You may have noticed this interesting little article recently:
It popped up here and there on Facebook, and on further inspection it appears this topic has been discussed before:
So the question we need to ask ourselves is...
Will the Propylene Glycol in my e-cig make me go deaf?
Vaping: you're doing it wrong.
OK, let's look at the facts.
The statement made in the article about Rob Swire and in both the reddit and e-cig forum posts is that Propylene Glycol is ototoxic.
For those of you unwilling or unable to click the link, "ototoxicity is the property of being toxic to the ear (oto-), specifically the cochlea or auditory nerve and sometimes the vestibular system". (Thanks Wikipedia!)
The claim that Propylene Glycol is ototoxic all seems to revolve around this study, which I found quoted in both the reddit and e-cig forum articles:
(Morizono et al, 1980)
In short, the study found that, YES, Propylene Glycol caused "...deterioration of the cochlear microphonics and the endocochlear direct current potential...", and also noted that "...morphologic changes were severe and included granulation tissue in the middle ear and destruction and ossification of the auditory bulla and bony cochlea."
In other words... yikes!
BUT... here at the Vapoureyes blog, we like to dig a little deeper on these things. So let's go further than most people and actually read the whole abstract, at which point we notice the following words that kind of put the whole thing into context:
"propylene glycol... was instilled into the middle ear of guinea pigs and chinchillas..."
So let's break this down a bit:
1. The results were in guinea pigs and chinchillas.
2. They dripped the stuff directly into the poor little guy's ears.
We should clarify that this study was examining the use of antibiotic ear treatments, of which Propylene Glycol was a common ingredient at the time. It should also be noted that they took the Mythbusters approach and just kept putting more and more PG in there until it started causing damage, so the amount in question was astronomically greater than that which you would normally be exposed to. So the results of the study were strong enough to recommend discontinuing the use of PG in ear drops. However, guinea pigs and chinchillas are not renowned for being good experimental models for effects in humans, so going beyond that is a bit of a stretch.
Moreover, considering as of the publication date of this study e-cigs were still 26 years away from being invented, the study was not intended to examine the effects of the odd stray wisp of PG (mixed with VG, nicotine, colours and flavours) happening to waft its way down into your inner ear on occasion, and most certainly made no claims regarding the highly improbable scenario of PG absorption via the mouth or lungs in such high concentrations that it managed to accumulate in the inner ear.
Pictured: seriously obscure nerd reference 99% of you won't get.
Advice for if you're worried about vaping damaging your hearing
Animal studies only go so far to correlate with effects on humans, so I feel that we should still offer some advice to see if vaping may represent a real hearing health risk to you. So:
1. If you're a DJ in the EDM scene and play very loud gigs on a regular basis and are likely to blame your hearing loss on literally anything other than your chosen career's OH&S hazards, don't use e-cigs.
2. If you're a guinea pig or chinchilla - probably best not to use e-cigs.
3. If you're in the habit of dripping your juice into your ear instead of your RDA - you've probably got more serious problems than potential hearing loss or tinnitus.
And whilst we're on the topic of handing out words of wisdom:
4. If you're an editor for an online magazine and the writer didn't quote anything other than a DJs tweets as evidence, maybe choose your headlines a little more carefully ;-)