cigarette smoking
cigar smoke
generating station
Oil Refinery
Oil Refinery Chimney
Oil Refinery
Oil Refinery
Industrial smoke
Air pollution
Industrial Smokestack
Industrial Chicago Skyline
Global warming
Cooling Tower
Fumes coming out of power plant
Fumes coming out of power plant
No engine Idling sign
Smoke Factory
Chimney against blue sky
Dense smoke
fumes from steel mill in the harbour
fumes from steel mill in the harbour
Polluting Vehicle
Damavand in Iran
Factory polluting air
Toxic Vapor Warning