dirtiness vs pollution

dirtiness and pollution both are nouns.

Word	Noun	Adjective	Verb	Adverb
dirtiness	Yes	No	No	No
pollution	Yes	No	No	No

As nouns, pollution is a hyponym of dirtiness; that is, pollution is a word with a more specific, narrower meaning than dirtiness:

dirtiness (noun)	pollution (noun)
obscenity in speech or writing	the act of contaminating or polluting; including (either intentionally or accidentally) unwanted substances or factors
the state of being unsanitary	undesirable state of the natural environment being contaminated with harmful substances as a consequence of human activities
the state of containing dirty impurities	the state of being polluted