“Dangerous” levels of mold, yeast, lead, E.coli and salmonella have been found in street cannabis in the UK.

Researchers from Manchester Metropolitan University, working with the Curaleaf Clinic, analyzed 60 samples seized by Greater Manchester and Northumbria Police.

And 90 percent of what was tested was contaminated with mold and yeast, eight percent with lead, and two percent with salmonella and E.coli.

Health experts warn that this could lead to respiratory problems, neurological damage and gastrointestinal infections in users.

Additional independent testing also detected highly dangerous synthetic cannabinoids, including Spice and K2, in 27% of samples.

The findings were revealed after a study of 500 drug users commissioned by medical cannabis clinic, Curaleaf Clinic (which found that 58 percent of illegal cannabis is purchased by those trying to manage health conditions.

These include anxiety (49%), depression (49%) and chronic pain (28%).

More than one in 10 people (11%) used the dark web, online retailers and even QR code stickers left by dealers to obtain the substance.

Meanwhile, a separate study of 2,000 adults found that only 46% of them know that medical cannabis is legal and available with a prescription from a specialist.

Dr Simon Erridge, director of research at the clinic, said: “It is crucial that consumers are aware of the hidden dangers of illegal cannabis, especially as many people buy it to manage health conditions that could be exacerbated by these dangerous substances.

“The law changed six years ago so there is a legal, regulated and quality-tested alternative for people with diagnosed chronic illnesses who have not responded to conventional therapies.

“A lot of people put themselves in danger when they don’t need to.”

Despite the risks, 18 percent of illegal cannabis users are unaware that the products they purchase may contain dangerous contaminants.

And 66 percent are unable to recognize cannabis contaminated with mold.

To raise awareness of the dangers of illegally sourced cannabis, Curaleaf launched a public health campaign, What Are You Smoking?, aimed at involving those most at risk.

Billboards revealing the study’s findings were removed in known drug trafficking hotspots based on data obtained through a Freedom of Information (FOI) request.

So far, a “publicity van” featuring the billboards has visited Tower Hamlets and Lambeth in London, and will also travel to Manchester Piccadilly and Merseyside.

Mirroring the tactics used by street dealers, biodegradable QR code stickers directing people to vital information about the dangers of unregulated cannabis are also being placed at hotspots.

Dr Oliver Sutcliffe, senior lecturer at Manchester Metropolitan University, said: “We hope to provide valuable information that will help consumers make safer choices.

“Our results are a stark reminder of the importance of vigilance and education in protecting public health. »