The study was conducted by scientists at Universidad Complutense in Madrid, including pharmacologist José Manuel Moreno Pérez, and will be published in the journal Forensic Science International in May.
Pérez collected 90 samples from street dealers, according to the BBC, because he was curious if the drugs were safe to use. In those samples, he found traces of E. coli and the Aspergillus fungus. He also found fecal matter.
He determined that 88.3 percent of the samples were not safe to be consumed.
The samples Pérez bought were wrapped in two kinds of containers — “acorns” and “ingots” or blocks, according to the study. The “acorns” are reportedly smuggled into Spain.
Pérez and his colleagues found that 93 percent of the “acorn” samples and 29.4 percent of the “ingot” samples were contaminated by high levels of E. coli. They also found that 10 percent of the samples had the Aspergillus fungus.
The “acorn” type also reportedly ended up having the most contaminants and even smelled like fecal matter.
He explained to El País that the extra contaminants and the smell were a result of how the drug is smuggled into Spain, where cannabis is illegal. Pérez said dealers in Morocco wrap small amounts of the drug in plastic “acorns” and swallow them alongside something to neutralize their stomach acids.
“When they get to Spain, they take a laxative and expel the bellotas,” he told the outlet. “And then they’re put on sale.”
Because they found such high numbers of contaminants, Pérez and his co-authors said their study proves that selling street cannabis is bad enough to be a “public health issue.”
“There are no filters on joints,” Pérez told El País. “You are not just breathing in smoke, but also particles.”