HARD (ER) KANJI - JLPT 2 KYUU

This sounds bad, but think of it as a man sitting on a dirty toilet and you will remember this one
けがto bring disgrace upon; to soilよごす:きたなto get dirty
汚す yogosu - to stain, to soil
汚染 o sen - pollution
大気汚染 tai ki o sen - air pollution