US EPA

Project will upgrade and expand the existing suite of BMD software models including the addition of a new multistage weibull time-to-tumor model for EPA's Benchmark Dose Software as well as well as provide user guides explaining how to use these models. Supporting materials: Reports describing development and testing of code.

Modified versions of quantal models will be provided that fit an alternative background parameter (additive to dose) and existing quantal models (with "independent" background parameter) will still be available to the user. Addition of time-to-tumor model will provide for better risk estimates then can be gotten from the quantal cancer or multistage model; applied when time-to-event data is available.