Risks

Risks (health impacts) are defined as a function of exposure and hazard characterisation at a chosen biological level (external or internal). Risk metrics are margins of exposure (MOE) or hazard indices (HI) or more generalised MOE or HI distributions.

This module has as primary entities: Substances Effects Populations

Output of this module is used by: Single value risks

Calculation of risks

Risk (health impact) is quantified as exposure relative to hazard characterisation, which in MCRA is called a hazard index (HI) for any type of inputs, or as hazard characterisation relative to exposure, which in MCRA is called a margin of exposure (MOE) for any type of inputs. Exposures or hazards can be single values or distributions, the risk metric is a distribution if at least one of the inputs is a distribution (if both are single values, see the module Single value risks). Risk metrics are valid for a specific biological level (external or internal at a specific organ).

Inputs used: Dietary exposures Exposures Hazard characterisations Human monitoring analysis Relative potency factors

Settings used

Settings and Tiers

Risks are expressed as distribution of margin of exposure or hazard index. The distribution is summarised by percentiles, and by the probability to exceed the specified threshold value (e.g. 1 or 100). The hazard vs. exposure plot compares the exposures and the hazard characterisation for individuals or individual-days in a population. Exposures, hazard characterisations and risks can be acute or chronic. The default unit for exposures and hazard characterisations is \(\mu g/kgBW/day\), but this can be changed by choosing non-default units for consumptions, concentrations and/or body weight.

By using probabilistic tiers for both exposure and hazard characterisation, the calculated MOE distribution is equal to the Integrated Margin Of Exposure (IMOE) distribution, as described for the Integrated Probabilistic Risk Assessment (IPRA) approach in van der Voet and Slob (2007) and van der Voet et al. (2009).