The workers were 'exposed to' dangerous chemicals. [=they were placed in conditions that left them unprotected from dangerous chemicals]
His mistakes have 'exposed' him 'to' ridicule. [=he has been ridiculed because of his mistakes]
Children are being 'exposed to' violence on television.
(..) But in the middle of the ten paces, Dad turned to ask the guy if he'd actually read the book and what he thought, but, not looking where he was going, tripped over an exposed root and bashed his head on a rock. I wish I'd known to go to Jack in the Box then. I could have gotten a free churro. (..)2018 TvShow: BoJack Horseman Title: Free Churro Season: 5 Episode 6