A reporter at a San Francisco television station sent six samples of medical marijuana to a laboratory in Berkeley, Calif., for testing, and the results have raised some red flags, according to a Feb. 6, 2017, article posted at the KPIX website.
The reporter got five samples from San Francisco-area medical marijuana dispensaries, and one sample from an illegal source. The samples were sent to Steep Hill Lab in Berkeley, Calif.
“Only one of those six had no detectable pesticides,” Dr. Donald Land, a researcher at Steep Hill Lab, said.
Tony Daniel, who has been analyzing California’s marijuana at Steep Hill Lab since the 1990s, said, “We see cannabis that comes through the lab that would have to be destroyed in other states.”
States like Oregon, Washington, Massachusetts, Colorado, and Nevada have either limited or banned some agricultural chemicals used on marijuana crops.
A fungicide called Myclobutanil drew criticism in Colorado—and showed up in the samples obtained by KPIX in California. The danger does not come from eating foods with the residue of the fungicide. The danger comes from heating marijuana leaves with the residue.
“If you smoke it, if you heat it, it produces a chemical called hydrogen cyanide,” Land said. “It’s very toxic to humans.”
One of the medical marijuana samples, purchased by KPIX at a legal dispensary, had Myclobutanil levels 13 times the level allowed in Oregon.
Only one of the six samples, from another dispensary, was clean. So now that adult-use marijuana is legal in California, new questions about regulating agricultural chemicals will come to the forefront.