Analysis: Unregulated Cannabis Products Far More Likely to Contain Pesticides

Ottawa, Canada: Cannabis flower provided by Canadian-licensed marijuana cultivators are far less likely to test positive for the presence of pesticide residues than are similar products obtained from unregulated sources, according to data published in the Journal of Cannabis Research.

Researchers affiliated with Health Canada analyzed samples of cannabis flower obtained from the legal and unregulated market. (Canada legalized the adult-use marijuana market in 2018.)

They reported that only six percent of the samples obtained from the licensed marketplace contained trace levels of pesticide residues. By contrast, 92 percent of unregulated flower products tested positive for the residual presence of pesticides.

“Pesticides were detected in 92 percent of Canadian illicit cannabis inflorescence samples with 23 unique pesticide active ingredients quantified,” investigators determined. “Illicit cannabis contained on average 3.7 different pesticides per sample, and 87 percent of positive samples contained more than one different pesticide.”

They concluded: “To the authors’ knowledge, this study is the only extensive pesticide multiresidue analysis that compares pesticides in the licensed and illicit cannabis markets in a nationwide jurisdiction where cannabis has been legalized. Albeit being a small study, our results do support the government of Canada’s messaging where ‘Consuming illegal products could lead to adverse effects and other serious harms.’”

Since Canada legalized the adult-use cannabis market, the percentage of consumers who say that they obtain marijuana products exclusively from legally licensed retailers has risen steadily every year.

Data from the United States estimates that 43 percent of cannabis consumers nationwide now obtain their products from state-licensed retailers. Among those residing in legal marijuana states, only six percent of respondents say that they obtain their cannabis primarily from the unregulated market.

Full text of the study, “High levels of pesticides found in illicit cannabis inflorescence compared to licensed samples in Canadian study using expanded 327 pesticides multiresidue method,” appears in the Journal of Cannabis Research.