School children in England may be unwittingly smoking vapes spiked with the synthetic street drug spice, according to new research.

Professor Chris Pudney, from the University of Bath, tested 596 vapes confiscated from schools in England and found 16.6 per cent contained spice, which has a range of dangerous side effects including cardiac arrest.

It is believed the substance is being substituted into vapes which are sold as containing cannabis oil, as it is cheaper.

In total, 38 schools from across London, the West Midlands, Greater Manchester and South Yorkshire took part in the research.

Results from a device that instantly detects synthetic drugs found spice was present in vapes from 28, or 74 per cent, of these schools.

The device also revealed 1.17 per cent of the vapes tested contained THC, the psychoactive component of cannabis.

Prof Pudney said: “Teenagers think they are purchasing vapes or vape fluid containing THC or nicotine when, in fact, they are laced with spice.

“We know children can have cardiac arrests when they smoke spice, and I believe some have come quite close to death.

“Headteachers are telling me pupils are collapsing in the halls and ending up with long stays in intensive care.”

He warned parents that his findings were not “a niche, one-off occurrence that happens in a school far away from you” but something common.

Prof Pudney is now urging people to talk with children about the risks faced from spice and vaping, as well as the Government to prioritise the issue on a national level.

Schools that believe they have problems with spice-spiked vapes should come forward for testing, he said.

“Currently, this issue is being addressed regionally, but I urge the government to elevate it to a national harm reduction priority,” Prof Pudney added.

“I call on the Home Office and the Department for Education to highlight this problem and to provide police forces and schools with comprehensive harm reduction guidance and support.”

Headteacher Ben Davis, of St Ambrose Barlow RC High School in Salford, invited Prof Pudney to test a batch of confiscated vapes at the school in July.

He said his school had incidents of young people under the influence of spice, with two children collapsing including one in the playground.

“We’ve been fortunate so far, but I believe it’s only a matter of time before serious injuries or fatalities occur,” Mr Davis said.

“My message to families is, don’t assume your child is not involved. There’s a high chance they are, or they know someone who is.

“Please talk to them about it. Be open, non-judgmental, and accepting. As soon as you judge or blame, barriers will go up, and you won’t reach your child. This conversation is crucial for their safety.”

One of Prof Pudney’s spice detectors has been deployed to Devon and Cornwall Police for testing within the force area.

Chief Inspector Sarah Johns, said the device would help police ascertain the scale of the issue there.

Policing teams have visited all secondary schools in the Devon and Cornwall area to educate students on the health issues of using illegal vapes containing THC or spice.

“Our clear message to all young people is that the risks associated with unregulated vapes are not worth it,” Ch Insp Johns said.

“Young people obtaining these fluids, or being offered them, will never be able to know for sure what’s in them and as Dr Pudney’s work indicates, if its spice then that could lead to serious harm.”

Prof Pudney has tested vapes in four schools in Greater Manchester, working with Greater Manchester Police.

Detective Sergeant Laura Bell, of the force, said it was important to take a “proactive approach” and engage with young people and schools.

“Students are educated about the risks of drug use and illegal vapes, the potential impact on their health and the wider long-term consequences it can have on their futures,” Det Sgt Bell said.

“We encourage parents and guardians to discourage their children from getting involved in any illegal activities and continue to remind them of the negative consequences that using drugs can have.”

The force has seized “countless vapes” through store visits, raids and warrants, Det Sgt Bell added.

Police have issued safety warnings relating to vapes in areas including Cornwall, Devon, Kent, Lincolnshire, Lancashire, London, Middlesborough, Somerset and the West Midlands.

Prof Pudney will publish an academic paper on his vape testing findings in due course.

Sarah MacFadyen, of Asthma + Lung UK, said the results of the study were “deeply concerning” and called for “proper regulation and enforcement” of e-cigarette laws.

“If you’re a smoker and you want to quit tobacco, vaping can be a helpful way to give up smoking. But for children and those who don’t smoke, starting to vape is not recommended, especially if you have a lung condition,” she said.

“We are concerned about the recent rise in teenagers vaping and want to see a ban on disposable vapes, as their attractive packaging and flavouring, and pocket-money prices, are particularly appealing to children.”

She added that the charity hoped the Tobacco and Vapes Bill, which was introduced in the House of Commons in March, would become legislation “as soon as possible”.