Risk-based assessment of under-researched PFAS: identification, exposure and impact

Problem statement
Per- and polyfluorinated compounds (PFAS) are used in various industries and represent an increasingly important social problem. Because of their longevity, toxicity, rapid spread in water and accumulation in crops, PFAS present a growing hazard for the environment and human health. Thus, they also increasingly attract public attention. PFAS pollution is also associated with high follow-up costs.
PFAS includes molecules of various structural classes with different properties. However, they all share a high persistence. Corresponding regulations are often based on the available data of a few, well-studied PFAS. An exposure-based risk assessment is therefore only possible for a fraction of the PFAS. This screening gap can be identified by measuring PFAS sum parameters. The proportion of unexplained, organically bound fluorine can be up to 90% and is also present in human blood. The protection of humans and the environment from PFAS by current measures is therefore incomplete, as unknown PFAS are not considered.

Objectives of the project
The aim of the PhD project is to evaluate previously undiscovered or insufficiently investigated PFAS regarding their exposure and effect.
Contaminated samples from various sources of contamination will first be analyzed for new PFAS compounds aiming to identifying new and under-researched PFAS (WP1). Suitable chromatographic techniques will be used to include polar short-chain PFAS.
The PFAS identified in this way are then searched for in environmental samples to assess their exposure. Thus, the PFAS can be prioritized according to their detected frequency and concentration (WP2).
Subsequently, the transformation and toxicity in higher organisms of a small selection of the highly prioritized PFAS will be tested to assess their impact on humans (WP3).
Finally, a conclusion is drawn from the results of the environmental screening and the data on transformation and toxicity to evaluate the PFAS investigated regarding their risk. Based on the data, a recommendation for risk-based regulation will be formulated. 

This project is funded by the German Federal Environmental Foundation through a doctoral scholarship.