Section 410. Exemption from taxes and legal process

The right of a person
  to  a  pension,  a   pension-providing-for-increased-take-home-pay,   an
  annuity  or  a retirement allowance, to the return of contributions, the
  pensions, the pension-providing-for-increased-take-home-pay, annuity, or
  retirement allowance itself,  any  optional  benefit,  any  other  right
  accrued  or  accruing to any person under the provisions of this chapter
  and the monies in the various funds continued under this chapter:
    1. Are hereby exempt from any  state  or  municipal  tax,  except  the
  estate tax, and
    2.  Shall not be subject to execution, garnishment, attachment, or any
  other process whatsoever, and
    3. Shall be unassignable,  except  as  in  this  chapter  specifically
  provided.