Labor Code § 3208.1 “An injury may be either:

(a) ‘specific,’ occurring as the result of one incident or exposure which causes disability or need for medical treatment; or

(b) ‘cumulative,’ occurring as repetitive mentally or physically traumatic activities extending over a period of time, the combined effect of which causes any disability or need for medical treatment. The date of a cumulative injury shall be the date determined under Section 5412.”