acid

asthmatic

atmosphere

background

breathe

changing

chimney

climate

cloud

cloudy

damage

deleterious

demolish

dioxide

dirty

ecological

ecologically

ecology

emissions

exhaust

factory

fumes

gas

global

growth

harmful

health

industrial

industry

intoxication

large

noxious

ozone

pipe

poison

poisoning

pollution

power

precipitation

problems

send

sky

smog

smoke

stack

station

steam

tower

warning