Trophic transfer of hexabromocyclododecane in the terrestrial and aquatic food webs from an e-waste dismantling region in East China

Trophic transfer of hexabromocyclododecane (HBCD) was investigated in both the terrestrial and aquatic food webs from an e-waste dismantling region in East China. The mean Σ 3 HBCD concentrations in the terrestrial species varied from 0.91 (0.16-1.85) ng g -1 lipid weight (lw) in dragonflies (Pantala flavescens) to 40.3 (22.1-51.1) ng g -1 lw in rats (Rattus norvegicus). The isomeric profile indicated that α-HBCD presented a decreasing trend along the trophic level (TL) (from 97.2% to 16.3% of Σ 3 HBCDs), while γ-HBCD showed a reverse trend (from 2.8% to 73.6% of Σ 3 HBCDs). The trophic magnification factor (TMF) derived from the slope of the regression line between TLs and ln-transferred Σ 3 HBCDs was 0.10, suggesting a trophic dilution of HBCD in the terrestrial food web. By contrast, in the aquatic species, Σ 3 HBCD concentrations varied from 5.02 (3.5-6.55) ng g -1 lw in apple snails (Ampullaria gigas spix) to 45.9 (14.9-67.8) ng g -1 lw in grass carps (Ctenopharyngodon idellus). α-HBCD was the dominant isomer, followed by γ-HBCD in the majority of species. A positive linear relationship was observed in the plots of ln Σ 3 HBCDs versus TLs (R 2 = 0.81, p = 0.06). The TMF for Σ 3 HBCDs was 6.36, indicating a trophic magnification of HBCD in the aquatic food web. Although these results demonstrated the distinct trophic transfer of Σ 3 HBCDs in different ecosystems, further research is needed to eliminate the uncertainty of the tendencies, due to the non-significant relationship and limited species.