exhaust (expand with variations)

At the end of the ramp was a bullet-ridden stop sign where a van idled, as if the driver was uncertain, exhaust drifting lazily through the air.

By the end of the first week of June, the weather had turned stagnant, oppressive, rank: day after day of torpid, greenish skies; the air clogged with garbage fumes and exhaust; heat rising from every brick and concrete slab.

Even this did not exhaust the pyrotechnic potential of the impacting comet.

They brought a gust of cold air with them and the smell of auto exhaust.

Typically, gasoline engines draw air for combustion past a partly open throttle plate before mixing it with fuel, igniting it and forcing the combustion byproducts out through the exhaust valves.

More examples in news.google.com [exhaust]