On Amazon Mechanical Turk's Privacy Page you can request and collect all the privacy and GDPR related information that Amazon Mechanical Turk is providing.
The privacy policy by is a legal document or statement that discloses how Amazon Mechanical Turk gathers, uses, discloses, and manges their customers' data.
The basis for Amazon's Mechanical Turk sharing, adding, uploading, hosting, accessing or sending personal data out of Europe. Vendors can also add a description of their own impact assessment for data transfers.
Subprocessors are companies that provide a service for Amazon's Mechanical Turk and who has or potentially will get access to personal data of their customers.