Approaches to Integrating the Toxicology and Epidemiology Evidence on PFAS

Abstract

S05: PFAS Research Reaches its Adolescence: What Have We Learned and Where Are We Going?, Beatrix Theater, August 26, 2019, 10:30 AM - 12:00 PM Per- and polyfluoroalkyl substances (PFASs) have gained wide attention the last two decades. At present 4,600 CAS Registry Numbers are associated with PFASs that may have been on the global market (OECD 2018), while only some very few of these have been studied extensively. Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), belonging respectively to the sub groups of perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFSAs), are the best studied PFASs. Under the European REACH regulation, some PFCAs and PFSAs have been identified as substances of very high concern (SVHC), demonstrating a need for undertaking risk assessments. The risk assessment process include several steps, including hazard assessment and identification of the critical effect. The importance of integrating data from both experimental animal studies and human epidemiological studies have been highlighted, as both types of data have specific advantages and disadvantages. However, for many PFASs the amount of data is very limited, making this impossible. In the case of PFOS and PFOA data from both animal studies and human epidemiological studies are available for several endpoints. In this presentation, there will be a discussion on how these complementary types of data can be used in hazard assessments and how to utilize this knowledge for other PFASs where the data, in particular epidemiological data, are more limited or do not exist. However, for some endpoints such as changes in blood lipids, contradictory results have been observed between studies on experimental animals and humans. This, along with differences in exposure and toxicokinetics, needs to be considered when combining data from experimental animal studies and epidemiological studies. Reference OECD. 2018. Toward a New Comprehensive Global Database of Per- and Polyfluoroalkyl Substances (PFASs): Summary Report on Updating the OECD 2007 List of Per- and Polyfluoroalkyl Substances (PFASs). OECD Series on Risk Management No. 39.