Closing In On Vaping’s Most Toxic Ingredient

(Credit: Mike Orlov/shutterstock)

(Credit: Mike Orlov/shutterstock)

How many breathless older smokers rue the day they first inhaled nicotine and tar?

Someday, adolescents sucking tobacco-free Mods and Juuls could face similar regret.

Initially hailed as a smoking cessation breakthrough, e-cigarettes have now been raising red-flags for years. Thanks to nicotine, vaping can be just as addictive as true cigarettes. And even if youthful vapers never drag on a Camel, preliminary evidence suggests they may still get chronic bronchitis – or even suffer a serious case of pneumonia, according to a study in the European Respiratory Journal earlier this year.

In their research, scientists cultured cells and exposed them to e-cigarette vapor. The cells showed a three-fold increase in the kind of molecular receptors that Streptococcus pneumoniae happily attach to. This microbe, commonly known as pneumococcus, is the world’s leading cause of life-threatening bacterial lung infection. The researchers also reported identical results from studies of “vaped” mice and nasal cells scraped from human vapers who, an hour earlier, had puffed on their gadgets at least 10 times over five minutes.

The study’s lead author, Jonathan Grigg of Queen Mary University London, has also studied how welding and fossil-fuel fumes affect human airways. He says he was worried from the first moment he saw how these microbes attached to vapers’ cells. For smokers’ sake, Grigg had hoped his results might be underwhelming.

He’s not the only one concerned, either. Jonathan Samet, senior editor of the Surgeon General’s Report on Smoking and Health, is similarly worried about the growing trend. “Vape products are changing far more quickly than the scientific community can evaluate them,” Samet says. “It’s a big problem for tobacco control researchers.”

And there’s still one question left unanswered: What is vape’s most toxic ingredient?

A Witchy Brew

That’s an easy question to answer for conventional cigarettes, where tar causes a marked increase in lung cancer risk. But e-cigarettes don’t have that same smoke and tar.

Vapes, in contrast, were designed to deliver flavored nicotine via a pleasing aerosol. They don’t have smoke or tar. All of the devices share the same basic components: a battery, heating device and liquid housed in various casings. And these nicotine liquids now feature more than 7,000 flavors. Some researchers say the gadgets’ appearance, flavorings, and ease of use are especially attractive to teens.

“Since e-cigarettes are currently unregulated, you can add anything to them,” says UCLA’s Holly Middlekauff who studies the negative effects of inhaled nicotine on vapers’ hearts.

Last year, Middlekauff and her colleagues published a paper in JAMA Cardiology that showed increased adrenaline-like tone and cell-damaging “oxidative stress” in habitual e-cigarette users. Both can make smokers more prone to cardiac arrhythmias and coronary artery disease.

But for Samet, the potential lung harm caused by inhaling flavorings is just as unsettling as the heart problems. He cited the cautionary tale of diacetyl, a buttery chemical flavoring added to microwave popcorn and other foods. In 2002, fifteen years after the earliest evidence surfaced, inhaled diacetyl was finally linked to a severe, irreversible lung disease called “bronchiolitis obliterans” in popcorn factory workers. In 2007, most major manufacturers removed diacetyl from their popcorn products.

Whether or not inhaled flavorings end up known as vape’s most toxic component, experts say there’s one diacetyl lesson should never be forgotten. Compounds that the Food and Drug Administration deems “generally safe for ingestion” can cause very different effects when humans breathe them in rather than eat them.

CATEGORIZED UNDER: Health & Medicine, top posts
MORE ABOUT: cancer, personal health
  • lump1

    It sounds like you need to get a lab with a whole lot of rats, hotbox it with vape mist, and report the results. You might be onto something with the diacetyl clue; it’s worth investigating. But the diacetyl story is one where the regulatory system did its job and the issue has a remedy. If we find something dangerous in vape juice, we should follow the same path. I’d even say: If we see some sort of respiratory problem spiking, we will want to start getting worried. But since tubs of vape juice have been absorbed by the lungs of teens already without some “smoking” gun – haha – I’m getting less worried over time, not more.

  • CarolAST

    Tobacco Control scientific fraud: falsely blaming smoking for heart disease that’s really caused by cytomegalovirus tinyurl(.)com/jmskkmz

    In NHANES data, 40% of cardiovascular disease is due to CMV, with more among working class, which includes more smokers. That difference in the rates of CMV infection between smokers, ex-smokers and never smokers creates the illusion that smoking causes heart disease.


    • Erik Bosma

      Sounds like someone who either doesn’t smoke or who hasn’t smoked much or for long. I smoked between 2 and 4 packs a day for 15 years and in my late twenties I could barely climb a flight of stairs. Within a year of quitting I was again swimming 3 km a day. It was also the most difficult drug I have ever quit.

  • CarolAST

    “Nicotine addiction” is a lie that “could only be sustained by systematically ignoring all contradictory evidence.” The Surgeon General claims are flagrantly corrupt and biased, and were clearly concocted to serve the political agenda of outlawing tobacco.

    • darryl

      Smoking isn’t bad for you, it’s just a big conspiracy brought forth by all of those companies getting rich off of making “no smoking” signs.

      • Niels Smits

        Smoking is bad he never said it wasnt.
        He is saying that NICOTINE on its own isnt as addictive as thought.
        And i agree w him.
        Why are so many people still smoking if they could get ther “fix” from some gum or a transdermal patch.
        That wont kill them.
        But how many people have succesfully done that?
        Not alot.
        Its most likely a mix of mono amine oxidase inhibitors and nicotine.
        Inhibiting the breakdown of dopamine and therefor enhancing the addictive propertys of nicotine.
        Just search tobacco maoi on google and do your own research.

  • CarolAST

    “Jonathan Samet, senior editor of the Surgeon General’s Report on Smoking and Health,” ought to be prosecuted by the Department of Justice for conspiracy, fraud and racketeering for his egregious charlatanism. As well as being lead editor of the SG reports, he was chairman of the most important “independent” groups it cited as support, such as the IARC monograph on ETS, the EPA report on ETS, and the ASHRAE Position Document on ETS. It’s practically a one-man band, with no independent input allowed.

  • Brian E. Erkkila

    I would be cautious about raising the alarm on diacetyl. I looked into this in the past during my time at the FDA. Diacetyl exposure from combusted cigarettes is generally much, much higher than from electronic cigarettes and the epidemiological evidence does not show an association between cigarette smoking and bronchiolitis obliterans (“popcorn lung”). I mean the fewer things one inhales, probably for the better, but the time spent sounding of diacetyl alarms seems could be better spent designing better studies to examine potential health effects of products.

    • Mark Stave

      You point directly to the effect of the lack of 15 minutes of online research – a click bait article that masquerades as science journalism

  • Uncle Al

    The “smoke” base is typically propylene glycol plus glycerin flash vaporized on a very hot ribbon. This leads to flash pyrolysis. Is breathing acrolein and epoxides a bad idea?


    • Niels Smits

      Its mostly vg these days and round wire nor ribbon

  • jennjenn

    Smoke Cannabis instead


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