and pollution
biology
bottles
canal
chemical
chemistry
clean
creek
danger
decline
dirt
dirty
disaster
ecological
ecology
ecosystem
environment
garbage
global
hazardous
horror
impure
industrial
material
nature
oil
oil industry
plastic
pollution
pond
problems
river
rotting
sanitation
sewage
smelling
toxicsubstance
trash
treatment
ugliness
waste
wastewater
water