air
asphalt
background
billow
billowing
bomb
cloud
conflict
danger
dangerous
demonstration
emission
event
exhaust
fight
flow
fog
fumes
gasoline
ignition
pollutant
pollute
pollution
problem
protest
rebel
rebellion
revolt
riot
rioter
road
smog
smoke
smoky
street
symbol
terror
terrorism
ultra
urban
vapours
violence
violent
war
white