The electronic cigarette (e-cigarette) industry is growing rapidly. It is projected to make approximately $1.5 billion dollars in 2014. There is much debate regarding its safety among the general population, regulatory agencies, and the scientific community. There are major concerns regarding the marketing of e-cigarettes toward young people through the use of appealing flavors and the perception of being safer than tobacco cigarettes.
E-cigarettes work by using a heating coil to vaporize a liquid solution containing nicotine and flavor compounds. As a person draws the vapor out from the e-cigarette it will rapidly cool and condense to form a visible vapor cloud creating the sensation of smoke. Although there are several types and brands of e-cigarettes, the mechanism for generating this “smoke” remains the same. E-cigarettes do not produce the same toxic chemicals in the same amount as tobacco cigarettes. Research studies to date have conflicting results regarding the toxicity of e-cigarettes. The lack of knowledge on e-cigarettes and its potential toxicity have made the regulation of it difficult. Many cities and institutions have banned the use of e-cigarettes by categorizing them with tobacco products. Such regulations are often met with resistance from e-cigarette supporters. Therefore, more research studies are needed to help regulators make informed decisions. One major challenge is, understanding what is being emitted by e-cigarettes and what important factors affect these emissions. Studies to date have found some levels of toxic compounds but whether this is generalizable across all the different brands and type of e-cigarettes remains a mystery. The other major challenge is how e-cigarettes affect indoor air quality. When e-cigarettes are being used, surrounding people are exposed to the second-hand emissions or second-hand vaping (SHV), which is similar to second-hand smoking. Studies to date have found that SHV does occur, but SHV related exposure and health impacts remain largely unknown.
We hypothesize that the amount and characteristics of e-cigarette emissions (ECEs) are affected by the e-cigarette heating coil temperature. We also postulate what is contained in the e-cigarette liquid solution (e-liquid) will affect the amount and characteristics of ECEs. Furthermore, we expect that ECEs will have a strong impact on indoor air quality. It is possible that chemicals in ECEs can undergo reactions with ozone to form new pollutants called secondary organic aerosols (SOAs). SOAs have been found to be potentially more toxic than the original compounds. In addition, the ventilation conditions in indoor spaces can affect how long ECEs remain. The studies being proposed are to 1) understand how the heating coil temperature and e-liquid composition will affect the amount and characteristics of ECEs; and 2) determine to what extent SOAs are generated from interactions between ozone and ECEs and how ventilation conditions can extend the life of ECEs in indoor spaces. As mentioned previously, regardless of the brands and types of e-cigarettes, the mechanism to generate ECEs is quite similar. Therefore, the heating coil temperature may be a crucial parameter that can be used by researchers to develop a standard testing protocol for e-cigarettes. Meanwhile, the formation of SOAs may be an important factor in assessing health impacts from SHV. Findings from this research will provide more insight to the safety of e-cigarettes and ultimately result in proper regulations based on scientific evidence.