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Sustainability 2022, 14, x FOR PEER REVIEW 5 of 37

coatings lubricants for membranes, machines, and foams used in extinguishing fires. The manufacture 126

of PFAS or their use as adjuvants in pesticides, in medical treatments and products, as well as in many 127
other applications [28]. 128
Zhong et al, reported the first occurrence of perfluoro-1-butanesulphonamide (FBSA) and 2,3,3,3- 129

tetrafluoro-2-(1,1,2,2,3,3,3-heptafluoropropoxy) propanoic acid (HFPO-DA) as marine sediments in 130

yellow sea and East China sea, suggesting a switch in PFAS production from established industries to 131

new ones, as well as in eastern coastal cities of China. The results of the identification of probable 132
sources showed that the primary sources of PFAS were metal plating factories, textile treatments, 133

fluoropolymer products, food packaging, and the breakdown of volatile precursor chemicals of the area 134
[29]. A multivariate receptor modelling tool called positive-definite matrix factorization (PMF) was 135

used in this study that breaks down a given sample data matrix into factor contributions and profiles in 136
order to identify the variables or sources that have an impact on the given sample data [30]. A previous 137

study suggested the source of PFAs in Bohai sea in China as well as yellow and East China sea was 138
due to ocean currents [31]. 139

Around the Yangtze River basin in China, there are also numerous well-known large-scale fluoride 140

industrial parks that acts as the main source of PFAS entering the Yangtze River is industrial 141

wastewater, which may subsequently be released into the YS through the estuary of the Yangtze River, 142
resulting in a significant concentration of PFAS contamination [32]. In certain research, the source of 143

PFAS has been identified using the ratio of PFOS/PFOA; the higher the ratio, the closer to the source 144
[33]. Compounds like PFNA, PFDA, and PFUnA (perfluoroundecanoic acid) are not widely 145

manufactured commercially, atmospheric oxidation of their volatile precursors is a significant source 146
of these substances in the environment [34]. The Figure 2, represents the PFAS-Map [36,37]. 147

148

149
150
2.3 Occurance of PFAS: 151

The use of aqueous film-forming foams (AFFF), a firefighting surfactant, at airfields, refineries, fire 152

training facilities, and bulk storage facilities often results in the application of the greatest amounts of 153
PFAS in the environment [37, 38]. Because of their better surfactant qualities, PFAS were first used 154

into AFFF used for fire suppression in the late 1960s [39]. Since then, the majority of uses of AFFF 155
products have resulted in the release of PFAS. 156

While PFOS and PFOA have received the most of the attention in relation to environmental 157

contamination to far, the USEPA has gathered nationwide occurrence data on six perfluorocarbons 158