Health Risks of Vaporizing Cannabis Leaves
Vaporizing cannabis leaves carries significant health risks including respiratory problems, cardiovascular complications, and mental health effects, with dried herb vaporizers presenting lower but still substantial risks compared to cartridges containing concentrates with potentially harmful additives. 1, 2
Respiratory Risks
- Vaporizing cannabis leaves affects lung function and is associated with pulmonary conditions like chronic bronchitis and chronic obstructive pulmonary disease (COPD), though the link to lung cancer remains unclear 1, 2
- While vaporization reduces some respiratory risks associated with cannabis combustion by eliminating many combustion byproducts, it still exposes users to potentially harmful compounds 3, 4
- Dried herb vaporizers present lower respiratory risks than smoking cannabis but still deliver active cannabinoids that can have systemic effects 4, 5
Cardiovascular Risks
- Cannabis use, including vaporization, is associated with adverse cardiovascular events including tachycardia, myocardial infarction, stroke, and arrhythmias 1, 2
- A recent study of Danish patients with chronic pain found an increased risk for 180-day new-onset arrhythmia among those who used medical cannabis compared with those who did not 1
- Vaporized cannabis can cause orthostatic hypotension with both acute and chronic use 2
Mental Health and Neurological Risks
- High doses of THC from vaporized cannabis may be associated with psychosis in vulnerable individuals 1, 2
- Cannabis use may increase risk for developing depressive disorders and may exacerbate existing psychiatric disorders 2
- Early onset of cannabis use, especially weekly or daily use, strongly predicts future dependence 2
- Approximately 10% of adults with chronic cannabis use may develop cannabis use disorder, characterized by clinically significant impairment or distress 2
Toxin Exposure from Vaporization
- When cannabis leaves are vaporized, users may be exposed to concerning degradants such as methacrolein, benzene, and methyl vinyl ketone, though at lower levels than with smoking 6
- The presence of terpenes in cannabis leaves can lead to higher levels of gas-phase products compared to THC alone when vaporized 6
- While vaporization typically produces fewer toxins than smoking, the thermal degradation of cannabis components still generates potentially harmful compounds 6
Comparison Between Leaf Vaporization and Cartridges
- Dried cannabis vaporizers present lower safety risks compared to cartridge-based systems due to a lower risk of toxin exposure and typically lower THC potency 3
- The 2019 outbreak of acute lung injury (EVALI) was primarily associated with THC-containing e-cigarette cartridges that contained vitamin E acetate, not dried herb vaporization 1
- The CDC and FDA specifically warned against "THC-containing e-cigarette, or vaping, products, particularly from informal sources like friends, family, or in-person or online dealers" 1
Special Population Considerations
- Older adults who use vaporized cannabis may have higher risk for behavioral health issues, including anxiety and depression 1
- Cannabis-related emergency department visits among older adults have increased, with acute cannabis toxicity potentially associated with sedation, obtundation, and myocardial ischemia or infarction 1
- Cannabis use during pregnancy may negatively affect fetal brain development and increase risk for premature birth 1
Harm Reduction Approaches
- If cannabis is used, dried herb vaporizers operating at controlled temperatures (typically 180-210°C) may reduce some risks compared to smoking or using concentrate cartridges 3, 5
- Vaporization devices that allow precise temperature control can help minimize the formation of harmful byproducts while still effectively delivering cannabinoids 5
- Studies have shown that properly designed vaporizers can deliver approximately 54% of loaded THC in a reproducible manner, providing more consistent dosing than smoking 5