acid
air
atmosphere
blue
breathe
burner
catalytic
chemical
chimney
climate
coal
corporation
deleterious
dirty
dusk
ecological
ecologically
ecology
emission
emissions
energy
engine
environmental
exhaust
factory
fuel
fumes
gas
global
industrial
industry
manufacturing
metal
ozone
pipe
plant
poison
pollution
power
production
sky
smog
smoke
stack
station
steam
tower
toxic
warming
white