(1) In this Act:
"disease" means:
(a) an ailment suffered by an employee; or
(b) an aggravation of such an ailment;
that was contributed to, to a significant degree, by the employee's employment by the Commonwealth.
(2) In determining whether an ailment or aggravation was contributed to, to a significant degree, by an employee's employment by the Commonwealth, the following matters may be taken into account:
(a) the duration of the employment;
(b) the nature of, and particular tasks involved in, the employment;
(c) any predisposition of the employee to the ailment or aggravation;
(d) any activities of the employee not related to the employment;
(e) any other matters affecting the employee's health.
This subsection does not limit the matters that may be taken into account.
(3) In this Act:
"significant degree" means a degree that is substantially more than material.