BACKGROUND AND AIMS People who use synthetic cannabinoids (SCs) report debilitating side effects and withdrawal symptoms, coupled with dependence. In the UK, SC use was believed to be largely restricted to prison, where they are the most common drug and associated with nearly half of non-natural deaths, or poly-drug users in the community who are also likely to be homeless. However, national media reporting has increasingly identified cases of children collapsing in schools, which are claimed to be associated with vaping and putatively involving a drug such as delta-9-tetrahydrocannabinol (THC) or SCs. We therefore conducted the first study to identify and quantify SCs in e-cigarettes routinely collected from schools in England.

DESIGN E-cigarette and e-liquid samples seized by teachers in schools were identified through engagement with police forces and city councils in England. We sought agreements across broad geographical areas and based on acquiring the relevant approvals at a local level. Sample bias is considered in the analysis and reporting.

SETTING AND CASES Samples were submitted from 27 secondary (age 11-18) schools from geographically distinct regions of England, representing a broad range of social metrics (free school meals, persistent absenteeism and special educational needs). All submitted samples were anonymised and no identifying information was collected. Analysis of samples was conducted both in a laboratory setting and in-field at local police stations.

MEASUREMENTS Qualitative gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry were used to identify SCs and THC in e-cigarettes/liquid, with concentration measured by quantitative nuclear magnetic resonance spectroscopy. A subset of samples was screened for SCs and THC using a portable detector based on combined fluorescence and photochemical discrimination.

FINDINGS E-cigarettes containing SC were identified in 77.8% of all participating schools and were detected in 17.4% of all samples seized. These were almost entirely in refillable devices and liquid bottles, with very few in single use products. The percentage of SC e-cigarettes in schools positively correlated with the fraction of pupils eligible for free school meals, a social deprivation metric (Pearson's correlation r = 0.65 and P = 0.003). Positive samples contained a median SC concentration of 0.42 (interquartile range = 0.77) mg mL with a maximum of 3.6 mg mL. In contrast, few samples contained THC (1.2%).

CONCLUSIONS E-cigarettes containing synthetic cannabinoids were identified in three quarters of 27 secondary schools in England that were sampled.