Human Exposure to PFAS and their Precursors in the Human Environment and their Biotransformation Processes

National Health and Medical Research Council

A comprehensive understanding of exposure pathways is essential for chemical risk assessment, management, and mitigation. It is evident that available evidence linking per- and poly-fluoroalkyl substance (PFAS) exposure to negative health effects has fundamental limitations, including the inadequate assessment of exposure pathways. Even less is known for PFAS derivatives or precursors as many of them were only very recently identified. These derivatives or precursors have the potential to bio-transform to specific PFAS that bioaccumulate in humans (e.g. perfluoroalkyl acids, PFAAs). Through public consultation, it has been identified that along with occupational exposure, skin contact was amongst the most concerning pathways of exposure to the respondents. Furthermore, there are very limited studies on dermal penetration of PFAS, as these studies are currently limited to perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA). Therefore, it is critical to conduct a systematic study on the dermal penetration of a range of recently identified PFAS, including the PFAS precursors.

The general aim of this proposed project is to characterise PFAS exposure pathways of air inhalation, dust ingestion and dermal contact for exposed cohorts, and evaluate the role of precursor exposure and biotransformation as a source for body burden of PFAS. 


Human exposure pathways for PFAS have never been comprehensively evaluated and there is a significant lack of data on PFAS in the environment for affected communities in Australia and the world. The outcomes of this project include for the first time characterising PFAS in the environment, for Australian affected communities. These outcomes expect to contribute to quantifying human exposure to PFAS with a comprehensive understanding of exposure pathways.

It has been confirmed that PFAS precursors can undergo biotransformation processes that produce PFAAs. However, these processes have not been characterised by PFAS exposure from the environment of affected communities that have a (much) higher burden of PFAS and Pre-FAS compared to the general population. This project will for the first time identify and quantify PFAS that are produced from precursors during in-vitro reactions using human liver microsomes, from environment samples in Australian affected communities. The outcomes contribute to advancing the understanding of results from human biomonitoring studies, in terms of translating the body fluid concentration to human exposure profiling and risk.

This project will provide information on the extent of skin contact to PFAS containing products on the human body burden of PFAS of exposed populations. This project will clarify the concern of the occupational exposed groups with newly identified dermal penetration factors for a range of PFAS that were not available before.

Project members

Dr Xianyu (Fisher) Wang

Senior Research Fellow

A/Prof Phong Thai

Co-Theme Leader, Environmental Health Risk Assessment