Neoplastic Effects of Vinyl Chloride in Mouse Lung Lower Doses and Short-Term Exposure, 1982

摘要

Effects of exposure to 1 to 600 parts per million (ppm) vinyl-chloride (75014) over 4 week periods were investigated in 220 male CDI-Charles-River-mice. At 12 weeks, 88.8 percent of those exposed to 600 ppm and 6.6 percent of those exposed to 300 ppm were found to have alveologenic tumors. In the 300 ppm group these were all single tumors whereas the 600 ppm group all had multiple tumors. A dose/response relationship was noted for tumor incidence as well as a dose related latency period. Dose and the recovery period after exposure seem to be the factors which determine the incidence of multiple alveologenic tumors. Larger tumors appeared to occur in the group receiving the higher dose levels and also in animals whose recovery period was longer. Spontaneous alveologenic tumors occurred in six animals. Neoplastic cells in both the tubulopapillary and adenomatous forms of the pulmonary tumors possessed all or some of the ultrastructural characteristics of type-II alveolar cells. Other tumors included hemangiosarcomas in the subcutaneous connective tissue of the ear and the liver.