air
atmosphere
boiler
building
carbon
chemical
chimney
cloud
coal
contamination
dirty
electricity
emission
energy
environment
environmental
exhaust
factory
fume
fumes
generation
global
health
industrial
industry
manufacturing
outdoors
pipe
plant
polluting
pollution
power
production
refinery
safety
sky
smog
smoke
smokestack
smokestacks
station
steam
stormy
structure
technology
tower
toxic
vapor
warming