First some background: When solid particles are burned, they release a variety of molecules as smoke due to the addition of energy in the form of fire. With this addition of energy, a series of chemical reactions occur that release liquid particles and gases that often are of different composition than the original compound. Most often, when an organic compound, such as cannabis, is burned, it emits gases such as carbon monoxide and hydrogen cyanide that may be harmful to the user. Aside from the stigma attached to the name, the potential harmful effects of smoke are one of the main reasons why marijuana is not widely accepted in the medical community. However, there are other ways of administration besides inhaling smoke, such oral or inhaling vapor. Vaporizers heat the cannabis to around 400⁰ F without burning the plant material, reaching the boiling point of most cannabinoids and releasing them in a mist, with not enough heat applied to release other, more harmful compounds.
The new information: In this experiment, twenty frequent cannabis smokers were used to determine the differential effects of inhaling smoke or vapor. The twenty smokers had previously reported at least two respiratory side-effects and were asked to self-report their severity of symptoms. Additionally, their forced expiratory volume (FEV1) and forced vital capacity (FVC) were measured. FEV1 refers to the maximum volume of air that can be exhaled in 1 second, and FVC refers to the total volume of air that the lung can hold. The smokers were then switched to using vaporizers for one month and the measurements were repeated. Initially, average self-reported symptoms were graded to be 26.1, FVC was 4.54L, and FEV1 was 3.22L; after 1 month of vaporizer use, average self-reported symptoms dropped to 6.92, FVC was 4.76L, and FEV1 was 3.6L. The study used 8 males and 4 females (8 of the subjects ended up smoking during the 1 month period) with an average age of 20 years. For these figures, the normal values for FVC and FEV1 should be 4.89 and 4.06L respectively. It should also be noted that approximately a quarter (3) of the subjects also reported tobacco use.
What this means: The results of this experiment indicate that utilizing vaporized cannabis instead of smoke may improve respiratory side-effects and overall pulmonary function. Additionally, this study only represented the improvement after one month of switching to vaporized cannabis, and improvements may increase with an increased time interval. Therefore, utilizing cannabis in vaporized form is significantly safer than smoking it.
Earleywine, M. and Van Dam, N.T. “Pulmonary Function in Cannabis Users: Support for a Clinical Trial of the Vaporizer.” The International Journal on Drug Policy. (2010): preprint.