1.   And indeed, New Yorkers ran only far enough to escape the choking clouds of ash and cement.

2.   As the vehicles twisted up stunning mountain gorges, the more aggressive drivers bolted ahead, passing slower-moving traffic and raising choking clouds of dust.

3.   As the vehicles twisted up stunning mountain gorges, the more aggressive drivers bolted ahead, passing slower moving traffic and raising choking clouds of dust.

4.   A choking grey cloud billowed out, blocking out the bright sunshine and chasing thousands of panicked workers through the canyons of Lower Manhattan.

5.   A choking cloud of marijuana smoke.

6.   Choking clouds of fish shimmered blue against the tannic brown.

7.   Debris continues to wash down from battered neighborhoods, littering the waters of the main bay, and a choking cloud of brown dust sits above the central city.

8.   In Beijing and other Chinese metropolises ordinary people have been driven to riot by pollution ranging from incessant noise to choking clouds of coal dust.

9.   It crashes to a halt in a choking cloud of dust.

10.   Choking clouds of dust from the rubble hung like fog in the air.