Your confidentiality agreement with a study can preclude them from even releasing the anonymized raw data, invaliding a study in the eyes of the EPA.
It also mandates reproducibility. It isn't exactly easy or even possible to reproduce a 70-year long study or a study of victims of a disaster which is the point of the American College of Obstetricians and Gynecologists and The American Academy of Pediatrics.
https://www.regulations.gov/document?D=EPA-HQ-OA-2018-0259-2...