NEW HAVEN, Conn. – Yale researchers found in a study that one in four high schoolers who use electronic cigarettes are inhaling vapors produced by dripping e-liquids directly onto heating coils, instead of inhaling from the e-cigarette mouthpiece, possibly increasing exposure to toxins and nicotine.

Yale News reports that teens who use e-cigarettes say “dripping” produces thicker clouds of vapor, a stronger hit in the back of the throat when inhaled and a more pleasurable taste. The Yale School of Medicine Report study was published online Feb. 6 in the journal Pediatrics.

The news source notes that applying the liquid directly to the battery-powered coil heats it at a higher temperature than inhaling from a cartridge or tank, possibly increasing exposure to chemicals like formaldehyde, acetaldehyde and acrolein in the vapors.

“One of the concerns I have is when you are looking at the safety and risk of e-cigarettes, one really has to look at the risks of alternative uses also,” said Suchitra Krishnan-Sarin, professor of psychiatry at Yale and first author of the study. “What we are discovering with our work with youth is that kids are actually using these electronic products for other behaviors, not just for vaping e-liquids from cartridges or tanks.”

Researchers reviewed survey responses from 1,080 e-cigarette users at eight Connecticut high schools and learned that 26.1% had tried dripping. White, male, teen students who had tried multiple tobacco products, and those who used e-cigarettes on more days in the past month, were more likely to use the devices for dripping, according to the study.

CNN reports that Ray Story, CEO of the Tobacco Vapor Electronic Cigarette Association, suspects the number of teens who have tried dripping may not be as high as the study indicates.

"Do we think it's going to become a trend or very popular? No," he told CNN, adding that he believes there will always be an extreme group that uses any product, including e-cigarettes, in alternative ways.