; and (2) submit a report to the Committees on Transportation and Infrastructure, Energy and Commerce, and Appropriations of the House of Representatives and the Committees on Commerce, Science, and Transportation, Health, Education, Labor, and Pensions, and Appropriations of the Senate. 536. Oxygen mask design study Not later than 180 days after the date of enactment of this Act, the Administrator shall conduct a study to review and evaluate the design and effectiveness of commercial aircraft oxygen masks. In conducting the study, the Administrator shall determine whether the current design of oxygen masks is adequate, and whether changes to the design could increase correct passenger usage of the masks. 537. Air cargo study (a) In general Not later than 6 months after the date of enactment of this Act, the Comptroller General of the United States shall begin a study of international air cargo services among the United States and Central American, South American, and Caribbean Basin countries, that— (1) analyzes the supply of and demand for air cargo transportation services among the United States and Central American, South American, and Caribbean Basin countries; (2) analyzes the supply of and demand for air cargo transportation services between— (A) the United States, Central American, South American, and Caribbean Basin countries; and (B) African and European countries; (3) identifies the busiest routes in terms of cargo capacity and frequency of air service; (4) identifies any air carrier or foreign air carrier hubs in Central American, South American, and Caribbean Basin countries at which a significant amount of air cargo is sorted, handled, or consolidated for transportation to or from the United States