Well, I thought this thread was about inhaling substances from a vaporizer, not about cannabis. Of course vaporizers pose considerably less health risk than smoke, but then it depends what you vaporize and how often. Even relatively harmless herbs can have unexpected effect on the ventilation and cardiovascular functions, so if you push your breath-holds, your organism may react differently than normally, or the perceptions can be different, so you risk blacking out or harming yourself.
This is true for cannabis as well as practically for any other substance. The risk may be in some cases and to certain degree reduced by experience, but you have to keep on mind that you add another level of complexity to the already complicated physiology of freediving.
As for cannabis alone, we already discussed some of its effects for example in this thread:
http://forums.deeperblue.com/beach-bar/69294-breath-holding-smoke.html I highly recommend reading it - there are some references that may interest those using it regularly, regardless in which way. However, as wrote earlier in this thread, the topic is somehow sensitive on this forum - not only it is designated to all age groups, but there are members from countries where any use of hemp is completely illegal, and in some countries even speaking about it publicly may cause troubles. Hence I suggest we let the discussion of pro's and con's of cannabis to other platforms than DB.
Now back to the topic of vaporizing - it seems to be indeed much more efficient and less harmful method of introducing substances into the organism than smoking. However it does not mean it is perfectly harmless and healthy. I would split the problematics into several subtopics:
1) Risks caused by the substance itself - you will need to make a closer study on the substance you vaporize. Since there are many of them, it not possible to tell in advance whether they are perfectly harmless for a freediver or not
2) Risks caused by byproducts, additives, preservatives, pesticides, and other substances, or particles that you inhale with the vapor. That greatly depends not only on the quality and purity of the vaporized product, but also on the vaporizer type and quality, and on the temperature used. It is true that at good quality vaporizers the content of tar will be greatly reduced, and also the content of other toxins may be lowered or even eliminated. So for example CO content is typically also much lower at vaporizers than at smoking, but still there is some, and since the CO is very critical at freediving, you will probably want to avoid it as much as you can. Also diverse resins present in most herbal products will do it through the vaporizer to your lungs, and hence regular and frequent use may pose a risk to the lungs. Then there may be other components that are chemically being broken down by the combustion when smoking, but will survive the process of vaporizing at lower temperatures. Most of this is quite little studied, and in comparison to smoking there is still quite little of statistical data, so you won't find much reliable information about it.
3) The temperature of the vapor - it is not only the tar that destroys the lungs of smokers. To big part the high temperature of the smoke is at the root of a lot of lung damage.
Quote from
Understanding the harmful effects of smoking - by Sam Midling - Helium
Your lungs are not just open pouches of meat that fill with air like a balloon, they are actually made up of hundreds of thousands of tiny little tubes that branch off and get narrower every time, these tubes are called bronchial passageways. Your lungs use this structure in order to maximize the surface area of whatever you breathe in, usually air. Within these tiny little corridors there are millions of tiny little hairs called cilia, these perform a vital function. The cilia are tiny little cleaners, clearing any particulate that might accidentally enter the lungs, like when you venture out in a dust storm. Unfortunately when you smoke something the temperature of the smoke is so high when it enters your lungs that these cilia get fried and can no longer do their job, this leads to a buildup of gunk and all kinds of stuff that would ordinarily be cleaned out of the lungs (...)
With these cilia gone we see an increase in particulate buildup as well as a decrease in lung function and efficiency, this will ultimately make it much easier to get chronic bronchitis as well as increase your chance of getting pneumonia
Again, from this point of view, vaporizing is less harmful than smoking, but it does not mean it is safe. Setting your vaporizer to lower temperatures may help reducing the damage, but may induce other problems - for example the previously reduced effect of eliminating some toxins by combustion. Lower vaporizing temperatures might perhaps also lead to increased bacteria build-up. At some vaporizers, for example at those combined with water filters, mold may build up too and enter your lungs. Hence careful and regular cleaning/disinfecting the vaporizer and early replacement of filters, is likely a good idea.
4) Then there is the problem of the quality of the vapor mixture you inhale - despite good filters, there are always some particles, and at many vaporizers the air is also quite dry - meaning if your lungs are already sensitive, they may get irritated easily. This is possibly one of the reasons many people with chronic respiratory problems who switched from smoking to vaporizers, continue having problems when vaping, too.
Well, in conclusion I'd tell that if you really feel the need to inhale some substances, the vaping is likely much gentler way than smoking, but personally at people being maximally dependent on their lungs, like freedivers are, I'd expect they'll try to avoid as much risk as they can. Sure, we'd have to avoid also smog of the cars, boats, dust, etc. and still would have no warranty of perfect health, but perhaps increasing the risk when it is not really needed, is not necessary. However, that's up to every individual - most of us are adults and can decide for ourselves. Still, I'd tell that knowing about the potential hazards, and being able to evaluate them properly is important.
