Chronic exposure assessment

In a chronic exposure assessment, usual exposure is defined as the long-run average of daily exposure to a substance or group of substances by an individual. Usually, for an individual, dietary recall data are available on 2 (or more) consecutive days. We assume an equal number of days for each individual, unless specified differently in table for Individuals.

For a chronic exposure assessment the available data are used to calculate exposures per person-day (daily exposure):

$$y_{ij} = \frac{ \sum_{k=1}^{p} x_{ijk}c_{ijk}} {bw_{i}}$$

where $y_{ij}$, $x_{ijk}$ and $bw_{i}$ are defined as before but now concentrations of the substance found in food $k$ enter the model as the estimated mean substance concentration value $c_{k}$. Using the person-day exposures MCRA, provides a number of exposure models to calculate the distribution of usual exposure at the person level.

Model details

• Chronic exposure models
• Model-Then-Add
• Chronic exposure as a function of covariates
• Total Diet Study