Demo Human Monitoring Analysis bisphenols

This standard action is of type: Biological matrix concentration comparisons

Human BioMonitoring (HBM) is a primary instrument to measure real-life exposure to chemicals. Because of the associated high costs, chemical levels in body fluids such as blood or urine would ideally be predictable from estimated external exposure levels, such as in the diet and/or from other non-dietary sources. It is needed to convert external exposures to internal concentrations by use of a kinetic (PBK) model or the application of a simple absorption factor.

This standard action provides a simple demonstration of this approach. It is based on the EuroMix bio-monitoring study (Husøy et al. (2019), Karrer et al. (2019)), and considers three of the investigated chemical substances in this study, i.e. the bisphenols BPA, BPS and BPF, which could have adverse estrogenic effects and therefore require risk assessment. These substances were measured in the urine of 144 adult individuals on two days (in this demo, we only use the data from day 1). Measurement values below the limit of detection were imputed. The specific gravity of the urine samples was measured as well, which is used in the calculation to calculate adjusted urine concentrations as decribed in Husøy et al. (Husøy et al. (2019)). The study subjects also kept detailed diaries on their food consumption, and use of personal care products. In this demonstrator standard action, the dietary exposure and optionaly also the non-dietary exposure from personal care products and thermal paper is modelled. The dietary exposure is predicted from the consumption data for 226 modelled foods derived from the food diaries and food monitoring concentration data for BPA, BPS and BPF in these foods. Additionally, non-dietary exposure from personal care products and from handling thermal paper was modelled separately by Karrer et al. (Karrer et al. (2020)) and these exposures are available as data for three non-dietary routes, i.e. dermal, oral and inhalation. In the demonstrator these exposures are aggregated with the dietary exposures at the individual level. In this demonstrator the conversion from external exposures to urine concentration is based on a simple absorption factor approach.

Note that this standard action only shows the principles of comparing modelled and measured biomonitoring levels. After conversion to a full MCRA action it will be possible to extend the example in various ways. The simple absorption factor could be replaced by a kinetic model. In fact, such a model (Karrer et al. (2018), Karrer et al. (2019)) is available in MCRA, but it needs further optimisation in the current implementation, e.g. in terms of running times. See Karrer et al. (Karrer et al. (2020)) for more information.

In this demonstrator standard action, several choices can be made:

  • Acute or chronic exposure. For acute, HBM data are taken per day and modelled dietary exposures are based on Monte Carlo integration of consumptions and food concentrations. For chronic, HBM data are averaged per individual (not relevant in this standard action because only one sample per individual is available) and dietary exposures are modelled using the observed individual means model.

  • Derive modelled concentrations from dietary exposur only or aggregate with non-dietary exposure sources.

  • For the modelled concentrations, replace censored values in the food concentration data (measurements below the limit of reporting LOR) with 0 or with 0.5 x LOR.

  • Choose from example data files with substance-specific absorption factors.

This standard action summarises data available from the EuroMix HBM study for bisphenols BPA, BPS and BPF in human urine. After imputing missing values and correcting for urine specific gravity, the resulting distribution is compared to the distribution of bisphenol concentrations predicted from dietary exposure and exposure from personal care products and thermal paper.

Table 211 Datasources for Demo Human Monitoring Analysis bisphenols.
Table Group Name Repository Type

Compounds

Demo_HBM_CataloguesAndSecondaryData.xlsx

Standard Actions/Demo Human Monitoring Analysis

Fixed

Effects

Demo_HBM_CataloguesAndSecondaryData.xlsx

Standard Actions/Demo Human Monitoring Analysis

Fixed

FoodTranslations

Demo_HBM_CataloguesAndSecondaryData.xlsx

Standard Actions/Demo Human Monitoring Analysis

Fixed

Foods

Demo_HBM_CataloguesAndSecondaryData.xlsx

Standard Actions/Demo Human Monitoring Analysis

Fixed

RelativePotencyFactors

Demo_HBM_CataloguesAndSecondaryData.xlsx

Standard Actions/Demo Human Monitoring Analysis

Fixed

Concentrations

Demo_HBM_ConcentrationsSSD.xlsx

Standard Actions/Demo Human Monitoring Analysis

Fixed

Survey

Demo_HBM_Consumptions.xlsx

Standard Actions/Demo Human Monitoring Analysis

Fixed

KineticModels

Demo_HBM_KineticModelsBisphenols_Sc1.xlsx

Standard Actions/Demo Human Monitoring Analysis

Variable

KineticModels

Demo_HBM_KineticModelsBisphenols_Sc2.xlsx

Standard Actions/Demo Human Monitoring Analysis

Variable

NonDietary

Demo_HBM_NonDietaryExposures.xlsx

Standard Actions/Demo Human Monitoring Analysis

Fixed

HumanMonitoringData

Demo_HBM_PhenolsUrinePooledOneDay.xlsx

Standard Actions/Demo Human Monitoring Analysis

Fixed