acid rain
air pollution
alte
car
carbon dioxide
chimney
climate change
closeup
co2
collection
concept
cut out
design element
dioxide
dirty
engine
environment
environmental damage
equipment
exhaust
exhaust pipe
factory
fossil fuel
fuel
fuel and power generation
garbage
gas
gasoline
group
hole
industry
iron
isolated
machine part
metal
metallic
part of
pipe
pollution
rusty
smog
smoke
smoke stack
social issues
stainless steel
steel
tube
variation
white background