Users and non-users of electronic cigarettes (e-cigarettes) have many legitimate questions about these nicotine-delivery devices. E-cigarettes represent a nearly $2-billion-a-year industry, and one that’s growing exponentially. The number of young people trying e-cigarettes doubled from 2011 to 2012, according to the Centers for Disease Control. So it is natural that so many people are interested in the health consequences of using e-cigarettes.
Research from the Department of Health Behavior at Roswell Park Cancer Institute has documented the impact of first-, second- and third-hand exposure to e-cigarette vapors. Our most recent research, done in collaboration with scientists from the Medical University of Silesia in Poland, offers insight into the user’s exposure to carcinogenic carbonyls.
The e-liquids used in e-cigarettes are primarily composed of glycerin and propylene glycol. We set out to find out what chemicals are generated during use of e-cigarettes, particularly at variable voltages. Some devices allow the user to adjust the voltage to increase vapor production and nicotine delivery.
We found that when e-cigarettes were operated at lower voltages, the vapors that were generated contained only traces of some toxic chemicals. These chemicals included the carbonyls formaldehyde, acetaldehyde, and acetone. However, when the voltage was increased, the levels of these toxicants also significantly increased.
The novel finding of our study is that the higher the voltage, the higher the levels of carbonyls. Increasing battery output voltage leads to higher temperature of the heating element inside the e-cigarette. Increasing the voltage from 3.2 to 4.8 volts resulted in increases of anywhere from 4 times to more than 200 times the exposure to formaldehyde, acetaldehyde and acetone. The levels of formaldehyde in vapors from high-voltage devices were similar to those found in tobacco smoke.
These results suggest that, under certain conditions, users might be exposed to the same or higher levels of carcinogenic formaldehyde than those contained in tobacco smoke. We believe that this finding is essential for public-health professionals as they assess product safety. Users should be warned about this increased risk of harmful effects. Smokers who are considering switching to e-cigarettes should know that it may be safer to use products with lower battery voltage limits/settings.
As for our earlier studies, here’s a brief summary of the findings from other scientific inquiries conducted at by Roswell Park:
- Nearly 80% of smokers who use e-cigarettes believe the devices are less harmful than traditional cigarettes and 85% were using the devices to help the quit smoking.
- E-cigarettes can expose non-users to secondhand emissions. While the emissions are lower than traditional cigarettes, e-cigarettes under certain conditions can generate similar levels of toxic compounds such as formaldehyde.
- E-cigarettes produce third-hand nicotine residue on surfaces such as glass, floors, walls, windows, wood and metal when used indoors, potentially exposing users and non-users to nicotine.
The scientific analysis of the health impact of e-cigarettes is in its infancy. While the devices appear to be safer than traditional cigarettes, this does not mean they are safe. Questions remain about product characteristics such as the types of heating elements, flavorings, additives and product storage conditions.
Still, these novel findings and the research conducted at Roswell Park and elsewhere will continue to advise the public-health community as it establishes regulations for these devices and offers much-needed information to consumers.
— Maciej Goniewicz, PhD, PharmD, Assistant Professor of Oncology, Department of Health Behavior, Roswell Park Cancer Institute
Dr. Goniewicz reports that in 2011, he received research funds from a pharmaceutical company that manufactures smoking-cessation medication and that another co-author of his recent study, “Carbonyl Compounds in Electronic Cigarette Vapors—Effects of Nicotine Solvent and Battery Output Voltage” (Nicotine Tob Res, 2014; doi: 10.1093/ntr/ntu078) received research funds from a manufacturer of e-cigarettes. Both awards apply to projects that fall outside the scope of this research.