assessment of the potential vaping-related exposure to carbonyls and epoxides using stable isotope-labeled precursors in the e-liquid.

Introduction:
This article presents a study that assesses the potential exposure to carbonyls and epoxides from using electronic cigarettes (ECs) by using stable isotope-labeled precursors in the e-liquid. The study compares the levels of these compounds in EC aerosol and cigarette smoke, as well as the corresponding biomarkers of exposure in the urine of EC users and smokers.

Key Points:

* The study used an EC containing an e-liquid replaced with 10% of 13C-labeled propylene glycol and glycerol in a controlled use clinical study with 20 EC users.
* Seven carbonyls and epoxides were measured in the aerosol and smoke, and corresponding biomarkers of exposure were determined in the user’s urine samples.
* 13C-labeled formaldehyde, acetaldehyde, and acrolein were found in EC aerosol, while all seven labeled carbonyls were detected in smoke.
* The labeled biomarkers of exposure to formaldehyde, acrolein, and glycidol were present in the urine of vapers, indicating an EC use-specific exposure to these toxicants.
* however, other sources than vaping contribute to a much higher extent by several orders of magnitude to the overall exposure of these toxicants.
* Comparing data for the native (unlabeled) and the labeled (exposure-specific) biomarkers revealed vaping as a minor source of user’s exposure to these toxicants.
* Other carbonyls and epoxides were not detectable in the EC aerosol.

Main Message:
The study found that while EC use results in exposure to carbonyls and epoxides, it is a minor source compared to other sources. The study’s use of stable isotope-labeled precursors allowed for a more accurate assessment of exposure specific to EC use. The findings suggest that while ECs may not be a major source of exposure to these toxicants, further research is needed to fully understand the health effects of EC use.

Landmesser a, Scherer M, Scherer G, et al. assessment of the potential vaping-related exposure to carbonyls and epoxides using stable isotope-labeled precursors in the e-liquid. archives of toxicology. 2021;95(8):2667-2676. doi:10.1007/s00204-021-03097-x