; and (2) a final rule not later than 1 year after the date of enactment of this Act. (c) Consultation In conducting the rulemaking proceeding required under subsection (a), the Secretary may consult with the heads of such other Federal departments or agencies as the Secretary considers appropriate. 4. Study on transmission of infectious diseases in airplane cabins (a) In general Not later than 180 days after the date of enactment of this Act, the Administrator shall seek to enter into an agreement with the National Academies to conduct a study on the transmission of infectious diseases, including airborne diseases, in the cabins of passenger airplanes. (b) Parameters of study The study required under subsection (a) shall consider, at a minimum— (1) air flow patterns and humidity levels in the cabins of passenger airplanes and the extent to which such patterns and humidity levels increase or decrease the possibility that a passenger may be exposed to an airborne pathogen communicated by another individual on board an airplane; (2) how uniformly the cabin air supply is completely exchanged and whether air in certain areas of the cabin is exchanged more quickly or slowly than in other areas of the cabin; (3) the extent to which various recirculation systems and the respective filtration systems of such recirculation systems increase or decrease the likelihood of exposure to a pathogen; (4) the extent to which the use of preconditioned air during embarkation and disembarkation changes the likelihood of a passenger’s exposure to a pathogen as opposed to the use of air conditioning packs fed by the auxiliary power unit