Formaldehyde in e-cigarettes

Recently while I was browsing the forum, I noticed some threads about formaldehyde in e-cigarettes which caught my attention. Specifically, it mostly involved this article:

http://www.cspnet.com/news/tobacco/articles/study-e-cig-vapor-less-injurious-cigarette-smoke

According to the article, e-cigarettes are generally safer than analogs but "the study found similar amounts of formaldehyde in tobacco cigarettes, e-cigarettes and medicinal inhalers--although the amount of formaldehyde found in the 12 different brands of e-cigarettes ranged from 3.2 micrograms per 150 puffs (comparable to the levels from the nicotine inhaler) to 56.1 micrograms per 150 puffs."

I'm aware that formaldehyde is a carcinogen so I'm pretty concerned about this. But after doing some research, it doesn't seem that formaldehyde is one of the MAIN carcinogens in cigarettes, and that the air we breath contains formaldehyde anyway. For example, according to this article,

[Evaluation of total exposure to benz... [Epidemiol Prev. 2005 Sep-Dec] - PubMed - NCBI

"Outdoor concentrations (of formaldehyde) vary from 7 to 153 microg/m3," and "formaldehyde concentrations in public buildings and offices vary from 3 to 30 microg/m3."

In addition, this article:

Harpocrates Speaks: Demystifying Vaccine Ingredients - Formaldehyde

states that "Health Canada lists a 'No Observable Adverse Effect Level; NOAEL for indoor air concentrations of formaldehyde of 615 μg/m[SUP]3[/SUP]"

So even if we vape the "worst" e-cig at 56 microgram per 150 puffs, that's only about 150 microgram per cubic meter, given that we breath about a cubic meter of air in 400 or 500 breathes or "puffs".

So if regular outdoor air can have up to 153 microg/m3 of formaldehyde, and indoors can have up to 30, then maybe vaping isn't that bad, because we are only vaping a tiny percentage of time compared to breathing throughout the day.

What do you think?

Anyone interested in delving more into this, feel free to do so. I'm highly interested in this matter