against
air
atmosphere
blue
building
business
chemical
chimney
clear
climate
cloud
coal
construction
day
dioxide
dirty
emission
energy
environment
environmental
exhaust
factory
fuel
fume
gas
generation
global
industrial
industry
nature
pipe
plant
pollution
power
production
refinery
sky
smog
smoke
snow
stack
station
steam
sunny
sunshine
technology
tower
toxic
vapor