Summary of the workshop on the power of aggregated toxicity data.

In this workshop, ongoing federal agency (i.e., EPA, ATSDR, FDA, NIEHS and others) projects that employ toxicity data were discussed, as well as the possibility of innovative approaches for use of existing and new sources of information in risk assessment. Quantitative risk assessment relies upon having detailed exposure-response data, such as number of animals and incidence by exposure group in dichotomous measures and values by individual animal for continuous measures; this level of detail is often not reported in peer-reviewed studies. Additionally, biologically-based models (e.g., PBPK) are useful in risk assessment but require knowledge or collection of parameters as inputs (both chemical-specific and more general physiological parameters), and this information is not always readily available. Structure activity relationship information is also being called upon to help fill in knowledge gaps about specific chemicals where data from related chemicals may be available. Some existing data sources have been developed by various agencies for specific applications, such as those mentioned, and advantage should be taken of those existing resources; however, a great deal more is possible. The purpose of this workshop was to gather together many of the stakeholders using and developing shared toxicological information, determine the potential for greater collaboration, and determine the best course to facilitate the further development of joint information resources. A number of recommendations (development of a consensus toxicological review format, standardization of terminology and data sharing formats, and agreement on primary data elements) and topics for additional discussion were the major products of this workshop.