Acute Pulmonary Toxicity of E-Cigarettes

Assistant Professor, Dept. of Medicine

Since their introduction a decade ago, e-cigarettes (e-cigs), which use a heated coil to aerosolize nicotine-containing e-liquids, have been aggressively promoted by tobacco companies as safe alternatives to cigarettes. The use of these devices has increased at an alarming rate across all segments of society and especially among adolescents, with 13% of US high school students reporting recent use in 2014. Short-term effects of e-cig use include coughing and increased airway resistance, while longer-term health effects remain unknown. There is an urgent need to develop model exposure systems to test how these aerosols affect lung biology. Similarly, there is a compelling public health interest in translating scientific insights about toxicity into regulatory standards.
   
Several research groups have recently developed rudimentary e-cig aerosol generation systems and provided evidence of toxicity using in vitro and in vivo approaches. However, there are major limitations of these approaches from a regulatory standpoint which include limited control over puff generation, use of non-human or malignant cell lines of questionable relevance, and minimal assessment of the chemical correlates of aerosol toxicity.
   
We have extensive experience with in vitro models of pulmonary toxicity using primary cell cultures obtained from human lungs declined for transplant. My overall objective is to test the pulmonary toxicity of e-cig aerosols using an exposure system that is ideally suited and practical for regulatory science. Working within the Tobacco Control group here at UCSF, including experts in analytical chemistry as applied to tobacco products, we are now exposing cultured primary human bronchial (airway) and human alveolar type II (airspace) epithelial cells to e-cig aerosols to test for direct toxicity and predisposition to clinically relevant inflammatory insults.