A Luxembourg study, from the Health Protection and Forensic Medicine Departments of the National Health Laboratory (LNS), and published in the journal Mycotoxin Researchstudied the presence of dangerous mycotoxins in 142 samples of illegal cannabis seized by the Luxembourg police.
Using chromatography analyses, which make it possible to separate the different substances present in a product, the study revealed that around a third of the samples were contaminated with ochratoxin A, at concentrations that could reach 16mg/kg.
Ochratoxin is produced by different species ofAspergillus and of Penicillium, molds that can reduce the effectiveness of the immune system and even prove to be neurotoxic. Mycotoxins are also resistant to sterilization and heat. Mycotoxins most often develop during cultivation rather than during storage. These fungi are known to be mutagenic and carcinogenic due to their ability to break DNA strands and inhibit their repair mechanisms.
Maximum levels set by the European Commission in food are 15-20mg/kg.
Among the samples, no significant difference was observed between those of resin and those of grass. Overall, the concentrations remain low and do not suggest a human health problem if cannabis consumption remains moderate.
The Luxembourg researchers write that “Recreational cannabis is legalized in more and more countries, and methods for determining contaminants, and therefore mycotoxins, are beginning to appear in the scientific literature. On the other hand, cannabis continues to be available on the illegal market without any quality control”.
A previous Spanish study had determined that 75% of Madrid hashish was contaminated with faecal bacteria, making it clearly unfit for human consumption.