Luxembourg cannabis and hashish seized by the police were subject to a study by the LNS which was published in specialist journal Mycotoxin Research. The detected toxins are produced by microscopic fungi that are normally not visible to the naked eye and that thrive in humid conditions on plants, seeds, fruits, and their by-products.

The toxins can pose health risks when consumed with food, but LNS’s study indicates that most of the analysed samples were below the limits set by the European Commission. A concentration of ochratoxin between 1.0 and 16.2 µg/kg, averaging at 4.30 µg/kg were found in the 142 samples examined by the LNS. The maximum permitted limit for ochratoxin in food set by the Commission is between 15 and 20 µg/kg. The concentration of toxins did not vary between the cannabis samples and the hashish samples.

"The results indicate that a high proportion of illegal cannabis is contaminated with mycotoxins. However, the majority of contaminations are below the European tolerated limits. The effects of mycotoxins include immune system depression, neurotoxic conditions, development of allergies, pneumonia and even cancer. They are resistant to sterilisation and heat and can therefore easily enter the food chain," said Dr Claude Schummer and Dr Serge Schneider in a joint statement by LNS.

Cannabis is the most commonly used drug, with 4.9% of the total population aged 15-64 using it at least once per year, according to the 2014 European Health Interview Survey. For young adults (ages 15-34) and young scholars (15-18), this figure rises to 9.8% and 11.1% respectively. Some 27% of youths aged 15-18 have used cannabis at least once in their lifetime.