TR 104 – Framework for the Integration of Human and Animal Data in Chemical Risk Assessment

TR 104 : Framework for the Integration of Human and Animal Data in Chemical Risk Assessment | January 2009

Human data form the most direct evidence for an association between health effects and exposure to chemicals.  The availability and quality of human data vary greatly from one chemical to another; this may be strongly related to the prevalence of exposure and to concern about potential health effects.  Guidance is currently available on the evaluation and use of animal toxicological data and human exposure data in the risk assessment process.  However, such specific guidance is not available for human health effects, despite the fact that most international authorities recognise that the incorporation of human data would improve the utility and robustness of the risk assessment process.

Consequently, ECETOC identified the need to review and evaluate the different types of human data that are available, and to provide guidance on how such data could be used best in the risk assessment process.  A multidisciplinary Task Force was thus assembled to address the problem and to consider in particular, when and where human data could be used to support risk assessment and risk management decisions, and how human and animal findings could be integrated and used in tandem.

Quality aspects play an important role in the choice of data sources regarding the leading health effect that will be crucial in the risk assessment process.  Thus, quality aspects of human data, as well as of animal data, have been extensively addressed in this report.

Following the description of the quality aspects of the human and animal data, a framework for the integration of these data and their use in the risk assessment process is proposed.  The framework takes into account human as well as animal data; it is strongly encouraged to use both sources in a combined approach.  Ideally, human data and animal data will be complementary and should confirm each other (i.e. both indicate excess risk, or both indicate the absence of risk).  In cases where they are in apparent contradiction, efforts should be made to develop a better understanding of the biological basis for the contradiction.  This will often be informative and result in a more reliable basis for risk assessment.

With this report, ECETOC provides guidance on how human data can be used and integrated into chemical risk assessment and management processes.  The proposed framework is illustrated by a number of examples.