Public Health - As introduced, specifies that the county mayor, in unincorporated areas, and the highest-ranking elected official in a city in the official's jurisdiction, have the authority to establish and implement health policies that affect the county or city, as applicable, during a health emergency; directs the county health director, health officer, and board of health to provide advice to the mayor and city official to develop the policies; applies only in Shelby, Davidson, Knox, Hamilton, Sullivan, and Madison counties. - Amends TCA Title 5 and Title 68, Chapter 2, Part 6.