By Dr Farsalinos
A new study was published few days ago in International Journal of Environmental Research and Public health by our team. The study (available with free access to the full text) evaluated the levels of tobacco specific nitrosamines (TSNAs) in the aerosol (vapor) compared to the liquid content.
The reason for performing this study was a study by Korean researchers evaluating TSNAs in >100 liquids available in South Korean market. We sent a letter to the editor for that study, noting that the levels found were orders of magnitude lower compared to tobacco. The Korean researchers responded that to assess exposure we have to measure TSNAs in the aerosol, and mentioned that heating of the liquid could result in the production of more TSNAs. Although we found this extremely unlikely to happen, we decided to evaluate the validity of this assumption.
We evaluated TSNAs in the liquid and the aerosol of 3 commercially available liquids. “Unfortunately” the levels of TSNAs in the liquid were so low that we could not find any TSNAs in the aerosol. Thus, we decided to make a spiked sample (add known amounts of TSNAs in one of the liquids). By testing the spiked sample we validated that the levels of TSNAs in the aerosol were identical to those present in the liquid.
The study concluded that exposure to TSNAs through aerosol inhalation is only associated with the levels of TSNAs in the liquid. Low levels of TSNAs through use of pharmaceutical grade nicotine will ensure minimal exposure to consumers. Finally, if regulators want to evaluate TSNAs exposure (as the EU is currently proposing), measuring them in the liquid is enough and would avoid the added expenses and complexity of evaluating aerosol levels.