Cumulative dietary exposure assessment of pesticides that have chronic effects on the thyroid using MCRA software

In the context of the second framework partnership agreement between the National Institute for Public Health and the Environment of the Netherlands (RIVM) and the European Food Safety Authority (EFSA) chronic cumulative exposure assessments were performed for two cumulative assessment groups (CAGs) of pesticides that affect the thyroid: pesticides associated with hypertrophy, hyperplasia and neoplasia of C-cells (TCP, 18 active substances) and pesticide associated with hypothyroidism (TCF, 124 active substances).The exposure assessments used monitoring data collected by Member States under their official pesticide monitoring programmes in 2014, 2015 and 2016 and individual food consumption data from ten populations of consumers from different countries and from different age groups. Exposure estimates were obtained for each group of pesticides by means of a 2-dimensional Monte Carlo simulation, which was implemented in the Monte Carlo Risk Assessment (MCRA) software. The scope of the assessment and the parameters to be used for cumulative exposure assessment were discussed and agreed by the Standing Committee on Plants, Animals, Food and Feed (SC PAFF). Based on those discussions, a very conservative tier I modelling approach and a refined, but still conservative tier II modelling approach were used. In these assessments, common risk assessment practice was followed and the cumulative exposure was calculated as the total margin of exposure (MOET) at the 50th, 90th, 95th, 99th and 99.9th percentiles of the exposure distribution.Four sensitivity analyses were performed to better understand the uncertainties such as the replacements of non-detects in the monitoring data and the availability of processing factors. The exposure estimates obtained in this report are used in EFSA's scientific report on the cumulative dietary risk characterisation of pesticides that have chronic effects on the thyroid.