Embryo toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin to the wood duck (Aix sponsa)

摘要: We examined the sensitivity of wood duck (Aix sponsa) embryo to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) by injecting toxicant into their eggs. Six groups eggs (n = 35 211 per trial) were injected with 0 4600 pg TCDD/g egg between 2003 and 2005. Injections made yolk prior incubation, subsequently incubated assessed weekly for mortality. Significant TCDD-induced mortality was not observed through day 25 (90% incubation). Liver, heart, eye, brain histology generally unremarkable. Hepatic ethoxyresorufin-O-deethylase activity, a biomarker dioxin-like compound exposure, induced 12-fold in pg/g treatment relative controls. The median lethal dose chicken (Gallus domesticus) we dosed identically about 100 pg/g, similar other assessments chickens. Among lethality data 15 avian genera, no-observed-effect level ranks near middle. Because no higher doses tested, ducks may be like waterfowl (order Anseriformes), which are comparatively tolerant from polychlorinated dibenzo-p-dioxins dibenzofurans when exposed injection.