Applying benchmarking methods to estimate persistence and bioaccumulation potential for emerging PFASs

The project shall improve the understanding of the persistence, bioaccumulation and biodegradation of emerging PFAS substances. The project focuses on the water environment and mostly on sediment samples and processes. To better describe emerging PFASs, for which no analytical standards and little information exists, so called benchmarking methods shall be used.

They allow to express the emerging PFASs’ concentrations and characteristics in relation to those of well-studied PFASs. The data can support future hazard assessment of PFASs.

Identifying emerging PFASs in complex samples

One research aim is to develop and validate benchmarking methods to simultaneously use different analysis techniques for identifying emerging PFASs in complex samples. Two projects will serve this purpose and improve the understanding on which PFASs are emitted from a production site and by another industry.

Sediments taken in 2014 and 2016 along the Xiaoqing River in China with wastewater inlets from known fluoropolymer production facilities are investigated. The samples are analysed for a wide range of PFASs by target, suspect screening, and total fluorine as well as extractable organic fluorine analysis. The generated data will cover many PFASs, and the fluorine mass balance will be calculated to identify the share of the emerging PFASs and the unknow PFASs.

In a second research project, Norwegian sediment core samples from a lake affected by a production facility of paper products are analysed. Non-target data are generated to monitor the trend of PFASs over time in the different sediment layers. Additional high resolution mass spectrometry shall confirm the identities of certain PFAS suspect compounds.

Microbial biodegradation half-lives of emerging PFASs

A benchmarking methodology shall be validated to determine microbial degradation half-lives for emerging PFASs. For this, certain layers of the Norwegian sediment core are extracted to use the existing PFASs as starting compounds in biodegradation experiments. The degradation of the PFASs will be monitored over time to calculate microbial degradation half-lives for emerging PFASs in sediments. New biodegradation products will likely be identified.

Bioaccumulation potential of emerging PFASs

The third research aim is to validate a benchmarking methodology to determine the bioaccumulation potential of emerging PFASs. Carp fish from the Xiaoqing River in China were analysed together with matching surface water and sediment samples. Tissue distribution ratios and whole-body bioaccumulation factors were calculated. The methodology can be used as a tool to assess the potential hazards from emerging contaminants for which no authentic standards exist.

The project outcome is already published, see the scientific article External link, opens in new window..