Vape cartridges, commonly referred to as “carts,” are self-contained units that hold concentrated substances like cannabis oil, nicotine, or flavored e-liquids. These devices have gained popularity as a modern delivery system, often perceived as a less harmful alternative to traditional smoking. The rapid increase in their use has prompted public concern regarding potential long-term health consequences, particularly the risk of developing lung cancer. The central question is whether inhaling these heated aerosols directly contributes to pulmonary malignancies.
Understanding “Carts” and Vaping Aerosols
A vape cartridge uses a battery to power a heating element, or atomizer, which raises the temperature of the liquid contents. This process converts the liquid into an inhalable aerosol. This product differs fundamentally from the smoke produced by combustible tobacco or cannabis, as it is created through heating rather than burning.
The material inside the cartridge typically consists of concentrated cannabinoids, such as THC or CBD, mixed with carrier liquids. Liquids like propylene glycol (PG) and vegetable glycerin (VG) are used to dilute the thick oils for the device’s wick and coil system. Flavoring additives are also common, complicating the final chemical composition of the inhaled aerosol, which carries active compounds deep into the user’s lungs.
The Current Scientific Consensus on Lung Cancer Risk
The primary limitation in establishing a direct causal link between cart use and lung cancer is the relatively recent emergence of the technology. Since lung cancer typically takes decades to develop after exposure to carcinogens, long-term epidemiological data is not yet available. Therefore, scientists cannot definitively confirm or deny a direct correlation in human populations.
Pre-clinical research provides concerning evidence about carcinogenic potential despite the lack of decades-long human studies. Studies using human lung cells and animal models show that exposure to vaping aerosols can induce cellular stress and cause DNA damage. These biological changes are recognized as molecular precursors to cancer development. The presence of known carcinogens in the aerosol suggests a plausible mechanism by which prolonged use could increase risk.
Toxic Components That Damage Lung Tissue
The health risk from carts stems from harmful substances introduced into the lungs during the heating process. Carrier liquids, such as propylene glycol and vegetable glycerin, can decompose when heated to high temperatures, forming carbonyl compounds. These thermal decomposition products include known carcinogens like formaldehyde and acetaldehyde. These aldehyde compounds disrupt cellular function and promote an inflammatory environment within the pulmonary tissue.
Another source of toxicity is the hardware itself, where metallic heating coils can leach heavy metals into the aerosol. Metals like nickel, lead, chromium, and tin have been detected, which can accumulate in the body and damage the lungs. Additionally, flavorings added to the liquids pose a separate risk, notably diacetyl, which is linked to the severe lung condition bronchiolitis obliterans, often called “popcorn lung.”
Furthermore, unauthorized thickening or cutting agents pose an immediate danger, as highlighted by the 2019 outbreak of e-cigarette or vaping product use-associated lung injury (EVALI). Vitamin E Acetate was strongly implicated in these cases, causing acute lung injury through severe inflammation and oxidative damage. These toxic exposures contribute to chronic irritation, inflammation, and cellular death in the lungs, increasing the likelihood of long-term respiratory disease.
Comparison of Risk to Traditional Cigarettes
Traditional combustible cigarettes are the most significant known cause of lung cancer, responsible for the vast majority of all diagnoses. The smoke from burning tobacco contains over 7,000 chemicals, including hundreds of toxins, at least 70 established carcinogens, and tar. In comparison, the aerosol from a cart is chemically less complex and typically contains lower concentrations of many priority toxicants found in cigarette smoke.
This difference suggests that cart use presents a lower, but not negligible, exposure risk compared to traditional smoking. However, carts introduce different toxicological concerns, such as heavy metal exposure and unique thermal decomposition products. Individuals who use both traditional cigarettes and carts, known as dual users, face a significantly higher risk of lung cancer than those who only smoke cigarettes.