A miner employed at an underground coal mine or at a surface work area of an underground coal mine who has exercised the option under the old section 203b program (36 FR 20601, October 27, 1971), or under 90.3 (Part 90 option; notice of eligibility; exercise of option) of this part to work in an area of a mine where the average concentration of respirable dust in the mine atmosphere during each shift to which that miner is exposed is continuously maintained at or below 1.0 mg/m₃of air, and who has not waived these rights.