VOICE-OVER: Welcome to one of ConsExpo Web's online tutorials.
Previous ConsExpo Web tutorials...
have helped you perform simulations within the programme.
You are now ready to explore the analytical options available to you...
within ConsExpo Web.
This video will give you guidance on how to perform probabilistic assessments...
and sensitivity analyses...
as well as teaching you about the different ways...
to display the model results graphically.
Performing a probabilistic analysis provides insight into the exposure distribution.
It can show the range and ratio between high-end exposed subjects...
or the exposure situation and median or average exposures.
Performing probabilistic assessments starts with using distributional data...
as inputs for a single parameter or multiple parameters.
Care should be taken that the distributional data are not correlated.
Such correlations result in unrealistic combinations of input data.
When using distributional data for inputs...
such as product amount and treated surface area, for example...
you should make sure that the extremes of the distributional data...
are still realistic when combined.
For example, it is not possible to cover 100 square metres of wall...
with one litre of paint.
Make sure that such a combination cannot exist.
Alternatively, use a fixed value for one of the parameters.
You can add distributional data to a parameter in ConsExpo Web...
by clicking on the button with the parabola symbol.
This gives access to entry fields...
where users can indicate the type of distribution to be used...
and enter the required information.
For example, if a uniform distribution is selected...
the user must enter a lower and upper bound value.
The other options are normal, log-normal, triangular and beta distributions.
Probabilistic calculations are performed...
using a one-dimensional Monte Carlo simulation...
with a minimum of 1,000 and a maximum of 50,000 runs.
It cannot discern variability from uncertainty.
Here, the users themselves need to study the input data...
to determine if the input and output distributions...
are mainly the result of variability, uncertainty or both.
If at least one input parameter contains distributional data...
ConsExpo Web will run probabilistic calculations...
and yield outputs containing the mean, median, standard deviation...
as well as 95th and 99th percentile values of the exposure estimates.
By clicking on the plot distribution...
users can access both a histogram of the distribution...
and a cumulative fraction plot, as shown in the graph.
A link below the graph reads 'Show data table'.
Clicking on that link shows a tabular representation of the histogram.
The sensitivity analysis feature allows users to investigate which parameters...
have a major or minor impact on the selected output.
This way, users are able to evaluate...
what parameter has the highest impact on the output.
A sensitivity analysis can be performed after a simulation of the exposure.
Users select the sensitivity settings for exposure route...
input parameter and output...
in the output window on the 'Sensitivity analysis' tab.
Depending on the exposure route and output...
users can select a variety of input parameters...
to perform the sensitivity analysis.
An input range is required for the parameter to be evaluated.
The analysis shows the relation...
between the input parameter for the specified range and the output.
For example, a mean event concentration.
In the case of an exponential relationship, for example...
the impact of an input parameter change can either be significant or almost minimal...
depending on the input range.
The results of the sensitivity analysis can be exported...
using the standard ConsExpo Web functionalities...
for copying graphs and exporting data tables.
We hope this tutorial has helped you to familiarise yourself with ConsExpo Web.
Our support does not end here.
Visit the ConsExpo website to find help pages...
that provide information on ConsExpo Web and a user manual.
You can also access the 'i' and '?' icons within the software...
which are there to give you extra help when needed.
If you still have questions or need assistance...
please contact us at consexpo@rivm.nl.