ok, was just asking the opinions of those who might have more knowledge on this subject than me. My own conclusion is who knows? I have no idea.
Far from posing a threat to our health, the propylene glycol in e-smoking liquids might help keep us healthy. It would accomplish that by its germicidal action. It kills many of the major bacteria that threaten lung entry into our bodies.
Until yesterday, I was unfamiliar with this potentially beneficial consequence of propylene glycol vapor.
Back in the late '30s, researchers at the University of Chicago stumbled onto its effectiveness as a germ-killer, as related in this Time magazine story from Nov. 16, 1942:
"A powerful preventive against pneumonia, influenza and other respiratory diseases may be promised by a brilliant series of experiments conducted during the last three years at the University of Chicago's Billings Hospital. Dr. Oswald Hope Robertson last week was making final tests with a new germicidal vapor propylene glycol to sterilize air. If the results so far obtained are confirmed, one of the age-old searches of man will finally achieve its goal...
"...the researchers found that the propylene glycol itself was a potent germicide. One part of glycol in 2,000,000 parts of air would within a few seconds kill concentrations of air-suspended pneumococci, streptococci and other bacteria numbering millions to the cubic foot.
"How did it work? Respiratory disease bacteria float about in tiny droplets of water breathed, sneezed and coughed from human beings. The germicidal glycol also floats in infinitesimally small particles. Calculations showed that if droplet had to hit droplet, it would take two to 200 hours for sterilization of sprayed air to take place. Since sterilization took place in seconds, Dr. Robertson concluded that the glycol droplets must give off gas molecules which dissolve in the water droplets and kill the germs within them.
"Dr. Robertson placed groups of mice in a chamber and sprayed its air first with propylene glycol, then with influenza virus. All the mice lived. Then he sprayed the chamber with virus alone. All the mice died."
The complete Time story can be read here: Air Germicide - TIME
In a scientific summary of the discovery, it was noted that "Tests on possible deleterious effects of breathing propylene glycol containing atmospheres over long periods of time are being carried out."
Those tests were done and a second summary report on propylene glycol vapor was released:
"Propylene glycol is harmless to man when swallowed or injected into the veins. It is also harmless to mice who have breathed it for long periods. But medical science is cautious there was still a remote chance that glycol might accumulate harmfully in the erect human lungs which, unlike those of mice, do not drain themselves. So last June Dr. Robertson began studying the effect of glycol vapor on monkeys imported from the University of Puerto Rico's School of Tropical Medicine. So far, after many months' exposure to the vapor, the monkeys are happy and fatter than ever. Dr. Robertson does not expect mankind to live, like his monkeys, continuously in an atmosphere of glycol vapor; but it should be most valuable in such crowded places as schools and theaters, where most respiratory diseases are picked up."
The monkeys lived in enclosures filled with propylene glycol vapor. No deleterious effect was ever reported. And the concentrations of PG we inhale on a regular basis surely must equal the amount inhaled by the monkeys for this test. Obviously, no scientist saw a time when a device would atomize a PG mist that would then be inhaled for fun. But time and technology has given us the electronic cigarette. With each inhalation, we are washing our lungs with a germicidal agent used today in some "air sanitizers".
Glycerine, by the way, has some germicidal impact, but not, apparently, to the degree provided by inhaling propylene glycol vapor. Glycerine is now used by dairy farmers to help prevent bacteria entering a cow's teats after milking. Glycerine both softens the teats and kills bacteria.
One more quote on PG: "The vapour from as little as 0.5 mg of propylene glycol can kill nearly all the microorganisms in a liter of heavily contaminated air within 15 seconds."
The initial experiments with PG vapor were part of a search to find ways to create clean rooms, so the 1918 Spanish Flu pandemic that killed so many millions would never be repeated. Today, researchers have wondered online if propylene glycol vapor might not offer protection against a widely feared coming pandemic of bird flu, tagged H5N1.
Imagine e-smokers being healthier than non-smokers in such a scenario.
Dammmmmm ........ Im glad to see that this post is still on the go .... New Members should read from the start before posting![]()
Why do you folks ignore this from his quoted excerpt:
"But medical science is cautious — there was still a remote chance that glycol might accumulate harmfully in the erect human lungs which, unlike those of mice, do not drain themselves."
...not drain themselves. So last June Dr. Robertson began studying the effect of glycol vapor on monkeys imported from the University of Puerto Rico's School of Tropical Medicine. So far, after many months' exposure to the vapor, the monkeys are happy and fatter than ever.
The report is positive. Its a good study that bob has found and i believe it talks about the positives. nice for all of us to hear. The only real questions i still have, even though I liked the positive news of the study; is what were the concentrations the chimps were actually breathing in from PG being distributed in the air as opposed to directly inhaled. 2) Do you think breathing "atmospheric" PG for a few months is a sufficient enough of time to see adverse effects? Do you think it might take longer? Even the deadly cigarettes take a longer time than this to show real negative effects.
and lastly. maybe i overlooked it. but why does PG kill germs? and if it can kill bad germs and bacteria, can it also kill good bacteria that we need ?
These are just a couple of questions I can think of from reading the study.
Assuming that PG can do what it's alleged to do (i.e., works as a germicidal inside the lungs when vaped with an e-cig), suddenly there's a whole new line of defense in regards to bacterial superinfection. If the lungs can be treated directly, with a germicidal vapor such as PG, it seems reasonable to think that if the dosage were correct, a significant number of bacterial pneumonia infections could be averted and/or treated with direct administration, i.e., inhalation of a PG vapor.
I've had bacterial pneumonia twice (once when I was 7 and once when I was 25), and it's absolutely horrible. If PG has the possibility of preventing it from possibly killing me, I'm more than willing to take that chance.
I've heard people saying that the filler in their cartridges changes colour after a while and suspect that can't be a good thing. Some folk do replace the filler and clean mouthpieces. I don't use cartridges myself, I just drip directly onto the atomiser.
Here's some more discussion about safety that might interest you - http://www.e-cigarette-forum.com/fo...ing/12317-how-valid-vaping-health-claims.html
Bless you. And I'm with you. I so wish some would stop this running in circles and waving our hands and shouting "what about PG", what about "the dangers." They are threatened with suffocation under the science, yet they doubt on ....
I am absolutely positive that smoking was bad. 100% positive
Exactly. I'm also 100% posiitive that vaping nicotine is bad for me... but I trust it is less bad than smoking. At this point, vaping really is a matter of weighing a known risk versus something we believe is safer.
What facts or research convinced you that vaping nicotine is bad for you? I looked, but couldn't really find anything that definitely told me this would be harmful.
What facts or research convinced you that vaping nicotine is bad for you? I looked, but couldn't really find anything that definitely told me this would be harmful.
I think the key word there is nicotine.
I think the harder thing to do would be to find a currant study not "pay for results" from big tobacco that shows nicotine is NOT harmful.
People believe nicotine is healthy? huh?