All exposures of the employee occurring prior to September 1, 1971, to the hazards of an occupational disease, as defined in this article, while in the employ of the employer, shall be deemed for all purposes to be subject to the provisions of this article, and the employee, his personal representative, parents, surviving spouse, dependents, and next of kin shall be entitled to compensation or other benefits and barred from other rights and remedies as provided in this article for exposures occurring after September 1, 1971.