A solid article in City Journal about the tainted history of the EPA, and the challenge that the new leader has in making the agency follow a more rigorous methodology:
The EPA has been plagued by politicized science since its inception in 1970. One of its first tasks was to evaluate the claim that the use of DDT pesticide was causing an epidemic of cancer. The agency held extensive hearings that led to the conclusion that DDT was not a carcinogen, a finding that subsequent research would confirm.
Since then, the agency has repeatedly been criticized for relying on weak or cherry-picked evidence to promote needless alarms justifying the expansion of its authority (and budget).
Pruitt’s new policy will force the EPA to rely on studies for which data is available to other researchers, ensuring the transparency that enables findings to be tested and confirmed.