Mass. Gen. Laws ch. 17, § 7: District health officers

Section 7. The commissioner, with the approval of the public health council, shall appoint a district health officer for each health district provided in section four of chapter one hundred and eleven. Such officers shall be graduates of incorporated medical schools, admitted to practice in the commonwealth, or shall have had at least five years' experience in public health duties and sanitary science, shall give their entire time to the performance of their duties, and shall be subject to chapter thirty-one.