Bioaccumulation Behavior and Human Health Risk of Polybrominated Diphenyl Ethers in a Freshwater Food Web of Typical Shallow Lake, Yangtze River Delta

Polybrominated diphenyl ethers in bivalves: metabolites, accumulation, quantification and ecological risks

Polybrominated diphenyl ethers (PBDEs) are extensively used as flame retardants in plastics but have emerged as persistent environmental pollutants due to their bioaccumulation and toxicity. Analysis of 74 studies from 2000 to 2024 highlights the increasing research interest in PBDE contamination, particularly in aquatic ecosystems and bivalves. Recurring themes such as "health risk," "bioaccumulation," and "risk assessment" dominate the discourse, emphasizing the need for deeper investigations into PBDE pathways and impacts. This trend underscores the critical importance of evaluating PBDE contamination in seafood species like oysters, mussels and clams, which are integral to human diets and aquatic food chains. Building on these insights, this study focused on analyzing PBDEs and their metabolites (MeO-BDE, OH-BDE) in commonly consumed bivalve species. Advanced methods for extraction, purification and simultaneous analysis revealed significant variations in PBDE concentrations: oysters (29-101 ng/g lw), mussels (10-274.8 ng/g lw) and clams (23-64,900 ng/g lw). Notably, metabolites MeO-BDE and OH-BDE were frequently detected, sometimes surpassing PBDE levels, indicating complex bioaccumulation processes. Bioaccumulation and bio-sediment accumulation factors (BAF and BSAF) showed that PBDEs and their metabolites accumulate more effectively through water pathways than sediment. Trophic magnification factor (TMF) analysis further revealed higher TMF values for PBDEs compared to their metabolites, categorizing PBDEs and MeO-BDE as low-risk TMFs. These findings align with citation analysis trends, which emphasize "risk assessment" as a pivotal theme, particularly concerning human exposure. The human health risk assessment based on bivalve consumption highlights potential exposure concerns in regions with high seafood intake. This study not only enriches the understanding of PBDE distribution and bioaccumulation in bivalves but also emphasizes the importance of effective monitoring, regulatory control and continued investigation into their ecological and human health impacts.

Polybrominated diphenyl ethers in dust, hair and urine: Exposure, excretion

Polybrominated diphenyl ethers (PBDEs) have been detected in various environmental media and human tissues. PBDEs concentrations in dust from college buildings and homes and in paired hair and urine samples from students were determined. This is of great significance to explore the accumulation and excretion patterns of PBDEs in the human body. The median PBDEs concentrations in the dust (College: 84.59 ng/g; Home: 170.32 ng/g) and hair (undergraduate: 6.16 ng/g; Home: 3.25 ng/g) samples were generally lower than were found in the majority of previous studies. The PBDEs concentrations in the hair and urine samples were subjected to principal component analysis, and the results combined with the PBDEs detection rates confirmed that hair is a useful non-invasive sampling medium for assessing PBDEs exposure and the risks posed. Body mass indices (BMIs) were used to divide students who had not been exposed to large amounts of PBDEs into groups. Body fat percentage is an important factor affecting the accumulation of PBDE in the human body. Environmental factors were found to affect the PBDEs concentrations in the hair and urine samples less for normal-weight students (BMI≤24) than overweight students (BMI>24). Short-term environmental changes to more readily affect the PBDEs concentrations in the tissues of the normal-weight than overweight students. PBDEs with seven or more bromine substituents were found not to be readily excreted in urine. Performing molecular docking simulations of the binding of isomers BDE-99 and BDE-100 to megalin. The binding energy was higher for BDE-100 and megalin than for BDE-99 and megalin, meaning BDE-99 would be more readily excreted than BDE-100.