Ammonia release from heated ‘street’ cannabis leaf and its potential toxic effects on cannabis users

Authors

  • Roger N. Bloor,

    Corresponding author
    1. Academic Psychiatry Unit, Keele University Medical School, Academic Suite, Harplands Hospital, Hilton Road, Harpfields, Stoke-on-Trent, UK,
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  • Tianshu S. Wang,

    1. Institute for Science and Technology in Medicine, School of Medicine, Keele University, Thornburrow Drive, Hartshill, Stoke-on-Trent, UK and
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  • Patrik Španěl,

    1. J. Heyrovský, Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic
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  • David Smith

    1. Institute for Science and Technology in Medicine, School of Medicine, Keele University, Thornburrow Drive, Hartshill, Stoke-on-Trent, UK and
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Roger N. Bloor, Academic Psychiatry Unit, Keele University Medical School, Academic Suite, Harplands Hospital, Hilton Road, Harpfields, Stoke-on-Trent ST4 6TH, UK. E-mail: r.n.bloor@psyct.keele.ac.uk

ABSTRACT

Aims  To use selected ion flow tube mass spectrometry (SIFT-MS) to analyse the molecular species emitted by heated ‘street’ cannabis plant material, especially targeting ammonia.

Materials and methods  Samples of ‘street’ cannabis leaf, held under a UK Home Office licence, were prepared by finely chopping and mixing the material. The samples were then heated in commercially available devices. The air containing the released gaseous compounds was sampled into the SIFT-MS instrument for analysis. Smoke from standard 3% National Institute on Drug Abuse (NIDA) cannabis cigarettes was also analysed.

Findings  For ‘street’ cannabis, ammonia was present in the air samples from the devices at levels approaching 200 parts per million (p.p.m.). This is compared with peak levels of 10 p.p.m. using NIDA samples of known provenance and tetrahydrocannabinol content (3%). Several other compounds were present at lower levels, including acetaldehyde, methanol, acetone, acetic acid and uncharacterized terpenes.

Conclusions  Awareness of the risks of inhaling the smoke directly from burning cannabis has led to the development of a number of alternative methods of delivery, which are claimed to be safer than direct smoking. Ammonia at toxic levels is produced from heating ‘street’ cannabis in these commercially available devices. Thus, the use of these devices to deliver ‘street’ cannabis is now open to question and further research is needed to investigate their safety.

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