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.
(..) to the Dark World, and draw the enemy away from Asgard. When Malekith pulls the Aether from Jane, it will be exposed and vulnerable. And I will destroy it and him. If you fail, you risk this weapon falling into the hands (..)2013 Thor: The Dark World