S.C. Code Ann. § 42-11-90: Amount of compensation when noncompensable cause or disease affects occupational disease.

When an occupational disease prolongs, accelerates or aggravates or is prolonged, accelerated or aggravated by any other cause or infirmity not otherwise compensable, the compensation payable for disability or death shall be limited to the disability which would have resulted solely from the occupational disease if there were no other such cause or infirmity and shall be computed by the proportion which the disability from occupational disease bears to the entire disability.