Section 70. There shall be a board of certification of health officers, in this section and sections seventy-one and seventy-two called the board, consisting of nine members to be appointed by the governor, one of whom shall be an educator in the field of public health administration, one of whom shall be a member of the department of public health in an administrative capacity, five of whom shall be certified local health officers with at least five years experience in public health administration and who shall provide broad geographical representation to the board, one of whom shall be a member of a nongovernmental voluntary health agency with at least five years of public health administrative experience, and one of whom shall be a representative of the public, subject to the provisions of section nine B. Each member shall serve for a term of four years.