I hear eww (sometimes spelt as ew) fairly regularly on American sitcoms, usually uttered by a scatterbrained beautiful blonde girl when she sees or hears something disgusting. I don't recall it ever being said when I was a child living in London, and the word gross was virtually unknown. In the 1970s, the utterances yuck or ugh were commonly blurted out. Moreover, on my frequent visits to the UK I don't seem to hear eww ever being used but I tend to mix with people closer to my age.
The dictionary, Online Etymology offers no guidance, and Oxford Dictionaries limits itself by saying
ew
/ˈɪəuː/, /ˈiːuː/
EXCLAMATION
INFORMAL
Used to express disgust or distaste:
ew, I’d hate to think what has been trampled into that carpet
eww, how can you eat that?
Origin
1970s: imitative.
Has ew/eww crossed the Atlantic and become common parlance in old Blighty i.e. the UK? If it has, when did it more or less occur? And are the expressions ugh and yuck still popular with the young in both the US and the UK? If not, which exclamation of disgust is gaining territory?
If anyone is still confused about which sound I'm referring to, click on the YouTube link to hear a perfect example. The young American child (who coincidently happens to be blonde) is called Georgie and she is tasting a variety of foods while blindfolded, the resulting "eww!" is spontaneous and unaffected and happens at 56 seconds.
Best Answer
It has definitely crossed over to the UK. My 15 year old (a couple of years ago) daughter used it as expression of choice when faced with a gross situation. Sadly I have even used it myself but I like to think in a post-modern ironic sense ;)
Like many Americanisms that cross the pond I imagine it is likely to have transferred through TV programmes, such as Friends.