New study shows e-cig users exhale nicotine and fine particles into the air where bystanders are breathing

The research group at Roswell Park Cancer Center has just published a nice paper in which they measure the amount of nicotine, fine particles, and several other toxins in the air around someone using e-cigarettes.  They also collected the same information for conventional cigarettes. 

It is also consistent with work showing that passive vapers absorb nicotine.

The e-cigarettes were used for 5 minutes and, separately, two cigarettes were smoked during a 30 minute period.
 
There were significant increases in nicotine and ultrafine particles following use of both products, with the cigarettes producing about 10 times as much nicotine and 7 times as much particulate matter as the e-cigarettes.

Bottom line:  For a given level of consumption, e-cigarettes pollute the air less than conventional cigarettes.

But they pollute the air than nonsmokers are breathing,

The fact that e-cigs are only 1/7 or 1/10 as polluting as cigarettes doesn't mean that they cannot generate substantial pollution in the real world.  It is not unusual for bars and casinos where a lot of people are smoking have particulate pollution levels of 500 mcg/m3 ro 1000 mcg/m3.  What the new study means is that the same density of vapers would lead to pollution levels of about 70 to 140 mcg/m3, which is still 5-10 times what is considered acceptable.

Thus, this study adds to the case that e-cigarettes should not be allowed anywhere that cigarettes are not allowed.