For any person participating in the Tennessee consolidated retirement system pursuant to §§ 8-35-101, 8-35-103, [former] 8-35-115 [repealed], 8-35-116, 8-35-122 [repealed], and 8-35-226, or as a state judge, county judge, county official, commissioner, county chair or attorney general whose membership in the retirement system is optional, and who thereafter elects to become a member, such election is irrevocable. Such member shall thereafter be subject to the same terms and conditions applicable to members whose participation is mandatory under this title as may be amended.