(to produce) a mark etc. that spoils the beauty or perfection

flaw

(an example of) the state or quality of being crude

obscenity, vulgarity

a dirty mass; obscene language, pictures etc

dirt, pollution

the process of infecting or being infected, especially the communication of disease through the air or water; an infectious disease

contamination

(an instance of) being obscene, bad language etc

indecency, immorality; vulgarism

the act of polluting; (a mixture of) substances that pollute

dirtiness, contamination