Section 551. Department; commissioner

a. There shall be a department of
  health and mental hygiene, the head of which shall be  the  commissioner
  of  health  and  mental hygiene who shall be appointed by the mayor. The
  department shall  have  and  exercise  all  powers  of  a  local  health
  department set forth in law. Notwithstanding any other provision of this
  charter  to  the  contrary,  the  department  shall be a social services
  district for purposes of the  administration  of  health-related  public
  assistance  programs  to  the  extent agreed upon by the department, the
  department of social services and the department of  homeless  services.
  Appropriations  to  the department for mental health, mental retardation
  and alcoholism services shall be set forth  in  the  expense  budget  in
  separate  and distinct units of appropriation. In determining the annual
  amount of city funds to be appropriated by the city for  mental  health,
  mental  retardation  and  alcoholism  services,  the following provision
  shall apply: in the event that the executive budget proposes a  decrease
  in  city  funds measured against the budget for the current fiscal year,
  as modified in accordance with section one hundred seven, for the  units
  of  appropriation  for  mental health, mental retardation and alcoholism
  services, the executive budget shall not propose  a  greater  percentage
  decrease  in  city  funds  measured  against  the budget for the current
  fiscal year, as modified in accordance with section one  hundred  seven,
  for the units of appropriation for mental health, mental retardation and
  alcoholism   services   than   has   been  proposed  for  the  units  of
  appropriation for public health services. If, however,  in  his  or  her
  discretion,  the mayor determines that it is in the city's best interest
  to submit an executive budget at variance with the requirements of  this
  provision,  the mayor shall include an explanation of the basis for this
  variation as part of the budget message.
    b. The commissioner shall be a doctor of medicine and:
    (1) hold a degree of master of public health or a degree of master  of
  business  administration  with  concentration  in  the health field or a
  degree of master of public  administration  with  concentration  in  the
  health  field  or  the  equivalent of any one of the specified foregoing
  degrees received from a college or university and have had at least five
  years' experience in college or university public health teaching, or
    (2) have  had  at  least  five  years'  experience  in  public  health
  administration.