A study published in the journal Nicotine & Tobacco Research demonstrates that "secondhand vapor" from e-cigarettes poses very little risk to bystanders.
(See: Czogala J, et al. Secondhand exposure to vapors from electronic cigarettes. Nicotine & Tobacco Research 2014; 16(6):655-662.)
The study methods were as follows: "We
measured selected airborne markers of secondhand exposure: nicotine,
aerosol particles (PM(2.5)), carbon monoxide, and volatile organic
compounds (VOCs) in an exposure chamber. We generated e-cigarette vapor
from 3 various brands of e-cigarette using a smoking machine and
controlled exposure conditions. We also compared secondhand exposure
with e-cigarette vapor and tobacco smoke generated by 5 dual users."
The results were as follows: "The
study showed that e-cigarettes are a source of secondhand exposure to
nicotine but not to combustion toxicants. The air concentrations of
nicotine emitted by various brands of e-cigarettes ranged from 0.82 to
6.23 µg/m(3). The verage concentration of nicotine resulting from
smoking tobacco cigarettes was 10 times higher than from e-cigarettes
(31.60±6.91 vs. 3.32±2.49 µg/m(3), respectively; p = .0081)."
The study demonstrated that both in an experimental chamber and with actual vaping taking place, there were low concentrations of nicotine, transient increases in fine particulate matter, no increase in carbon monoxide levels, and no exposure to volatile organic compounds. The authors conclude that although "secondhand vaping" is associated with low-level nicotine exposure, it does not result in exposure to toxic tobacco-specific combustion products.
The Rest of the Story
In spite of these findings, which demonstrate that secondhand vaping is not a significant health threat, Dr. Stan Glantz has nevertheless informed the public that the study provides evidence that "e-cigarettes pollute the air and expose bystanders."
According to Dr. Glantz, the study found that "e-cigarettes pollute the air with nicotine and fine particles." His argument that secondhand vapor is a health hazard is based on the finding that vaping results in exposure to nicotine and fine particles.
Here is why Stan's argument is faulty:
Nicotine exposure: First, let's quantify the exposure to nicotine for a bystander. Assuming the highest nicotine level detected (6.2 micrograms per cubic meter), a breathing rate of 600 liters/hour and exposure of a full work-day (8 hours), the nicotine exposure will be 4.8 times 6.2, or about 30 micrograms per day. This is the equivalent of 0.03 cigarettes per day. Even if you were exposed for 8 hours every day for a year, your total nicotine exposure would amount to the equivalent of only 11 cigarettes.
Obviously, this is an extremely low level of nicotine exposure, and it is not going to pose any significant health risk.
Fine particle exposure: The average particulate exposure from vaping (152 micrograms per cubic meter) was more than 5 times lower than particulate exposure from secondhand smoke (819 micrograms per cubic meter). But even more importantly, the exposure to particulate matter from vaping was only transient, as the vapor particles dissipated within minutes. In contrast, smoke lingers and so exposure to the particulate matter is constant. The overwhelming majority of time that a bystander is in the room with the vaper, the bystander is not being exposed to particulate matter. Thus, fine particle exposure from vaping is dramatically lower than with smoking, and is unlikely to pose significant health risks.
Why then, are anti-tobacco advocates presenting these results differently? I believe it's because the findings are not consistent with their pre-conceived conclusion that both vaping and secondhand vaping are substantial health hazards. The only way to preserve the pre-existing ideology is to twist the results to fit the ideology, rather than to change the ideology to fit the science.