Particle size distribution is an important factor governing whether aerosols can be deposited in various respiratory tract regions in humans. Recently, electronic cigarette (EC), as the alternative of tobacco cigarette, has become increasingly popular all over the world. However, emissions from ECs may contribute to both indoor and outdoor air pollution; moreover, comments about their safety remain controversial, and the number of users is increasing rapidly. In this investigation, aerosols were generated from ECs and studied in the indoor air and in a chamber under controlled conditions of radon concentration. The generated aerosols were characterized in terms of particle number concentrations, size, and activity distributions by using aerosol diffusion spectrometer (ADS), diffusion battery, and cascade impactor. The range of ADS assessment was from 10−3 μm to 10 μm. The number concentration of the injected aerosol particles was between 40 000 and 100 000 particles/cm3. The distribution of these particles was the most within the ultrafine particle size range (0–0.2 μm), and the other particle were in the size range from 0.3 μm to 1 μm. The surface area distribution and the mass size distribution are presented and compared with bimodal distribution. In the radon chamber, all distributions were clearly bimodal, as the free radon decay product was approximately 1 nm in diameter, with a fraction of ~0.7 for a clean chamber (without any additional source of aerosols). The attached fraction with the aerosol particles from the ECs had a size not exceeding 1.0 μm.
1. WHO. (2008). Monitoring tobacco use and prevention policies prevalence of adult tobacco use in the 14 countries that completed the global adult tobacco survey.
2. WHO. (2004). Tobacco smoke and involuntary smoking. (IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Vol. 83). Lyon: WHO, IARC.
3. Glasser, A. M., Collins, L., Pearson, J. L., Abudayyeh, H., Niaura, R. S., Abrams, D. B., & Villanti, A. C. (2017). Overview of electronic nicotine delivery systems. Am. J. Prev. Med., 52(2), e33–e66. doi: 10.1016/j.amepre.2016.10.036.
4. Brown, C. J., & Cheng, J. M. (2014). Electronic cigarettes: product characterisation and design considerations. Tobacco Control, 23, ii4–ii10.
5. Abul, M., Prasad, S., Liles, T., & Cucullo, L. (2016). A decade of e-cigarettes: Limited research and unresolved safety concerns. Toxicology, 365, 67–75.
6. Grana, R., Benowitz, N., & Glantz, S. A. (2014). E-cigarettes: A scientific review. Circulation, 129, 1972–1986.
7. Wieslander, G., Norbäck, D., & Lindgren, T. (2001). Experimental exposure to propylene glycol mist in aviation emergency training: Acute ocular and respiratory effects. Occup. Environ. Med., 58, 649–655.
8. Fuoco, F. C., Buonanno, G., Stabile, L., & Vigo, P. (2014). Influential parameters on particle concentration and size distribution in the mainstream of e-cigarettes. Environ. Pollut., 184, 523–529.
9. Sosnowski, T. R., & Odziomek, M. (2018). Particle size dynamics: Toward a better understanding of electronic cigarette aerosol interactions with the respiratory system. Front. Physiol., 9, article 853, 1–8. doi: 10.3389/fphys.2018.00853.
10. Ciuzas, D., Prasauskas, T., Krugly, E., Sidaraviciute, R., Jurelionis, A., Seduikyte, L., Kauneliene, V., Wierzbicka, A., & Martuzevicius, D. (2015). Characterization of indoor aerosol temporal variations for the real-time management of indoor air quality. Atmos. Environ., 118, 107–117.
11. Robinson, R. J., & Yu, C. P. (2001). Aerosol science and technology deposition of cigarette smoke particles in the human respiratory tract deposition of cigarette smoke particles in the human respiratory tract. Aerosol Sci. Technol., 34, 202–215.
12. Ingebrethsen, B. J., Alderman, S. L., & Ademe, B. (2011). Coagulation of mainstream cigarette smoke in the mouth during puffing and inhalation. Aerosol Sci. Technol., 45(12), 1422–1428.
13. Manigrasso, M., Buonanno, G., Fuoco, F. C., Stabile, L., & Avino, P. (2015). Aerosol deposition doses in the human respiratory tree of electronic cigarette smokers. Environ. Pollut., 196, 257–267.
14. Belka, L., Lizal, F., Jedelsky, J., Jicha, M., & Pospisil, J. (2017). Measurement of an electronic cigarette aerosol size distribution during a puff. EPJ Conf., 143, 02006. DOI: 10.1051/epjconf/201714302006.
