Distribution and Bioaccumulation Characteristics of Perfluoroalkyl substances (PFASs) in the East China Sea = 동중국해 해수, 해저 퇴적물과 생물체내 PFASs 분포와 생물농축특성

다국어 초록 (Multilingual Abstract)

First synthesized in the 1940s, perfluoroalkyl substances (PFASs) have attracted substantial global concern for more than eight decades. Owing to their exceptional persistence and unique physicochemical properties, PFASs have been extensively used in a wide range of industrial applications and consumer products. However, PFASs and their related compounds are characterized by extreme environmental persistence and the capacity for long-range transport across multiple environmental media, including air, water, soil, sediment, and biota. Consequently, both human populations and ecosystems face significant exposure risks to various PFASs, among which perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) have been identified as compounds of particular concern. Numerous studies have demonstrated that PFASs can induce a wide range of adverse effects on human health, aquatic organisms, and the environment. Therefore, investigations into the occurrence and temporal trends of PFASs in the environment are essential, as they provide a scientific basis for evaluating potential human health risks and ecological impacts associated with PFASs contamination. The study region is located in the northwestern East China Sea and encompasses the western sea of Jeju Island (YE) and the southern sea of Jeju Island (EC). These regions were selected because they represent dynamic marine environments influenced by a combination of natural processes and anthropogenic activities. As open-sea systems, they receive substantial pollutant inputs from multiple sources, including surrounding coastal activities, domestic riverine discharge, atmospheric deposition, and large-scale oceanic circulation. Numerous potential PFASs emission sources, such as fluorochemical industries, textile manufacturing facilities, and wastewater treatment plants, are distributed along adjacent coastlines or discharge into rivers, thereby contributing to PFASs contamination in the marine environment. In addition, the study region is strongly affected by complex oceanographic and meteorological processes, including the Kuroshio Current and the East Asian monsoon system, which play a critical role in the long-range transport and redistribution of persistent organic pollutants. Despite its considerable environmental and economic importance particularly in relation to fisheries and aquaculture, PFASs contamination in this region has remained relatively understudied. Therefore, investigating the occurrence and behavior of PFASs in seawater, sediment, and marine biota from the northwestern East China Sea is essential for improving our understanding of their transboundary transport and environmental fate in East Asian coastal ecosystems. This study was conducted to (1) determine the concentrations and distribution characteristics of PFASs in seawater, sediment, and marine biota, and (2) assess the potential ecological risks posed by PFASs to marine habitats, thereby providing baseline data on PFASs contamination in the northwestern East China Sea. Seawater and sediment samples were collected from the YE and EC sites in 2024. A total of 60 samples were collected from the YE region, including 20 surface seawater samples, 20 sediment samples, and 20 biota species samples representing different species. In the EC region, 58 samples were collected, comprising 24 surface seawater samples, 24 sediment samples, and 10 biota species samples. The results showed that 10 out of 19 target PFASs were detected in surface seawater samples from both regions. Among the detected PFAS compounds, PFBA, PFOA, and PFNA were present at higher concentrations than the other compounds, with detection frequencies reaching 100%. The concentrations of PFASs in seawater from the YE region (2.64–4.81 ng/L, mean = 3.55) were higher than those measured in the EC region (2.41–3.60 ng/L, mean = 3.03). PFAS alternatives, including GenX and F- 53B, were detected in seawater; however, their concentrations were relatively low. The total concentration of PFASs in the sediment samples ranged from 0.21–0.80 (mean = 0.50) ng/g dw and 0.15–0.81 (mean = 0.41) ng/g dw in YE and EC sites, respectively. Among the 19 target compounds analyzed, only 4 PFASs were detected, including PFOA, PFNA, PFUnDA, and PFOS. No alternative target compounds were detected in sediment samples in both regions. Regarding biota samples, 20 species in YE and 10 species in EC were collected and analyzed. The results showed that 7 out of 19 target compounds were detected in marine biota. The total PFASs concentrations ranged from 0.38–7.86 (mean = 1.98) ng/g ww and 0.43–7.53 (mean = 2.89) ng/g ww in biota samples from YE and EC regions, respectively. Long-chain PFAS were more abundant, with PFOS identified as the dominant compound across all species. Alternatives (F-53B and GenX) were not detected in any biota samples. Variations in total PFASs concentrations among species indicate species-specific accumulation patterns, which are likely influenced by multiple factors such as trophic position, feeding behavior, and habitat preference. In this study, bioaccumulation factors (BAFs) were calculated to evaluate the accumulation potential of PFASs in marine biota species. The BAF values of PFOS and PFHxS in most samples exceeded the bioaccumulation threshold defined under EU REACH, indicating a strong bioaccumulation potential of these compounds in marine organisms. In contrast, no BAF values were obtained for alternatives, including F-53B and GenX, suggesting lower bioaccumulation potential and/or higher excretion rates in marine biota. Water Quality Criteria (WQC) were applied to assess potential adverse effects of PFASs contamination in water and sediment in marine habitats. The concentrations of PFOA, PFOS, and PFBS in seawater samples were compared with guideline values reported by Giesy et al., 2010. The results showed that the concentrations of these compounds were lower than the corresponding criteria values. This finding indicated that the levels of PFOA, PFOS, and PFBS in seawater are unlikely to cause adverse effects on aquatic organisms and avian wildlife. In addition, the environmental risks of sediment-associated PFOS and PFOA to aquatic systems, including benthic organisms, were assessed by using a risk quotient (RQ) in the sediment environment. In this study, all calculated RQ values were below one, suggesting negligible environmental risks from PFOA and PFOS exposure in sediment.

