HBM analysis settings
Calculation settings
| Name | Type | Description |
|---|---|---|
Seed for pseudo-random number generator
|
Numeric |
A value of 0 will use a pseudo-random seed in each run, a value > 0 will provide the same results in a repeated run. |
Exposure type
|
ExposureType | The type of exposure considered in the assessment; acute (short term) or chronic (long-term). |
Multiple substances analysis
|
Boolean |
Specifies whether the assessment involves multiple substances. |
Compute cumulative exposures
|
Boolean |
Specifies whether the assessment involves multiple substances and results should be cumulated over all substances. |
Report consumptions and exposures per individual instead of per kg body weight
|
Boolean |
Specifies whether body weights should be ignored and consumptions and exposures should be expressed per individual. Otherwise, the consumptions and exposures are per kg body weight. |
Sampling method
|
AlphaNumeric |
The sampling method that should be included in the action. |
Censored values handling method (also used as fallback for censored lognormal approach)
|
NonDetectsHandlingMethod | Method for dealing with censored value samples in human monitoring data. Note that this method is also used as a fallback when fitting a censored lognormal model to the concentration data fails. |
Fraction for censored value replacement
|
Numeric |
Factor used for replacing the censored value. |
Imputation method for non detect values
|
NonDetectImputationMethod | Imputation method for non detect values: replace nondetects based on by f*LOD/LOQ) or from left tail censored lognormal distribution. |
Missing value imputation method
|
MissingValueImputationMethod | Imputation method for missing values: 1) By zero, 2) Impute from data, 3) No missing value imputation |
Apply kinetic conversions
|
Boolean |
Convert substance concentrations from other biological matrices using kinetic conversion models. The substances for conversion are designated within the kinetic models module. Substance conversion proves valuable when a biomarker was not directly measured for a matrix of interest. |
Convert to single exposure surface (biological matrix or external route)
|
Boolean |
Convert all substance concentrations from other biological matrices to the same target biological matrix. This conversion is applied when the number of substances measured on the target biological matrix is limited. Substances measured on other matrices can be converted using kinetic conversion models. |
Target level
|
TargetLevelType | Select whether the assessment is at the level of external dose, internal (target) concentration or internal (systemic) dose. For an aggregate assessment, combining dietary and nondietary exposures, the target level is always internal concentration or internal (systemic) dose. When only dietary exposures are available, the target level is optional and may be an external (administered) dose, an internal (tissue) concentration or an internal (absorbed) dose. |
Specify the minimum percentage of non-missing values (%)
|
Numeric |
Specify the minimum percentage of non-missing values required for imputation. No imputation is done when the percentage of non-missing values in the data is smaller than the specified percentage. |
Standardise blood concentrations for lipid-soluble substances
|
Boolean |
Standardise blood concentrations for lipid-soluble substances: 1) Standardise by total lipid measured via gravimetric analysis, 2) Standardise by total lipid measured via enzymatic summation, 3) Standardise by derived total lipid content of Triglycerides/Cholesterol (Bernert et al. 2007). |
Specify the standardisation method of blood concentrations for lipid-soluble substances
|
StandardiseBloodMethod | Specify the standardisation method of blood concentrations for lipid-soluble substances. |
Subset selection: exclude substances from lipid standardisation
|
Boolean |
Select this option to exclude one or more lipid-soluble substances from standardisation. |
Select substances to exclude from lipid standardisation
|
AlphaNumeric |
The selected (lipid-soluble) substances will be excluded from lipid standardisation. |
Normalise or standardise urine concentrations for specific gravity or creatinine
|
Boolean |
Normalise or standardise urine concentrations for specific gravity or creatinine: 1) Normalise by specific gravity, 2) Standardise by creatinine concentration. |
Specify the normalisation/standardisation method of urine concentrations for specific gravity or creatinine
|
StandardiseUrineMethod | Specify the normalisation/standardisation method of urine concentrations for specific gravity or creatinine. |
Subset selection: exclude substances from urine normalisation/standardisation
|
Boolean |
Select this option to exclude one or more substances from normalization for specific gravity or creatinine standardisation. |
Select the substances to exclude from urine normalisation/standardisation
|
AlphaNumeric |
The selected substances will be excluded from urine normalization/standardisation. |
Substance weighting in mixtures
|
ExposureApproachType | Risk based: exposures in equivalents of the reference substance; standardised: standardised exposures per substance have variance 1; or unweighted exposures: RPFs are equal to 1. |
Perform MCR analysis
|
Boolean |
Perform a Maximum Cumulative Ratio (MCR) analysis to determine co-exposure between substances. |
