; and (B) may not determine that testing of full-body exposure to a covered substance did not occur at a site based solely on— (i) information contained in the Department of Defense and Department of Veterans Affairs Chemical Biological Warfare Database; or (ii) any list of known sites of testing of full-body exposure to a covered substance maintained by the Department of Veterans Affairs or the Department of Defense. (5) Presumption of exposure In carrying out paragraph (1), when the Secretary of Veterans Affairs makes a determination regarding whether a veteran experienced full-body exposure to a covered substance, the Secretary— (A) shall presume, unless there is affirmative evidence to establish otherwise, that the veteran experienced such exposure by reason of the service of the veteran in World War II— (i) based on the locations listed in paragraph (3); and (ii) consistent with the places, types, and circumstances of service of the veteran in accordance with section 1154 of title 38; and (B) shall resolve each reasonable doubt in favor of the veteran. (6) Effective date of award The effective date of any award of disability compensation resulting from reconsideration of a claim under paragraph (1) shall be fixed in accordance with the facts found, but shall not be earlier than the date of the receipt of the claim for compensation described in paragraph (2). (b) Investigation and report by the Secretary of Defense Not later than 180 days after the date of the enactment of this Act, the Secretary of Defense shall— (1) investigate and assess each site— (A) where the Army Corps of Engineers has uncovered evidence of testing conducted by the Department of Defense during World War II to assess the effects of full-body exposure to a covered substance on humans; or (B) with regards to which more than two veterans have been denied claims for compensation under chapter 11 of title 38, United States Code, in connection with exposure to a covered substance at such site