Fate of Persistent, bioaccumulative and toxic chemicals (PBTs) in waste: A spotlight on poly and perfluoroalkyl substances (PFAS)

There is growing international concern regarding the many types of chemicals (such as perfluoroalkyl substances (PFAS) and brominated flame retardants (BFRs)) used in household consumer products and industrial applications. As society’s prevailing consumer model is linear (i.e. create – use – dispose) most products (and their associated chemicals) are destined for the waste streams. Assessing the concentrations of consumer chemicals in landfill leachate, wastewater and biosolids is of importance as they represent significant secondary sources of release to the environment. To investigate the levels and profiles of consumer chemicals in waste, a spatial sampling program was undertaken at 34 landfills and 16 WWTPs across Australia. The temporal trends of 31 PFAS in wastewater influent was also investigated by accessing a sample archive dating back to 2010.  

Overall, this thesis presents a greater understanding of the how waste streams play a central role in the continuous cycling of contaminants through the environment. Regulatory and voluntary action against PFAS appear to be reducing use and potential exposure in daily life, however industrial inputs into wastewater remain significant, and their sources are still unknown. The PFAS story highlights the difficulties in managing (i.e. containing or treating) persistent chemicals at the ‘end of pipe’ and should serve as an urgent warning to reconsider the use of certain chemicals in consumer products.