In Fiore v. Consolidated Freightways, 140 N.J. 452, 659 A.2d 436 (1995), the Court discussed at length the requirements of proof under this statute in the context of occupational heart disease. Since leukemia, like heart disease, may also be caused by natural, non-occupational circumstances, we believe Fiore provides the relevant legal standards for this case. Accordingly, petitioner was required to satisfy the three requirements described in Fiore: To satisfy the standard, a petitioner claiming occupational heart disease must fulfill three requirements. First, as section 31 provides, the petitioner must show that the disease is due in "a material degree" to causes "arising out of the workplace and that are or were characteristic of or peculiar to a particular trade, occupation, process or place of employment." Second, the petitioner must prove "by suitable medical evidence that the employment exposure did indeed cause or contribute to the disease--especially in the light of the competing claim of the smoking to be the causal agent." We doubt that the Legislature, when enacting section 7.2, contemplated that employers should compensate employees for coronary disease caused substantially by a lifetime of smoking or other personal-risk factors and immaterially by occupational exposure. Thus, a petitioner asserting an occupational heart-disease claim must show that the work exposure exceeds the exposure caused by the petitioner's personal-risk factors. Third, the petitioner must show that the employment exposure substantially contributed to the development of the disease. An occupational exposure substantially contributes to the development of coronary-artery disease when the exposure is so significant that, without the exposure, the disease would not have developed to the extent that it caused the disability resulting in the claimant's incapacity to work. Id. at 472-73, 659 A.2d 436.