; and (2) served on active duty in a military occupational specialty or career field with a primary responsibility for firefighting or damage control for at least five years in the aggregate. (d) Degree of disability The degree of disability specified in this subsection is 10 percent or more. (e) Period The period specified in this subsection is within 15 years of the date on which the veteran separated from active military, naval, or air service. (f) Effective date of award The effective date of an award under this section shall be determined in accordance with section 5110 of this title. . (b) Clerical amendment The table of sections at the beginning of such chapter is amended by inserting after the item relating to section 1120 the following new item: 1120A. Presumptions of service connection for diseases associated with firefighting. .