## 4 Contamination in Environment and Food
### Environmental Contamination  
In order to estimate the risk posed by PFAS to human health, it is important to monitor the possible source to which humans can be exposed. In this respect, wastewater is known to play a significant role and several studies [73; 74] have studied the level of contamination of sludge from wastewater treatment plants (WWTPs) in Europe. In particular, [PERSON] et al. [75] detected novel perfluoralkyl sulfonamide-based (FASA) copolymers in WWTPs in Sweden. The study demonstrated that these copolymers come from both domestic and industrial sources. In New Zealand, [PERSON] et al. [76] detected, in addition to 20 PFASs, ultrashort-chain perfluoropropionic acid (PFPrA) in urban waters, coming from two urban WWTPs. A step forward is understanding the contribution of groundwaters. Several studies carried out in Europe and US addressed this point and showed high levels of contamination. In particular, 12 out of 29 PFASs were found in Sweden [77] and 14 out of 24 in the Eastern United States [78]. Given the large number of PFAS documented in commercial use and the environment, the PFASs examined here might not reflect the entire PFAS inventory in groundwater. Also, crude oil, according to EPA [79], needs to be tested due to its presence in the interface between soil and groundwater. [PERSON] et al. [80] proved that crude oil may be a significant source of PFAS contamination in the environment because they are applied \begin{table}
\begin{tabular}{c c c} \hline \hline
**Source** & **GenX or Novel PFAS** & **Sum of PFAS** \\ \hline WWTPs & EU, New Zealand & EU, New Zealand, US \\ Groundwater & EU, US, China & EU, US, China, Canada, and \\ (freshwaters) & & India \\ Crude oil & China & China \\ Wild animals & EU & EU \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Summary of relevant data from the literature for contamination of PFAS in environment. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Source** & **GenX or Novel PFAS** & **Sum of PFAS** \\ \hline Drinking water & US, Korea & EU, US, China, Korea \\ Blood serum & N.A. * & EU, US, China, Canada \\ Breast milk & China & EU, US, China, Canada \\ Fish & EU & EU, US, China, Vietnam \\ Eggs & N.A. * & EU \\ \hline \hline \end{tabular}  
* N.A. = not available.  
\end{table} 
Table 5: Summary of relevant data from the literature for contamination of PFAS in food and from FCMs. in oil exploitation activity. PFACs (27%) and p-perfluorousnonenoxybenzene sulphonate (OBS) (31%) made up the majority of the crude oil sample, while PFSAs (16%), ether-substituted polyfluoroalkyl (linear) sulphonic acids (OPFLSAs) (10%), 6:2 fluorotelomer sulfonamidealkyl betaine (6:2 FTAB) (7%) and hydrogen-substituted polyfluoroalkyl (linear) carboxylic acids (HPFLCAs) (5%) made the rest of the samples. Their findings showed that certain new PFASs appeared in crude oil as a result of the use of chemical oil additives during the oil drilling process. [PERSON] et al. [81] focused their study on rivers, another important possible source of contamination, looking for the occurrence of PFAS in the Danube River Basin. The researchers used both target and suspect screening (non-targeted) approaches that allowed them to detect a total of 82 PFAS, 72 of which were detected only by suspect screening. PFOS was the only compound found in all of the water and biota matrices studied. Five PFAS were detected only in influent wastewater samples and not in effluent wastewater samples, indicating that they were successfully removed during wastewater treatment. Another approach for assessing contamination coming from the terrestrial environment is to use wild animals as indicators to monitor PFAS. [PERSON] et al. [82] determined legacy and emerging poly- and per-fluoropolyethers in 28 wild bears using an HPLC-HRMS method. Boars were chosen because they are already confirmed to be suitable models to monitor PFAS contamination in the terrestrial environment [83, 84]. The boars come from Italy and the analysis was carried out by sampling the boars' livers.