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

Gac Sanit. Nov-Dec 2019;33(6):575-578. doi: 10.1016/j.gaceta.2018.07.016. Epub 2018 Oct 28.


Objective: To assess the levels of a tobacco-specific nitrosamine (NNAL) in non-smokers passively exposed to the second-hand aerosol (SHA) emitted from users of electronic cigarettes (e-cigarettes).

Method: We conducted an observational study involving 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). We obtained urine samples from all volunteers to determine NNAL.

Results: We detected NNAL in the urine of volunteers exposed to e-cigarettes (median:0.55 pg/mL; interquartile range: 0.26-2.94 pg/mL). The percentage of urine samples with quantifiable NNAL differed significantly among the three groups of homes: 29.2%, 66.7% and 76.0%, respectively (p=0.004).

Conclusions: We found NNAL nitrosamine in urine samples from people exposed to SHA from e-cigarettes. However, these results could be confirmed with more studies with larger sample sizes.

Keywords: Aerosol de segunda mano; Biomarcadores; Biomarkers; Cigarrillo electrónico; Electronic cigarette; Nitrosaminas; Nitrosamines; Second-hand aerosol.

Publication types

  • Observational Study

MeSH terms

  • Aerosols
  • Air Pollution, Indoor* / adverse effects
  • Electronic Nicotine Delivery Systems*
  • Humans
  • Nitrosamines / urine*
  • Non-Smokers*
  • Pilot Projects
  • Residence Characteristics


  • Aerosols
  • Nitrosamines