Section 85A.12 - Disablement or death following exposure - limitations1. An employer shall not be liable for any compensation for an occupational disease unless such disease shall be due to the nature of an employment in which the hazards of such disease actually exist, and which hazards are characteristic thereof and peculiar to the trade, occupation, process, or employment, and such disease actually arises out of the employment, and unless disablement or death results within three years in case of pneumoconiosis, or within one year in case of any other occupational disease, after the last injurious exposure to such disease in such employment, or in case of death, unless death follows continuous disability from such disease commencing within the period above limited for which compensation has been paid or awarded or timely claim made as provided by this chapter and results within seven years after such exposure.2. In any case where disablement or death was caused by latent or delayed pathological conditions, blood, or other tissue changes or malignancies due to occupational exposure to X rays, radium, radioactive substances or machines, or ionizing radiation, the employer shall not be liable for any compensation unless claim is filed within ninety days after disablement or death or after the employee had knowledge or in the exercise of reasonable diligence should have known the disablement was caused by overexposure to ionizing radiation or radioactive substances, and its relation to employment.C50, 54, 58, 62, 66, 71, 73, 75, 77, 79, 81, §85A.12