; and (ii) any other available and relevant scientific studies, to the extent that such studies are relevant to the occupational exposures that have occurred at Department of Energy cleanup sites; and (B) review and summarize the scientific and medical evidence concerning the association between exposure to toxic substances found at Department of Energy cleanup sites and resultant diseases. (2) Scientific determinations concerning diseases In conducting each review of scientific evidence under subparagraphs (A) and (B) of paragraph (1), the National Academy of Sciences shall— (A) assess the strength of such evidence; (B) assess whether a statistical association between exposure to a toxic substance and a disease exists, taking into account the strength of the scientific evidence and the appropriateness of the statistical and epidemiological methods used to detect an association; (C) assess the increased risk of disease among those exposed to the toxic substance during service during the production and cleanup eras of the Department of Energy cleanup sites; (D) survey the impact to health of the toxic substance, focusing on renal, liver, neurological, skin, respiratory, ear, nose, eye, and throat diseases, including dementia, chemical sensitivities, and emphysema; and (E) determine whether a plausible biological mechanism or other evidence of a causal relationship exists between exposure to the toxic substance and disease. (e) Additional scientific studies If the National Academy of Sciences determines, in the course of conducting the studies under subsection (d), that additional studies are needed to resolve areas of continuing scientific uncertainty relating to toxic exposure at Department of Energy cleanup sites, the National Academy of Sciences shall include, in the next report submitted under subsection (f), recommendations for areas of additional study, consisting of— (1) a list of diseases and toxins that require further evaluation and study