Epithelial Research

Posted 14th April 2015 by Dave Cross
A team made up of researchers from Cultex Laboratories (one of the world’s leaders in the research and development of cell-based exposure systems), the German Institute of Pathology and Bielefield Hospital’s Department of Thoracic Surgery have released their findings in a paper titled “Evaluation of E-Cigarette Liquid Vapor and Mainstream Cigarette Smoke after Direct Exposure of Primary Human Bronchial Epithelial Cells” – or, in plain English, the effects of vape and smoke on human airways.

The team noted that previous studies looking at the cytotoxic nature of eliquid used stem cells or neurons and this was unsatisfactory as vapour comes into contact with lung cells. Also, they note that the cells do not come into contact with liquid and this was another flaw in previous studies.

The team grew cell cultures from the bronchial region of the respiratory tract and exposed them to 200 puffs of eliquid vapour, the equivalent smoke from 10 cigarettes, PG and VG.  The Liquid used was 0% and 24% nic “Tennessee Cured” Johnson’s Creek. The cells were cultivated from two cancer patients: a 75yr-old and a 69yr-old. These two samples are identified as NHBE33 and NHBE48 in the results graphs below.

People aware of the limitations of using smoking robots to provide a real-world vaping scenario will already be wincing at the mention of 200 puffs. The equipment being puffed on was a Reevo Mini-S kit obtained from In-Smoke. The 2.2Ω atomiser was powered by the 900mAh and connected to the piston pump of a smoking robot. The 200 35ml puffs were taken successively, one after each other, lasting 2 seconds each.

The team then looked at the cell viability (comparing live to dead cells) and oxidative stress (how the cells managed to repair themselves if damaged).

Viability results

Stress results

The team identified that they had not adjusted for the difference in the concentrations between vape and smoke. Once this had been carried out the graph showing the cells ability to recover, the stress, alters dramatically – highlighting the far safer nature of vaping over smoking.

Adjusted results

The research team’s conclusions:

  • “Our results clearly demonstrate that the tested e-cigarette vapor had toxicological effects on primary NHBE cells when exposed directly at the air-liquid interface.”

As we already knew – vaping is safer than smoking, not safe.

  • “Interestingly, the presence of nicotine had no effect on the cell viability.”

Welcome news that nicotine does not possess the properties that the California Department of Public Health would have everyone believe.

  • “Combustible cigarettes are smoked in exposure experiments according to ISO 3308, meaning a puff volume of 35 mL, a puff time of 2 s, and an interpuff interval of 60 s, but these smoke parameter do not resemble the vaping topography in e-cigarette users.”

The team recognise that the experiment does not replicate real-world vaping.

  • “However, if the toxicity of e-cigarette vapor and cigarette mainstream smoke is compared on basis of the same smoking parameters as well as the same number of puffs, the cell viability is about 4.5–5 times lower and the oxidative stress levels 4.5–5 times higher in combustible cigarettes.”

Vaping is better than smoking...well, there you go.

 Dave Cross
Article by Dave Cross
Freelance writer, physicist, karateka, dog walker