air
atmosphere
breathe
carbon
chemical
chimney
climate
co2
coal
conditions
construction
contamination
danger
dioxide
dirty
ecological
effect
emission
energy
environment
environmental
exhaust
factory
fume
garbage
gas
global
growth
harmful
industrial
industry
ozone
pipe
plant
pollute
pollution
power
production
refinery
sky
smog
smoke
stack
station
steam
tower
toxic
vapor
warming
white