Some recent advances in modelling dietary exposure to ochratoxin A

One of the key questions when assessing the exposure to contaminants is the choice of the method and the impact of this choice on the result to be compared with the toxicological reference value. This problem is particularly significant in the case of ochratoxin A (OTA) for which the use of crude estimates can provide results close to the current provisional tolerable weekly intake (PTWI). This paper compares different exposure assessment models for OTA using the same data set for food consumption (i.e. French INCA survey 1999) for the same groups of the population (i.e. adults excluding under-reporters and children 3-14 years-old) but with various ways of handling the occurrence of OTA in food. The consumption and contamination data were combined through 11 different scenarios based on parametric and non-parametric modelling and on the use of analytical results obtained on raw commodities or on foodstuffs ready-to-eat. In order to assess exposure to OTA using data on consumption of processed and composite foods it was necessary to use recipe information in order to utilize available contamination data which only exists for raw materials. The impact of such an adjustment appears to be essential to avoid an overestimation of the exposure. The impact of the other assumptions and the choice of mathematical models influence the results less but should be considered and detailed carefully in future dietary exposure assessments.