Free Radicals in Cannabis Smoke.

Area of Science:

• Chemistry
• Toxicology
• Biomass Combustion

Background:

• Combustion of biomass materials like tobacco and cannabis produces complex chemical mixtures.
• Free radicals in tobacco smoke are well-documented, but their presence in cannabis smoke remains uncharacterized.
• Similarities between tobacco and cannabis smoke suggest potential shared radical species.

Purpose of the Study:

• To analyze and quantify free radicals in cannabis smoke using electron paramagnetic resonance (EPR) spectroscopy.
• To compare the radical profiles of cannabis smoke with those of tobacco smoke.
• To investigate the influence of burning method and cannabinoid composition on radical concentrations in cannabis smoke.

Main Methods:

• Electron paramagnetic resonance (EPR) spectroscopy was employed to detect short-lived and environmentally persistent free radicals (EPFRs).
• Spin-trapping techniques were utilized for the identification of short-lived radicals.
• Quantitative analysis determined radical concentrations per cannabis preroll or tobacco cigarette.

Main Results:

• Short-lived, oxygen-centered radicals were detected in the gas phase of cannabis smoke, with EPR spectra differing slightly from tobacco smoke.
• Environmentally persistent free radicals (EPFRs) were identified in the particle phase of cannabis smoke, consistent with tobacco smoke findings.
• Cannabis smoke exhibited comparable radical concentrations to tobacco smoke (approx. 10^15 gas-phase spins and 10^14 particle-phase spins).
• Puffing reduced radical concentrations, while cannabinoid composition had no significant effect.

Conclusions:

• Cannabis smoke, like tobacco smoke, contains significant concentrations of both short-lived and persistent free radicals.
• The radical composition and concentration in cannabis smoke are comparable to tobacco smoke.
• Burning method influences radical levels, but cannabinoid profile does not appear to be a determining factor.