To establish eligibility for compensation under this subpart, a claimant or eligible surviving beneficiary of a claimant must establish each of the following:
(a) The claimant was employed as an ore transporter in a specified state;
(b) The claimant was so employed for at least one year (12 consecutive or cumulative months) during the period beginning on January 1, 1942, and ending on December 31, 1971; and
(c) The claimant contracted primary lung cancer, a nonmalignant respiratory disease, primary renal cancer, or chronic renal disease (including nephritis and kidney tubal tissue injury) following at least one year of such employment.