impure air

References in classic literature ?
No doubt of it, unless he is fortunate enough to catch the small-pox, and even that is difficult, for we never get any impure air here.
The other section which features a grade B processing room, validation room, and a cryogenic storage facility has its own air handling unit and the pressure inside is higher than that outside, to ensure that impure air stays out and dust and contaminants are pushed out.
The nation would have welcomed a fresh breeze of normality in that rarified, sometimes impure air which our monarchy has been gasping since the marriages of the Queen's three eldest children went bust.
It's only a matter of time before we are charged for every lung full of slightly impure air.
Smoothing, soothing and hydrating to the skin, herbal baths are a perfect antidote to combat impure air and water conditions.
Breathing impure air contaminated by polluted water also had "pernicious effects.