Overview of the procedures currently used at EFSA for the assessment of dietary exposure to different chemical substances
The health impact of chemical hazards in food is estimated by comparing dietary exposure to toxicological levels of concern. Exposure assessments combine data on concentrations of a chemical substance present in food with the quantity of those foods consumed. Some guidance documents have been produced over the last ten years at international level that describe the current state-of-the-art of methodologies for dietary exposure assessment with little harmonisation across disciplines. A number of different methods exist ranging from quick worst-case estimations to refined methods aimed at assessing actual exposure. As the accuracy of dietary exposure assessments increases, the cost of undertaking the assessments also increases. An EFSA opinion affirms that exposure assessment has to be conservative and that a stepwise approach should be used commensurate with specific needs. However, some of the methodological differences among Panels are not fully justified by the specific requirements of the class of substances under evaluation. There is potential to further harmonise the way exposure is estimated with the availability of more refined and accurate food consumption information in EFSA. To improve chemical concentration data statistically based sampling frames could be developed in collaboration with Member States for their monitoring programs and a coordinated approach of using data from Total Diet Studies could be promoted. There is a need to further harmonise the screening methods used across Panels and the modelling of high consumers for calculating chronic exposure using individual data and summary statistics. It is suggested to always consider children, and in particular toddlers, since they are often at the high end when calculating exposure. It is considered useful to explore the use of probabilistic dietary exposure assessments on a more routine basis in case refinements are needed, of cumulative exposure assessment for all metabolically or structurally related chemical substances, and to test statistical methodologies for the estimation of usual intake from short-term dietary data.