en_tn/lev/05/03.md

if he touches the uncleanness of someone, whatever that uncleanness is

The abstract noun "uncleanness" can be stated as an adjective. AT: "if he touches anything that makes a person unclean" (See: rc://en/ta/man/translate/figs-abstractnouns)

the uncleanness

Something that Yahweh has declared unfit for a person to touch or eat is spoken of as if it were physically unclean. (See: rc://en/ta/man/translate/figs-metaphor)

he is unaware of it

"he does not realize it" or "he does not know about it"