Significantly, this court recently held that a mere showing that one's conditions of employment aggravate a pre-existing emphysematous condition thus contributing to disablement, or hasten the development of the disease, is not sufficient to support an award of compensation. Rockford Transit Corp. v. Industrial Com., 38 Ill.2d 111. The petitioner relies heavily on our decision in Allis-Chalmers Manufacturing Co. v. Industrial Com., 33 Ill.2d 268, to sustain her position. Therein we determined that a compensable occupational disease will be deemed to exist under the statute presently concerned where there is a showing both that a disabling disease arose out of and in the course of employment, and that the employee contracted the disease, "due to exposure to hazards of a peculiar or unusual condition of work in a greater degree and in a different manner than the public generally * * *." ( 33 Ill.2d at 271.)

Furthermore, we do not believe the legislature intended that the Workers' Occupational Diseases Act provide compensation for any malady. Had such been the intention of the legislature, there are a variety of other terms it could have used to better convey that intention, e.g., illness, sickness, defect, ailment. Occupational disease laws were designed to compensate employees for injury, disease, or death occasioned by slow, gradual, and insidious processes arising out of and in the course of employment. ( Allis-Chalmers Manufacturing Co. v. Industrial Com. (1965), 33 Ill.2d 268, 272, 211 N.E.2d 276, 278.) Historically, the Workers' Occupational Diseases Act has provided compensation for silicosis, asbestosis, pulmonary tuberculosis, pneumoconiosis (cases collected at Ill. Ann. Stat., ch. 48, par. 172.

However, even prior to the 1975 amendment to the Act, the fact that an employee's disease was an ordinary disease of life did not bar the employee from recovering. Instead, the Act was interpreted in Allis-Chalmers Manufacturing Co. v. Industrial Com. (1965), 33 Ill.2d 268, 271, 211 N.E.2d 276, 278, to allow recovery where an employee's disease resulted from "exposure to hazards of a peculiar or unusual condition of work in a greater degree and in a different manner than the public generally * * *." Where an employee is so exposed, the resulting disease is deemed to be an occupational disease.

We find apposite here the statement in Payne v. Industrial Com., 61 Ill.2d 66, that "The resolution of questions of fact, including questions as to the nature and extent of disability and as to causation, is primarily for the Industrial Commission. ( General Steel Industries v. Industrial Com., 49 Ill.2d 552.) We cannot substitute our judgment for that of the Commission ( Allis-Chalmers Manufacturing Co. v. Industrial Com., 33 Ill.2d 268) unless its finding is contrary to the manifest weight of the evidence. ( Rysdon Products Co. v. Industrial Com., 34 Ill.2d 326, 330; Leason v. Industrial Com., 55 Ill.2d 486, 493.)

"The resolution of questions of fact, including questions as to the nature and extent of disability and as to causation, is primarily for the Industrial Commission. ( General Steel Industries v. Industrial Com., 49 Ill.2d 552.) We cannot substitute our judgment for that of the Commission's ( Allis-Chalmers Manufacturing Co. v. Industrial Com., 33 Ill.2d 268) unless its finding is contrary to the manifest weight of the evidence. ( Rysdon Products Co. v. Industrial Com., 34 Ill.2d 326, 330; Leason v. Industrial Com., 55 Ill.2d 486, 493.)

The resolution of questions of fact, including questions as to the nature and extent of disability and as to causation, is primarily for the Industrial Commission. ( General Steel Industries v. Industrial Com., 49 Ill.2d 552.) We cannot substitute our judgment for that of the Commission's ( Allis-Chalmers Manufacturing Co. v. Industrial Com., 33 Ill.2d 268) unless its finding is contrary to the manifest weight of the evidence. ( Rysdon Products Co. v. Industrial Com., 34 Ill.2d 326, 330; Leason v. Industrial Com., 55 Ill.2d 486, 493.)

This court denied recovery because the claimant failed to prove the definite-time-place-and-cause requirement of an accidental injury. In Allis-Chalmers Mfg. Co. v. Industrial Com., 33 Ill.2d 268, at 272, this court said: "Since benefits under workmen's compensation laws were for the most part restricted to accidental injuries or death, many injustices arose where there was no accident and, instead, injury, disease or death were occasioned by slow, gradual, and insidious processes arising out of and in the course of employment. (See, e.g., Peru Plow and Wheel Co. v. Industrial Com., 311 Ill. 216.) Occupational disease laws were designed to correct these injustices and to stand side by side with workmen's compensation laws as humane and remedial statutes to place upon an employer the responsibility for disease and injury directly attributable to the employment." For a history of the development of the Workmen's Occupational Diseases Act in this State, see First National Bank of Ottawa v. Wedron Silica Co., 351 Ill. 560.

It is evident that under the statutory language a disease which does not arise out of the employment is not an occupational disease, and it is compensable only if it follows as an incident of an occupational disease. ( Allis-Chalmers Manufacturing Co. v. Industrial Com., 33 Ill.2d 268.) Nor is it enough that conditions of the employment aggravate a pre-existing disease, or have a direct influence in re-activating a dormant one, or hasten the development of disease and the disability therefrom, unless such aggravations followed as incidents of an occupational disease as defined in the statute. ( Stewart Warner Corp. v. Industrial Com., 376 Ill. 141.) There is no indication in the case at bar that the claimant had an occupational disease to which his emphysema might have been an incident, and it must follow that the award cannot stand.

Thus, the Supreme Court construed the statute to authorize compensation for a disease for which there were "many hundreds" of known non-occupational causes, provided it be otherwise shown that the disease was actually a result of the exposure occasioned by the nature of the employment. The latest decision of the Illinois Supreme Court which construes the occupational disease statute of that state (the identically worded prototype for our own) is Allis-Chalmers Manufacturing Company v. Industrial Commission, 33 Ill.2d 268, 211 N.E.2d 276. The question confronting the court was whether dermatitis is an occupational disease. The medical evidence was that dermatitis in its various forms is an ordinary disease of life, not peculiar to any particular employment.