Any condition or impairment of health of any member of a volunteer fire department caused by any disease of the respiratory system shall be held and presumed to be an occupational disease unless the contrary be made to appear in rebuttal by satisfactory proof; providing

(a) Such disease develops or first manifests itself during a period while such member is an active member of such department; and

(b) Said member, upon entering said volunteer fire service, has or shall have undergone a medical examination, which examination failed or fails to disclose the presence of such disease or diseases; and

(c) Such disease develops or first manifests itself within 90 days from the event medically determined to be the cause thereof.

Any present member who did not undergo a medical examination upon entering said volunteer fire service, may undergo such examination within 180 days after the effective date of this act and in the event such examination does not disclose the presence of such disease or diseases, he shall thereafter be entitled to the benefits of this act.

L.1964, c. 291, s. 1. Amended by L.1965, c. 65, s. 1.