Multi-Disciplined Approach to the Safety Evaluation of Chemicals with Special Emphasis on Carcinogenic Toxicity. The ED01 Study

摘要

As the science of toxicology continued to develop during the 1960s and 1970s, it became evident that many questions needed to be answered regarding biological responses to chemical carcinogens. The lack of information about the nature of the dose-response relationships at very low dose rates for a carcinogen and the significance of its relationships to the requirements of the Delaney Amendment became one of the prime factors that needed to be addressed. A firm understanding of the dose response relationship of a carcinogen was needed before rational approaches could be made to downward extrapolations from the high test levels that are used in carcinogenesis studies. The mice were allocated to the study over a 9 month period and the lifespan group was terminated after 33 months of study; therefore, the animal exposure period required approximately 42 months to complete. Dose levels of 0, 30, 35, 45, 60, 75, 100 and 150 ppm were used.