Non-dietary exposures data formats
Non-dietary exposures may be specified for multiple routes of exposure (dermal, oral and inhalation), for multiple substances, and for multiple exposure sources. Also, they can be provided as single deterministic exposure levels or as probabilistic exposure estimates and it is possible, but not mandatory, to specify uncertainty. The non-dietary exposures may be short term (acute) or longer term averages (chronic), and the user must ensure to supply appropriate non-dietary data for the type of exposure assessment of interest. For chronic assessments this means the non-dietary exposure is averaged over an appropriate time interval.
Non-dietary exposures are defined by non-dietary surveys to which dietary exposures are linked. For these surveys, individual properties can be specified to define non-dietary exposures for particular sub-groups of the population (e.g., specific age groups, or a specific gender). For each non-dietary survey a percentage of the target population that is not exposed from this source can be specified by means of a percentage. Uncertainty about non-dietary exposures can be specified by specifying multiple records for each individual in an additional table.
The use of multiple surveys can be used when multiple sources are relevant. For example, when modelling individuals taking part in various activities involving pesticide use or incidental exposures as a resident. Each non-dietary source is characterised in a particular user-selected or user-supplied non-dietary survey. By default, exposures from separate non-dietary surveys (sources) are considered to be independent events, but as explained below correlations between substances and/or activity types per individual can be represented if generated prior to uploading to MCRA. When including multiple non-dietary surveys it is possible to supply some with uncertainty/variability and others without variability/uncertainty according to the requirements and data availability.
When the user supplies probabilistic non-dietary exposure estimates (i.e., there is a distribution for the non-dietary exposure rather than a single nominal value), then this information will be propagated as part of the exposure assessment. Distributions may be included to represent variability, uncertainty or both, and in these cases the aggregate exposure estimates are reported with variability and/or uncertainty as appropriate. Multiple (uncertain) values from the non-dietary exposure distribution may be supplied per individual and per substance.
Exposures within a non-dietary survey may be expressed as correlated or independent for the different substances. For example, if the exposures are a mixture of substances in a known ratio (e.g. from a specific tank mix of pesticides), or if exposure to one substance strongly implies that exposure to another is likely, these relationships may be included in the non-dietary data supplied by the user. Inference for the matched-case scenario with uncertainty analysis can use exposure sets. These are specific sets of exposures defined for each individual and in any uncertainty iteration an individual will receive exactly one of the exposure sets for that individual. Alternatively, independence may be represented by generating sets drawn from independent distributions when generating these tables.
Non-dietary exposure data is provided per non-dietary surveys. Each non-survey has some general information about the exposed population and the origin of the non-dietary exposure data. Also, a number of properties, such as specific age groups, can be specified for a survey. To each non-dietary survey, non-dietary exposures can be linked. These exposures may originate from dermal, oral and/or inhalatory exposure routes.
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Non-dietary surveys
This table provides detail about non-dietary surveys (source of non-dietary exposure): description, location, date and unit of exposure).
Accepted table names: NonDietarySurveys, NonDietarySurvey.
| Name | Type | Description | Aliases | Required |
|---|---|---|---|---|
idNonDietarySurvey |
AlphaNumeric (50) |
The survey identification number. |
idNonDietarySurvey |
Yes |
Name |
AlphaNumeric (100) |
Name of the non-dietary survey. |
Name |
No |
Description |
AlphaNumeric (200) |
Description of non-dietary survey. |
Description |
No |
Location |
AlphaNumeric (50) |
The location of survey. |
Location |
No |
Date |
DateTime |
The date of survey. |
Date |
No |
NonDietaryIntakeUnit |
ExternalExposureUnit | The unit of the non-dietary exposure. |
Unit, NonDietaryIntakeUnit, NonDietaryExposureUnit |
Yes |
PercentageZeros |
Numeric |
The proportion zeros, specified as a percentage (%). |
PercentageZeros |
No |
idPopulation |
AlphaNumeric (50) |
Unique identification code of the population. |
IdPopulation, PopulationId |
No |
Non-dietary survey properties
This table specifies demographic properties that apply to the individuals in the surveys. These properties could be used to link the individuals of a non-dietary survey with individuals from dietary surveys. That is, if demographic criteria are defined, only those individuals in the dietary survey that meet these criteria will be assigned non-dietary exposures. This table is not relevant when matching is switched on (i.e., when individuals are matched based on individual id).
