Global net on consumer exposure modelling : proceedings of the Workshop no. 3 on exposure modelling framework issues, 22 June 2005, Intra (Italy)

The general rationale of the Global Net on "Consumer Exposure Modelling" Workshop no. 3 on "Exposure Modelling Framework Issues" took place on 22 June 2005 in Intra (Italy) was: The Workshop focus was on predictive consumer exposure models. Exposure modelling framework issues cover consumer exposure model applications, model requirements and harmonisation. Based on exposure model applications in mostly regulatory framework, requirements are set for the transparency of the models and precision of the model predictions, and also for the availability and quality of input data for the exposure models. Main focus of model harmonisation is not the models 'per se' but, model documentation, terminology, validation and input data. The present workshop tried to provide guidance for consumer exposure model selection and application, discussed requirements for model documentation, validation and application input data, and the potentials and benefits of model harmonisation in line with the recommendations of WHO IPCS Harmonization Project, Exposure Assessment Working Group. The purpose of this workshop was to: 1. review and discuss the needs and application of consumer exposure models. 2. discuss and identify the requirements for the models and model documentation. 3. discuss the data requirements of the models and to identify the sources for these data. 4. make recommendations for model harmonisation, future consumer exposure research and model development. The outcome of the Workshop is summarized below: In the Global CEM Net Workshop 3 on "Exposure Modelling Framework Issues", it was discussed and agreed that the harmonized consumer exposure modelling framework should be developed in a way that identifies model information needs and the supporting structures necessary to deliver and manage these. Several 'ideal' visions developed within the workshop that ultimately foresaw an open modelling universe capable of describing person and/or event-oriented exposures through life with Bayesian integration of multiple scenarios. It was reinforced that the utility of concepts, such as the Intake Fraction, can calibrate whether the models actually ask the right question or focus on the right question. The extent to which models rely on differing levels of data (their 'data intensity') and their relationship to data sources (databases) was identified as an area requiring more attention e.g., an evaluation of the adequacy of existing databases for key determinants such as consumer product contact rates, use frequency, etc.