Whenever air pollution conditions in any area of the state become such as, in the opinion of the director, to create an emergency and to require immediate action for the protection of the public health, the director may, with the written approval of the governor, so find and enter such order as it deems necessary to reduce or prevent the emission of air pollutants substantially contributing to such conditions. In any such order the director shall also fix a time, not later than twenty-four hours thereafter, and place for a hearing to be held before it for the purpose of investigating and determining the factors causing or contributing to such conditions. A true copy of any such order shall be served upon persons whose interests are directly prejudiced thereby in the same manner as a summons in a civil action may be served, and a true copy of such order shall also be posted on the front door of the courthouse of the county in which the alleged conditions originated. All persons whose interests are prejudiced or affected in any manner by any such order shall have the right to appear in person or by counsel at the hearing and to present evidence relevant to the subject of the hearing. Within twenty-four hours after completion of the hearing the director shall affirm, modify or set aside said order in accordance and consistent with the evidence adduced. Any person aggrieved by such action of the director may thereafter apply by petition to the circuit court of the county for a review of the director's action. The circuit court shall forthwith fix a time for hearing de novo upon the petition and shall, after such hearing, by order entered of record, affirm, modify or set aside, in whole or in part, the order and action of the director. Any person whose interests shall have been substantially affected by the final order of the circuit court may appeal the same to the supreme court of appeals in the manner prescribed by law.