I'm just curious, do you eat potatoes, tomatoes, eggplant, or cauliflower? If so, you are already ingesting that evil, evil nicotine[1]. In all honesty, I doubt we would be put more at risk by inhaling any trace amounts of nicotine in secondhand vap than we would from interacting with everything else in our everyday lives. Hell, sitting in front of this computer and typing this response is probably shortening my lifespan more than a minuscule amount of nicotine.

[1]: http://www.huffingtonpost.com/2012/06/15/nicotine-in-vegetab...