from the Newsletter of the Multidisciplinary Association for Psychedelic Studies
MAPS - Volume 6 Number 2 Winter 1995-96

Marijuana Water Pipe / Vaporizer Study

In 1996, MAPS will try to develop a proposal, find a capable lab and raise funds to continue to refine vaporizer technology. However, the research and development costs for the production of a sophisticated, efficient and inexpensive vaporizer are likely to be in excess of $50,000 and could reach as high as $200,000. These sums are not currently available. In late 1995, the initial study by MAPS and California NORML into the effectiveness of water pipes and vaporizers in filtering tars from marijuana smoke was completed. This project was initiated in order to respond to the FDA's concerns about the stress that marijuana may place on the immune systems of patients with already compromised immune systems. It is important to demonstrate that MAPS takes seriously the necessity to study both the benefits and the risks of marijuana. MAPS therefore initiated the study to determine if any drug delivery systems could selectively reduce the amount of tars that are inhaled and thereby reduce any stress on the immune system.

The results of the study will be described in detail in the next MAPS Bulletin. In short, the water pipes proved counterproductive compared to an unfiltered marijuana cigarette. The water pipes removed proportionately more of the cannabinoids than the particulate matter (tars) from the smoke. This result was not expected and was very disappointing.

Another disappointment is that the lab did not conduct the additional analyses, specified in our contract, into the effectiveness of the water pipes and vaporizers in filtering harmful gases in the smoke. The lab informed MAPS that technical difficulties prevented it from conducting the gas analysis portion of the study. While we agreed to reduce the amount of the contract accordingly, we would rather have obtained the data. Though water pipes are likely to have been helpful in reducing gases, we have no direct evidence to support that possibility nor do we know if the magnitude of any positive effect would counterbalance the increase in particulate matter. The one bright spot in the study was the finding that vaporizers were indeed a cleaner method of smoking than an unfiltered marijuana cigarette.

If water pipes would have been proven effective in reducing tars, this study would have identified a very simple and useful harm reduction technique to minimize what is arguably the most important risk associated with marijuana smoking, namely the effects of smoke inhalation on the mouth, throat and lungs. We could persuasively have argued that some paraphernalia laws had harmful consequences, much like laws against access to clean syringes. We could have claimed that two small organizations, MAPS and California NORML, had contracted for a $25,000 study that had done more to develop information about how to reduce the harm of marijuana smoking than the tens of millions of dollars spent by the Federal government. Ah, what might have been if only the data had cooperated! The only thing we can console ourselves with is the thought that perhaps our credibility will be solidified by making the results public instead of keeping them quiet and trying to sweep them under the rug.