Amid increasing concerns about the safety of electronic cigarettes, which have become a popular alternative to traditional smoking, especially among teens and young adults, the findings of new research indicate that vaping may release high levels of benzene, a known carcinogen.
In a study published last week in the medical journal PLOS One, researchers found that e-cigarette vapor contains levels of the chemical benzene that are much higher than what is found in the ambient environment.
Researchers from Portland University tested electronic cigarettes by heating the fluids in a variety of power levels in three different e-cigarette and vaping devices.
Prior testing has shown more cancer-causing chemicals are released when e-cigarette liquid is heated, up to 10 times the amount of traditional cigarettes. Some studies indicate the flavoring used in e-cigarettes convert to high amounts of toxic chemicals.
The vapes tested included the JUUL pod system, which does not allow the user to access the power settings, and utilizes flavor cartridges that are able to be swapped out. They also tested two refill tank systems that also allow a range of user accessible power settings, including the EVOD atomizer and Subtask Nano tank-type atomizer. They also tested e-cigarette fluids containing propylene glycol, glycerol benzoic acid and flavor chemical benzaldehyde, as well as nicotine.
Heating e-cigarette fluid causes a wide range of degradation. Researchers wanted to investigate the formation of benzene, a human carcinogen known to cause cancer, as other studies have shown chemicals like acrolein, formaldehyde and acetaldehyde are released when the liquid is vaporized.
In the two tank systems, benzene was found to form from both propylene glycol and glycerol and from the additives benzoic acid and benzaldehyde, especially at higher power settings. Benzene formation was not detected in the JUUL closed pod system at all.
The EVOD device was tested at 6 watt and 13 watt settings. The device produced benzene at concentrations of 1.9 and 750 μg/m3, respectively.
Benzene formation was not detected in the Nano device system at 6 watts; however it was detected at 25 watts in concentrations of 1.8 μg/m3.
When benzoic acid and benzaldehyde were introduced into the liquid, the benzene formation for the EVOD device tested at 13 watts was as high as 5,000 μg/m3. For the Nano device tested at 25 watts, benzene was detected at 100 μg/m3.
Comparatively, conventional tobacco cigarettes have a benzene output of 200,000 μg/m3. While the output from the e-cigarettes is much less than tobacco cigarettes, researchers note the output of benzene is quite high for non-smokers.
Benzene is a component of gasoline, which is found in urban air from industrial emissions and unburned gasoline in exhaust and fuel tank leaks. Benzene outputs in urban air measure 1 μg/m3.
High levels of benzene output, similar to those found in the study, are considered a serious risk to people who have chronic and repeated exposure to the chemical, such as from smoking e-cigarettes.
Benzene is considered the largest single cancer-risk to the general population, simply from exposure to the toxin from ambient air in the U.S.