A new poll finds Americans are divided about the risks and benefits of e-cigarettes.

The HealthDay/Harris Poll found 43 percent of adults feel e-cigarettes are more dangerous than traditional cigarettes; 41 percent say the devices are healthier than traditional cigarettes; and 42 percent say they are an excellent way to quit smoking.

The poll found 85 percent of adults said they were concerned that the long-term health effects of e-cigarettes are unknown, while 83 percent said they were at least somewhat concerned about teens using e-cigarettes.

Last month, The Wall Street Journal reported the number of high school students who say they used e-cigarettes in the past 30 days has jumped 75 percent since last year. About 3 million—or 20 percent—of high school students are vaping, according to the findings. In contrast, last year 1.73 million—or 11.7 percent—used e-cigarettes, according to recently published federal data.