from the Newsletter of the Multidisciplinary Association for Psychedelic Studies
MAPS - Volume 4 Number 3 Winter 1993-94


Marijuana Water Pipe Study


Included in the Medical Marijuana Clinical Plan is a study of the effectiveness of water pipes in filtering marijuana smoke. This project has been mentioned in previous MAPS newsletters. The study is designed to determine if there are safer ways than a standard marijuana cigarette to administer the therapeutic components of marijuana, while at the same time still retaining the advantages of smoking over the oral THC pill. These advantages include smoked marijuana's rapid onset of effects, the patients' ability to self-titrate their dose, and the delivery of a complex set of constituents of the marijuana plant which may work more effectively than THC alone. If we can demonstrate that a specific water pipe does indeed have a beneficial advantage over a standard marijuana cigarette, we will distribute the pipe to all AIDS patients in the wasting syndrome study. Good news - all the funds needed for this study, $28,800, have been successfully raised. The study will take place under the direction of Dr. Hoffman at the Institute for Smoking and Health in New York. This study is possible primarily because MAPS received a grant for this project of $18,000 from a single donor who gave $14,000 outright, and also submitted the winning bid of $2,000 each in the MAPS auction of the two original art Doonesberry cartoons donated to MAPS by Garry Trudeau. The remaining funds for the study were obtained from Dale Gieringer of California NORML and Ed Rosenthal of Quick Trading and Ask Ed fame, both of whom donated $5,000 each. Rounding out the sum, an additional $800 is coming from numerous small donations to MAPS.

Sending the wrong message?

Some medical marijuana advocates have cautioned that this study could "send the wrong message" that smoked marijuana is too risky to use as is, thus slowing down or preventing altogether FDA-approval of smoked marijuana in rolled cigarette form. To the contrary, I feel that we should be able to acknowledge that for some patients, smoking marijuana carries certain risks which are nevertheless exceeded by its therapeutic benefits. Studying ways to possibly improve the delivery of marijuana should not undercut the effort to secure prescription availability of marijuana as rapidly as possible. On the contrary, this study might even hasten the day that the FDA approves medical marijuana by reducing the efficacy of arguments against it. Demonstrating scientifically that there is a way to reduce the risks of smoking favorably alters marijuana's risk/benefit ratio, improving its chances of securing FDA-approval. More compelling reasons for this study are that we are exploring the use of marijuana in AIDS patients whose immune systems are already compromised. For some of marijuana's other medical applications, like spasticity, patients may need to smoke marijuana every day of their life. It simply makes good sense to see if the ratio of marijuana's therapeutic components to tars and particulate matter can be increased through some simple sort of water pipe.

Water pipe patent search

In preparation for this study, MAPS had a patent attorney conduct a patent search of water pipes. The search indicated that more pipes than one might have imagined had been patented. Some of the patented pipes were very humorous. One was a combination water pipe/drink holder with separate liquid containers for the drink and the water that would filter the smoke (perhaps for those who can't decide if they prefer alcohol or marijuana). Other designs were made to be more difficult to spill (a not uncommon and messy problem), or involved an efficient way to refill the bowl though the use of a separate chute filled with "expensive tobacco" that deposited a measured amount into the bowl when a knob was rotated.

Only two of the pipes made health claims. One inventor installed a filter in the inhalation tube between the water bowl and the mouthpiece. No evidence was presented indicating that the filter selectively filtered out particulate matter as opposed to simply reducing both particulate matter and THC. The other designer placed stones in the water to lengthen the path of the smoke through the water. Once again, there was no evidence that this actually increased the amount of filtering done by the water.

Putting pipes to the test

Previous studies, reported by Nick Cozzi in the last issue of the MAPS newsletter, have demonstrated that water pipes do filter some of the potentially harmful constituents of marijuana smoke. Dr. Hoffman's study will be the first to quantify the specific components that various smoking devices filter out of marijuana smoke. What we seek to determine are the exact differences, if any, in the amounts of THC, other cannabinoids, tars and particulate matter contained in water-filtered smoke compared to unfiltered smoke.

The study has two phases. First, smoke from three different types of pipes will be tested in a rough, quick way to determine their relative amounts of THC and one representative tar. Second, the water pipe that delivers the highest THC/tar ratio will then be run through a very comprehensive analysis comparing the materials in the smoke from the water pipe to the materials in the smoke from a standard unfiltered marijuana cigarette.

The three pipes to be tested in the first phase of the study are quite different from each other. The first is a rather interesting water pipe with a small battery operated fan blade immersed in the water. The fan blade creates turbulence in the water in order to increase the mixing of the smoke with the water. Theoretically, this should result in more filtering action than if the water was still. The second water pipe is being designed by Nick Cozzi and a MAPS member who was inspired by Nick's article to see if he could design an efficient water pipe that would incorporate various filters. Nick will suggest the filters (a gas diffusion frit and a cigarette-type particulate filter) and the MAPS member will build the prototype.

The third pipe that will be tested is not a water pipe. This pipe exploits the fact that THC and other cannabinoids will vaporize at a temperature below that of the burning point of marijuana. The pipe enables people to inhale marijuana vapor containing THC and other cannabinoids rather than marijuana smoke containing THC along with all sorts of particulate matter, tars, and some gaseous products of combustion. This pipe is likely to produce very little particulate matter and deliver little or no undesirable gas combustion products.

The pipe uses an electric heating plate rather than matches. It works by heating the marijuana enough to vaporize the THC. It then gathers the vapor in an enclosed space and delivers the vaporized smoke to the smoker through a standard mouthpiece. While this pipe is likely to be the best from a health standpoint, it will probably take some further refinement before it can be made easy to use, reliable, and efficient in terms of getting as much of the THC out of the marijuana as possible. Because of the more practical nature of the water pipes compared to the vaporization device, we will conduct the comprehensive test with whichever water pipe performs the best in the initial trial.

Harm reduction

This water pipe study is a classic example of the harm reduction approach to drug use. If water pipes really reduce the harm associated with marijuana smoking, non-medical users can be educated about the benefits of water pipes and encouraged to use them whenever possible. Since smoking is one of the main harms associated with the use of marijuana (accidents are another), this simple water pipe study may help lay the groundwork for significantly reducing the harmfulness of marijuana smoke. If US drug policy ever moves to a harm-reduction approach to marijuana, studies such as this one will play an important role in helping users to identify and minimize the health risks of marijuana. The shift to prevention rather than treatment is consistent with the current health care debate and seems likely to reduce costs in the long run.

After over a year of effort, the MAPS study of the effectiveness of water pipes in filtering marijuana smoke is about to begin. I would like to express my deep appreciation for the generosity of the MAPS member who believed in the importance of this study, and in putting this matter to a scientific test.

MAPS Logo