sales in the United States “in excess of $2 billion” a year.
Experts say tank systems appeal to young people who like products that can be customized with flavors and power, and are comfortable with fast-changing technology.
“Technology is way ahead of the science,” Dr. Shihadeh said. “We’re creating this stuff, and we don’t understand the implications.”
根據即將發表在本月份 「尼古丁與菸草研究」期刊的一項研究報告,有菸液槽的強力電子菸除了釋出使用者吸入的含尼古丁煙霧,還會產生已知致癌物甲醛。液態尼古丁與電子菸的其他成分接觸高溫就會產生毒素。另一研究也有類似發現。