The Secretary is authorized to establish and appoint as many special advisory committees as may be necessary to advise and confer with the Department concerning the public health. Members of any special advisory committee shall serve without compensation but may be allowed travel and subsistence expenses in accordance with N.C. Gen. Stat. § 138-6 (1957, c. 1357, s. 1; 1975, c. 281; 1983, c. 891, s. 2.)