acid
architecture
atmosphere
chimney
chimneys
cloud
clouds
contamination
day
daytime
ecology
electric
electricity
energy
environment
environmental
exterior
factory
fumes
gas
greenhouse effect
industrial
industry
overall
ozone
poison
pollutant
pollute
pollution
power
problem
production
rain
smoke
smokestack
smokestacks
smoking
stack
stacks
tall
thermal
toxic
vapor
white
wind