Electronic cigarettes may cause, worsen respiratory diseases, among youth

Researchers examined particles emitted by e-cigarettes, an alternative nicotine delivery device, to understand what a user inhales and how these particles may affect the teen user's lungs. In a cellular model, the study found some e-cigarette emissions cause acute toxicity, or lung damage, similar to that caused by conventional tobacco smoke.

"The emerging trend of e-cigarette use is posing public health concerns and new issues for regulatory agencies," said Jonathan Thornburg, Ph.D., senior research engineer and program manager at RTI and the project's manager. "E-cigarettes produce a significant number of very small particles that impact a teen user's airway viability. To understand what the user inhales, we collected data to characterize the small particles in the vapor and to determine the chemical and toxicological characteristics of e-cigarette emissions."

The study found up to 40 percent of particles emitted by an e-cigarette can deposit in the deepest area of a youth's lungs. The chemicals contained in these small particles may irritate airways or worsen pre-existing respiratory conditions

To conduct the study, researchers developed an e-cigarette vapor collection and sampling system equipped with a custom apparatus to mimic the conditions found inside the human mouth and respiratory tract. The system is attached to an e-cigarette to uniformly generate and capture the vapor emissions. The system is flexible to be representative of realistic smoking patterns among adolescents and adults.

According to the researchers, the type and quality of e-cigarette liquids will affect the size, content and concentration of generated particles. The size and toxicity of particles are also impacted by different fragrances, preservatives and other additives.

The study did not examine secondhand vapor exposure by e-cigarettes.

"Our soon-to-be published data indicate that we need to do more research to understand how different liquids and device features alter particles and thus impact respiratory health," Thornburg said. "What we learned from this first study will allow the design of scientifically defensible and comparable studies to further the understanding of the effects of e-cigarettes on a user's health."