A hearing board shall consist of:
(a) One member admitted to the practice of law in this state.
(b) One member who is a professional engineer registered as such pursuant to the Professional Engineers Act (Chapter 7 (commencing with Section 6700) of Division 3 of the Business and Professions Code).
(c) One member from the medical profession whose specialized skills, training, or interests are in the fields of environmental medicine, community medicine, or occupational/toxicologic medicine.
(d) Two public members.