If it is determined that an injured worker had, at the time of his or her injury, a preexisting disease and that such disease delays or prevents complete recovery from such injury, it shall be ascertained, as nearly as possible, the period over which the injury would have caused disability were it not for the diseased condition and the extent of permanent partial disability which the injury would have caused were it not for the disease, and compensation shall be awarded only therefor.
[ 1977 ex.s. c 350 § 49; 1971 ex.s. c 289 § 44; 1961 c 23 § 51.32.100. Prior: 1957 c 70 § 34; prior: 1949 c 219 § 1, part; 1947 c 246 § 1, part; 1929 c 132 § 2, part; 1927 c 310 § 4, part; 1923 c 136 § 2, part; 1919 c 131 § 4, part; 1917 c 28 § 1, part; 1913 c 148 § 1, part; 1911 c 74 § 5, part; Rem. Supp. 1949 § 7679, part.]
NOTES:
Effective dates—Severability—1971 ex.s. c 289: See RCW 51.98.060 and 51.98.070.