Bioaccumulation and distribution of per- and polyfluoroalkyl substances and organophosphate flame retardants in marine organisms from the Vietnamese coast: Links to species traits and environmental exposure

Per- and polyfluoroalkyl substances (PFASs) and organophosphate triester flame retardants (OPEs) are extensively utilized in both domestic and industrial applications, dispersing in the environment and accumulating in marine species. This study examines the prevalence, distribution, and bioaccumulation of PFASs and OPEs in marine organisms and seawater from the Vietnamese coastal area. Surface seawater (n = 20) and marine organisms (n = 96) were collected and examined for 15 OPEs and 14 PFASs utilizing ultra-high-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS). The findings indicate that Cl-alkyl OPEs, especially TCEP and TDCIPP, were most prevalent in seawater, but short-chain PFCA predominated the PFAS profile (p < 0.05). Mollusca demonstrated the highest contamination levels among marine creatures for both PFASs (22.68 ng/g-dry weight (dw)) and OPEs (33.48 ng/g-dw), possibly attributable to their filter-feeding behavior and accessibility to sources of contamination. Analysis of the bioaccumulation factor (BAF) indicated that long-chain PFASs and hydrophobic OPEs had higher bioaccumulation potential, with TBOEP (log BAF = 4.30) demonstrating the highest accumulation among OPEs. A statistically significant positive correlation was observed between log BAF and log K_OW values of PFAS compounds in mollusca (r = 0.59, p < 0.05). Principal component analysis indicates species-specific contamination patterns, emphasizing notable differences related to feeding behavior and habitat exposure. This study presents the inaugural evaluation of PFASs and OPEs bioaccumulation in Vietnamese marine species, delivering critical insights into pollutant transport along coastal food webs and underscoring the necessity for regulatory interventions to mitigate contamination risks in marine ecosystems.