Deterministic model dietary exposure

Dietary Exposure Potential Model (DEPM) Model and database system for deterministic dietary exposure Exposure from pesticides in diet combines food consumption and residue data USEPA (2003a)... 

There is a transition away from nsing a deterministic approach in which high end or upper bound point estimates and defanlt valnes are nsed towards nsing a probabilistic approach in distribntional models which incorporate complex data sets to build realistic estimates of exposure. While probabilistic dietary exposure assessments can now be carried out routinely for many pesticides, available occupational and residential exposure data sets are typically insufficiently robust. Work on developing newer exposure databases (e.g. ARTF, ORETF, AHETF and EUROPOEM II) and distributional use pattern data would facilitate this transition. The topic of probabilistic exposure assessment is covered in Chapter 8. 

Regardless of whether chronic or acute dietary exposure is being estimated, and regardless of whether the model used is deterministic or probabilistic, dietary exposure is a simple function of the amount of food consumed and the residue concentration on the food ... 

Deterministic models are used to estimate chronic, or long-term, dietary exposures. Although research is currently being conducted on the use of distributional techniques for chronic dietary risk assessment, the author is not aware of any working model at this time. 

When calculating chronic dietary exposure, the deterministic models use point values for both food consumption and residue concentration, thereby yielding a point estimate of dietary exposure. In the US, the initial chronic dietary exposure estimate is the Theoretical Maximum Residue Contribution (TMRC) and is analogous to the Theoretical Maximum Daily Intake (TMDI) used to estimate chronic dietary exposure in the EU. Both the TMRC and the TMDI are relatively conservative estimates of dietary expostire. The TMRC is calculated as the product of the mean consumption value and the US pesticide tolerance [6]. In the EU, the TMDI is calculated as the product of the mean consumption value and the Maximum Residue Limit (MRL) [7]. The objective of both calculations is essentially identical to calculate an estimate of the central tendency of the dietary exposure. Both calculated values use the central tendency dietary exposure estimate as the estimate of chronic (long-term) dietary exposure and calculate it using mean consumption data and the maximum residue permitted on the commodity. 

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