Modelling environmental and human health chemical exposure

Understanding the nature and extent of exposure is key to understanding the risk to human health from exposure to environmental contaminants. With growing scientific insight on exposure pathways and how chemical substances affect humans, new tools are required to address increasingly complex exposure scenarios and to aid regulatory decision making.

In Human Health risk assessment exposure assessment is often the weakest point for the following reasons: a lack of integrated approaches for combined stressors (mixtures), widespread use of over-conservative ‘worst-case’ scenarios, an estimation of external exposures and not of internal exposures, and a lack of uncertainty/sensitivity tools for identification of key exposure drivers.

In response, advanced modelling software, called MERLIN-Expo, is now being developed under the 4FUN project. This software has numerous features, including the integration of multimedia and PBPK models - crucial considering the future development of ‘Equivalent Biomonitoring Reference Doses’ and the coverage of the total exposure assessment chain and estimates of internal exposures for different human populations. Another feature is that exposure through multiple pathways for multiple chemicals is able to give estimates for combined exposures. There is also the functionality for uncertainty and sensitivity analysis – an essential element in-line with risk assessment guidelines published by the WHO.

The EU-funded 4FUN project builds on the previously developed modelling software 2FUN to model and simulate human and environmental exposure to harmful chemicals.

While 2FUN was a prototype tool containing various models for exposure assessment, 4FUN developers are testing, improving and standardising the software for market release. They aim to demonstrate the reliability of the modelling estimations, and the feasibility of building complex realistic scenarios using case studies based on actual datasets.

The 4FUN project will develop a business model to bring the software to market, and will provide support through training to ensure long-term technical and economic viability.

Ultimately, MERLIN-Expo software will benefit regulators and industries as well as researchers interested in the environmental or health impacts of chemicals.