Notwithstanding any other section of this article, the Legislature in providing for the creation, establishment, maintenance, and operation of a hospital district, shall not be required to provide that such district shall assume full responsibility for the establishment, maintenance, support, or operation of mental health services or mental retardation services including the operation of any community mental health centers, community mental retardation centers or community mental health and mental retardation centers which may exist or be thereafter established within the boundaries of such district, nor shall the Legislature be required to provide that such district shall assume full responsibility of public health department units and clinics and related public health activities or services, and the Legislature shall not be required to restrict the power of any municipality or political subdivision to levy taxes or issue bonds or other obligations or to expend public moneys for the establishment, maintenance, support, or operation of mental health services, mental retardation services, public health units or clinics or related public health activities or services or the operation of such community mental health or mental retardation centers within the boundaries of the hospital districts; and unless a statute creating a hospital district shall expressly prohibit participation by any entity other than the hospital district in the establishment, maintenance, or support of mental health services, mental retardation services, public health units or clinics or related public health activities within or partly within the boundaries of any hospital district, any municipality or any other political subdivision or state-supported entity within the hospital district may participate in the establishment, maintenance, and support of mental health services, mental retardation services, public health units and clinics and related public health activities and may levy taxes, issue bonds or other obligations, and expend public moneys for such purposes as provided by law.