WASHINGTON, Jan. 23 (Xinhua) -- E-cigarettes, widely promoted as an alternative to smoking, are actually attracting young people who might not otherwise have smoked tobacco products, a new U.S. study suggested Monday.
E-cigarettes are thought by some to be responsible for a decline in American youth cigarette smoking, but researchers from the University of California, San Francisco (UCSF) indicated the reality is the opposite.
The USCF researchers concluded that many kids who went on to smoke regular cigarettes may not have used nicotine at all if e-cigarettes did not exist.
"We didn't find any evidence that e-cigarettes are causing youth smoking to decline," said lead author Lauren Dutra of the UCSF.

"While some of the kids using e-cigarettes were also smoking cigarettes, we found that kids who were at low risk of starting nicotine with cigarettes were using e-cigarettes," Dutra said. "Recent declines in youth smoking are likely due to tobacco control efforts, not to e-cigarettes."
The findings, published in U.S. journal Pediatrics, built on a growing body of evidence that adolescents who start with e-cigarettes are more likely to subsequently smoke traditional cigarettes.
For the study, researchers examined data from more than 140,000 middle and high school students who completed a U.S. government tobacco survey between 2004 and 2017.
They found that cigarette smoking among U.S. adolescents declined during that decade, but did not decline faster after the advent of e-cigarettes in the U.S. between 2007 and 2009.
In fact, combined e-cigarette and cigarette use among adolescents in 2017 was higher than total cigarette use in 2009, according to the study.
"E-cigarettes are encouraging -- not discouraging -- youth to smoke and to consume nicotine, and are expanding the tobacco market," said senior author Stanton Glantz, UCSF professor of medicine and director of the UCSF Center for Tobacco Control Research and Education.
E-cigarettes are battery-powered devices that look like cigarettes and deliver an aerosol of nicotine and other chemicals.
In August 2016, the U.S. Food and Drug Administration restricted e-cigarette purchases to adults ages 18 and older.
The FDA will also require a warning label on e-cigarettes, starting August 2018, regarding the addictive nature of nicotine.
However, the FDA's ruling does not regulate advertising or flavors, and e-cigarettes continue to be sold in flavors that appeal to youth, the UCSF researchers said.
考研备考:“两遍阅读法”促进英语单词的记忆
考研背单词要注意的几个方面
16天记住7000个考研英语单词(第5天)
考研寒假备考:英语单词轻松记(2)
16天记住7000个考研英语单词(第6天)
考研英语:知识运用高频词组总结5
考研英语84分:教你背单词
考研英语:词汇记忆六大误区
16天记住7000个考研英语单词(第4天)
考研英语历年真题完型词汇辨析
考研英语复习:词汇记忆诀窍
考研:坚持是掌握词汇的基础
名师指导:考前如何高效背诵英语词汇
考研英语词汇复习要注意什么
16天记住7000个考研英语单词(第9天)
考研英语:单词更上“忆”层楼
考研寒假备考:英语单词轻松记(1)
考研寒假备考:英语单词轻松记(4)
考研英语词汇与句法复习指南
考研英语备考:传授背单词技巧
16天记住7000个考研英语单词(第1天)
考研英语:常用词汇解析
考研英语二初级词汇复习规划
考研英语词汇复习:储备足够的词汇量
考研寒假备考:英语单词轻松记(6)
考研寒假备考:英语单词轻松记(5)
考研英语指导:历年真题完型词汇辨析
考研英语:整理词汇,逻辑记忆
考研英语:单词的记忆要从词性开始
考研英语词汇练习(八)2
| 不限 |
| 英语教案 |
| 英语课件 |
| 英语试题 |
| 不限 |
| 不限 |
| 上册 |
| 下册 |
| 不限 |