What’s in the Weed You’re Smoking?


While filming the upcoming documentary Toxic Profits over the last six months, I have been speaking with people about extremely hazardous pesticides that are used in agriculture across the world. These discussions about pesticide use on food for animal and human consumption prompted my discovery of a very under-reported and interesting phenomenon: the use of large amounts of unregulated pesticides to grow cannabis.

Dan Tomaski, who runs northern Michigan's most comprehensive medical marijuana testing lab service, found that some marijuana contains mold and pesticides at levels more than 60 times those allowed for store-bought spinach. Yet, unlike pesticides on produce, there are zero regulations for pesticides on marijuana, and no single pesticide has ever been approved for use on marijuana.

Despite the lack of regulation, some marijuana growers continue to maximize profit by heavily spraying their marijuana to grow as much pot as quickly as they can — so much so that Agent Patrick Foy of the California Department of Fish and Game estimated that 1.5 pounds of fertilizers and pesticides are used for every 11.5 plants. His message to weed smokers is: “You ain’t just smoking pot, bud. You’re smoking some heavy-duty pesticides.” 

What is even more disturbing is that many of these “heavy-duty pesticides” being used on marijuana are actually only approved for non-human consumption and intended for use on lawns, golf courses, and sports fields, for example. In an interview for this article, Chris Van Hook, a former farmer and California medical marijuana attorney, stated that “initial pesticide screening results of medical cannabis out in the marketplace show a widespread use of insecticides and pesticides that are not registered for edible crops, much less medical cannabis.” Van Hook also noted that expansions of these studies, as well as the development of safe pesticides for use on cannabis, are hindered by the continued federal illegality of marijuana use, growth, and possession.

Part of the problem is that since marijuana is illegal under federal law, the United States Department of Agriculture does not allow for it to be certified organic under the guidelines used for produce. Yet, there are people like Chris Van Hook who are fighting back and demanding access to safe marijuana. Van Hook is also a USDA organic food inspector and has used the USDA’s organic model to start his own marijuana certification organization called “Clean Green Certified.” Though not legally certified “organic,” a Clean Green Certified stamp of approval on your medical marijuana in California ensures that it was grown under the same conditions as organic produce. Clean Green Certified takes a soil sample from each certification applicant annually and uses a federally-licensed lab for testing (not an unregulated, profit-hungry “pot lab”).

While it is possible to at the least wash off non-organic fruits and vegetables to remove some pesticide residue before consumption, there is no way to wash the pesticides off a cannabis flower or bud. As a result, when marijuana is inhaled or ingested for the effects of its natural chemical compound, tetrahydrocannabinol (THC), additional unknown chemical residues enter one’s system as well. Since many of the pesticides being used to grow marijuana are not even approved for general edible crop use, the dangers to one’s body and health can only be imagined. Recent state-based efforts across the country to legalize both medical and recreational cannabis could lead to a greater awareness of and demand for clean, pesticide-free marijuana, but until then, you may be left wondering, “what’s on the pot I’m smoking?”