목차 (Table of Contents)

• LIST OF TABLES iii
• LIST OF FIGURES iv
• ABSTRACT i
• CHAPTER 1: INTRODUCTION 1
• 1.1. Perfluoroalkyl substances 1
• 1.1.1. Structure 1
• 1.1.2. Physicochemical properties 4
• 1.1.3. Type of PFASs 6
• 1.1.4. Application and regulation 9
• 1.2. PFASs fate in the environment 12
• 1.3. Adverse effects and exposure pathway 16
• CHAPTER 2: MATERIALS AND METHODS 19
• 2.1. Sampling area 19
• 2.2. Sample collection 22
• 2.3. Chemicals and standards 30
• 2.4. Sample extraction 31
• 2.5. Instrumental analysis 34
• 2.6. Quality assurance and quality control (QA/QC) 38
• CHAPTER 3: RESULTS AND DISCUSSIONS 41
• 3.1. PFASs concentrations in water samples 41
• 3.1.1. Western sea of Jeju Island (YE) 41
• 3.1.2. Southern sea of Jeju Island (EC) 51
• 3.1.3. Environmental implications of PFASs in seawater samples 61
• 3.2. PFASs concentration in sediment samples 62
• 3.2.1. Western sea of Jeju Island (YE) 62
• 3.2.2. Southern sea of Jeju Island (EC) 70
• 3.2.3. Environmental implications of PFASs in sediment samples 78
• 3.3. PFASs concentration in biota samples 80
• 3.3.1. Western sea of Jeju Island (YE) 80
• 3.3.2. Southern sea of Jeju Island (EC) 86
• 3.3.3. Environmental implications of PFASs in biota samples 92
• 3.4. Role of the Yangtze River in the transport of PFASs 94
• 3.5. Profile trending 99
• 3.6. Global comparison of PFASs profiles 103
• 3.6.1. Seawater 103
• 3.6.2. Sediment 106
• 3.6.3. Biota 108
• 3.7. Bioaccumulation factors in biota samples (BAFs) 112
• 3.7.1. BAFs in biota samples from YE 112
• 3.7.2. BAFs in biota samples from EC 115
• 3.7.3. Comparative implications for PFASs bioaccumulation 118
• 3.8. PFASs risk assessment 119
• 3.8.1. Water quality criteria 119
• 3.8.2. Environmental risk assessment 125
• 3.8.3. Human health risk 129
• 3.9. Environmental implications 131
• 3.10. Total daily intake (TDI) 133
• CHAPTER 4: CONCLUSIONS 137
• REFERENCES 140
• ABSTRACT (KOREAN) 165
• ACKNOWLEDGMENT 169