EPA and USDA participation in this cooperative agreement should not be construed as an endorsement of the LifeLineTM model at the exclusion of all other models. EPA encourages all efforts to develop models for performing aggregate and cumulative risk assessments. All models used to estimate aggregate and cumulative risk in support of pesticide tolerances will be judged on their own merits based on risk assessment principles independently developed by the Agency and available to all interested parties. The initial version of the LifeLineTM software estimates aggregate exposure to pesticides, and calculates distribution of dose rates for exposure periods ranging from one day to a lifetime. This background document presents a brief description of the conceptual basis of the initial version of the LifeLineTM software, and the modeling approaches employed by the software.
Emphasis is placed on key scientific and technical issues in modeling aggregate exposure.
The purpose of the session is to describe to the Scientific Advisory Panel the concepts and modeling approaches used by the LifeLineTM software to calculate aggregate exposure, and to solicit advice from the Panel at this stage of development of the software. The LifeLine TM Model combines information on daily activity and dietary patterns from well known surveys to evaluate daily exposures to an individual. And uses transition rules to specify how model input values are initially selected and when and how input values change over time.