Bioaccumulation patterns, trophic transfer characteristics and dietary exposure potential of tetrabromobisphenol A analogs in a coral reef food web of the Xisha Islands, South China Sea

As a typical class of novel organic pollutants, tetrabromobisphenol A (TBBPA) analogs have been widely detected in various environmental matrices. Several toxicological studies have highlighted that the accumulation of pollutants is the basis for assessing their ecological effects and potential risks. However, the bioaccumulation and trophic transfer of TBBPA analogs in marine food webs are not fully understood. This study selected the most important coral reef islands in the South China Sea as the study area to investigate the bioaccumulation patterns and trophic transfer characteristics of TBBPA analogs within the tropical marine food web. TBBPA, tetrabromobisphenol S (TBBPS), TBBPA bis(2-hydroxyethyl ether) (TBBPA-BHEE), and TBBPA bis(glycidyl ether) (TBBPA-BGE) are prevalent in water, sediment, and organisms around the Xisha Islands. The concentrations of these compounds varied significantly among species (P < 0.05), with notably higher concentrations of ∑TBBPA analogs observed in invertebrates than in fish. Moreover, the Log BAFs of TBBPA, TBBPS, and TBBPA-BHEE were all lower than 3.30, whereas TBBPA-BGE exhibited high bioaccumulation potential in some species. The concentrations of TBBPA, TBBPS, TBBPA-BHEE, and TBBPA-BGE in organisms were significantly negatively correlated with trophic level (P < 0.05), indicating pronounced trophic dilution effects throughout the food web. In addition, hydrophobicity and metabolism were found to be important factors affecting the bioaccumulation of TBBPA analogs. The results revealed that dietary exposure to seafood poses no significant health risks to the local population.