Considering that most people vape around 2-3ml a day, that is also, obviously, the largest amount of PG that can escape into the air. Actually, of course, it's less, since
juice is not just PG, and some stays inside you. And the next question then is, how much of that a person in the same room can inhale? Even less.
Those are really not numbers you need to worry about, even with small kids. Wouldn't even be if they somehow managed to get the whole 2-3ml into them.