1 00:00:00,960 --> 00:00:06,040 VOICE-OVER: Welcome to one of ConsExpo Web's online tutorials. 2 00:00:06,160 --> 00:00:08,720 Previous ConsExpo Web tutorials... 3 00:00:08,840 --> 00:00:12,440 have helped you perform simulations within the programme. 4 00:00:12,560 --> 00:00:16,200 You are now ready to explore the analytical options available to you... 5 00:00:16,320 --> 00:00:18,880 within ConsExpo Web. 6 00:00:19,000 --> 00:00:23,440 This video will give you guidance on how to perform probabilistic assessments... 7 00:00:23,560 --> 00:00:25,640 and sensitivity analyses... 8 00:00:25,760 --> 00:00:27,960 as well as teaching you about the different ways... 9 00:00:28,080 --> 00:00:31,440 to display the model results graphically. 10 00:00:31,560 --> 00:00:37,320 Performing a probabilistic analysis provides insight into the exposure distribution. 11 00:00:37,440 --> 00:00:41,640 It can show the range and ratio between high-end exposed subjects... 12 00:00:41,760 --> 00:00:46,360 or the exposure situation and median or average exposures. 13 00:00:46,480 --> 00:00:50,880 Performing probabilistic assessments starts with using distributional data... 14 00:00:51,000 --> 00:00:55,040 as inputs for a single parameter or multiple parameters. 15 00:00:55,160 --> 00:00:59,720 Care should be taken that the distributional data are not correlated. 16 00:00:59,840 --> 00:01:04,960 Such correlations result in unrealistic combinations of input data. 17 00:01:05,080 --> 00:01:08,120 When using distributional data for inputs... 18 00:01:08,240 --> 00:01:12,560 such as product amount and treated surface area, for example... 19 00:01:12,680 --> 00:01:16,120 you should make sure that the extremes of the distributional data... 20 00:01:16,240 --> 00:01:19,440 are still realistic when combined. 21 00:01:19,560 --> 00:01:23,920 For example, it is not possible to cover 100 square metres of wall... 22 00:01:24,040 --> 00:01:26,400 with one litre of paint. 23 00:01:26,520 --> 00:01:29,760 Make sure that such a combination cannot exist. 24 00:01:29,880 --> 00:01:35,040 Alternatively, use a fixed value for one of the parameters. 25 00:01:35,160 --> 00:01:39,400 You can add distributional data to a parameter in ConsExpo Web... 26 00:01:39,520 --> 00:01:43,920 by clicking on the button with the parabola symbol. 27 00:01:44,040 --> 00:01:46,440 This gives access to entry fields... 28 00:01:46,560 --> 00:01:50,040 where users can indicate the type of distribution to be used... 29 00:01:50,160 --> 00:01:52,800 and enter the required information. 30 00:01:52,920 --> 00:01:56,640 For example, if a uniform distribution is selected... 31 00:01:56,760 --> 00:02:00,880 the user must enter a lower and upper bound value. 32 00:02:01,000 --> 00:02:07,880 The other options are normal, log-normal, triangular and beta distributions. 33 00:02:08,760 --> 00:02:11,320 Probabilistic calculations are performed... 34 00:02:11,440 --> 00:02:14,920 using a one-dimensional Monte Carlo simulation... 35 00:02:15,040 --> 00:02:20,280 with a minimum of 1,000 and a maximum of 50,000 runs. 36 00:02:20,400 --> 00:02:24,560 It cannot discern variability from uncertainty. 37 00:02:24,680 --> 00:02:28,480 Here, the users themselves need to study the input data... 38 00:02:28,600 --> 00:02:31,880 to determine if the input and output distributions... 39 00:02:32,000 --> 00:02:37,160 are mainly the result of variability, uncertainty or both. 40 00:02:37,280 --> 00:02:41,280 If at least one input parameter contains distributional data... 41 00:02:41,400 --> 00:02:45,080 ConsExpo Web will run probabilistic calculations... 42 00:02:45,200 --> 00:02:50,240 and yield outputs containing the mean, median, standard deviation... 43 00:02:50,360 --> 00:02:57,360 as well as 95th and 99th percentile values of the exposure estimates. 44 00:02:57,480 --> 00:02:59,720 By clicking on the plot distribution... 45 00:02:59,840 --> 00:03:03,120 users can access both a histogram of the distribution... 46 00:03:03,240 --> 00:03:07,400 and a cumulative fraction plot, as shown in the graph. 47 00:03:07,520 --> 00:03:11,880 A link below the graph reads 'Show data table'. 48 00:03:12,000 --> 00:03:17,840 Clicking on that link shows a tabular representation of the histogram. 49 00:03:17,960 --> 00:03:22,720 The sensitivity analysis feature allows users to investigate which parameters... 50 00:03:22,840 --> 00:03:27,560 have a major or minor impact on the selected output. 51 00:03:27,680 --> 00:03:29,960 This way, users are able to evaluate... 52 00:03:30,080 --> 00:03:34,280 what parameter has the highest impact on the output. 53 00:03:35,280 --> 00:03:41,280 A sensitivity analysis can be performed after a simulation of the exposure. 54 00:03:41,400 --> 00:03:45,560 Users select the sensitivity settings for exposure route... 55 00:03:45,680 --> 00:03:48,200 input parameter and output... 56 00:03:48,320 --> 00:03:52,440 in the output window on the 'Sensitivity analysis' tab. 57 00:03:53,400 --> 00:03:55,760 Depending on the exposure route and output... 58 00:03:55,880 --> 00:03:59,200 users can select a variety of input parameters... 59 00:03:59,320 --> 00:04:02,920 to perform the sensitivity analysis. 60 00:04:03,040 --> 00:04:07,880 An input range is required for the parameter to be evaluated. 61 00:04:08,000 --> 00:04:09,680 The analysis shows the relation... 62 00:04:09,800 --> 00:04:14,040 between the input parameter for the specified range and the output. 63 00:04:14,160 --> 00:04:17,480 For example, a mean event concentration. 64 00:04:17,600 --> 00:04:21,000 In the case of an exponential relationship, for example... 65 00:04:21,120 --> 00:04:26,600 the impact of an input parameter change can either be significant or almost minimal... 66 00:04:26,720 --> 00:04:29,480 depending on the input range. 67 00:04:29,600 --> 00:04:33,160 The results of the sensitivity analysis can be exported... 68 00:04:33,280 --> 00:04:36,600 using the standard ConsExpo Web functionalities... 69 00:04:36,720 --> 00:04:40,640 for copying graphs and exporting data tables. 70 00:04:41,480 --> 00:04:47,160 We hope this tutorial has helped you to familiarise yourself with ConsExpo Web. 71 00:04:47,280 --> 00:04:49,960 Our support does not end here. 72 00:04:50,080 --> 00:04:53,360 Visit the ConsExpo website to find help pages... 73 00:04:53,480 --> 00:04:58,760 that provide information on ConsExpo Web and a user manual. 74 00:04:59,800 --> 00:05:05,520 You can also access the 'i' and '?' icons within the software... 75 00:05:05,640 --> 00:05:09,000 which are there to give you extra help when needed. 76 00:05:09,120 --> 00:05:11,640 If you still have questions or need assistance... 77 00:05:11,760 --> 00:05:19,360 please contact us at consexpo@rivm.nl.