The Great Unknown

Dr. Fatima Alshbool is investigating the effects of e-cigarettes on the cardiovascular system.


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By Adrianne Grubic
Population Health Scholar
University of Texas System
Ph.D. Student, School of Journalism
UT Austin Moody College of Communication The University of Texas at Austin

In order to model the effects that e-cigarette use (vaping) may have on humans, Dr. Fatima Alshbool exposed mice to five days of e-cigarettes similar to what human vapers tend to inhale.

Even in that short time, Alshbool observed harmful activity that increased the risk of thrombosis, or clotting, in the mice’s blood vessels. This could in turn increases the risk of clots traveling to the mice heart or brain, where they can cause stroke or heart attacks.

“We found that the platelets were hyperactive,” says Alshbool, Assistant Professor of Pharmacy and a member of Border Biomedical Research Center (BBRC) at The University of Texas at El Paso.

In 2015, Alshbool and her husband, chair of pharmaceutical sciences Dr. Fadi Khasawneh, were also among the first group of researchers to demonstrate that third-hand smoke from traditional cigarettes could cause blood clots.

Third-hand smoke is the chemical residue left on surfaces where smoking has occurred, such as floors, furniture and clothes. It is particularly harmful for children who inhale or ingest the residue as they crawl on carpets or play on furniture.

It is too soon to say whether third-hand e-cigarette emissions pose a health risk, says Alshbool, but it is also far too soon to say that they don’t.

 “They do not have the tar of traditional cigarettes,” she says, “but there is a significant overlap between the toxicant profile of traditional and e-cigarettes. They are not emission-free, as many believe them to be.”

Because there are so many devices and flavors on the market—more than 400 brands of devices and some 8,000 flavors—it’s impossible to develop a universal profile of the ingredients or their effects. At least some solutions and emissions, however, contain heavy metals like nickel, tin and lead. Almost all of the vapors contain nicotine and propylene glycol, and the flavoring agents are widely variable in their composition.

“Bystanders can also breathe in what the e-cigarette user exhales,” says Alshbool. “So second-hand vaping could be an issue.”

The research on humans is still in the preliminary stages, and Alshbool is cautious about extrapolating from her mice studies. What’s needed, she says, are more studies, including research on second- and third-hand vaping and dual users of both tobacco products and e-cigarettes.

“From a pharmaceutical perspective, the effect of dual use could be additive or synergistic,” she says. “We can’t draw a conclusion at this stage. We need more studies. The bottom line, however, is that it is not harmless.”