Exploring parameter uncertainty and seasonal variability for human health intake fractions in life cycle assessment

Abstract

The intake fraction (iF) is the fraction of an emitted mass of chemical that is ultimately taken in by an entire population and it is used as an indicator of human health potential impacts related to environmental chemical persistence and bioaccumulation in the food chain. In chemical screening applications, the iF can be predicted using multimedia and multipathway fate and exposure models. However, it yields uncertainty from parameter uncertainty and variability and model and scenario uncertainty. The objectives of this study are to i) carry an importance analysis to determine the parameters that contribute the most to overall iF uncertainty and identify where to focus efforts to better define these parameters and, by the same token, reduce the overall uncertainty of the model outcome and ii) perform a seasonal scenario analysis on the most important parameters to determine the relevance of including seasonal differentiation when assessing iFs.