Secondhand exposure to aerosol from electronic cigarettes: pilot study of assessment of tobacco-specific nitrosamine (NNaL) in urine.

Introduction:
This text is a summary of a scientific study that aimed to assess the levels of a tobacco-specific nitrosamine (NNaL) in urine samples of non-smokers passively exposed to secondhand aerosol (Sha) from electronic cigarette users in their homes. The study also compared these concentrations with those of non-smokers passively exposed to conventional cigarettes in their homes and with those of non-smokers not exposed to aerosol from e-cigarettes or conventional cigarettes in their homes.

Key Points:

* The study involved a convenience sample of 55 non-smoking volunteers divided into three groups: 25 living at home with conventional smokers, 6 living with e-cigarette users, and 24 in control homes (smoke-free homes).
* The researchers obtained urine samples from all volunteers to determine NNaL concentrations.
* The study found detectable levels of NNaL in the urine samples of volunteers exposed to e-cigarettes.
* The percentage of urine samples with quantifiable NNaL differed significantly among the three groups of homes.
* The concentrations of NNaL in urine samples of non-smokers exposed to Sha from e-cigarette users were lower than those exposed to conventional cigarettes.
* The study also found a strong correlation between NNaL levels in urine among e-cigarette users and those of the non-smokers exposed to Sha at home from e-cigarette users.
* The levels of NNaL among non-smokers exposed to Sha from e-cigarettes are very low; however, there is no safety level of exposure, and the risk increases with the intensity and duration of exposure.

Main Message:
The study found quantifiable levels of NNaL in urine samples of non-smokers passively exposed to Sha from e-cigarette users. although the levels are very low, the study emphasizes the importance of regulating e-cigarettes to protect bystanders from exposure to harmful substances. The study also highlights the need for further research to understand the long-term health effects of exposure to Sha from e-cigarettes. Overall, the study suggests that e-cigarette use is not harmless and that regulations are necessary to protect public health.

Martínez-Sánchez JM, Ballbè M, Pérez-Ortuño R, et al. Secondhand exposure to aerosol from electronic cigarettes: pilot study of assessment of tobacco-specific nitrosamine (NNaL) in urine. Gaceta sanitaria. 2019;33(6):575-578. doi:10.1016/j.gaceta.2018.07.016