during WWII and korean conflict, some words did join english, but in the past 20 years, our local school (apx 300 students) has gone from having apx 7 koreans enrolled (about 1 per grade) to have 90-- over 12 per grade...1/3 of the class! this influx should have local kids picking up some korean words.. but i haven't seen it happening yet.

in the past 20 years, there has been a real movement of chinese/korean/japanese from self selected ghettos ("china towns") to main stream neighborhoods. at least in NY