environmental
air
atmosphere
background
blue
building
business
carbon
chemical
chimney
climate
cloud
coal
construction
contamination
damage
dirty
ecology
economy
emission
energy
environment
exhaust
factory
firing
fog
fuel
fume
gas
industrial
industry
manufacturing
nature
pipe
plant
pollution
power
refinery
smog
smoke
smokestack
smoking
stack
station
steam
steamshop
technology
tower
toxic
tube
vapor
warming