Occurrence and abundance of poly- and perfluoroalkyl substances (PFASs) on microplastics (MPs) in Pearl River Estuary (PRE) region: Spatial and temporal variations

Although the occurrence and distribution of various chemicals on microplastics (MPs) has been widely studied, little was known about the concentrations of poly- and perfluoroalkyl substances (PFASs) on MPs. In this study, MPs from eight rivers draining into Pearl River Estuary (PRE) region were collected and analyzed. Higher concentrations of PFASs on MPs (105-9.07 x 10(3) ng g(-1)) were found in the drain outlets receiving wastewater from most urbanized cities with large population densities. On the other hand, lower concentrations of PFASs on MPs (10.3-227.8 ng g(-1)) were found in the drain outlets receiving wastewater mostly from agricultural and forested areas. Specially, 8:2 disubstituted poly-fluoroalkyl phosphates (8:2 diPAP) was detected with the highest frequency, in 92.5% of the samples. Furthermore, a positive Spearman correlation was found between 6:2 disubstituted polyfluoroalkyl phosphates (6:2 diPAP) and perfluorotetradecanoic acid (PFTeDA) (r(s) = 0.621, p = 0.012), indicating they might share similar sources. PFASs on MPs were found to vary significantly with different seasons. Higher concentrations of PFASs on MPs were found in dry seasons, while lower concentrations were observed in wet seasons. The results of this study should be important for the understanding of PFAS occurrence and distribution on MPs and the partitioning mechanism of PFASs on MPs in estuary systems. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

This study found variations in the concentrations of PFASs on MPs at different outflow points, which were related to factors such as urban population density. Certain PFASs were detected at a high frequency in the samples, suggesting they may share similar sources. The study also revealed seasonal variations in PFAS concentrations on MPs.