15. Schripp, T., Markewitz, D., Uhde, E., & Salthammer, T. (2013). Does e-cigarette consumption cause passive vaping? Indoor Air, 23(1), 25–31.
16. Yuness, M., Mohamed, A., AbdEl-hady, M., Moustafa, M., & Nazmy, H. (2015). Effect of indoor activity size distribution of 222Rn progeny in-depth dose estimation. Appl. Radiat. Isot., 97, 34–39.
17. Yuness, M., Mohamed, A., Nazmy, H., Moustafa, M., & Abd El-hady, M. (2016). Indoor activity size distribution of the short-lived radon progeny. Stoch. Environ. Res. Risk Assess., 30(1), 167–174.
18. Mohamed, A., Abd El-hady, M., Moustafa, M., & Yuness, M. (2014). Deposition pattern of inhaled radon progeny size distribution in human lung. J. Radiat. Res. Appl. Sci., 7(3), 333–337.
19. Mostafa, Y., Mohamed, A., Abd El-hady, M., Moustafa, M., & Nazmy, H. (2015). Indoor activity of short-lived radon progeny as critical parameter in dose assessment. Solid State Phenom., 238, 151–160.
20. Mostafa, Y. A. M., Vasyanovich, M., Zhukovsky, M., & Zaitceva, N. (2015). Calibration system for radon EEC measurements. Radiat. Prot. Dosim., 164(4), 587–590.
21. Khalaf, H. N., Vasyanovich, M., Mostafa, M. Y. A., & Zhukovsky, M. (2019). Comparison of radioactive aerosol size distributions (Activity, number, mass, and surface area). Appl. Radiat. Isot., 145, 95–100.
22. Nazmy, H., Mostafa, M. Y. A., & Zhukovsky, M. (2018). Particle size distribution of e-cigarette aerosols in indoor air. J. Radiat. Nucl. Appl., 3(2), 111–117.
23. Khalaf, H. N. B., Mostafa, M. Y. A., & Zhukovsky, M. (2018). Radiometric efficiency of analytical filters at different physical conditions. J. Radioanal. Nucl. Chem. https://doi.org/10.1007/s10967-018-6347-6.
24. Vasyanovich, M., Mostafa, M. Y. A., & Zhukovsky, M. (2017). Ultrafine aerosol influence on the sampling by cascade impactor. Radiat. Prot. Dosim., 177(1/2), 49–52.
25. Nazaroff, W. W. (1980). An improved technique for measuring working level of radon daughters in residences. Health Phys., 45, 509–523.
26. Mostafa, Y. A. M., Vasyanovich, M., & Zhukovsky, M. (2016). Prototype of a primary calibration system for measurement of radon activity concentration. Appl. Radiat. Isot., 107, 109–112.
27. Mostafa, Y. A. M., Vasyanovich, M., & Zhukovsky, M. (2017). A primary standard source of radon-222 based on the HPGe detector. Appl. Radiat. Isot., 120, 101–105.
28. Zhukovsky, M., Rogozina, M., & Suponkina, A. (2014). Size distribution of radon decay products in the range 0.1–10 nm. Radiat. Prot. Dosim., 160(1/3), 192–195.
29. Rogozina, M., Zhukovsky, M., Ekidin, A., & Vasyanovich, M. (2014). Thoron progeny size distribution in monazite storage facility. Radiat. Prot. Dosim., 162(1/2), 10–13.
30. Biennann, A. H., & Sawyer, S. S. (1995). Attachment of radon progeny to cigarette-smoke aerosols. U.S. Department of Energy by Lawrence Livermore National Laboratory. (Contract no. W-740S-ENG-48).
31. Muller, W. J., Scherer, P. W., & Hess, G. D. (1990). A model of cigarette smoke particle deposition. Am. Ind. Hyg. Assoc. J., 51(5), 245–256.
32. Morawska, L., & Phillips, C. R. (2007). Aerosol science and technology attachment of radon progeny to cigarette smoke aerosol attachment of radon progeny to cigarette smoke aerosol. Aerosol Sci. Technol., 17(3), 149–158.
33. Tu, K. W., & Knutson, E. O. (1988). Indoor radon progeny particle size distribution measurements made with two different methods. Radiat. Prot. Dosim., 24(1/4), 251–255.
34. Holub, R. F., Knutson, E. O., & Solomon, S. (1988). Tests of the graded wire screen technique for measuring the amount and size distribution of unattached radon progeny. Radiat. Prot. Dosim., 24(9), 265–268.