ment by using the scientific knowledge gained from major advances in developmental and molecular biology over the past 10-15 years. This study was undertaken with a public health goal of understanding mechanisms of developmental defects to improve our preventive actions. The Committee on Developmental Toxicology was formed to evaluate the current understanding of the mechanisms of action of developmental toxicants and to make recommendations for the improvement of developmental toxicity risk assessment. The specific tasks of the committee were as follows: (1) evaluate the evidence supporting hypothesized mechanisms of developmental toxicity; (2) evaluate the state of the science on testing for mechanisms of developmental effects; (3) evaluate how that information can be used to improve qualitative and quantitative risk assessment for developmental effects; and (4) develop recommendations for future research in developmental toxicology and developmental biology; focus on those areas most likely to assist in assessing risk for developmental defects.
The project was conducted in two phases. The first phase consisted of a symposium entitled “New Approaches for Assessing the Etiology and Risks of Developmental Abnormalities from Chemical Exposure,” which was held December 11-12, 1995, in Washington, D.C. The proceedings from that symposium were published in Reproductive Toxicology1 and were used as background information for the second phase of the project. In the second phase, a multidisciplinary committee with expertise in developmental biology and developmental toxicology was asked to address the tasks described above.
In this report, the committee documents many recent advances in research in the areas of developmental biology and genomics. These extraordinary advances are significant for developmental toxicology and risk assessment because they present opportunities to improve substantially the detection of developmental toxicants and to elucidate the mechanisms by which toxicants induce developmental defects. The committee makes recommendations for incorporating the new scientific information with existing experimental methods to improve the understanding of the role of environmental agents in human developmental disorders.
In approaching its charge, the committee evaluated current methods used to assess risk for developmental defects. Specifically, the committee reviewed the types of data commonly used to evaluate chemicals for potential developmental toxicity and explored the limitations of the risk assessment process. The limitations include the lack of information on the mechanisms of action of chemicals