air
atmosphere
carbon
chemical
chimney
climate
conditions
conservation
contamination
danger
dioxide
dirty
ecological
ecologically
effect
emission
energy
environment
environmental
exhaust
factory
fog
fume
fumes
gloomy
harmful
industrial
industry
light
ozone
pipe
pollute
pollution
production
refinery
silhouette
sky
smog
smoke
stack
station
steam
tower
toxic
vapor
warming
white
wind