Developmental and reproductive toxicity of Hexabromocyclododecane (HBCD) in Tigriopus japonicus

• 1、College of the Environment and Ecology, Xiamen University, Xiamen, 361102

Abstract：Hexabromocyclododecane (HBCD) is the third most widely used brominated flame retardant in the world, owing to the good flame retardant effect and the low cost. HBCD is persistent in the environment, bioaccumulative and toxic to the environmental organisms. Technical HBCD (tHBCD) is comprised of several stereoisomers, with three pairs of enantiomers (±) of alpha-, beta- and gamma-HBCD as the major components. However, only a few studies compared the toxicities of individual HBCD isomers. Additionally, most of the existing studies focus on the fresh water environment and use freshwater organisms as the test species. As the sensitivity of the freshwater species and the marine species to the environmental pollutants could be significantly different, the current study used the marine copepod, Tigriopus japonicus, to provide information of the toxicities of HBCD stereoisomers on marine organisms. The results showed that all three HBCD isomers (α-, β- and γ-HBCD) had significant effect on the developmental time of T. japonicus. The delay in development was in a dose dependent manner. The second generation (F1) was more sensitive to HBCDs than the first generation (F0). The three HBCD isomers had similar potency in the growth delay of T. japonicus. Whereas, three isomers had no significant effect on the sex ratio and fecundity of T. japonicus. γ-HBCD did not cause the death of T.japonicus in nauplii and copepodite stages. However, α- and β-HBCD exposure at higher concentrations led to significant mortality. The lethal LOELs for α- and β-HBCD were 0.08 and 0.03 mg/L, respectively. The order of lethality is: β-HBCD > α-HBCD >> γ-HBCD.

Keywords： Environmental toxicology HBCD Tigriopus japonicus Developmental and reproductive toxicity