Legacy and Emerging Per- and Polyfluoroalkyl Substances Behave Distinctly in Spatial Distribution and Multimedia Partitioning: A Case Study in the Pearl River, China

Abstract

Per- and polyfluoroalkyl substances (PFASs) have attracted worldwide attention due to their ubiquitous occurrence, bioaccumulation, and toxicological effects, yet the fate of PFASs in a lotic ecosystem is largely unknown. To elucidate spatial distribution and multimedia partitioning of legacy and emerging PFASs in a lotic river flowing into an estuary, PFASs were synchronously analyzed in water, suspended particulate matter (SPM), sediment, and biota samples collected along Guangzhou reach of the Pearl River, South China. Geographically, the concentrations of PFASs in the water phase showed a decreasing trend from the upper and middle sections (urban area) to the down section (suburban area close to estuary) of the river. While perfluorooctanoic acid predominated in water and SPM, more diverse compositions were observed in sediment and biota with the increase in contributions of long-chain PFASs. Field-derived sediment–water partitioning coefficients (K d) and bioaccumulation factors (BAFs) of PFASs increased with the increase in perfluorinated carbons. Besides hydrophobicity, water pH and salinity significantly affected the multimedia partitioning of PFASs in a lotic ecosystem. In addition, 87 homologues (63 classes) were identified as emerging PFASs in four media using suspect analysis. Interestingly, K d and BAF of the emerging PFASs were often higher than legacy PFASs containing the same perfluorinated carbons, raising a special concern on the environmental risk of emerging PFASs.

Widespread Occurrence and Transport of p-Phenylenediamines and Their Quinones in Sediments across Urban Rivers, Estuaries, Coasts, and Deep-Sea Regions

“…It should be pointed out that, in addition to waterborne transport, airborne transport may be another pathway for transporting these chemicals by atmospheric deposition, but its contribution to the concentrations of PPDs in marine sediment needs further study in the future. Compared to general organic pollutants in the riverine, estuarine, and coastal sediments of this study area, the median pollutant levels of ∑PPDs were much lower than those of short-chain chlorinated paraffins (173 ng/g, PRD rivers) 46 and organophosphate triesters (330 ng/g, PRD rivers) 47 but were substantially higher than those of per-/polyfluoroalkyl substances (0.74−0.79 ng/g, PRD rivers and the PRE) 48,49 and polybrominated diphenyl ethers (2.98 ng/g, coasts of the SCS). 50 These findings highlighted the abundant, pervasive occurrence of PPDs across freshwater and oceanic waterbodies and implied that riverine outflows are an important route to transport tire rubber-derived chemicals to global oceans.…”

Legacy and Emerging Per- and Polyfluoroalkyl Substances in a Subtropical Marine Food Web: Suspect Screening, Isomer Profile, and Identification of Analytical Interference

“…uPFCA homologues with perfluorinated carbon chain lengths of C3−C12 and C14 were also reported to be widely detected in the Pearl River. 40 Nevertheless, the uPFCAs identified in the present work might be attributed to ESI in-source fragmentation of PFCAs since the proposed uPFCA homologues could also have been present in our high-purity PFCA standards (10 ng/mL) and could not be differentiated by retention time under the current LC conditions. This phenomenon was also observed in a previous study.…”

“…Three PFASs were additionally found in the seawater via suspect screening (Table S8), which were also reported in a recent paper on suspect screening of PFASs in the Pearl River. 40 − , m/z = 602.9564), which is mainly used as a surfactant in oil production, was identified in 2 of the 13 sites with a confidence level of 2b. Additionally, 5:2 Cl-PFESA (C 7 F 14 SO 4 H − , m/z = 480.8988), a homologue of 6:2 Cl-PFESA, was identified in 5 of the 13 sites with a confidence level of 2b.…”

Text Mining-Based Suspect Screening for Aquatic Risk Assessment in the Big Data Era: Event-Driven Taxonomy Links Chemical Exposures and Hazards

“…Suspect screening presents a way to expand the contaminant list (from hundreds to thousands) during instrumental analysis and potentially improve explanatory capabilities for observed effects in the environment. , While suspect screening is attracting more attention, it is still limited by subjective preselection of analytes, although much larger contaminant lists instead of target analysis are applied. Meanwhile, an expanded list of analytes requires increased labor and cost, so most suspect screening can provide only semiquantitative results for a limited number of samples. − Thus, it is imperative to advance cost-efficient new approach methodologies (NAMs) as complementary tools to costly instrument-based technologies.…”