Legal Marijuana Sold in Colorado Contains Contaminants, Study Finds

A study of the legal recreational marijuana sold in Colorado is calling into question current levels of regulation.

“It’s pretty startling just how dirty a lot of this stuff is,” Andy LaFrate, the study’s architect, told Smithsonian Magazine March 23. LaFrate is the founder of Charas Scientific, a lab in Denver that’s licensed to test cannabis. His report is based on 600 samples from merchants and sellers of recreational marijuana, some voluntarily supplied.

LaFrate found that many of the samples were contaminated with fungi, some covered in up to a million spores. And while he noted that all natural products have a certain level of microbial growth, he said better thresholds for safety should be established.

He also found that some pot “concentrates” (essentially extracts) contained solvents such as butane.

The marijuana being sold for recreational use is also much stronger than what most people have had access to in the past — “This is is not your father’s weed,” NBC noted in its coverage of the report. Potency is measured in tetrahydrocannabinol, or THC, concentration, as that’s the compound that produces a psychoactive effect.

LaFrate’s lab tests, the first of their kind, revealed that most marijuana being sold in Colorado is almost twice as strong as the illegal pot sold in the past, with a few options being three times as potent.

Medical Properties

What he didn’t find in the marijuana samples also surprised LaFrate. One of the most common arguments given in favor of marijuana legalization is that it can be used to ease the pain of terminally ill patients or people with chronic pain; according to recent research, about 1.5 billion people around the globe suffer from chronic pain, and there has been a growing debate on how to address that pain while also curbing abuse of opioid painkillers.

Some parents have even moved their families to Colorado to have greater access to a marijuana strain known as “Charlotte’s Web,” which is thought to control seizures in some children.

But the compound thought to be responsible for these medical purposes, cannabidiol or CBD, was found only in very low concentrations in the marijuana tested by Charas Scientific. According to the report, the average amount of CBD is only 0.1%.

“It’s disturbing to me because there are people out there who think they’re giving their kids Charlotte’s Web. And you could be giving them no CBD — or even worse, you could be giving them a THC-rich product which might actually increase seizures,” LaFrate told NBC News March 23. “So, it’s pretty scary on the medical side.”