Experimental exposure of eggs to polybrominated diphenyl ethers BDE‐47 and BDE‐99 in red‐eared sliders ( Trachemys scripta elegans ) and snapping turtles ( Chelydra serpentina ) and possible species‐specific differences in debromination

Polybrominated diphenyl ethers (PBDEs) are a bioaccumulative, persistent, and toxic class of flame retardants that can potentially impact turtles in natural habitats via exposure through maternal transfer. To simulate maternal transfer in the present study, PBDE congeners BDE‐47 and BDE‐99 were topically applied to the eggshell and were allowed to diffuse into the egg contents of the red‐eared slider ( Trachemys scripta elegans ) and snapping turtle ( Chelydra serpentina ). Eggs were topically dosed over 8 d to achieve a target concentration of 40 ng/g in the egg contents. Transfer efficiency was higher for BDE‐47 than for BDE‐99 in the red‐eared sliders (25.8 ± 1.9% vs 9.9 ± 1.1%) and snapping turtles (31.3 ± 1.6% vs 12.5 ± 1.4%), resulting in greater BDE‐47 and lower BDE‐99 egg content concentrations relative to the 40 ng/g target. However, only 25.8 and 31.3% of the total BDE‐47 and 9.9 and 12.5% of the total BDE‐99 dose applied could be accounted for in the red‐eared slider and snapping turtle egg contents, respectively. Additionally, increased BDE‐47 in red‐eared slider egg contents dosed with only BDE‐99 indicate that BDE‐99 might have been debrominated to BDE‐47. The efficacy of topical dosing for administering desired embryonic exposures is clearly affected by the chemical properties of the applied compounds and was more successful for BDE‐47 in both species. Environ. Toxicol. Chem. 2013;32:393–400. © 2012 SETAC