The European Food Safety Authority (EFSA), the UN Food and Agriculture Organization (FAO) and the World Health Organization (WHO) have published a joint guidance document to harmonise the use of the Total Diet Study (TDS) approach to estimate population exposure to chemicals from dietary sources.
The guidance proposes general principles for harmonising TDS methods internationally, which the organisations conclude is an effective tool to estimate dietary exposure to both harmful and beneficial chemicals across the overall diet and is best suited to calculating chronic exposure to substances and identifying trends. It provides principles for carrying out a study, including the planning phase, collection of results, exposure assessment calculation and communication on the results.
The TDS approach can be used for screening or for refined dietary exposure assessment. "Countries that already have established monitoring or surveillance programs can use the TDS approach as a more refined dietary exposure assessment tool, which includes analysis of a greater number of less pooled samples often separately covering different seasons and regions," EFSA says.
The guidance emphasises that global harmonisation of TDS studies would support scientific advice on potential risks in the food chain, and allow comparisons between different regions.