Much
public concern has been aroused about the potential health hazards of
marijuana smoking. An alarming new editorial in the British Medical
Journal alleges fallaciously that marijuana could be as dangerous as
tobacco smoking, ignoring extensive scientific evidence to the contrary.
As pointed out by NORML, the BMJ vastly exaggerates the potential health
hazards of marijuana smoking, in large part because pot smokers typically
consume far less material than tobacco smokers http://www.norml.org/index.cfm?Group_ID=5616.
Nonetheless, marijuana users do have good reason to avoid smoking. Like
tobacco, marijuana smoke is known to contain chemicals that are irritating
to the lungs, and chronic pot smokers have been shown to suffer an increased
risk of bronchitis and respiratory infections.
Fortunately, there is mounting new evidence that these risks can be
avoided thanks to a rapidly developing technology known as vaporization,
in which cannabis is heated to a point where pharmaceutically active
vapors form, but below the temperature of combustion.
A new study sponsored by California NORML and MAPS with support from
MPP has found that a vaporizer known as the Volcano® (http://
www.storz-bickel.com) drastically reduces harmful gases in marijuana
smoke, delivering a nearly pure stream of active cannabinoids with very
few byproducts of combustion. This is the second study by Cal NORML
and MAPS demonstrating impressive benefits from vaporizers.
California NORML and MAPS are supporting efforts to have vaporizers
approved by the FDA for use in human subjects and to make them more
widely available to medical cannabis patients seeking to reduce their
exposure to smoke.
Results of the new vaporizer study are discussed below.
Study
Shows Vaporizer Can Drastically Reduce Toxins in Marijuana Smoke
Harmful toxins in marijuana smoke can be effectively avoided by a vaporization
device, according to a new study by California NORML and MAPS (Multidisciplinary
Association for Psychedelic Studies) with support from a grant from
the MPP (Marijuana Policy Project).
The study, conducted by Chemic Labs in Canton, Mass., tested vapors
from cannabis heated in an herbal vaporizer known as the Volcano®
(manufactured by Storz & Bickel GmbH&Co. KG, Tuttlingen, Germany;
http://www.storz-bickel.com) and compared them to smoke produced by
combusted marijuana. The Volcano® is designed to heat material to
temperatures of 130° to 230° C (266° to 446° F) where
medically active vapors are produced, but below the threshold of combustion
where smoke is formed.
The vapors from the Volcano® were found to consist overwhelmingly
of THC, the major active component in marijuana, whereas the combusted
smoke contained over 100 other chemicals, including several polynuclear
aromatic hydrocarbons (PAHs), carcinogenic toxins that are common in
tobacco smoke. The respiratory hazards of marijuana and tobacco smoke
are due to toxic byproducts of combustion, not the active ingredients
in the plant, known as cannabinoids.
The study suggests that medical marijuana patients can avoid the respiratory
hazards of smoking by using a vaporizer. In its 1999 report on medical
marijuana, the Institute of Medicine recommended against long-term use
of smoked marijuana because of the health risks of smoking. However,
the IOM failed to take account of vaporizers.
Previous studies have found that vaporizers can reduce harmful toxins
in cannabis smoke. However, this is the first study to analyze the gas
phase of the vapor for a wide range of toxins. A previous NORML/MAPS
study conducted by Chemic Labs found that a vaporizer known as the M-1
Volatizer® (http:// www.volatizer.com) completely eliminated three
specific toxins (naphthalene, benzene and toluene) in. the solid phase
of the vapor (D. Gieringer, "Cannabis Vaporization: A Promising
Strategy for Smoke Harm Reduction," Journal of Cannabis Therapeutics
Vol. 1#3-4: 153-70 (2001); http://www.canorml.org/ healthfacts/vaporizerstudy1.html).
The new study used a gas chromatograph mass spectrometer (GCMS) to examine
the gas components of the vapor. .The analysis showed that the Volcano®
vapor was remarkably clean, consisting 95% of THC with traces of cannabinol
(CBN), another cannabinoid. The remaining 5% consisted of small amounts
of three other components: one suspected cannabinoid relative, one suspected
PAH, and caryophyllene, a fragrant oil in cannabis and other plants.
In contrast over 111 different components appeared in the gas of the
combusted smoke, including a half dozen known PAHs. Non-cannabinoids
accounted for as much as 88% of the total gas content of the smoke.
The study used standard NIDA cannabis with 4% THC content. A quantitative
analysis found that the Volcano® delivered 46% of the THC into vapor
following three 45-second exposures of the sample to the heat. This
compares favorably with the typical efficiency of marijuana cigarettes
as observed in other studies, which depending on conditions can fall
below 25% due to loss of THC in sidestream smoke. An important feature
of the Volcano® is that it uses a balloon to capture the vapor,
thereby avoiding leakage to the air. It is possible that higher THC
efficiencies could have been reached with the Volcano® by stirring
the sample around and exposing it to more heat.
The combusted sample achieved a relatively high THC efficiency of 78%
upon complete combustion. The high efficiency seems due to the fact
that the sample was completely consumed by combustion, and that smoke
leakage was effectively prevented by the laboratory setup. Similar conditions
do not obtain under normal circumstances when a marijuana cigarette
is smoked and much of the THC is lost to the air or left in the unburned
"roach."
Two other cannabinoids , cannabidiol (CBD) and cannabinol (CBN), were
detected in the NIDA cannabis in trace amounts of 0.1%. Both the Volcano®
and combustion delivered an apparent increase in CBD and CBN, but the
variance of the data was too high to reach statistically significant
conclusions.
Sponsors believe that the study results lend support for wider use of
vaporizers by medical marijuana patients and researchers. At present,
the only FDA-approved method for administering marijuana to human research
subjects is via smoking NIDA cigarettes. NORML and MAPS are supporting
efforts to have vaporizers approved by the FDA. As a first step in this
effort, Dr. Donald Abrams of the University of California, San Francisco,
has submitted a grant proposal to the California Center for Medical
Cannabis Research in San Diego to test the Volcano® in human subjects.
If the protocol is funded and the Volcano® approved by the FDA for
human research, it will be the first human study using a vaporizer.
If the FDA requests additional laboratory data about the Volcano@, additional
funding may be necessary.
For more information on vaporizers, see http://www.maps.org/mmj/vaporizer.html
http://www.canorml.org/healthfacts/vaporizers.html
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