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.
(..) Complete loss of pressure boiled off most of the water. Any bacteria that survived, died in the subzero temperatures... When exposed to Mars' atmosphere. How long does he have? He can still eat the potatoes he has, he just can't (..)2015 The Martian