Certain impairments of health; presumption

§ 363-d. Certain impairments of health; presumption. Notwithstanding any other provisions of this chapter to the contrary, any (i) melanoma or (ii) condition of cancer affecting the lymphatic, digestive, hematological, urinary, neurological, breast, reproductive, endocrine/thyroid or prostate systems, resulting in total or partial disability or death to a paid firefighter, who successfully passed a physical examination on entry into firefighter service, which examination failed to reveal any evidence of such melanoma or condition, shall be presumptive evidence that, unless the contrary be proven by competent evidence, such disability or death (a) was caused by the natural and proximate result of an accident, not caused by such firefighter's own willful negligence, and (b) was sustained in the performance and discharge of duty. The provisions of this section shall remain in full force and effect pursuant to section four hundred eighty of this chapter.