# Bioaccumulative characteristics of tetrabromobisphenol A and hexabromocyclododecanes in multi-tissues of prey and predator fish from an e-waste site, South China

## TL;DR

This study examines how two brominated flame retardants accumulate in different tissues of prey and predator fish near an e-waste site in South China.

## Contribution

The study reveals distinct bioaccumulation and enantiomer preferences of HBCDs in prey and predator fish.

## Key findings

- HBCD levels in fish tissues correlated with lipid content, but only for mud carp in the case of TBBPA.
- Northern snakehead showed higher HBCD levels but lower TBBPA levels compared to mud carp.
- Mud carp enriched (+)-α-HBCD enantiomer, while northern snakehead enriched (−)-α-HBCD enantiomer.

## Abstract

Tetrabromobisphenol A (TBBPA) and hexabromocyclododecanes (HBCDs) were analyzed in 12 tissues of prey (mud carp) and predator (northern snakehead) fish from an e-waste area, South China. The TBBPA concentrations in different tissues ranged from 0.03 to 2.85 ng/g wet weight (ww) in mud carp and 0.04 to 1.30 ng/g ww in northern snakehead. The concentrations of HBCDs ranged from 0.07 to 96.9 ng/g ww in mud carp and 0.18 to 240 ng/g ww in northern snakehead. HBCD levels in tissues were correlated with lipid content for both fish species, while this correlation was only found in mud carp for TBBPA. Meanwhile, northern snakehead exhibited higher HBCD levels but lower TBBPA levels than mud carps. These observations are attributed to the more polar and reactive properties of TBBPA than HBCDs. α-HBCD was the predominant diastereoisomer of HBCDs in all tissues of mud carp and northern snakehead, except for chyme of mud carp. All the analyzed tissues in mud carp showed an enrichment of (+)-α-HBCD enantiomer with EF (enantiomeric fraction) values of 0.53–0.62, but that in northern snakehead showed an enrichment of (−)-α-HBCD enantiomer with EF values of 0.35–0.5. Considering the fact that the mud carp is one of the diet items of northern snakehead, the different enantiomer accumulation characteristics of α-HBCD between the two fish species in the present study indicated that prey and predator fish could prefer to biotransform different enantiomers of α-HBCD.