Accepted table names: NonDietarySurveyProperties, NonDietarySurveyProperty.
| Name | Type | Description | Aliases | Required |
|---|---|---|---|---|
IndividualPropertyName |
AlphaNumeric (50) |
Name of demographic criteria for non-dietary exposures in a particular survey e.g. age, gender, height (must correspond to a column name in Individuals table). |
IndividualPropertyName |
Yes |
idNonDietarySurvey |
AlphaNumeric (50) |
The code of survey (must correspond to values in id column of the non-dietary surveys table). |
idNonDietarySurvey |
Yes |
IndividualPropertyTextValue |
AlphaNumeric (50) |
Text value of the property e.g. male or female, smoker or non-smoker. |
IndividualPropertyTextValue |
No |
IndividualPropertyDoubleValueMin |
Numeric |
Inclusive lower bound value of the property. E.g., a value of “18” for an individual property name called Age would mean that only individuals aged 18 and above receive the non-dietary exposures. |
IndividualPropertyDoubleValueMin |
No |
IndividualPropertyDoubleValueMax |
Numeric |
Inclusive upper bound value of property e.g. a value of “65” for an IndividualPropertyName called Age would mean that only individuals aged 65 and below receive the non-dietary exposures. |
IndividualPropertyDoubleValueMax |
No |
Non-dietary exposures
This table defines nominal non-dietary exposure values (such as means) for individuals within the non-dietary surveys. It can also be used to specify non-dietary exposures for individuals within the food surveys. Each exposure comprises a non-dietary survey (source of exposure); a string identifying an individual, which may or may not correspond to the ID of an individual in a food survey; a substance; and dermal, oral and inhalation exposure values. Exposures are assumed to be external doses.
Accepted table names: NonDietaryExposures, NonDietaryExposure.
| Name | Type | Description | Aliases | Required |
|---|---|---|---|---|
idIndividual |
AlphaNumeric (50) |
Non-dietary individual identification number. This id may 1) match with the individual ids of the dietary survey (dietary exposures matched to food survey individuals), 2) not match with the individual ids of the dietary survey (unmatched individuals), or contain a default exposure (indicated by idIndividual = ‘General’) linking the dietary exposures to individuals based on the demographic criteria defined in the non-dietary survey properties table. |
idIndividual |
Yes |
idNonDietarySurvey |
AlphaNumeric (50) |
The code of the survey (must correspond to values in id column of non-dietary surveys table). |
idNonDietarySurvey |
Yes |
idSubstance |
AlphaNumeric (50) |
The substance code. |
idSubstance, SubstanceId, SubstanceCode, Substance |
Yes |
Dermal |
Numeric |
The dermal (non-dietary) exposure value. |
Dermal |
Yes |
Oral |
Numeric |
The oral (non-dietary) exposure value. |
Oral |
Yes |
Inhalation |
Numeric |
The inhalation (non-dietary) exposure value. |
Inhalation |
Yes |
Non-dietary exposure uncertainty records
This table may be used to supply uncertainty sets of multiple (uncertain) non-dietary exposure values for individuals within the non-dietary surveys. Multiple non-dietary values are generated by probabilistic exposure calculations i.e. when there is a distribution for the non-dietary exposure rather than a single nominal value. If this table is supplied, aggregate exposure estimates will be reported with uncertainty using the uncertainty set approach. Each exposure set comprises a non-dietary survey (source of exposure); an individual ID; a substance; and dermal, oral and inhalation exposure values. In addition, the id column is used to define the uncertainty set. Summarizing, an uncertainty set is identified by column id and contains all exposure sets defined for each individual. In each uncertainty run (outer loop) an uncertainty set is sampled and in each iteration (inner loop) nondietary individuals are sampled from this set.
Accepted table names: NonDietaryExposuresUncertain, NonDietaryExposureUncertain.
| Name | Type | Description | Aliases | Required |
|---|---|---|---|---|
idIndividual |
AlphaNumeric (50) |
Non-dietary individual identification number. The idIndividual value may correspond to an id in the Individuals table (dietary exposures matched to food survey individuals), may not correspond to an id in the Individuals table (unmatched individuals), or may contain a default exposure (indicated by idIndividual = ‘General’ - demographic criteria for the assignment of exposures are defined in the NonDietarySurveyProperties table). For matching to occur, the user will need to tick the option to ‘match specific dietary survey individuals’ in the user-interface. The software will then assign non-dietary exposures to the dietary individuals according to the values in this column. Any idIndividual values that do not correspond to individuals in the food survey will be ignored, unless a value ‘General’ is specified. Then the individual should meet the demographic criteria as defined in the NonDietarySurveyProperties table. If this box is left unticked, the non-dietary exposures will be randomly allocated to the dietary population provided they meet the demographic criteria. |
idIndividual |
Yes |
idNonDietarySurvey |
AlphaNumeric (50) |
code of survey (must correspond to values in id column of NonDietarySurveys table) |
idNonDietarySurvey |
Yes |
idCompound |
AlphaNumeric (50) |
Substance code (must correspond to values in id column of Substances table). |
idSubstance, SubstanceId, SubstanceCode, Substance |
Yes |
id |
AlphaNumeric (50) |
Uncertainty set identification number. |
id |
Yes |
Dermal |
Numeric |
Dermal non-dietary exposure value. |
Dermal |
Yes |
Oral |
Numeric |
Oral non-dietary exposure value. |
Oral |
Yes |
Inhalation |
Numeric |
Inhalation (non-dietary) exposure value. |
Inhalation |
Yes |