air
amonium
architecture
atmosphere
black
blue
building
carbon
chimney
climate
ecology
energy
environment
environmental
facility
factory
fertilizers
fuel
gas
grey
harmful
industrial
industry
landmark
manufacture
manufacturing
mill
mures
pipe
plant
pollute
pollution
power
production
refinery
sky
smog
smoke
smoke stack
smokestack
stack
steam
sugar mill
summer
technology
tradition
tully
waste
work