Dirty, dangerous and demeaning

"Dirty, dangerous and demeaning" (often "dirty, dangerous and demanding" or "dirty, dangerous and difficult"), also known as the 3Ds, is an American neologism derived from the Asian concept, and refers to certain kinds of labor often performed by unionized blue-collar workers. The term originated from the Japanese expression 3K: kitanai, kiken, kitsui (respectively 汚い "dirty", 危険 "dangerous", きつい "demanding"), and has subsequently gained widespread use, particularly regarding labor done by migrant workers and burakumin.

Source: Wikipedia — Dirty, dangerous and demeaning (CC BY-SA 4.0)