Per- and polyfluoroalkyl substances (PFAS) are considered to be forever chemicals. Many are toxic; others are highly mobile or accumulate in the food chain. However, all are extremely persistent and are spread throughout the environment. The contamination hot-spots of the PFAS can be proven only with a great deal of effort. This is why indicators are needed.
Click here for original story, Finding a bioindicator for the occurrence of PFAS
Source: Phys.org