Display ratio total exposure/ maximum (in MCR plot)
|
Numeric |
For MCR plot: specify ratio total exposure/ maximum for individual(day) exposures . |
Show tail percentiles (MCR plot) for:
|
Numeric |
Give specific percentiles of exposure distribution (%), e.g. 97.5 99 (space separated). |
Set minimum percentage contribution per substance to the tail exposure (MCR plot)
|
Numeric |
Set minimum percentage contribution per substance to the tail exposure. |
Cutoff MCR
|
Numeric |
For selection of individual(day) exposures with maximum cumulative ratio (MCR = total exposure/maximum) above the cutoff. |
Cutoff percentage in population ranked on total exposure
|
Numeric |
For selection of individual(day) exposures above the cutoff percentage in the set of individual(day)s ranked on total exposure. |
Apply exposure biomarker conversions
|
Boolean |
Use this option to translate HBM concentrations derived from measured substances (biomarkers) to concentrations of other substances. This can be usefull when the measured substance is a combination of multiple substances, e.g., to translate measured total arsenic (t-As) to toxicologically relevant arsenic (TRA). This option can also be used to translate between different expression types (e.g., from measured urine concentration to urine concentrations standardized for specific gravity), but not for translation between different biological matrices. |
Target biological matrix
|
BiologicalMatrix | The target biological matrix (internal compartment) for which exposures are computed. |
Specific gravity conversion factor
|
Numeric |
A specific gravity adjustment is applied by multiplying a creatinine adjusted concentration with a factor (default 1.48 for adults 18 - 68 year). |
Kinetic conversion method
|
KineticConversionMethodType | Method for kinetic conversion. Use kinetic conversion factor models, PBK models, or a combination of both to convert substance concentrations from other biological matrices. |
Exposure events and dose generation method
|
ExposureEventsGenerationMethod | Generates doses and events for PBK model |
Number of simulated days
|
Numeric |
The total duration (in days) of the PBK model simulations. |
Number of initial days skipped
|
Numeric |
The initial period (or burn-in period, specified in days) that needs to be skipped when calculating the steady-state or peak internal exposures from the simulated time series. |
Use PBK model parameter variability
|
Boolean |
When specified, use parameter variability. |
Number of events per day for the DERMAL dose
|
Numeric |
The daily dose is administered in equal portions (dose / number of events) per event. |
Number of events per day for the INHALATION dose
|
Numeric |
The daily dose is administered in equal portions (dose / number of events) per event. |
Number of events per day for the ORAL dose
|
Numeric |
The daily dose is administered in equal portions (dose / number of events) per event. |
Specify the hours (events).
|
Numeric |
Specify the hours on which exposure events are simulated. Allowed numbers are 1, 2, 3, 4,…, 24 separated by spaces. |
Specify event timings
|
Boolean |
If checked, a specific sequence of hours on a day can be specified on which exposure events are simulated. Otherwise the events are derived based on the number of exposure events per day. |
PBK simulation method
|
PbkSimulationMethod | Specifies in which mode to run the PBK model |
Expected life time in years
|
Numeric |
The total expected lifetime (in years) of the PBK model. |
Use bodyweight adjusted exposures
|
Boolean |
Use bodyweight adjusted exposures in PBK model simulations. |
PBK output resolution time unit
|
PbkModelOutputResolutionTimeUnit | Time unit in which the output resolution of PBK model simulations is specified. |
PBK output resolution step size
|
Numeric |
PBK model simulation output step size/length, specifying the evaluation resolution in terms of the step length (period) between two evaluations. For example, a step length of 12 with a resolution time unit of hours is interpreted as every 12 hours. |
Output settings
| Name | Type | Description |
|---|---|---|
Exclude privacy sensitive data from outputs
|
Boolean |
Use this setting to not report the parts of the results (i.e., figures, tables, or sections) that are marked as (potentially) privacy sensitive. |
Lower percentage for variability (%)
|
Numeric |
The default value of 25% may be overruled. |
Upper percentage for variability (%)
|
Numeric |
The default value of 75% may be overruled. |
Percentage for upper tail
|
Numeric |
Gives detailed output for this upper percentage of the exposure distribution. |
Store simulated individual day exposures
|
Boolean |
Store the simulated individual day exposures. If unchecked, no additional output will be generated. If checked, the output will contain an additional section with the simulated individual day exposures. |
Uncertainty settings
| Name | Type | Description |
|---|---|---|
Lower uncertainty limit (%)
|
Numeric |
Percentage lower bound, e.g. 2.5%. |
Upper uncertainty limit (%)
|
Numeric |
Percentage upper bound, e.g. 97.5%. |
Monte Carlo iterations per uncertainty run
|
Numeric |
Specifies the number of Monte Carlo iterations in each uncertainty cycle (default 10,000). |
Resample HBM individuals
|
Boolean |
HBM individual data are resampled from the original database using the bootstrap methodology (Efron 1979, Efron & Tibshirani 1993). |