We're all familiar with the dangers of passive smoking. Breathing in someone else's cigarette smoke can put you just as much at risk of all the diseases that go with it as if you lit one up and puffed on it yourself. But what about vaping? Is passive vaping a Thing?
To answer this question, we head once again into peer-review land, and read a little study called:
"Acute effects of electronic and tobacco cigarette smoking on complete blood count" (2012).
In this study, as the title suggests, the researchers wanted to find out specifically if inhaling second-hand vapour breathed out by e-cigarette users had any impact on bystander's blood. They pointed out that the effects of second-hand cigarette smoke are well known and documented, but no such research exists on e-cigs.
Materials and methods
So, they took 15 smokers and 15 never-smokers, and put them through three experimental sessions, separated by one week of wash-out. There was the control session (sitting in a room doing nothing), an active tobacco cigarette smoking session (sitting in a room filled with cigarette smoke) and an active e-cigarette smoking session (sitting in a room filled with e-vapour). Blood samples were taken immediately before, immediately after, and one hour after each session.
For the control session, the smokers had to sit and suck miserably on an unlit cigarette for half an hour. For the active cigarette session they were restricted to two cigarettes of their own choice of brand within the half hour. And for the active vaping session they had to take a pre-determined number of puffs (based on the strength of their own choice of ciggies) on an eGo filled with 11mg/L e-liquid.
For the control session, the never-smokers had to sit in a room presumably making slightly uncomfortable small talk for half an hour. For the active ciggie session, they had cigarette smoke pumped into the room at a measured carbon monoxide level the same as you would get in a bar or restaurant for half an hour. And for the active vaping session, they had e-vapour pumped in at levels equivalent to the amount of tobacco smoke they were subjected to for half an hour.
Blood sample analysis
I won't bore you with the details. But trust me when I say they extracted a standard amount of blood from these people and subjected it to every type of blood test known to man. They were very thorough, resulting in a bunch of words that described exactly how thorough they were. You can read the paper yourself if you want to make sure.
Now we get to the juicy stuff! What happened? Well.....
||Lots of nasty stuff
||Lots of nasty stuff
For those who are after specifics, the "lots of nasty stuff" was an increase in leukocyte, lymphocyte, and granulocyte count for at least one hour afterwards, and leukocyte count remaining abnormally high for some time. In other words, all three cell types are types of white blood cell, which form part of our immune response. They tend to freak out and spring into action whenever "lots of nasty stuff" enters our bloodstream. You may know this reaction by the more common term of "inflammation".
Here is a picture of it:
Fig. 1. White blood cell count, lymphocyte count, and granulocyte count prior to, immediately following, as well as 1 h following active (left graphs) and passive (right graphs) smoking in smokers and never smokers, respectively. Results are presented as median ± mean absolute deviation. Squares with solid lines represent tobacco cigarette smoking, triangles with dashed lines represent e-cigarette smoking, while circles with dotted lines indicate the control session. Asterisks indicate statistically significant change from baseline (i.e., pre) values.
2012 Elsevier Ltd. All rights reserved.
Hang on a second, do you mean to say that...
- not only does passive vaping not cause an immune response in either smokers or never-smokers, but
- active vaping doesn't cause an immune response in either smokers or never-smokers either?
Yes, gentle reader, that is exactly what this study shows.
There is absolutely no difference between either vaping or second-hand vaping to breathing in pure fresh air when it comes to the immune inflammatory response.
Now this study may not help you when you're asked to stop vaping in a bar or restaurant. Responding with "aha! But a recent study showed that neither active nor passive vaping had any significant effect on blood-plasma levels of leukocytes, lymphocytes and granulocytes! So ner!" isn't exactly going to win you friends, and you'll probably still end up outside.
But where this study can help you is if you are concerned about the effect your vaping may be having on your significant other, or your kids, or your pets. For all intents and purposes, it isn't having any.
There are more studies on the topic of passive vaping, so perhaps we can look at them some other time. I'm all nerded out for now.