Elegran the answer is, erm, well, you've got me there!
Jalima, and there was me thinking you hosed down with a big old bar of carbolic! 
On a serious note, When I first read about micro beads and the environment, my assumption was they were in products like body scrubs and exfoliating soaps with grit in (hate those, I wash my face with soap and the grit gets in my eyes). Which you would assume (someone mentioned above) would be filtered out through the sewage system. But I think microbeads are different and are in makeup? (to produce a glow? sheen?)but other products like shower gels. In their case I'm not sure what for? And they are too 'micro' to be filtered out it seems but can still be ingested by marine life. Take 'em out. We all managed without them before and looked stunningly beautiful!